Insight into a gap in science: Dietary protein intake in
neuromuscular diseases - an observational study
Authors: Anouk Holman and Loes van de Winckel Company: HvA Lectorate Weight Management Institute: Amsterdam University of Applied Sciences Department: Nutrition and Dietetics
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Insight into a gap in science: Dietary protein intake in
neuromuscular diseases - an observational study
Author: Anouk Holman Student number: 500705752
Email adress: anouk.holman2@hva.nl
Author: Loes van de Winckel Student number: 500730998
Email adress: loes.van.de.winckel@hva.nl
Project number: 2019200
Supervisor: Dr. ir. Michael Tieland
Company: HvA Lectorate Weight Management Institute: Amsterdam University of Applied Sciences
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Prologue
This thesis is written as graduation project, for the assignment of the Innovative Health Practice of the Amsterdam University of Applied Sciences, Faculty of Sports and Nutrition, for the education Nutrition and Dietetics. We focused on the dietary protein intake in patients with neuromuscular diseases (NMD) in the Netherlands.
Currently, the recommendations of dietary protein intake for patients with NMD are not based on research, due to lack of data. This signifies a gap in science. Therefore, the main goal of this study is to map as much information as possible about the dietary protein intake of these patients.
The terminus will also include a representation of protein sources and timing of dietary protein intake per day. In addition, this study dives into variation and differences of sex, age and categories of NMD. This information will help to determine the patient group with the highest need to give recommendations. Adequate recommendations may improve their quality of life. The goal of this study is achieved when there is an insight of dietary protein intake in patients with NMD.
We would like to thank the patients who gave permission to use their nutritional and personal data. Without their effort and input, this study would have been impossible.
We also express our gratitude to Dr. ir. Michael Tieland from the Innovative Health Practice of the Amsterdam University of Applied Sciences who guided and supported us in writing our first thesis. Dr. ir. Michael Tieland gave us the opportunity to cooperate with the Consortium and to contribute to this important study.
We would like to thank all members of the Consortium, including dieticians who delivered us the dietary reports. Their input made this study possible.
At last, we want to thank Carliene van Dronkelaar for helping us analyze gathered data in SPSS, and Anna Tuz-Holman for assisting us with formulating our thesis in English.
Amsterdam, 7 June 2019
Anouk Holman Loes van de Winckel
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Abstract
Introduction: Neuromuscular diseases (NMD) are a heterogeneous group of acquired or inherited diseases affecting the peripheral nervous system and muscle mass. The consequences of NMD are loss of muscle mass, function, and posture. Loss of muscle mass causes weakness, a decrease in mobility and cardiac and respiratory function. These consequences influence the quality of life in a negative way. An adequate dietary protein intake stimulates the protein synthesis of muscle mass or at least, inhibit the muscle tissue from breaking down during disease. There is a gap in science, concerning the dietary protein intake among patients with NMD. The main goal of this study is to gather as much information as possible about the dietary protein intake, in order to point out deviant values. The final product contains recommendations about dietary protein intake for the established high risk groups within this study.
Methodology: This study studied 146 patients with NMD. The included NMD are Amyotrophic Lateral Sclerosis, Progressive Spinal Muscular Atrophy, Hereditary Spastic Paraparesis, Primary Lateral Sclerosis, Arthrogryposis Multiplex Congenita, Ataxia of Friedreich, Chronic Idiopathic Axonal Polyneuropathy, Congenital and Metabolic Muscular Dystrophies, Small-Fiber Peripheral Neuropathy, hereditary muscle dystrophies and distal myopathies (Duchenne), Hereditary Polyneuropathies, Facioscapulohumeral Muscular Dystrophy, Guillain Barré Syndrome/Chronic Inflammatory Demyelinizing Polyneuropathy, Myotonic Dystrophy, Myasthenia, Myositis, Post-Polio Syndrome and Spinal Muscular Atrophy. The NMD were categorized into three groups (1: slowly progressive , 2: quickly progressive and 3: regressive). The dietary protein intake, source and timing were studied with the following variables; age, sex, weight, height, BMI and mobility.
Results: The study population included 57 men and 89 women, with an age range of 2 to 84 years old. The current dietary protein intake of patients with NMD is 79.4 +/- 31.3 grams per day . This equals 16.2 energy percent per day and 1.19 +/- 0.52 grams per kilogram bodyweight per day, which is above the recommended daily protein intake for healthy adults in The Netherlands (0.8 grams per kilogram bodyweight per day). The mean dietary protein intake of category 1 is 76.3 +/- 30.3 grams per day, category 2 is 87.3 +/- 35.7 grams per day and category 3 is 85.2 +/- 24.9 grams per day. The mean dietary protein intake during breakfast is 13 grams, during lunch 19 grams, during dinner 32 grams and during snacks 6 grams. The primary source of protein is animal-based (65%). The majority of patients is ambulatory (74%) and has the highest mean dietary protein intake (82.9 +/- 33.4 grams).
Conclusion: Although, the mean dietary protein intake in patients with NMD is well above the recommended daily allowance of 0.8 grams per kilogram bodyweight per day, still a significant
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proportion (59.5% of the adults) does not meet the higher recommended intake of 1.2 grams per kilogram bodyweight per day. Dietary protein intake may be improved by increasing protein intake during breakfast, lunch and snacks. This is recommended to reach an equal and higher distribution of high- quality dietary protein intake during the day. Children among this study do reach the general dietary protein recommendation in energy percent. This implies there is no need to improve their dietary protein intake.
Keywords: Neuromuscular Diseases, Dietary protein intake, Protein sources, Protein timing,
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Table of content
1. Introduction ... 9 2. Backbone ... 11 3. Methodology ... 13 3.1.Research Design ... 133.2.Participants and Sampling ... 13
3.3. Data collection method ... 15
3.4. Data Analysis ... 16 4. Results ... 19 4.1. Neuromuscular diseases ... 19 4.2. Study population ... 20 3.3. Nutritional Intake ... 22 5. Discussion ... 27 5.1. Recommendations ... 27 5.2 Dietary protein in NMD ... 27 5.3. Population ... 28 5.4. Data collection... 29 5.5. Quality of life ... 30 5.7. Conclusion ... 31 7. Recommendations ... 33 7.1. Nutritional recommendation ... 33 7.2. Follow-up studies ... 33 7.3. Interventions ... 35 8. Bibliography ... 37 Appendix ... 39 Appendix 1. Codes ... 39
Appendix 2. Information letter and informed consent ... 40
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1. Introduction
Neuromuscular diseases (NMD) are a heterogeneous group of acquired or inherited diseases affecting the peripheral nervous system and muscle mass. The majority of NMD are incurable and with great consequences regarding the quality of life (1,2). In The Netherlands, the estimated prevalence of this patient group is widely 100.000 patients. This study will research the most common NMD (3).
Several consequences of NMD are loss of muscle mass, function, and posture. Diminution of muscle mass sequences weakness, a decrease in mobility and cardiac and respiratory function (4). A majority of patients are experiencing symptoms like pain and problems with communication, swallowing and taking personal care (5).
Studies of specific NMD determine that an inadequate nutritional intake induces a low nutritional status, with a deficiency in dietary protein (6-8). The current recommendation for dietary protein intake is 0.8 g/kg-bw/d, applying to healthy adults in the Netherlands. A higher dietary protein intake (1.2 g/kg-bw/d) has been proven to be significant to support the health of some of the vulnerable groups in our population, such as patients with a chronic or inflammatory disease and elderly (9). In addition to this, other studies have proven that sufficient dietary protein intake is beneficial to prevent muscle mass from breaking down (11). It has been suggested that 20 to 25 grams of dietary protein intake per meal is required to allow an optimal muscle synthesis. However, the synthetic rate of muscle synthesis can vary following the ingestion of different protein sources. Insight into specific intake, sources and timing of dietary protein might disclose valuable information to locate inadequacies (13).
