Inclusion Body Myositis
Conditions
Keywords
Inclusion Body Myositis, IBM, Skeletal muscle, Aging, Muscle function, Muscle strength, Case-control study, Diet, Nutrition
Brief summary
The goal of this observational study is to understand how diet may influence the disease characteristics of inclusion body myositis (IBM). Research findings will help determine whether dietary factors could play a role in managing IBM. The study aims to answer the question: Does diet affect the muscle health and functional ability of people living with IBM? Researchers will compare adults with IBM to healthy volunteers aged 40 years and older. This comparison will help to identify which findings are related to normal ageing and which are specific to IBM. Participants will: Attend an initial screening visit at the Manchester Metropolitan University Institute of Sport to confirm eligibility and explain study procedures. Complete four weeks of home-based monitoring, including dietary records, physical activity monitoring, and questionnaires about lifestyle and symptoms. Attend a second university visit for assessments of body composition, metabolism, and muscle function.
Detailed description
This study will employ an observational, case-control design. A sample size of 32 participants with inclusion body myositis (IBM) has been determined based on a power calculation designed to detect a strong association (r = ±0.5) between dietary protein practices and various outcome measures related to muscle mass and function. Using a two-tailed test with an alpha level of 0.05 and power of 80% (β = 0.2), the analysis indicated a required sample size of 29 participants. The sample size equation used was appropriate for Pearson's Correlation analysis. To account for an estimated 10% dropout rate, the final target recruitment number is 32. In addition, 15 age- and activity-matched control participants will be recruited. Power calculations for comparisons between IBM and control groups returned lower sample size requirements, reflecting the lower variability typically observed in healthy populations. Identification of participants with IBM will be carried out at the Tertiary Neuromuscular Service, Salford Royal Hospital (Manchester, UK), and the Neuromuscular Centre (Winsford, Cheshire, UK). Those identified will be approached in clinic or by email with a Participant Information Sheet, the study poster and a Consent to Contact Form. The completed Consent to Contact Form will allow the Manchester Metropolitan (ManMet) research team to follow up with an invitation to a screening visit at the ManMet Institute of Sport (IoS)- a phone call or email. Control participants will be recruited from the local community. If agreed, a phone call will take place to arrange a screening and enrolment visit. The screening visit to the IoS will last up to 1.5 hours but may end prematurely if the participant is found to be ineligible. During the visit, participants will meet with a researcher who will provide a detailed explanation of the study, including time commitment, risks, and participant rights. Informed consent will then be obtained. Participants will then complete four questionnaires to highlight any contraindications to testing and ensure appropriate matching between the disease and control group. These include: a Demographic and General Health Questionnaire, the sIBM Physical Functioning Assessment, an MRI Safety Checklist and the Physical Activity Scale for Individuals with Physical Disabilities. At the end of this visit, participants will be fitted with two activity monitors secured using medical-grade adhesive (one on the wrist and one on the thigh). They will also be given a paper-based food record or shown the Libro App that will serve as a digital alternative, and a set of questionnaires. Participants will then complete a four-week home-based monitoring period. During this time, they will wear the activity monitors continuously for seven days to record physical activity, sedentary behaviour, and sleep patterns. They will also complete two 3-day food diaries, spaced three weeks apart, to capture dietary intake (food and drink, excluding water). Additionally, participants will complete a Food Frequency Questionnaire, which asks how often different food items have been consumed over the past year. Throughout this period, participants will also complete the series of validated questionnaires at their own pace. These include a Quality of Life Questionnaire (Short Form-36v2) for overall health and wellbeing, the Nottingham Extended Activities of Daily Living (NEADL) Scale for independence in daily activities, the Modified Fatigue Impact Scale (MFIS), the Visual Analogue Scale (VAS) for pain, the Pittsburgh Sleep Quality Index (PSQI), and the SWAL-QOL questionnaire, which assesses how swallowing impacts quality of life. After the home-based data collection is complete, participants