Twin-sibling study and meta-analysis on the heritability of maximal oxygen consumption

Large individual differences exist in aerobic fitness in childhood and adolescence, but the relative contribution of genetic factors to this variation remains to be established. In a sample of adolescent twins and siblings (n = 479), heart rate (HR) and maximal oxygen uptake (Vo2max) were recorded during the climax of a graded maximal exercise test. In addition, Vo2max was predicted in two graded submaximal exercise tests on the cycle ergometer and the treadmill, using extrapolation of the HR/Vo2 curve to the predicted HRmax. Heritability estimates for measured Vo2max were 60% in ml/min and 55% for Vo2max in ml·min–1·kg–1. Phenotypic correlations between measured Vo2max and predicted Vo2max from either submaximal treadmill or cycle ergometer tests were modest (0.57 < r < 0.70), in part because of the poor agreement between predicted and actual HRmax. The majority of this correlation was explained by genetic factors; therefore, the submaximal exercise tests still led to very comparable estimates of heritability of Vo2max. To arrive at a robust estimate for the heritability of Vo2max in children to young adults, a sample size weighted meta-analysis was performed on all extant twin and sibling studies in this age range. Eight studies, including the current study, were meta-analyzed and resulted in a weighted heritability estimate of 59% (ml/min) and 72% (ml·min–1·kg–1) for Vo2max. Taken together, the twin-sibling study an...

Source: Physiological Genomics - March 1, 2016 Category: Genetics & Stem Cells Authors: Schutte, N. M., Nederend, I., Hudziak, J. J., Bartels, M., de Geus, E. J. C. Tags: Systems Biology of Exercise Source Type: research