In the past four years, guidelines have been developed including nutritional recommendations intended solely for patients with Amyotrophic Lateral Sclerosis (ALS), Duchenne and swallowing disorders due to a neurological disorder (11). Nonetheless, there is no specific information about dietary protein intake among patients with NMD. Research has shown that an intervention involving a higher dietary protein intake (1.2 g/kg-bw/d) may be relevant to patients with NMD (10). Therefore, lack of information about dietary protein intake among patients with NMD signifies a great gap in science, which inhibits dieticians in treating patients with NMD in a sufficient way (12).
The main goal of this study is to find an answer to the following question: ‘What is the dietary protein intake in patients with neuromuscular diseases?’. Dietary protein intake is studied within three categories of NMD, established by The Association of Neuromuscular Diseases in The Netherlands (VSN) (1: slowly progressive, 2: quickly progressive and 3: regressive) (3). These values will also be linked to source and timing of dietary protein intake in relation to sex,
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age, weight, height and Body Mass Index (BMI). Dietary protein intake in relation to mobility will also be part of this study.
At the end of this study, the target group can be divided and prioritized in categories with the lowest dietary protein intake. This information will make it possible to determine the patient groups with the highest need to give recommendations about dietary protein intake.
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2. Backbone
The main research question is: ‘What is the dietary protein intake patients with a neuromuscular diseases?’
Sub-questions are:
• What is the distribution of NMD among this study?
• What is the mean dietary protein intake in slowly progressive, quickly progressive and regressive neuromuscular diseases in relation to age, sex, weight, height and BMI? • What is the mean dietary protein intake in relation to the age groups 0-8, 9-17, 18-55
and 55+ years old?
• What is the mean dietary energy intake in slowly progressive, quickly progressive and regressive neuromuscular diseases in relation to age and sex?
• What is the distribution of protein sources (animal – and plant-based) among dietary intake?
• What is the distribution of dietary protein sources (animal – and plant-based) among breakfast, lunch, dinner and snacks?
• What is the mean dietary protein intake during breakfast, lunch, dinner and snacks? • What is the mean dietary protein intake among the levels of mobility?
Main goal: The main goal of this study is to gather as much information as possible about dietary protein intake in patients with NMD, in order to point out deviant values. The final product contains recommendations about dietary protein intake for the established high risk groups within this study.
Hypotheses: The highest need for dietary protein intake recommendations are found in age group 55+, in women and category 1 of NMD. For timing, snacks contain the least dietary protein and in source, plant-based is the least consumed. Patients among mobility level 2 consume the lowest amount of dietary protein.
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3. Methodology
3.1.Research Design
This was a quantitative and descriptive study conducted between the 4th of February 2019 and 7th of June 2019. The preparation part comprehended preliminary research about the subject: Dietary protein intake in patients with neuromuscular diseases. Also, we developed a project plan on how the thesis was going to be formalized. The executive part consisted of data research of dietary protein intake in patients with neuromuscular diseases. This incorporated collecting data via dietary reports and importing this into Excel. The final part was to enter and analyze all data that had been studied, using SPSS.
3.2.Participants and Sampling
The target group of this study consists of 146 patients with the most common NMD in the Netherlands. The included NMD are Amyotrophic Lateral Sclerosis (ALS), Progressive Spinal Muscular Atrophy (PSMA), Hereditary Spastic Paraparesis (HSP), Primary Lateral Sclerosis (PLS), Arthrogryposis Multiplex Congenita (AMC), Ataxia of Friedreich (AvF), Chronic Idiopathic Axonal Polyneuropathy (CIAP), Congenital and Metabolic Muscular Dystrophies, Small-Fiber Peripheral Neuropathy (SFPN), hereditary muscle dystrophies and distal myopathies (Duchenne), Hereditary Polyneuropathies (HP), Facioscapulohumeral Muscular Dystrophy (FSHD), Guillain Barré Syndrome (GBS)/Chronic Inflammatory Demyelinizing Polyneuropathy (CIDP), Myotonic Dystrophy (MD), Myasthenia, Myositis, Post-Polio Syndrome (PPS) and Spinal Muscular Atrophy (SMA). The coded NMD can be found in Appendix 1. Codes.
The target group included both sexes and all ages. Ages were divided into 4 categories: 0-8 years old, 9-17 years old, 18-55 years old and 55+ years old. The group of 55+ years old was determined on the basis of the amount of collected data. This depended on the number of dietary reports of patients older than 55 years old.
The study distinguished three categories of NMD, established by VSN (1: slowly progressive, 2: quickly progressive and 3: regressive) (Table 1).
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Table 1. Categorized neuromuscular diseases established by The Association of Neuromuscular
Diseases in The Netherlands.
1. Slowly progressive NMD
Diseases caused by slowly increasing progression (hereditary polyneuropathies, FSHD, PPS, AvF, CIAP, MD, SFPN Duchenne, AMC, Congenital and Metabolic Muscular
Dystrophies, SMA (1).
2. Quickly progressive NMD
Diseases known by the fast progression of muscle weakness in combination with declining vital functions (ALS, PSMA, HSP and PLS) (1).
3. Regressive NMD
Diseases containing an intermittent course (Myositis and Myasthenia gravis). Or diseases with a (partially) recovery, after a phase of increasing muscle weakness (GBS/CIDP) (1).
Distribution of neuromuscular diseases per category. NMD; Neuromuscular Diseases; Hereditary Polyneuropathies; FSHD: Facioscapulohumeral Muscular Dystrophy; PPS: Post-Polio Syndrome; AvF: Ataxia of Friedreich; CIAP: Chronic Idiopathic Axonal Polyneuropathy; MD: Myotonic Dystrophy; SFPN: Small-Fiber Peripheral Neuropathy; Duchenne: hereditary muscle dystrophies and distal myopathies; AMC: Arthrogryposis Multiplex Congenita; Congenital and Metabolic Muscular Dystrophies; SMA: Spinal Muscular Atrophy; ALS: Amyotrophic Lateral Sclerosis; PSMA: Progressive Spinal Muscular Atrophy; HSP: Hereditary Spastic Paraparesis; PLS: Primary Lateral Sclerosis; Myositis; Myasthenia; GBS: Guillain Barré Syndrome/ CIDP: Chronic Inflammatory Demyelinizing Polyneuropathy.
Patient data was gathered at hospitals and rehabilitation centers across the Netherlands. The participating hospitals and rehabilitation centers in this study are Radboud UMC, Roessingh Medical Rehabilitation, Rijndam Medical Rehabilitation, Revant Breda and Goes, UMC Groningen and Rehabilitation Centre Blixembosch Eindhoven. Patients were excluded when the NMD was not among the most common NMD and when dietary reports were illegible or incomplete. For example dietary reports with less than three days reported. Patients with parenteral nutrition were also excluded from this study.
Dietary reports were supplied by dieticians from participating hospitals and rehabilitation centers by different means, such as folders, e-mails and handwritten reports. They asked permission to the patients and let them sign a consent form (Appendix 2. Consent Form). Also, they instructed patients on how to document dietary reports, including information about sources, timing and portion size.
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3.3. Data collection method
The data we used can be found in databases digitized in Google Drive. The incomplete patient numbers were deleted from this study, which were number 8, 45, 82, 98-100 and 123. After this study was finalized, we did a complete evaluation of data that has been entered, to examine the input.
The main part of this study encompassed research of 3-day dietary reports, including 2 week days and 1 weekend day (Appendix 3. Dietary Report). Ethic approval from each subject has been given. Data was collected between 2013 and 2019 with a medical ethic approval from the VU Medical Centre. The period of 2013-2016 consisted of data exclusively concerning the nutritional intake in patients with Myotonic Dystrophy (MD). The remaining period contained data of NMD that were studied within this study. Nutritional and personal information were gathered by trained dieticians:
• Name of the study
• Number of patient
• Age (in years)
• Sex
• Anthropometry: height (m), weight (kg) and BMI (kg/m²)
• Day and date of intake
• Timing of intake (breakfast, lunch, dinner, and snacks)
• Source of intake
• Amount of intake (documented in household measures with the Dutch food measurements codebook) (14)
Microsoft Excel was used to collect and encode data. File 1 included information about personal details. File 2 included information about dietary intake, timing and portion size. The NEVO-Tabel was used to codate the nutritional intake and calculate dietary energy- and protein intake (15). Portion sizes which were vague or incomplete were searched on the internet, to calculate a representative portion size.
