Lower Muscle and Blood Lactate Accumulation in Sickle Cell Trait Carriers in Response to Short High-Intensity Exercise.

It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during intense physical activity. By triggering the polymerization-sickling-vaso-occlusion cascade, lactate accumulation-associated acidosis in response to high-intensity exercise is believed to be one of the causes of complications. However, our understanding of lactate metabolism in response to high-intensity exercise in SCT carriers is incomplete.

Delayed Rebound of Glycemia During Recovery Following Short-Duration High-Intensity Exercise: Are There Lactate and Glucose Metabolism Interactions?

Lactate constitutes the primary gluconeogenic precursor in healthy humans at rest and during low-intensity exercise. Data on the interactions between lactate and glucose metabolisms during recovery after short-duration high-intensity exercise are sparse. The aim of the present study was to describe blood glucose ([glucose]) and lactate ([lactate]) concentration curves during recovery following short-duration high-intensity exercise.

Evidence for a profound remodeling of skeletal muscle and its microvasculature in sickle cell anemia.

Sickle cell anemia (SCA) is a hemoglobinopathy leading to major hematologic, hemorheologic, and hemodynamic disorders that induce various complications, including organ failure, and ultimately lead to death. Here, we assessed for the first time repercussions of SCA on skeletal muscle and its microvasculature. Twenty-seven sedentary Cameroonian volunteer men participated in the study.

Effects of regular physical activity on skeletal muscle structural, energetic, and microvascular properties in carriers of sickle cell trait.

To assess the effects of regular physical activity on muscle functional characteristics of carriers of sickle cell trait (SCT), 39 untrained (U) and trained (T) hemoglobin (Hb)AA (CON) and SCT subjects (U-CON, n = 12; U-SCT, n = 8; T-CON, n = 10; and T-SCT, n = 9) performed a graded exercise and a time to exhaustion (T(ex)) test, and were subjected to a muscle biopsy. Maximal power, total work performed during T(ex), citrate synthase and cytochrome c oxidase (COX) activities, respiratory chain complexes I and IV content, and capillary density (CD), diameter (COD), and surface area (CSA) were upregulated by the same proportion in T-CON and T-SCT compared with their untrained counterparts. These proportionally similar differences imply that the observed discrepancies between U-SCT and U-CON remained in the trained subjects.

Exercise training blunts oxidative stress in sickle cell trait carriers.

The aim of this study was to analyze the effects of exercise training on oxidative stress in sickle cell trait carriers. Plasma levels of oxidative stress [advanced oxidation protein products (AOPP), protein carbonyl, malondialdehyde (MDA), and nitrotyrosine], antioxidant markers [catalase, glutathione peroxidase (GPX), and superoxide dismutase (SOD)], and nitrite and nitrate (NOx) were assessed at baseline, immediately following a maximal exercise test (T(ex)), and during recovery (T(1h), T(2h), T(24h)) in trained (T: 8 h/wk minimum) and untrained (U: no regular physical activity) sickle cell trait (SCT) carriers or control (CON) subjects (T-SCT, n = 10; U-SCT, n = 8; T-CON, n = 11; and U-CON, n = 11; age: 23.5 ± 2.

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.

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.