title: Skeletal muscle structural and energetic characteristics in subjects with sickle cell trait, alpha-thalassemia, or dual hemoglobinopathy.
abstract: 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. There were no observable differences in daily energy expenditure, maximal power output (Pmax), or time to exhaustion at 110% Pmax (Tex) among the groups. Blood lactate concentrations measured at the end of the Tex, muscle fiber type distribution, and mean phosphofructokinase (PFK), lactate dehydrogenase (LDH), beta-hydroxyacyl-CoA-dehydrogenase (HAD), and citrate synthase (CS) activities were all similar among the four groups. However, SCT was associated with a lower cytochrome-c oxidase (COx) activity in type IIa fibers (P<0.05), and similar trends were observed in fiber types I and IIx. Trends toward lower creatine kinase (CK) activity (P=0.0702) and higher surface area of type IIx fibers were observed in SCT (P=0.0925). In summary, these findings support most of the previous observations in SCT, such as 1) similar maximal power output and associated maximal oxygen consumption (VO2max) values and 2) lower exercise performances during prolonged submaximal exercise. Furthermore, performances during short supramaximal exercise were not different in SCT. Finally, the dual hemoglobinopathy condition does not seem to affect muscle characteristics.
authors.affiliation: Laboratoire de Physiologie de l'Exercice EA4338, Université de Savoie, Chambéry, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Vincent
authors.forename: Léonard
authors.initials: L
authors.lastname: Féasson
authors.forename: Samuel
authors.initials: S
authors.lastname: Oyono-Enguéllé
authors.forename: Viviane
authors.initials: V
authors.lastname: Banimbek
authors.forename: Géraldine
authors.initials: G
authors.lastname: Monchanin
authors.forename: Macias
authors.initials: M
authors.lastname: Dohbobga
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Wouassi
authors.forename: Cyril
authors.initials: C
authors.lastname: Martin
authors.forename: David
authors.initials: D
authors.lastname: Gozal
authors.forename: André
authors.initials: A
authors.lastname: Geyssant
authors.forename: Patrice
authors.initials: P
authors.lastname: Thiriet
authors.forename: Christian
authors.initials: C
authors.lastname: Denis
authors.forename: Laurent
authors.initials: L
authors.lastname: Messonnier
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002163:Cameroon; D004734:Energy Metabolism; D005080:Exercise Test; D017079:Exercise Tolerance; D006442:Glycated Hemoglobin / Q000378:metabolism; D006455:Hemoglobins, Abnormal / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology*; D010101:Oxygen Consumption; D012805:Sickle Cell Trait / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors; D055815:Young Adult; D017085:alpha-Thalassemia / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; D019344:Lactic Acid