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The information in the Excel sheet was formalized using 9 columns:
1. Number of patient (encoded)
2. Measurement (always 1, because there was only one moment of data collecting) 3. Day 1, 2 or 3 of the dietary report
4. Timing of intake (1 = breakfast, 2 = morning snack, 3 = lunch, 4 = afternoon snack, 5 = dinner, 6 = evening snack)
5. NEVO-code
6. Product name NEVO 7. Amount in grams
8. Amount of days reported (always 3, because more or less than 3 days were canceled from the study)
9. Possible notes to specify a product
3.4. Data Analysis
The Excel files of personal information and dietary intake were imported into two SPSS data files. We used a SPSS Syntax to create useable databases out of the coded data. The Syntax combined each patient with their nutritional information by merging the 2 different files. The Syntax calculated the dietary protein intake from plant- and animal-based sources (in grams, per day, per patient) and per mealtime. For every result, the standard deviation was given, which informed about the spreading of variables.
After combining the files into 1 database, we used several types of analyses in SPSS. This resulted in an outcome showing differences in dietary protein intake in relation to the categories of NMD, and the examined groups: age and sex. The dietary protein intake was expressed in three different ways: in grams per day, in energy percentages and in grams per kilogram body weight per day. The dietary energy intake was represented in kilocalories.
Data analyses were executed using the IBM SPSS Statistical software package, version 24. For most analysis, we used descriptive statistics such as means with standard deviation and percentages. We started this study with analyzing the distribution of researched NMD, represented in figure 1. Next, we described the total population in table 2, which included information about age categories (years), sex, weight (kg), height (m) and BMI (kg/m2) in relation
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Table 3 contained information about dietary energy and protein intake in relation to category 1, 2 and 3 of NMD. We used the recommendations for dietary protein intake applying to healthy adults in The Netherlands (0.8 g/kg-bw/d) in comparison to the mean dietary protein intake of the studied patients of 18+ years old.
Dietary protein sources (plant- and animal- based) in relation to the categories of NMD were represented in table 4. This was executed per protein source, in grams per day and in energy percentages. In addition to this, there was a distribution of sex and age categories per dietary protein source. Furthermore, the specific dietary protein intake per protein source and mealtime, and the distribution of dietary protein sources per mealtime (ratio in percentages) were displayed in figure 2. At last, the dietary protein intake in relation to mobility was demonstrated in table 5. This included the mean dietary protein intake in grams per day, per level of mobility (0,1 or 2).
The one-way ANOVA test was used to discover significant differences (p<0.05) between dietary protein intake in relation to the categories of NMD (1: slowly progressive, 2: quickly progressive and 3: regressive), protein sources and mobility.
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4. Results
4.1. Neuromuscular diseases
The population of this study included patients of all ages with NMD. The most common NMD were categorized from 0-14 (Appendix 1. Codes). Within this study the most researched NMD was Myotonic Dystrophy (46.6%) (Graphic 1). This NMD was part of category 1; slowly progressive.
Figure 1. Researched neuromuscular diseases. The number of patients researched per neuromuscular disease are represented by numbers. Neuromuscular diseases (NMD): Amyotrophic Lateral Sclerosis (ALS), Progressive Spinal Muscular Atrophy (PSMA), Hereditary Spastic Paraparesis (HSP), Primary Lateral Sclerosis (PLS), Arthrogryposis Multiplex Congenita (AMC), Ataxia of Friedreich (AvF), Chronic Idiopathic Axonal Polyneuropathy (CIAP), Congenital and Metabolic Muscular Dystrophies, Small-Fiber Peripheral Neuropathy (SFPN), hereditary muscle dystrophies and distal myopathies (Duchenne), Hereditary Polyneuropathies, Facioscapulohumeral Muscular Dystrophy (FSHD), Guillain Barré Syndrome (GBS)/Chronic Inflammatory Demyelinizing Polyneuropathy (CIDP), Myotonic Dystrophy (MD), Myasthenia, Myositis, Post-Polio Syndrome (PPS) and Spinal Muscular Atrophy (SMA). 31 2 1 3 3 1 8 3 8 3 68 5 4 0 9 0 10 20 30 40 50 60 70 80 N UM BE R O F R ES EA R CH ED PAT IE N TS NEUROMUSCULAR DISEASES
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4.2. Study population
Table 2 showed the study population characteristics. The population consisted of a total of 146 patients, which included 57 male patients (39%) and 89 female patients (61%). The mean age was 49 +/- 19.8 years old. The youngest patient was 2 years old and the oldest patient was 83 years old. The researched NMD were divided into three categories (1: slowly progressive, 2: quickly progressive, 3: regressive). Category 1 included the majority of patients with 71%. The mean age of category 2 was the highest with 61.3 +/- 15.0 years old. Distribution of sex per category showed that most women belonged to category 1 and 3. Category 2 represented an equal sex ratio. Within categories 0-8 and 9-17 years old there were no underweight patients. Within category 18-55 years old, 14% was underweight, which were 9 patients. Within category 55+ years old, 6% was underweight, which were 4 patients. In total, 9% of the population was underweight. The mean BMI-score was 24.1 +/- 5.3 kg/m2.
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Table 2. Study population characteristics
Study population
Characteristics Total (n=146) Category 1 (n=103) Category 2 (n=31) Category 3 (n=12)
Mean SD Mean SD Mean SD Mean SD
Age (years) 48.7 19.8 45.2 19.9 61.3 15.0 46.3 17.6 0-8 (years) (n= 4) 5.8 2.6 5.8 2.6 - - - - 9-17 (years) (n=11) 11.1 1.5 11.2 1.4 9.0 - - - 18-55 (years) (n=67) 40.5 10.1 39.7 10.6 46.7 7.0 40.0 7.1 55+ (years) (=64) 66.4 6.3 65.4 5.5 68.0 7.4 66.0 5.5 Men 48.9 22.8 44.5 22.7 61.1 19.1 44.8 25.3 Women 48.6 17.7 45.6 18.2 61.4 10.5 47.1 14.5 Sex, Men % 39.0 - 36.9 - 48.4 - 33.3 - 0-8 (years) 75.0 - 75.0 - - - - - 9-17 (years) 54.5 - 44.4 - 100.0 - 100.0 - 18-55 (years) 26.9 - 26.4 - 42.9 - 14.3 - 55+ (years) 46.9 - 45.9 - 47.8 - 50.0 - Sex, Women % 61.0 - 63.1 - 51.6 - 66.7 - 0-8 (years) 25.0 - 25.0 - - - - - 9-17 (years) 45.5 - 55.6 - 0.0 - 0.0 - 18-55 (years) 73.1 - 73.6 - 57.1 - 85.7 - 55+ (years) 53.1 - 54.1 - 52.2 - 50.0 - Weight (kg) 69.4 22.2 67.6 23.2 71.5 14.7 79.5 28.1 0-8 (years) 21.0 8.1 21.0 8.1 - - - - 9-17 (years) 42.9 18.4 44.0 20.4 38.0 - 38.4 - 18-55 (years) 71.5 21.2 70.2 21.7 72.7 17.5 79.5 21.2 55+ (years) 74.8 17.4 74.6 17.3 72.5 12.6 89.6 36.1 Men 76.1 26.4 74.7 28.7 77.8 13.7 83.4 43.6 Women 65.2 18.0 63.6 18.4 65.5 13.4 77.5 20.3 Height (m) 1.68 0.16 1.67 0.18 1.71 0.12 1.72 0.13 0-8 (years) 1.08 0.21 1.08 0.21 - - - - 9-17 (years) 1.47 0.15 1.49 0.16 1.39 - 1.41 - 18-55 (years) 1.72 0.11 1.71 0.11 1.76 0.13 1.74 0.04 55+ (years) 1.71 0.10 1.71 0.11 1.71 0.08 1.75 0.14 Men 1.73 0.21 1.72 0.24 1.76 0.13 1.73 0.23 Women 1.65 0.11 1.64 0.12 1.67 0.06 1.71 0.05 BMI (kg/m2) 24.1 5.3 23.8 5.5 24.2 3.6 26.4 6.7 0-8 (years) 17.3 2.4 17.3 2.4 - - - - 9-17 (years) 19.2 4.4 19.1 4.3 20.0 - 19.3 - 18-55 (years) 23.9 5.5 23.7 5.5 23.3 3.6 26.3 7.1 55+ (years) 25.5 4.4 25.7 4.6 24.6 3.6 28.3 6.3 Men 24.5 5.2 24.2 5.8 24.8 2.5 26.3 8.0 Women 23.8 5.3 23.5 5.3 23.6 4.4 26.4 6.5
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3.3. Nutritional Intake
The nutritional intake of the 146 patients with NMD was shown in Table 3. The mean energy intake was 1965 +/- 691 kcal/d. The mean energy intake of researched men (2026 +/- 582 kcal/d) was not significantly higher (p=0.38) than the mean energy intake of researched women (1925 +/- 753 kcal/d). However, 79.2% of the adult men against 62.7% of the adult women did not reach the daily recommended energy intake of 2500 kcal/d for men and 2000 kcal/d for women (20). The mean dietary protein intake was 79.4 +/- 31.3 g/d. For category 1, the mean dietary protein intake was 76.3 +/- 30.3 g/d, category 2 was 87.3 +/- 35.7 g/d and category 3 was 85.2 +/- 24.9 g/d. These differences were not significant (p=0.18). Category 1 showed the lowest dietary energy and protein intake overall. Results demonstrated an increase in dietary protein intake with older age. The dietary protein intake of adult patients within this study met the recommendation of daily dietary protein intake for healthy adults (0.8 g/kg-bw/d). However, the mean of all women in category 3, patients of 18-55 years old in category 3 and patients of 55+ years old in category 1 and 3 did not meet the higher dietary protein recommendation (1.2
g/kg-bw/d), accounting for 59.5% of the adults.