will return to the IoS for a single laboratory based testing session lasting approximately 3-4 hours. In preparation for this visit, participants will be asked to fast for at least three hours, avoid caffeine for 12 hours, and alcohol for 24 hours. They will also be advised to wear comfortable sports clothing with no or minimal metal components. At the start of the visit, height and weight will be recorded to calculate body mass index. Limb dominance will be ascertained. A small finger-prick blood sample will be taken to measure serum 25(OH)D. Resting metabolism will then be measured using indirect calorimetry. Following this, a whole-body DXA scan will be used to assess body composition, including total and regional fat mass, lean mass, and bone mineral density. This scan will only be undertaken once the participant completes the X-ray Imaging Checklist. Muscle strength and function will be assessed next. Leg strength will be evaluated using an isokinetic dynamometer. Handgrip strength will also be measured using a handheld dynamometer. Finally, participants will undergo an MRI scan lasting approximately 45 minutes. Images will be taken of the thigh and forearm muscles, as well as the head and neck, to assess muscle size, fat infiltration, inflammation, and swallowing function. Standard MRI safety procedures will be followed, including a repeat of the MRI safety checklist prior to scanning. With respect to the study's primary outcome (relationships between habitual dietary protein intake and total lean mass, as well as muscle strength and physical function measures) correlation analyses will be used to explore the relationships between continuous variables. Depending on data distribution, Pearson's correlation coefficients (parametric) or Spearman's rho (non-parametric) will be used to examine associations between protein intake (g/day, g/kg/day) and a) total lean mass/ fat-free mass (DXA), b) muscle strength (grip strength, knee extensor and flexor torque) and c) Functional capacity (sIFA and NEADL scores). Multiple linear regression models will be used to assess the predictive value of dietary variables (e.g., protein intake, total energy intake) on muscle-related outcomes (e.g., lean mass, strength, MRI-derived muscle volume). Models will adjust for relevant covariates, including age, sex, body mass index, and physical activity. These models will help establish whether dietary intake independently predicts muscle health beyond demographic and lifestyle factors. Between-group comparisons for continuous secondary outcomes will use independent samples t-tests or Mann Whitney U tests, as appropriate. ANCOVA will be applied for adjusted group comparisons. For MRI-derived outcomes, two-way mixed ANOVA will examine group × region effects, with post-hoc Bonferroni correction. Friedman tests will be used for repeated non-parametric comparisons where needed. Associations between dietary, metabolic, and functional outcomes will also be explored using correlation and regression techniques, as have been described. Subgroup analyses will be performed within the IBM group to assess how disease duration, physical activity level, or swallowing severity influence dietary intake, body composition, and function. Stratification may include disease duration (\<5 vs. ≥5 years), biological sex (male vs. female) and dysphagia severity (Swal-QOL scores) differences between subgroups will be tested using ANOVA or Kruskal-Wallis tests. Interaction effects may be examined via factorial ANOVA. This research is sponsored by ManMet University and funded by both the ManMet Faculty of Science and Engineering and Myositis UK.
Interventions
RADIATIONWhole-Body Dual-Energy X-ray Absorptiometry
A total body exposure scan to yield measurements of whole-body and regional body composition, including total fat mass, appendicular fat-free mass, bone mineral content, and bone mineral density.
OTHERAnthropometry
Heights and weight measurements.
A finger-prick blood sample to assess serum 25-hydroxyvitamin D concentrations.
OTHERIndirect Calorimetry
Resting energy expenditure measurement via indirect calorimetry.
OTHERMagnetic Resonance Imaging
Magnetic resonance imaging to assess muscle morphology and swallowing-related structures.
OTHERDynamometry
A hand-held dynamometer will be used to assess grip strength. An isokinetic dynamometer will be used to assess knee flexor and extensor strength.
OTHERBehavioural Monitoring
Encompassing food records, dual accelerometery and questionnaires, including a food frequency questionnaire, the sIBM Physical Functioning Assessment (s-IFA), the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), a quality of life questionnaire (Short Form-36v2), the Nottingham Extended ADL Scale, Modified Fatigue Impact Scale (MFIS), a visual analogue scale for pain, the Pittsburgh Sleep Quality Index (PSQI) and SWAL-QOL questionnaires.
