Skeletal muscle structural and energetic characteristics in subjects with sickle cell trait, alpha-thalassemia, or dual hemoglobinopathy.

Previous studies have shown that subjects with sickle cell trait (SCT), alpha-thalassemia (alpha-t), and the dual hemoglobinopathy (SCT/alpha-t) manifest subtle, albeit significant, differences during exercise. To better understand such differences, we assessed skeletal muscle histomorphological and energetic characteristics in 10 control HbAA subjects (C), 5 subjects with alpha-t (alpha-t), 6 SCT carriers (SCT) and 9 SCT carriers with alpha-t (SCT/alpha-t). Subjects underwent a muscle biopsy and also performed an incremental maximal exercise and a time to exhaustion test.

Habitual physical activity and endothelial activation in sickle cell trait carriers.

Purpose: It remains unclear whether habitual physical activity in sickle cell trait (SCT) carriers modulates the levels of resting and postexercise vascular adhesion and inflammatory molecules.

Methods: Plasma levels of pro-inflammatory (interleukin (IL)-4, IL-5, IL-8, sCD40L, and tumor necrosis factor α) and anti-inflammatory (IL-10) cytokines and adhesion molecules (soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), sP-selectin, or sE-selectin) were assessed at rest and in response to an incremental exercise to exhaustion in untrained (UT: no regular physical activity) and trained (T: soccer players, 8 h·wk minimum) SCT and control (CON) subjects (n = 8 per group; age = 23.5 ± 0.

Remodeling of skeletal muscle microvasculature in sickle cell trait and alpha-thalassemia.

The influence of sickle cell trait and/or alpha-thalassemia on skeletal muscle microvascular network characteristics was assessed and compared with control subjects [hemoglobin (Hb) AA] in 30 Cameroonian residents [10 HbAA, 5 HbAA alpha-thalassemia (alpha-t), 6 HbAS, and 9 HbASalpha-t] matched for maximal work capacity and daily energy expenditure. Subjects performed an incremental exercise to exhaustion and underwent a muscle biopsy. Muscle fiber type and surface area were not different among groups.

Plasma levels of adhesion molecules ICAM-1 and VCAM-1 in athletes with sickle cell trait with or without alpha-thalassemia during endurance exercise and recovery.

The aim of the study was to examine the effects of endurance exercise on circulating vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Five athletes with SCT, 7 athletes with both SCT and alpha-thalassemia (SCTAT) and 8 control athletes (CONT) performed an incremental test on cycloergometer followed 72 hours later by a 60-min endurance exercise with a workload set at 70% P(peak) (peak power). We assessed levels of sICAM-1, sVCAM-1 and TNF-alpha at rest, immediately after endurance exercise and 1, 2, and 24 hours of recovery.

Effects of progressive and maximal exercise on plasma levels of adhesion molecules in athletes with sickle cell trait with or without alpha-thalassemia.

The aim of the study was to examine the effects of exercise on soluble vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Six athletes with SCT, seven athletes with both SCT and alpha-thalassemia (SCTAT), and seven control athletes (Cont) performed an incremental and maximal test on cycloergometer. Levels of sICAM-1 and sVCAM-1 were assessed at rest, immediately after the end of exercise, and 1, 2, and 24 h after exercise.

Nocturnal autonomic nervous system activity impairment in sickle cell trait carriers.

Sickle cell trait (SCT) is a genetic disease affecting the synthesis of normal haemoglobin (Hb) and marked by the heterozygous presence of HbA and HbS. Some studies have suggested that SCT carriers might be prone to vascular alterations, cardiac ischaemia and arrhythmias leading, in some subjects, to sudden death. It is well known that a loss or a disequilibrium of autonomic activity are powerful predictors of sudden cardiac death.

Hemorheology, sickle cell trait, and alpha-thalassemia in athletes: effects of exercise.

Purpose: This study investigated hemorheological parameters in response to exercise in sickle cell trait (SCT) athletes with or without alpha-thalassemia

Methods: Six athletes with SCT (HbAS), 7 athletes with SCT and alpha-thalassemia (HbASAT), and 10 control athletes (HbAA) performed a progressive and maximal exercise test on cycloergometer. Blood viscosity (etab), plasma viscosity (etap), etab at corrected hematocrit (etab45), hematocrit (Hct), and red blood cell (RBC) rigidity were assessed at rest, at maximal exercise and 24 h after exercise

Results: etab and etap were not different between the three groups at any time. Exercise induced changes in etab in HbAA and HbASAT groups but not in HbAS group.