Considering the dietary protein recommendation of 0.8 g/kg-bw/d is intended for adults, patients younger than 18 years old were excluded from analysing the dietary protein intake in relation to the dietary protein need.
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Table 3. Nutritional intake
Nutritional intake
Total (n=146) Category 1 (n=103) Category 2 (n=31) Category 3 (n=12)
Mean SD Mean SD Mean SD Mean SD
Energy intake (kcal) 1965 691 1934 741 2060 569 1989 536
0-8 (years) 1298 328 1298 328 - - - - 9-17 (years) 1684 241 1692 268 1615 - 1685 - 18-55 (years) 1983 576 1945 548 2167 748 2084 648 55+ (years) 2036 831 2045 1011 2046 525 1819 391 Men 2026 582 1955 590 2177 527 2162 728 Women 1925 753 1922 821 1950 602 1903 447 Protein intake (g/d) 79.4 31.3 76.3 30.3 87.3 35.7 85.2 24.9 0-8 (years) 44.8 10.5 44.8 10.5 - - - - 9-17 (years) 59.7 10.0 58.6 10.5 58.4 - 70.6 - 18-55 (years) 81.0 34.3 78.8 35.8 87.3 30.5 91.3 25.9 55+ (years) 83.3 28.9 80.5 22.2 88.6 38.0 78.3 27.0 Men 81.0 27.6 75.3 18.8 93.8 40.2 87.2 32.2 Women 78.4 33.5 77.0 35.4 81.3 30.9 84.2 23.0
Protein intake (en%) 16.2 - 15.8 - 16.9 - 17.1 -
0-8 (years) 13.8 - 13.8 - - - - - 9-17 (years) 14.2 - 13.9 - 14.5 - 16.8 - 18-55 (years) 16.3 - 16.2 - 16.1 - 17.5 - 55+ (years) 16.4 - 15.8 - 17.3 - 17.2 - Men 16.0 - 15.4 - 17.2 - 16.1 - Women 16.3 - 16.0 - 16.7 - 17.7 - Protein (g/kg-bw/d) 18+ 1.19 0.52 1.18 0.54 1.23 0.51 1.10 0.39 18-55 (years) 1.21 0.59 1.22 0.64 1.20 0.31 1.18 0.32 55+ (years) 1.16 0.49 1.13 0.36 1.24 0.56 0.96 0.50 Men 1.22 0.59 1.21 0.63 1.22 0.49 1.26 0.68 Women 1.27 0.56 1.29 0.59 1.26 0.52 1.11 0.29
Values are means +/- SD; SD: standard deviation; n: number; kcal: kilo calories; g: grams; d: day; en%: energy percentage; bw: body weight; -: missing values.
The mean plant-based dietary protein intake of patients with NMD was 26.6 +/- 10.5 g/d and the mean animal-based dietary protein intake was 52.1 +/- 30.3 g/d. The ratio of plant-based and animal-based dietary protein intake between men and women was almost equal (respectively 33.7%-33.0%). As age increased, the plant-based dietary protein intake decreased with almost 20%.
The mean plant-based dietary protein intake between the categories of NMD (1: slowly progressive, 2: quickly progressive and 3: regressive) was significantly different (p=0.04). In contradiction, the mean animal-based dietary protein intake between the categories of NMD (1:
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slowly progressive, 2: quickly progressive and 3: regressive) was not significantly different (p=0.24). Category 1 showed a mean plant-based dietary protein intake of 26.3 +/- 9.5 g/d, category 2 24.6 +/- 10.9 g/d and category 3 33.5 +/- 15.1 g/d. Category 1 showed a mean animal-based dietary protein intake of 49.7 +/- 28.1 g/d, category 2 60.3 +/- 37.9 g/d and category 3 51.7 +/- 23.6 g/d.
Table 4. Nutritional intake protein sources
Nutritional intake
Protein sources Total (n=146) Category 1 (n=103) Category 2 (n=31) Category 3 (n=12)
Mean SD Mean SD Mean SD Mean SD
Plant-based protein (g/d) 26.6 10.5 26.3 9.5 24.6 10.9 33.5 15.1 Men 27.3 9.4 26.8 8.6 27.1 7.3 37.3 18.2 Women 25.9 11.2 26.1 10.1 22.3 13.2 31.6 14.3 0-8 (years) 21.7 6.5 21.7 6.5 - - - - 9-17 (years) 22.9 7.5 22.3 8.2 27.4 - 23.2 - 18-55 (years) 28.3 11.0 27.3 8.8 26.3 14.6 37.8 17.8 55+ (years) 25.7 10.5 26.5 10.9 24.0 10.1 28.5 9.8 Plant-based protein % 33.5 - 34.5 - 28.2 - 39.3 - Men 33.7 - 35.6 - 28.9 - 42.8 - Women 33.0 - 33.9 - 27.4 - 37.5 - 0-8 (years) 48.4 - 48.4 - - - - - 9-17 (years) 38.4 - 38.1 - 46.9 - 32.9 - 18-55 (years) 34.9 - 34.7 - 30.1 - 41.4 - 55+ (years) 30.9 - 32.9 - 27.1 - 36.4 - Animal-based protein (g/d) 52.1 30.3 49.7 28.1 60.3 37.9 51.7 23.6 Men 53.3 26.8 48.4 17.8 66.6 41.6 49.8 15.4 Women 51.4 32.4 50.5 32.8 54.4 34.4 52.7 27.7 0-8 (years) 23.2 5.6 23.2 5.6 - - - - 9-17 (years) 36.8 7.4 36.3 7.0 31.0 - 47.4 - 18-55 (years) 51.3 32.3 51.0 33.3 50.8 35.0 53.5 25.9 55+ (years) 57.5 29.7 54.0 22.1 64.5 39.3 49.7 26.1 Animal-based protein % 66.5 - 65.5 - 71.8 - 60.7 - Men 66.3 - 64.4 - 71.1 - 57.2 - Women 67.0 - 66.1 - 72.6 - 62.5 - 0-8 (years) 51.6 - 51.6 - - - - - 9-17 (years) 61.6 - 61.9 - 53.1 - 67.1 - 18-55 (years) 65.1 - 65.3 - 69.9 - 58.6 - 55+ (years) 69.1 - 67.1 - 72.9 - 63.6 -
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Mealtimes were subdivided into 4 moments, where morning- snacks, afternoon-snacks and evening-snacks were combined into one mealtime. Dietary protein sources were also combined with each mealtime. At dinnertime, dietary protein intake was the highest with 32 g/d. Results demonstrated the highest relative intake of animal-based protein during dinnertime and the lowest during breakfast. For every mealtime the intake of animal-based dietary protein (65%) was higher compared to plant-based dietary protein (35%) intake.
