An observational study in Muscle Strength, Healthy and Chronic Respiratory Diseases, sponsored by University of Alcala. Not yet recruiting at 1 site in Spain. Open to participants aged 18 Years to 89 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-08.
Sponsored by University of Alcala · Observational
This observational study aims to learn about peripheral muscle strength in healthy adults and people with chronic respiratory diseases. The study aims to develop reference data for quadriceps muscle strength and handgrip in adults living in Southern Europe and to assess whether these reference data can be used in people with chronic respiratory diseases.
The main questions it aims to answer are:
Participants will attend one study visit. During this visit, researchers will:
The RESTart study (Reference equations and normative data for isometric quadriceps and handgrip STrength in Southern European populations) is a multicentre observational cross-sectional study conducted in Spain, Portugal and Italy.
Peripheral muscle dysfunction, particularly reduced quadriceps muscle strength and handgrip, is common in people with chronic respiratory diseases and is associated with impaired physical function, hospitalisation and mortality. Accurate interpretation of muscle strength measurements requires population-specific reference equations and normative values. However, currently available reference data may not adequately represent Southern European populations.
The primary objective of the study is to develop reference equations and normative values for isometric quadriceps muscle strength and handgrip in healthy adults aged 18-89 years. A secondary objective is to validate/assess clinical application of these reference data in people with chronic respiratory diseases, including chronic obstructive pulmonary disease, interstitial lung disease, asthma, bronchiectasis and cystic fibrosis.
Healthy participants will be recruited from community settings using proportional stratification according to age, sex and country. Participants with chronic respiratory diseases will be recruited from collaborating clinical centres.
Primary outcomes are isometric quadriceps muscle strength and handgrip assessed using standardised dynamometry protocols. Secondary outcomes include functional capacity, mobility and balance, symptoms, physical activity, health-related quality of life, and anthropometric variables; lung function and laboratory parameters only when available from medical records.
The study is expected to provide robust reference equations and normative values for Southern European populations, supporting improved identification and monitoring of peripheral muscle dysfunction in both clinical practice and research.
5,520 studies on the registry are indexed under Pulmonary Disease, Chronic Obstructive; 856 are open to participants now.
This study's planned enrollment of 2,815 is above the median of 158 across 1,497 observational studies indexed under Pulmonary Disease, Chronic Obstructive.
Browse Pulmonary Disease, Chronic Obstructive studies →University of Alcala is the lead sponsor of 128 studies on the registry; 36 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Community-dwelling healthy adults and adults with chronic respiratory diseases recruited from participating centres in Spain, Portugal and Italy. Healthy participants will be recruited from the general population to develop reference equations and normative values for isometric quadriceps and handgrip strength. Participants with chronic respiratory diseases will be recruited from clinical settings to externally validate the developed reference equations and assess their clinical applicability.
Healthy adults cohort
Inclusion Criteria:
Exclusion Criteria:
Chronic respiratory disease cohort
Inclusion criteria:
Exclusion criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy community-dwelling adults aged 18-89 years recruited in Spain, Portugal and Italy for the development of reference equations and normative data for isometric quadriceps strength and handgrip.
Adults with stable chronic respiratory diseases recruited for external validation/clinical application of the developed reference equations and normative values. Eligible conditions include chronic obstructive pulmonary disease, interstitial lung disease, asthma, bronchiectasis and cystic fibrosis.
Isometric quadriceps muscle strength
Quadricpes maximum voluntary contraction measured using a handheld dynamometer according to the standardised RESTart protocol. Strength will be recorded as the highest value obtained during the assessment and expressed in kilograms-force (kgf).
Time frame: Day 1
Handgrip
Handgrip mMaximum voluntary contraction measured using a hydraulic handgrip dynamometer according to standardised assessment procedures. Strength will be recorded as the highest value obtained during the assessment and expressed in kilograms-force (kgf).
Time frame: Day 1
Five-repetition sit-to-stand test
Functional capacity assessed by the time required to complete five sit-to-stand repetitions according to standardised procedures. Results will be expressed in seconds. Lower values indicate better lower-limb functional capacity.
Time frame: Day 1
One-minute sit-to-stand test
Functional capacity assessed as the number of sit-to-stand repetitions completed in one minute according to standardised procedures. Higher values indicate better functional exercise capacity.