Sponsors
Manchester Metropolitan University
Northern Care Alliance NHS Foundation Trust
NeuroMuscular Centre (Winsford)
Myositis UK
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
(Adults with IBM): * Diagnosis of Inclusion Body Myositis: As defined by the revised European Neuromuscular Centre 2013 diagnostic criteria (Definite or Probable IBM) * Age: Adults aged ≥40 years at the time of consent. * Ability to Provide Informed Consent: Participants must be cognitively capable of providing written, informed consent. * Disease Progression: Participants must be able to walk short distances, with or without the use of an assistive aid (e.g., a cane or frame) for balance, so that they can undertake study procedures without safety concerns. Must be able to consume solid or modified-texture food, with or without dysphagia adaptations (i.e., not exclusively tube-fed). * Willingness to Participate: Willing to attend study visits and comply with all study procedures. Inclusion Criteria (Control Participants): * Disease-Free: Control participants must be generally healthy, with no known myopathies or metabolic diseases. They must not have any conditions that, in the judgement of a clinician, would compromise their safety, impair their ability to complete study procedures, or influence study outcomes. * Age: Adults aged ≥40 years at the time of consent. * Ability to Provide Written Informed Consent * Willingness to Participate * Matched to IBM participants according to their age and physical activity levels
Exclusion criteria
(Adults with IBM): * Coexisting Neuromuscular or Metabolic Disorders: Presence of other neuromuscular or metabolic disorders that may confound the outcomes of interest. * Severe Dysphagia: Participants requiring exclusive enteral or parenteral feeding, which would prevent participation in dietary intake assessments. * Enrolment in an interventional trial within the past 3 months: Participation in an interventional study within the past 3 months involving interventions that may affect dietary habits, physical activity, or muscle metabolism. * Contraindications to any Study Procedures: Any condition preventing safe completion of key assessments. For instance: severe osteoporosis contraindicating DXA scanning (T-score \< -3.0), respiratory conditions, severe claustrophobia, severe cognitive impairments or communication barriers that may impair participant ability to comply with study procedures. * Logistical Concerns: Any other logistical concern, as judged by the CI, that would compromise participant safety or the integrity of study data. * English Comprehension: Participants will be excluded if they are unable to understand written or verbal English to a degree that would impair their ability to provide informed consent or fully understand the study procedures.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Habitual Daily Protein Intake | Baseline | Habitual daily protein intake (g/day) estimated using two 3-day weighed food diaries. |
| Habitual Daily Protein Intake Relative to Body Mass | Baseline | Mean daily protein intake estimated using two 3-day weighed food diaries, normalised to body mass (g/kg/day). |
| Appendicular Lean Mass | Baseline | Appendicular lean mass (kg) measured using dual-energy X-ray absorptiometry (DXA). Appendicular lean mass represents the sum of lean soft tissue mass from both arms and both legs. |
| Handgrip Strength | Baseline | Maximal isometric handgrip strength (kg) measured using a hand-held dynamometer. Participants perform three maximal voluntary contractions with each hand; the highest value recorded is used for analysis. |
| Peak Knee Extensor Torque | Baseline | Peak knee extensor torque (Nm) represents the highest rotational force generated during knee extension across five maximal repetitions using an isokinetic dynamometer. |
| Peak Knee Flexor Torque | Baseline | Peak knee flexor torque (Nm) represents the highest rotational force generated during knee flexion across five maximal repetitions using an isokinetic dynamometer. |
| sporadic Inclusion Body Myositis Functional Assessment (sIFA) | Baseline | Functional status as determined by the sIFA total score. The sIFA is an 11-item patient-reported outcome measure evaluating functional ability in individuals with inclusion body myositis, including swallowing, mobility, and hand function. Each item is scored on a 0-10 scale, and item scores are summed to produce a total score ranging from 0 to 110. Lower scores indicate greater functional impairment, while higher scores indicate better functional ability. |