Figure 2. Intake and distribution dietary protein: source per mealtime. Values are means; g: grams.
Dietary protein intake of patients with NMD lowered with a decrease of mobility, but was not significant (p=0.06). The majority of patients (74%) belonged to category 0, which was ambulatory.
Table 5. Dietary protein intake in relation to mobility
Mobility Mean dietary protein intake g/d SD
Level 0 (n = 108) 82.9 33.4
Level 1 (n = 18) 75.9 27.2
Level 2 (n = 20) 64.5 18.2 Values are means +/- SD; 0: ambulatory; 1: ambulatory with tools; 2: confined to a wheelchair; g: grams; d: day; SD: standard deviation
46% 37% 24% 33% 54% 63% 76% 67%
Breakfast Lunch Dinner Snacks
0 5 10 15 20 25 30 35
Timing of dietary protein intake
Di etar y p ro te in in take ( g)
Intake and distribution dietary protein: source per mealtime
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5. Discussion
In this study we studied the dietary protein intake of patients with NMD. The mean dietary protein intake is 79.4 +/- 31.3 g/d, accounting for 16.2% of the total daily energy intake. Per kg/bw the dietary protein intake is 1.19 +/- 0.52 g/d. The mean dietary protein intake in patients with NMD is well above the recommended daily allowance of 0.8 g/kg-bw/d, still a significant proportion (59.5% of the adults) does not meet the higher recommended intake of 1.2 g/kg-bw/d. The majority of dietary protein is originative from animal-based sources (66.5%). Dinner is the mealtime with the highest amount of dietary protein intake (32 g). The distribution of plant-based and animal-based dietary protein sources is respectively 46-54% during breakfast, 37-63% during lunch, 24-76% during dinner and 33-67% during snacks. There is a significant difference in distribution of plant-based dietary protein intake among the categories of NMD (p=0.04). Category 1 consumes 26.3 +/- 9.5 g/d, category 2 consumes 24.6 +/- 10.9 g/d and category 3 consumes 33.5 +/- 15.1 g/d of plant-based dietary protein. The distribution of the mean dietary protein intake is 13 g/d during breakfast, 19 g/d during lunch, 32 g/d during dinner and 6 g/d during snacks.
5.1. Recommendations
There was no specific information about dietary protein intake of patients with NMD nor corresponding recommendations. However, there are 3 guidelines exclusively for patients with ALS, Duchenne and with swallowing disorders due to a neurological disorder. The recommendation for patients with ALS is set on 1.0-1.2 g/kg-bw/d. To optimize their nutritional status, the recommended intake is 1.2-1.5 g/kg-bw/d (11). For patients with Duchenne, the recommended dietary protein intake is 10-15 en% p/d, which is approximately similar to patients with a swallowing disorder (0.8-1.0 g/kg-bw/d). These recommendations also apply to healthy adults in The Netherlands. Additionally, the recommendation for vulnerable, older and underweight people is 1.2 g/kg-bw/d (18,19). Combining the different guidelines into a general recommendation will provide more clarity for dietitians and patients with NMD.
5.2 Dietary protein in NMD
Studies proved that a sufficient dietary protein intake is beneficial to prevent muscle mass from breaking down, which is crucial for patients with NMD (11). It has been suggested that 20 to 25 grams of dietary protein intake per meal is required to allow an optimal muscle synthesis. However, the synthetic rate of muscle synthesis can vary following the ingestion of different protein sources.
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Dietary protein is highly specific because of various compositions of amino acids. Protein molecules are too large for the body to absorb and therefore unusable for digestion. Protein molecules get chopped into amino acids through digestion, which are components of protein in body cells. Almost every nutritional product contains protein, in forms of plant- and animal-based sources. Plant-based protein sources are for example bread, grains, legumes, nuts and mushrooms. Meat, fish, poultry, dairy, cheese and eggs belong to animal- based protein sources.
The protein quality differs per source and therefore per product. For example, meat relatively possesses the most amount of protein: 20-30%. In addition, the amount of dietary protein in fish, comes second. The protein quality also depends on how efficient the body can digest the different kinds of protein sources. The efficiency of digesting differs per body.
The protein quality depends on the amount of essential amino acids.
T
here are 22 different kinds of amino acids that occur in dietary protein, with different compositions, sequences and structures. Therefore, every protein is unique and there are thousands of combinations possible. From 22 amino-acids, the body is able to create 13 themselves. The remaining 9 are only available in nutrition. These are the so-called essential amino- acids. Also, there are semi- essential amino-acids. The body normally creates those themselves, but in times of sickness or deficiency, supplements are necessary. Plant-based protein sources often possess a minority of essential amino acids and an incorrect ratio, in comparison to animal-based protein sources. The plant-based protein sources are also frequently harder to digest. The combination of a sufficient amount of essential amino acids and an efficient digestion determine the protein quality (20).5.3. Population
In order to obtain an answer to the main question of this study, and to reach a general recommendation, data has been collected from 146 patients across The Netherlands with several NMD. This population also includes patients who are immobile or experience fatigue and-or difficulty moving. These are often patients who are in a late stadium of disease. In all probability, these patients reduce the mean dietary protein intake. On the other hand, some patients consume dietary preparations, like drinks and/or tube feeding with added moisture, energy and protein. This probably increases the mean dietary protein intake. The 2 influencing factors possibly neutralize the mean number of dietary protein intake.
Dietary reports are from dieticians of participating hospitals and rehabilitation centers across The Netherlands. While implementing the data, we were dependent on the amount of dietary reports that were delivered in a short period of time, consisting of 3 months. The number of patients with NMD within this study is set on 146, but in order to create a general guideline, this
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study must be pursued. Hopefully, there are more hospitals and/or rehabilitation centers who are willing to participate to the next studies.
5.4. Data collection
Trained dieticians instruct selected patients to document dietary reports and ask them to sign consent forms. Without a signed consent form, an illegible or incomplete dietary report, patients data is not used. This reduces the total amount of researched patients within this study. When portion sizes are missing in a dietary report, suitable amounts are estimated to prevent more patients from being excluded. Estimating portion sizes makes the study less reliable. A possible solution is for dieticians to check the dietary reports on incomplete values and discuss missing information with the concerning patient. Another option is for partners, family or caregivers to also be instructed about documenting a dietary report and check if the dietary report is filled in correctly.
The answer to the main question is about the specific dietary protein intake among patients with NMD. In the virtue of different kinds of dietary protein sources, this alone is not a sufficient answer. In this study, the differences in dietary intake among plant- and animal-based protein sources are therefore researched.
Another point of discussion concerns implementing and analyzing data, and whether it is more convenient to work with age or date of birth. All used data, is collected with the variable date of birth. At the beginning of the analysis it became clear that it is necessary to use the variable age instead of date of birth. All dates of birth are converted into ages, to be able to analyze the different age groups in SPSS.
The NMD are categorized by the VSN (1: slowly progressive, 2: quickly progressive and 3: regressive) (3). These categories are chosen prior to the analyzing part of the thesis. Therefore, there is no insight into how many dietary reports are collected per NMD. The distribution of NMD over the categories is not equal. There also is an uneven distribution of patients among categories. This is probably caused during data collecting, which is not equally done per disease. For example, the period of time where Myotonic Dystrophy (MD) was gathered, is 3 years longer than the remaining NMD (22). MD belongs to category 1, which therefore makes this category bigger than the other categories. In order to get a representative perspective on dietary protein intake among the most popular NMD, the collecting period of time should be equal on all NMD.
A plus point of this study is that the obtained data is carefully used and saved. All dietary reports were scanned into a computer and digitized into databases. In order to respect the privacy of patients dietary reports were encoded and none of their names were used.