Time frame: Day 1
Timed Up and Go test
Mobility and dynamic balance assessed using the Timed Up and Go test. Results will be expressed in seconds. Lower values indicate better mobility and dynamic balance.
Time frame: Day 1
Modified Medical Research Council dyspnoea scale
Dyspnoea severity assessed using the modified Medical Research Council dyspnoea scale. Scores range from 0 to 4, with higher scores indicating greater breathlessness.
Time frame: Day 1
Modified Borg dyspnoea scale
Perceived breathlessness assessed using the modified Borg dyspnoea scale. Scores range from 0 to 10, with higher scores indicating greater breathlessness.
Time frame: Day 1
Dyspnoea-12
Dyspnoea assessed using the Dyspnoea-12 questionnaire. The total score ranges from 0 to 36, with higher scores indicating more severe breathlessness.
Time frame: Day 1
Functional Assessment of Chronic Illness Therapy-Fatigue
Fatigue assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire. Scores range from 0 to 52, with higher scores indicating less fatigue.
Time frame: Day 1
EuroQol 5-Dimension 5-Level
Health-related quality of life assessed using the EuroQol 5-Dimension 5-Level (EQ-5D) questionnaire. The index score will be calculated according to the appropriate national value set. Higher scores indicate better health status. Self-rated health assessed using the EQ-5D Visual Analogue Scale. Scores range from 0 to 100, with higher scores indicating better perceived health.
Time frame: Day 1
St George's Respiratory Questionnaire
Respiratory-specific health-related quality of life assessed using the St George's Respiratory Questionnaire. Scores range from 0 to 100, with higher scores indicating worse respiratory health-related quality of life.
Time frame: Day 1
International Physical Activity Questionnaire-short form
Physical activity assessed using the International Physical Activity Questionnaire-short form. Results will be expressed as minutes per week spent in vigorous/moderate/total physical activity, time per week spent walking and hours per day spent in sedentary behaviour (sitting).
Time frame: Day 1
Mini Nutritional Assessment-short form
Nutritional status assessed using the Mini Nutritional Assessment-short form. Scores range from 0 to 14, with higher scores indicating better nutritional status.
Time frame: Day 1
Age
Participant age recorded in completed years.
Time frame: Day 1
Weight
Participant weight recorded in kilograms.
Time frame: Day 1
Height
Participant height recorded in metres.
Time frame: Day 1
Body mass index
Body mass index calculated as weight divided by height squared.
Time frame: Day 1
Sex
Participant biological sex recorded as female or male.
Time frame: Day 1
Forced expiratory volume in one second percentage predicted (FEV1%pred)
Lung function measured by spirometry when available from medical records.
Time frame: Day 1
Forced vital capacity percentage predicted (FVC%pred)
Lung function measured by spirometry when available from medical records.
Time frame: Day 1
Systemic inflammation markers
CRP, IL-6, eosinophils, fibrinogen, neutrophil elastase, ESR, KL-6, SP-D, FeNO, IgE, calprotectin, if available, from medical records.
Time frame: Day 1
Charlson Comorbidity Index
Comorbidity burden assessed using the Charlson Comorbidity Index. Higher scores indicate greater comorbidity burden.
Time frame: Day 1
Anatomical Therapeutic Chemical (ATC) Classification System
Current medication use classified according to the Anatomical Therapeutic Chemical (ATC) Classification System.
Time frame: Day 1
Smoking Exposure (pack-year index)
Lifetime smoking exposure quantified using the pack-year index, calculated from self-reported smoking history.
Time frame: Day 1
Alcohol Use Disorders Identification Test-Consumption
Alcohol consumption assessed using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C). Higher scores indicate greater alcohol consumption and increased risk of hazardous drinking.
Time frame: Day 1
Plan to share: Yes — De-identified individual participant data underlying the results reported in publications arising from this study, including demographic characteristics, anthropometric measurements, peripheral muscle strength assessments, functional capacity outcomes, patient-reported outcomes/questionnaire scores, and other variables collected according to the study protocol, upon reasonable request to the principal investigator.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Analytic code
Time frame: Beginning 12 months following publication of the primary study results and ending 5 years after publication.
Access criteria: Researchers who provide a methodologically sound proposal for secondary analyses consistent with the aims of the study (e.g., individual participant data meta-analyses, validation studies, methodological research, and other scientifically justified secondary analyses).
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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Pulmonary Disease, Chronic Obstructive →