An interventional study of Blood sampling and Maximum Voluntary Contraction (MVC) test force in Sickle Cell Disease, sponsored by Hospices Civils de Lyon. Completed at 1 site in France. Open to participants aged 15 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-19.
Sponsored by Hospices Civils de Lyon · Not applicable, Interventional, and Basic science
Background : Sickle cell patients have profound remodeling of their muscle microcirculation networks with signs of amyotrophy. However, the consequences of these muscle alterations on the functional status of muscles are unknown. In addition, whether the poor physical fitness of sickle cell patients can be attributed, at least partly, to an hypothetical muscle dysfunction has never been tested.
Purpose : this study will compare the muscle function of legs between sickle cell patients (SS and SC genotypes) and healthy individuals (AA genotype) before, during and after a short localized muscle endurance exercise.
Abstract : Very recently, a study reported large differences between the muscle microcirculation networks of sickle cell patients compared to healthy individuals with decreased capillary density and higher proportion of large capillaries in the former population. In addition, the same study showed signs of amyotrophy in sickle cell patients. However, the muscle function of sickle cell patients has not been investigated and one may suggest that muscle dysfunction could participate in the decrease of physical fitness, in association with the hematological and hemorheological disorders, already reported in this population. The hypothesis is that muscle fatigue during a short localized muscle endurance exercise should be higher in sickle cell patients compared to healthy individuals, due to a greater recruitment of glycolytic fibers and a faster decrease of muscle oxygenation during exercise.
1,103 studies on the registry are indexed under Anemia, Sickle Cell; 235 are open to participants now.
This study's enrollment of 77 is above the median of 40 across 750 interventional studies indexed under Anemia, Sickle Cell.
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For Sickle cell patients :
For Healthy and non sickle cell subjects:
Exclusion Criteria:
Sickle cell patients with SS genotype. Each subject will undergo the following : 1. Blood sample 2. Maximum Voluntary Contraction (MVC) test force before and after a localized muscle endurance test 3. Localized muscle endurance test: 4 series of 20 submaximal dynamic contractions at 50% of the MVC interspaced with 1 min recovery. 4. Self-paced six-minute walk test will be conducted according to the guidelines of the American Thoracic Society
Biological: Blood sampling · Other: Maximum Voluntary Contraction (MVC) test force · Other: Localized muscle endurance test · Other: Self-paced six-minute walk test
Sickle cell patients with SC genotype. Each subject will undergo the following : 1. Blood sample 2. Maximum Voluntary Contraction (MVC) test force before and after a localized muscle endurance test 3. Localized muscle endurance test: 4 series of 20 submaximal dynamic contractions at 50% of the MVC interspaced with 1 min recovery. 4. Self-paced six-minute walk test will be conducted according to the guidelines of the American Thoracic Society
Biological: Blood sampling · Other: Maximum Voluntary Contraction (MVC) test force · Other: Localized muscle endurance test · Other: Self-paced six-minute walk test
Healthy subjects. Each subject will undergo the following : 1. Blood sample 2. Maximum Voluntary Contraction (MVC) test force before and after a localized muscle endurance test 3. Localized muscle endurance test: 4 series of 20 submaximal dynamic contractions at 50% of the MVC interspaced with 1 min recovery. 4. Self-paced six-minute walk test will be conducted according to the guidelines of the American Thoracic Society
Biological: Blood sampling · Other: Maximum Voluntary Contraction (MVC) test force · Other: Localized muscle endurance test · Other: Self-paced six-minute walk test
Blood sampling will be performed to assess hematological and hemorheological parameters
Maximum Voluntary Contraction (MVC) test force will be performed before and after a localized muscle endurance test
Subject will perform 4 series of 20 submaximal dynamic contractions at 50% of the MVC interspaced with 1 min recovery.
Self-paced six-minute walk test will be conducted according to the guidelines of the American Thoracic Society
Maximum isometric muscular strength
Isometric muscular strength will be determined by Maximum Voluntary Contraction (MVC) test force on dominant leg. Muscular function will be evaluated using Maximum Voluntary Contraction (MVC) test force and the muscle endurance ability, which will be highlighted by the degree of decline of MVC after a short localized muscle effort using the formula: ((post MVC force - pre MVC force) / pre MVC force)x100. Muscle weakness will be determined by a loss of maximum isometric strength ≥ 20 % compared with control group.
Time frame: Day 1
Surface Electromyography (EMG) Activity
Surface EMG signals will be recorded by non-invasive electrodes on the dominant leg.
Time frame: Day 1
Muscle oxygenation measurement
oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb) levels will be measured using Near-Infrared spectroscopy on the dominant leg.
Time frame: Day 1
Measurement of six-minute walk distance (6MWD)
In order to investigate the association between muscle endurance ability and physical fitness in sickle cell patients, patients will realize a six-minute walk test (6MWT). 6MWD will be measured = the distance that a patient has walked on a flat, hard surface in a period of 6 minutes (6MWT).
Time frame: Day 1
Complete Blood Count (CBC)
CBC will be performed in order to evaluate the role of hematological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Hematocrit
Hematocrit will be measured in order to evaluate the role of hematological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Blood viscosity
Blood viscosity will be measured by using viscosimetry, in order to evaluate the role of hemorheological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Red blood cell (RBC) deformability
RBC deformability will be assessed by using ektacytometry, in order to evaluate the role of hemorheological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Aggregation properties
Aggregation properties will be assessed by using syllectometry, in order to evaluate the role of hemorheological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Hemoglobin oxygenation level
Hemoglobin oxygenation level will be measured in order to evaluate the role of hemorheological disorders in the muscle fatigue of sickle cell patients.
Time frame: Day 1
Number of vaso-occlusive crises and acute chest syndrome within a 5 years retrospective period.
Number of vaso-occlusive crises and acute chest syndrome reflects of clinical severity of the sickle cell disease. Clinical severity will be retrospectively (5 years) collected in clinical record of sickle cell patients. These clinical data will be used to study the relationships between the degree of muscle dysfunction and the degree of clinical severity in sickle cell patients.
Time frame: Day 1
Plan to share: No
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Hospices Civils de Lyon