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The used data contains information about dietary protein intake of patients with NMD, scattered over 3 days, including information of 2 week-days and 1 weekend-day. This gives an adequate depiction of dietary protein intake per patient. There are 146 patients among this study, which counts for a total of 438 days of nutritional intake. All patients are instructed by trained dietitians on how to document their nutritional intake correctly. This makes the database of dietary protein intake wider and more reliable. In addition, several distinguished programs are used to collect and analyze data, such as Excel, NEVO-table and SPSS. Different types of syntaxes and tests are used in SPSS. These programs and the way they are used, make this study highly valid.
5.5. Quality of life
In this study, dietary protein intake is exclusively studied, without taking the body composition or other components into account. A decreased muscle mass is one of the major components that inhibits a proper quality of life (4). Research is necessary to indicate whether or not a higher dietary protein intake influences the body composition in patients with NMD. The inflammatory aspect is also of great importance regarding dietary protein intake, because this causes a higher need for dietary protein intake (11). Furthermore, the carbohydrate intake influences the muscle synthesis, which makes it relevant too (23).
In order to give a general and well substantiated recommendation, the rare NMD are excluded from this study and only the most common NMD are included. This makes the results generally interpretable, which leads to an answer to the main research question.
5. 6 Public relevance
Dietary protein intake of patients with NMD was unknown, which signified a gap in science. Through this study, there is an answer to this gap in the form of general
recommendations for patients with NMD. Dietary protein intake is not yet linked to muscle mass or an improvement of quality of life in patients with NMD. This also indicates a gap in science.
Other populations show the relevance of dietary protein intake, because there is often a higher need found in patients with diseases. A higher dietary protein intake also proves to retain muscle mass.
During this study it became clear that there are groups in this population, who are at higher risk in developing a deficiency in dietary protein intake. This study might bring awareness to these patients. The discovery of deficiencies in dietary protein intake will hopefully stimulate further research at this subject.
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5.7. Conclusion
The main question of this study refers to dietary protein intake in patients with NMD. However, the main goal is to support science in achieving a better quality of life for patients with NMD. An answer to the main question in this study will give insight into the gap in science and will therefore be a great contribution to this subject.
The mean dietary protein intake in patients with NMD is 79.4 +/- 31.3 g/d, accounting for 16.2% of the total daily energy intake. Per kg/bw the dietary protein intake is 1.19 +/- 0.52 g/d. This mean intake meets the general dietary protein recommendation of 0.8 g/kg-bw/d, but does not meet the higher dietary protein recommendation of 1.2 g/kg-bw/d.
In this study, the most common NMD are studied and categorized into three groups (1: slowly progressive , 2: quickly progressive and 3: regressive). PPS did not occur in this study population and Myotonic Dystrophy is the most researched NMD (46.6%).
The highest need for dietary protein recommendations is found in the variables: men (81.0 +/- 27.6 g/d; 16.0 en%; 1.22g/kg-bw/d), age category of 55+ years old (83.3 +/- 28.9 g/d; 16.4 en%; 1.16 g/kg-bw-d) and category 1 of NMD (76.3 +/- 30.3 g/d; 15.8 en%; 1.18g/kg-bw/d). The lowest mean dietary protein intake is during snacks (6 g/d). The lowest mean animal-based dietary protein intake is during breakfast (54%). Mobility level 2 has the lowest mean dietary protein intake (64.5 +/- 18.2 g/d). Referring to these results, the recommendation of this study is established on a minimum of 1.2 g/kg-bw/d for patients with NMD. Hopefully this is a step forward in retaining or increasing their quality of life.
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7. Recommendations
7.1. Nutritional recommendation
The majority of the population in this study achieves the higher recommendation of 1.2 g/kg-bw/d. However, several patient groups don’t meet this standard. These patients pertain to the following groups:
• 55+ years old in category 1
• Women in general and the age categories of 18-55 years old and 55+ years old in category 3
In order to obtain an optimal dietary protein intake for the study population, the general recommendation is to consume at least 1.2 g/kg-bw/d dietary protein. Also, the distribution of dietary protein intake can be improved. On average, dinner contains the highest amount of dietary protein (32 g/d). The recommendation is that the dietary protein intake for the rest of the main meals increases, containing 20 to 25 g/mealtime. For snacks, the recommendation is a higher intake of minimal 8 g/snack, based on the current intake and taking an achievable amount into account. The relatively lowest dietary intake of animal-based protein is during breakfast (54%). When taking the higher quality of animal-based dietary protein into consideration, the recommendation is a ratio of 75% (animal-based) -25% (plant-based) per mealtime. This should be achievable, taking the ratio of all mealtimes into account. In case patients are vegetarian or vegan, the general advice is to increase the dietary protein intake by 25% per day, which signifies 15 g of dietary protein. This recommendation is due to the lack of animal-based (high quality) protein intake.
This study shows a reduced dietary protein intake when mobility decreases. During these circumstances, dieticians need to strictly monitor dietary protein intake. Therefore, the recommendation is to document the dietary protein intake monthly through dietary reports, to prevent deficiency in dietary protein intake. When difficulties appear, trying to achieve the given recommendations, dietary preparations and/or tube feeding should be considered.
7.2. Follow-up studies
The collected data of this study is available for follow-up studies among the subject of dietary protein intake in patients with NMD, after consultation with Dr. ir. Michael Tieland. Follow-up studies should combine research of dietary protein intake with research of body composition,
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the inflammatory aspect of some of the NMD and dietary carbohydrate intake. These components influence the muscle synthesis and are therefore considered important (23).
Patients with NMD experience symptoms like progressive weakness, diminution of muscle mass, decreasing fat-free mass and increasing fat mass (24). Research at body composition in patients with NMD is of great importance to indicate whether or not the dietary protein intake can counteract with diminution of muscle mass due to NMD. In addition, body composition in patients with NMD needs to be studied in relation to quality of life. Referring to other studies with vulnerable patient groups, it is plausible that retaining muscle mass positively influences the downwards consequences in patients with NMD (9). Yet, there is no data of this relation.
Muscle mass is the most relevant part of body composition measurements for this target group. In this study, body composition is measured using Body Mass Index (BMI). However, this is not an adequate tool to determine muscle mass. Muscle mass can be measured using CT-scans, Dual-energy x-ray absorptiometry (DEXA) methods and skin fold measurements. Values of the outcomes of these measurements will provide useful information about muscle mass, fat-free mass and fat mass. This ratio in body composition could show an indication about the progression of NMD. In order to demonstrate a relation between the factors body composition and quality of life, patients need to be questioned about their daily well-being, using screening tools.
Influences of inflammatory aspects of some of the NMD are unknown, but of great importance to determine the need for dietary protein intake. This study gives insight into the gap in science about dietary protein intake, not about dietary protein need. A relation is proven between inflammatory reactions and a higher need for dietary protein (25). Through blood tests, the extent of inflammatory reactions can be determined. Based on the extent of inflammatory reaction, the need for dietary protein intake needs to be studied.
This study solely focusses on dietary protein intake, while dietary carbohydrate intake also stimulates muscle synthesis. Dietary carbohydrates get processed into glucose during digestion. With a glucose deficiency, the body creates glucose out of amino-acids. Protein in muscle mass is used for this process, which causes diminution in muscle mass (23). Therefore, these elements should be combined in studies. By using dietary reports, the amount of dietary protein and carbohydrate can be determined. In order to recommend the right amount of carbohydrates to stimulate this process, the optimum of dietary carbohydrate intake also needs to be studied.
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7.3. Interventions
Patients with NMD frequently experience a decrease in mobility. Therefore, an intervention where dieticians collaborate with physical therapists could be beneficial. A physical therapist assists with executing physical activity in the right way, to prevent injuries. Also, the right amount of physical activity per patient should be determined by a physical therapist. The combination of an adequate dietary protein intake and the required physical activity, is likely to stimulate the muscle synthesis.