| Activities of Daily Living: Nottingham Extended Activities of Daily Living Scale (NEADL) Total Score | Baseline | Functional independence measured using NEADL scale. The NEADL is a 22-item patient-reported questionnaire covering mobility, kitchen activities, domestic activities, and leisure activities. Each item is scored from 0 to 3, representing increasing levels of independence. Item scores are summed to produce a total score ranging from 0 to 66, with higher scores indicating greater independence in activities of daily living and lower scores indicating greater functional limitation. |
| Muscle Functional Cross-Sectional Area | Baseline | Functional cross-sectional area (cm²) of skeletal muscle derived from magnetic resonance imaging (MRI). Functional cross-sectional area represents the estimated contractile muscle area and is calculated from total muscle cross-sectional area adjusted for intramuscular fat fraction. |
| Skeletal Muscle Volume | Baseline | Muscle volume (cm³) derived from magnetic resonance imaging (MRI) of the thigh and forearm muscles using image segmentation techniques. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Broader Nutrient Intake | Baseline | Whilst protein intake (absolute and relative) will be a primary outcome for the study, mean daily intake of other macro and micronutrients (g or mg or µg per day) will also be estimated from two 3-day weighed food diaries. |
| Serum 25-Hydroxyvitamin D Concentration | Baseline | Serum 25-hydroxyvitamin D concentration (nmol/L) measured from a capillary blood sample obtained via finger-prick sampling. |
| Resting Energy Expenditure | Baseline | Resting energy expenditure (kcal/day) measured using indirect calorimetry. Resting energy expenditure will be calculated from respiratory gas exchange measurements using standard metabolic equations. |
| Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) Total Score | Baseline | Self-reported physical activity measured using the PASIPD. The PASIPD is a 13-item questionnaire capturing the frequency and duration of leisure, household, and occupational physical activities performed over the previous 7 days. Responses are weighted according to metabolic equivalent (MET) values and summed to produce a total physical activity score ranging from 0 to approximately 199 MET-hours per day, with higher scores indicating higher levels of physical activity. |
| Total Energy Intake | Baseline | Mean daily energy intake (kcal/day) estimated from two 3-day weighed food diaries. |
| Muscle T2 Relaxation Time | Baseline | T2 relaxation time (ms) of thigh and forearm skeletal muscles measured using magnetic resonance imaging (MRI) and derived from multi-echo T2 mapping sequences. |
| Maximum Laryngeal Elevation | Baseline | Maximum superior displacement of the larynx (mm) measured from real-time magnetic resonance imaging (MRI) recordings obtained during saliva swallowing (dry swallow) using sagittal imaging. The measurement represents the distance travelled by the larynx from its resting position to the point of maximum elevation during the swallowing sequence. |
| Time to Peak Laryngeal Elevation | Baseline | Time to peak laryngeal elevation (ms) measured from real-time magnetic resonance imaging (MRI) recordings obtained during saliva swallowing (dry swallow). The measurement represents the time interval from swallow initiation to the point of maximum superior displacement of the larynx. |
| Duration of Upper Oesophageal Sphincter Opening | Baseline | Duration of upper oesophageal sphincter opening (ms) measured from real-time magnetic resonance imaging (MRI) recordings obtained during saliva swallowing (dry swallow) using sagittal imaging. The measurement represents the time interval during which the upper oesophageal sphincter remains open during the swallowing sequence. |
| Total Swallow Duration | Baseline | Total swallow duration (ms) measured from real-time magnetic resonance imaging (MRI) recordings obtained during saliva swallowing (dry swallow). The measurement represents the time interval from swallow initiation to completion of the swallowing sequence. |
| Glottal Closure Duration | Baseline | Duration of glottal closure (ms) measured from real-time magnetic resonance imaging (MRI) recordings obtained during saliva swallowing (dry swallow). The measurement represents the time interval during which the vocal folds remain closed during the swallowing sequence. |
