title: Partially opposite hemorheological effects of aging and training at middle age.
abstract: Aging impairs blood rheology while various training protocols improve it. The purpose of this study was to delineate the respective role of aging and endurance training on blood rheology. Thirty-two subjects [16 middle-aged men: 8 cyclists (MAcy) and 8 sedentary men (MAsed) and 16 young men: 8 cyclists (Ycy) and 8 sedentary men (Ysed)] were compared in this study. Results showed higher red blood cell (RBC) rigidity and aggregability (AFFIBIO), lower RBC disaggregability (AFFIBIO) at middle age than at 25 yr, regardless of training status. However there was no age-related difference in whole blood viscosity at either native or corrected hematocrit, plasma viscosity, hematocrit, and Myrenne aggregation indexes M and M1. Training was associated with a reduced hematocrit in middle age subjects but not in 25 yr old ones. We evidenced no effect of training on red cell rigidity (Dintenfass's Tk index), in whole blood viscosity at either native or corrected hematocrit, and plasma viscosity. Thus, regular cycling at middle age maintains a low hematocrit but does not prevent aging-related increase in red cell rigidity and aggregability. Specific effects of cycling among other sports may explain this specific pattern.
authors.affiliation: Université Montpellier 1, UFR de Médecine, Laboratoire de Physiologie des Interactions, Montpellier Institut de Biologie, Boulevard Henri IV, F-34062 France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Manetta
authors.forename: Ikram
authors.initials: I
authors.lastname: Aloulou
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Varlet-Marie
authors.forename: Jacques
authors.initials: J
authors.lastname: Mercier
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Brun
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D001642:Bicycling; D001809:Blood Viscosity / Q000502:physiology*; D004903:Erythrocyte Aggregation / Q000502:physiology; D004907:Erythrocyte Deformability / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005951:Glucose Tolerance Test; D006400:Hematocrit; D018056:Hemorheology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology; D010992:Plethysmography, Impedance; D012044:Regression Analysis; D018709:Statistics, Nonparametric