The recommendation for higher dietary protein intake applying to elderly and vulnerable groups is 1.2 g/kg-bw/d. In order to obtain an optimal dietary protein intake for patients with NMD, the recommendation established by this study, is to consume at least 1.2 g of dietary protein/kg-bw/d. Patients with NMD need to be monitored concerning their muscle mass. When muscle mass decreases despite the higher dietary protein intake, the amount of dietary protein should be raised, as precaution. The recommendation of dietary protein intake should be combined with the Dutch Standard of Healthy Physical Activity (NNGB). The NNGB comprehends 30 minutes of physical activity, 5 times per week and could be beneficial retaining muscle mass (26). An increase in muscle mass may lead to a better quality of life. However, some patients experience difficulty in mobility, therefore this recommendation only applies to patients who are able to meet this recommendation. It is desirable to have the assistance of a physical therapist during this process.
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8. Bibliography
1. Szymanska.K, Szczaluba.K, Kostera-Pruszczvk. A, Wolanczyj. T, Clinical Applications For Next-Generation Sequencing, Chapter 6- Next Generation Sequencing in Neurology and Psychiatry, Acedemic Press, 2016: p97.
2. Sridhar Selvaraj, Rita C.R. Perlingeiro, Induced Pluripotent Stem Cells for Neuromuscular Diseases: Potential for Disease Modeling, Drug Screening, and Regenerative Medicine, Reference Module in Biomedical Sciences, 2018
3. R. Pangalila, H. Hijdra, E. Baars en J.P. Van den Berg (revalidatieartsen), A. Horemans en A. Groenen (Spierziekten Nederland), Behandelkader Neuromusculaire
aandoeningen. 2013: 1-3. Available at:
https://revalidatiegeneeskunde.nl/sites/default/files/attachments/Kwaliteit/Behandelkader s/behandelkader_nma_2013.pdf
4. McNally ME, Pytel P. Muscle Diseases: The muscular dystrophies. Annual Review of Pathology: Mechanisms of Disease. 2007;2:87-109. Available at: https://www.annualreviews.org/doi/full/10.1146/annurev.pathol.2.010506.091936
5. Spierziekten Nederland. Thema’s. Voeding Available at: www.spierziektennederland.nl 6. Lopes da Silva, H F, de Araújo Brito, A N, Silva de Freitas, E P, Teixeira Dourado Júnior,
M E, Maurício de Sena-Evangelista, K C, Leite-Lais L. Dietary intake and zinc status in amyotrophic lateral sclerosis patients. Nutrición Hospitalaria 2016;346(346):1361-1367. 7. Motlagh B, MacDonald JR, Tarnopolsky MA. Nutritional inadequacy in adults with
muscular dystrophy. Muscle & Nerve 2005 Jun;31(6):713-718.
8. Mehta, Nilesh M., MD|Newman, Haley, BA|Tarrant, Stacey, RD|Graham, Robert J., MD. 26 Nutritional Status and Nutrient Intake Challenges in Children With Spinal Muscular Atrophy. Pediatric Neurology 2016;57:80-83.
9. de Groot C.P.G, Haveman-Nies A, van de Rest O. Voeding. June 2017, Volume 33,Issue 4-5, p379–390. Available at: https://link.springer.com/article/10.1007/s12414-017-0239-5 10. Souza Genaro de P, Martini LA. Effect of protein intake on bone and muscle mass in the elderly. Nutrition Reviews. 2010;68(10):616–623. Available at: https://academic.oup.com/nutritionreviews/article-abstract/68/10/616/1811535
11. Dieetbehandelingsrichtlijnen. Richtlijn 34, 39, 50. Available at: www.dieetbehandelingsrichtlijnen.nl
12. Tieland, M, Voeding en Spierziekten: focus op eiwitbehoefte. Summary. Available at: https://www.nwo.nl/en/research-and-results/research-projects/i/18/32018.html
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13. Tieland M, Borgonjen-Van den Berg, Karin J, Van Loon, Luc J. C, de Groot, Lisette C. P. G. M. Dietary protein intake in Dutch elderly people: a focus on protein sources. Nutrients 2015;7(12):9697-9706
14. Portie-online. Available at: https://portie-online.rivm.nl
15. NEVO-online versie 2016/5.0, RIVM, Bilthoven. Available at: https://nevo-online.rivm.nl. 16. Zorg voor beter, eten en drinken, Wegen-BMI-ouderen. Available at:
https://www.zorgvoorbeter.nl/eten-en-drinken/wegen-bmi-ouderen
17. Voedingscentrum, BMI jongens en meisjes. Available at:
https://www.voedingscentrum.nl/professionals/kindervoeding-0-4-jaar/babyenkindervoeding/bmi-jongens-en-meisjes.aspx
18. Vermeulen H. Ondervoeding. NED TIJDS EVID PRACT 2011 Jul;9(3):3.
19. Richtlijnen goede voeding 2015. 2015; Available at: http://library.wur.nl/WebQuery/groenekennis/2102127.
20. Voedingscentrum. hoeveel calorien heb ik nodig? Available at: https://www.voedingscentrum.nl/nl/service/vraag-en-antwoord/gezonde-voeding-en-voedingsstoffen/hoeveel-calorie-n-heb-ik-nodig-.aspx
21. Voedingscentrum. Eiwitten. Available at:
https://www.voedingscentrum.nl/encyclopedie/eiwitten.aspx
22. Pouwer. J, Snijder. L, Dietary protein intake of Dutch people with Neuromuscular Diseases. An observational study of patients with Neuromuscular diseases. jan 2018.
23. Voedingscentrum. Koolhydraten. Available at:
https://www.voedingscentrum.nl/encyclopedie/koolhydraten.aspx
24.
McCrory MA, Kim HR, Wright NC, Lovelady CA, Aitkens S, Kilmer DD. Energy expenditure, physical activity, and body composition of ambulatory adults with hereditary neuromuscular disease. The American journal of clinical nutrition 1998 Jun;67(6):1162-1169. 25. Stuurgroep ondervoeding. Richtlijn ondervoeding. Available at:http://www.stuurgroepondervoeding.nl/wp-content/uploads/2017/08/Richtlijn-Ondervoeding-Stuurgroep-Ondervoeding-augustus-2017.pdf
26. Sportzorg. Nederlandse Norm Gezond Bewegen. Available at: https://www.sportzorg.nl/bibliotheek/nederlandse-norm-gezond-bewegen-nngb
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Appendix
Appendix 1. Codes
Sex: male = 0 female = 1 Date of Birth: month/day/year Length: rounded at 2 decimals Weight: rounded at 1 decimal BMI: rounded at 1 decimal
Mobility: ambulant = 0, tool = 1, wheelchair = 2 NEVO: available at www.nevo-online.rivm.nl
Neuromuscular diseases
0 = ALS, PSMA, HSP and PLS
1 = Arthrogryposis multiplex congenita (AMC) 2 = Ataxia of Friedreich (AvF)
3 = Chronic idiopathic axonal polyneuropathy (CIAP) 4 = Congenital and metabolic neuromuscular diseases 5 = Small-Fiber Peripheral Neuropathy (SFPN)
6 = Hereditary muscle dystrophy and distal myopathy (Duchenne) 7 = Hereditary polyneuropathy
8 = Facioscapulohumerale dystrophy (FSHD) 9 = Guillain Barré syndrome (GBS)/CIDP 10 = Myotonic Dystrophy (MD)
11 = Myasthenia 12 = Myositis
13 = Postpoliosyndrome (PPS) 14 = Spinal muscular atrophy (SMA)
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Appendix 2. Information letter and informed consent
Proefpersoneninformatie voor deelname aan onderzoek
Voeding en spierziekten: Focus op eiwitinname
Inleiding
Geachte heer/mevrouw,
Wij vragen u vriendelijk om mee te doen aan een wetenschappelijk onderzoek. Meedoen is vrijwillig. Om mee te doen is wel uw schriftelijke toestemming nodig.
Dit onderzoek wordt uitgevoerd door de Hogeschool van Amsterdam. De toetsingscommissie van de METc van VUmc heeft beoordeeld dat dit onderzoek niet onder de Wet
medischwetenschappelijk onderzoek met mensen (WMO) valt.