| Total Physical Activity Volume | Baseline | Total physical activity volume (mg) derived from wrist- and thigh-worn accelerometers worn continuously for 7 days. Physical activity volume is calculated from raw acceleration signals and expressed as mean acceleration over the monitoring period. |
| Daily Sedentary Time | Baseline | Sedentary time (minutes/day) derived from accelerometer recordings collected over a 7-day monitoring period. Sedentary behaviour is identified from posture and movement classification algorithms applied to wrist- and thigh-worn accelerometer data and expressed as the average number of minutes per day spent sedentary. |
| Average Daily Step Count | Baseline | Daily step count (steps/day) derived from wrist- and thigh-worn accelerometer recordings collected over a 7-day monitoring period. Step detection algorithms identify walking-related movements and calculate the average number of steps accumulated per day. |
| Total Sleep Time | Baseline | Total sleep time (hours/night) derived from wrist-worn accelerometer recordings collected over a 7-day monitoring period. Sleep duration represents the total time spent asleep each night based on accelerometer-derived sleep detection algorithms. |
| Sleep Efficiency | Baseline | Sleep efficiency (%) derived from wrist-worn accelerometer recordings collected over a 7-day monitoring period. Sleep efficiency represents the proportion of time spent asleep relative to the total time spent in bed. |
| Total Fat Mass | Baseline | Total body fat mass (kg) measured using dual-energy X-ray absorptiometry (DXA). The measurement represents the total mass of adipose tissue derived from whole-body DXA scanning. |
| Bone Mineral Content | Baseline | Bone mineral content (g) measured using dual-energy X-ray absorptiometry (DXA). Bone mineral content represents the total amount of mineral contained within bone tissue as determined from whole-body DXA scanning. |
| Bone Mineral Density | Baseline | Bone mineral density (g/cm²) measured using dual-energy X-ray absorptiometry (DXA). Bone mineral density represents the mineral content of bone normalized to bone area derived from DXA imaging. |
| Short Form-36 Health Survey (SF-36v2) Physical and Mental Health Scores | Baseline | Health-related quality of life measured using theSF-36v2. The questionnaire contains 36 items across eight domains including physical functioning, role limitations, bodily pain, general health, vitality, social functioning, and mental health. Responses are transformed into domain scores ranging from 0 to 100, where higher scores represent better perceived health status and lower scores represent poorer health-related quality of life. |
| Pain Intensity | Baseline | Self-reported pain intensity measured using a Visual Analogue Scale (VAS). Participants indicate their perceived level of whole-body pain on a 100-mm horizontal line, anchored by "no pain" at 0 mm and "worst imaginable pain" at 100 mm. The recorded value corresponds to the distance in millimetres from the lower anchor point, with higher values indicating greater pain intensity. |
| Pittsburgh Sleep Quality Index (PSQI) Global Score | Baseline | Subjective sleep quality measured using the PSQI. The PSQI is a 19-item questionnaire generating seven component scores related to sleep duration, disturbances, latency, efficiency, medication use, daytime dysfunction, and perceived sleep quality. Component scores (0-3) are summed to produce a global score ranging from 0 to 21, where higher scores indicate poorer sleep quality. |
| Swallowing Quality of Life Questionnaire (SWAL-QOL) Total Score | Baseline | Swallowing-related quality of life measured using the SWAL-QOL. The instrument contains 44 items across domains including swallowing burden, eating duration, communication, mental health, and social functioning. Responses are transformed to domain scores ranging from 0 to 100, with higher scores indicating better swallowing-related quality of life and lower scores indicating greater dysphagia-related impairment. |
| Body Mass Index | Baseline | Body mass index (kg/m²) calculated from measured body weight and height. Body weight will be measured using calibrated digital scales and recorded in kilograms (kg). Height will be measured using a stadiometer or estimated from segmental arm span where standing height cannot be measured due to posture limitations (m). Body mass index is calculated as body weight (kg) divided by height squared (m²). |
Countries
United Kingdom
Contacts
CONTACTCharlotte Emily Linscott, BSc
CONTACTDr Paul T Morgan, PhD
STUDY_DIRECTORPaul T Morgan, PhD
Manchester Metropolitan University
Outcome results
None listed