Voordat u beslist of u wilt meedoen aan dit onderzoek, krijgt u uitleg over wat het onderzoek inhoudt. Lees deze informatie rustig door en vraag de onderzoeker uitleg als u vragen heeft. U kunt er ook over praten met uw partner, vrienden of familie.
1. Doel van het onderzoek
Het doel van dit onderzoek is het verzamelen en analyseren van de huidige
voedingsconsumptie van de doelgroep, met een focus op de eiwitinname. Dit doen we door een 2/3-daags voedingsdagboek in te vullen van mensen met een spierziekte. De eiwit en energie-inname zal eerst worden geregistreerd en daarna geanalyseerd. Het invoeren en verwerken van de voedingsconsumptie zal gedaan worden door studenten van de Hogeschool van Amsterdam en zij zullen de resultaten gebruiken voor hun afstudeeronderzoek.
Het onderzoek wordt uitgevoerd door een onderzoeker van de Hogeschool van Amsterdam en worden gepubliceerd in een nationaal en internationaal tijdschrift. Tevens wordt een landelijk netwerk geformeerd die mee schrijft aan een projectvoorstel omtrent de behoefte en rol van eiwitinname bij mensen met een spierziekte.
2. Wat meedoen inhoudt
U doet mee aan een deelonderzoek binnen het project ‘Voeding en spierziekten: focus op eiwitinname’. Uit verschillende onderzoeken is gebleken dat eiwitten een rol kunnen spelen in het behoud van de spiermassa en er eventueel zelfs voor kunnen zorgen dat er spieropbouw plaatsvindt. Echter is er nog weinig informatie bekend over de rol van eiwit in de voeding bij
41
spierziekten. Om hier informatie over te verzamelen vragen wij u een 2/3-daags
voedingsdagboek in te vullen. Hierbij vult u in wat u de afgelopen 2/3 dagen zowel gegeten als gedronken heeft. Omdat we graag uw eiwitinname willen berekenen zijn ook de portiegroottes van belang en het tijdstip dat u de voeding geconsumeerd heeft. Op die manier krijgen we inzicht over wat u heeft gegeten, wanneer en hoeveel.
3. Mogelijke voor- en nadelen
U heeft geen voordeel van meedoen aan dit onderzoek.
Nadelen kunnen zijn: Als er nog geen eetdagboek bij u is afgenomen/door u is ingevuld, zal dit eenmalig ongeveer 60 minuten van uw tijd kosten verdeeld over de 2/3 dagen.
4. Als u niet wilt meedoen of wilt stoppen met het onderzoek
U beslist zelf of u meedoet aan het onderzoek. Deelname is vrijwillig.
Doet u mee aan het onderzoek? Dan kunt u zich altijd bedenken. U mag tijdens het onderzoek stoppen. U hoeft niet te zeggen waarom u stopt. Wel moet u dit direct melden aan de
onderzoeker. De gegevens die tot dat moment zijn verzameld, worden gebruikt voor het onderzoek. Hierdoor kunnen de studenten wel uw gegevens gebruiken voor hun
afstudeeronderzoek.
5. Gebruik en bewaren van uw gegevens
Voor dit onderzoek is het nodig dat uw persoonsgegevens worden verzameld en gebruikt. Tijdens een gesprek met de diëtist zal informatie verzameld worden over wat u de afgelopen 2/3 dagen geconsumeerd heeft. Daarnaast is uw medische diagnose van belang voor het onderzoek. Elk proefpersoon krijgt een code die op zijn/haar gegevens (gecodeerd), Uw naam wordt verder in het onderzoek niet meer gebruikt en is alleen bekent bij uw eigen diëtist.
Uw gegevens
Al uw gegevens blijven vertrouwelijk. Alleen de diëtist heeft u persoonsgegevens en zal deze gecodeerd aan de onderzoeker doorsturen. De onderzoeker heeft dan alleen een code met voedingsgegevens. U kunt de onderzoeker vragen om een elektronische kopie van uw
gegevens die u heeft aangeleverd of die direct bij u gemeten zijn. De onderzoeksgegevens zijn bij publicatie in een (wetenschappelijk) tijdschrift daardoor niet te herleiden naar u. Aan het eind van het onderzoek zullen de onderzoeksresultaten gedeeld worden met uw diëtist. Als u
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de resultaten graag in wil zien is dat mogelijk. Vraag hiervoor de resultaten op bij uw diëtist. De resultaten zullen eind januari 2019 bekend zijn.
Als u de toestemmingsverklaring ondertekent, geeft u toestemming voor het verzamelen, bewaren en inzien van uw medische en persoonsgegevens.
De onderzoeker bewaart uw gegevens 10 jaar. Daarna worden de persoonsgegevens vernietigd.
Indien u ontevreden bent over hoe wordt omgegaan met uw privacy dan kunt u een klacht indienen bij de Functionaris gegevensbescherming van de Hogeschool van Amsterdam. Roeland Reijers, u kunt contact opnemen via de email:
functionarisgegevensbescherming@hva.nl.
Ook kunt u terecht bij de Autoriteit persoonsgegevens.
Aanvullend gebruik gegevens
Wij willen uw gegevens graag bewaren. Misschien kunnen we daar later extra onderzoek mee doen. Het gaat dan om verder onderzoek naar de rol van eiwitten bij mensen met een
spierziekte. Op het toestemmingsformulier kunt u aangeven of u hiermee akkoord gaat. U kunt deze toestemming altijd weer intrekken. Uw persoonsgegevens worden dan vernietigd.
6. Vergoeding voor meedoen
Voor het meedoen aan dit onderzoek krijgt u geen onkostenvergoeding.
7. Heeft u vragen?
Bij vragen kunt u contact opnemen met de studenten Voeding en Diëtetiek van de Hogeschool van Amsterdam. Alle contactgegevens staan in Bijlage A op de volgende pagina.
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Bijlagen:
A. Contactgegevens onderzoeksteam. (Niet in scriptie opgenomen wegens privacy)
Indien de proefpersoon een kind is ontvangt u als ouders/voogden:
- Formulier: Proefpersoneninformatie voor deelname aan onderzoek; informatie voor
ouders/voogden en kind.
- Toestemmingsverklaring voor ouders/voogden van proefpersoon 0-11 jaar of
Toestemmingsverklaring voor kind 12-15 jaar en ouders/voogden van proefpersoon.
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Toestemmingsformulier proefpersoon
Voeding en spierziekten: focus op eiwitinname
- Ik heb de informatiebrief gelezen. Ook kon ik vragen stellen. Mijn vragen zijn voldoende
beantwoord. Ik had genoeg tijd om te beslissen of ik meedoe.
- Ik weet dat meedoen vrijwillig is. Ook weet ik dat ik op ieder moment kan beslissen om toch
niet mee te doen of te stoppen met het onderzoek. Daarvoor hoef ik geen reden te geven.
- Ik geef toestemming voor het verzamelen en gebruiken van mijn gegevens op de manier en
voor de doelen die in de informatiebrief staan. Ik geef toestemming om mijn gegevens nog 10 jaar na dit onderzoek te bewaren.
- Ik wil meedoen aan dit onderzoek.
□ Ik geef toestemming om mijn gegevens nog na dit onderzoek te bewaren. Mogelijk kan dit later nog voor meer onderzoek worden gebruikt, zoals in de informatiebrief staat. □ Ik geef toestemming om mij na dit onderzoek opnieuw te benaderen voor een vervolgonderzoek. Naam proefpersoon:
………..……… Handtekening: ……….…… Datum: __ / __ / ____
Ik verklaar dat ik deze proefpersoon volledig heb geïnformeerd over het genoemde onderzoek.
Als er tijdens het onderzoek informatie bekend wordt die de toestemming van de proefpersoon zou kunnen beïnvloeden, dan breng ik hem/haar daarvan tijdig op de hoogte.
Naam onderzoeker (of diens vertegenwoordiger): ………..
Handtekening: ……….…… Datum: __ / __ / ____
De proefpersoon krijgt een volledige informatiebrief mee, samen met een kopie van het getekende toestemmingsformulier.
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Appendix 3. Dietary report
Deelnemer nummer:………
Voedingsdagboek
Voeding en spierziekten
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