Genetic effects in the response of adipose tissue lipoprotein lipase activity to prolonged exercise. A twin study

Our laboratory has reported large inter-individual differences in the metabolic response of adipose tissue to prolonged exercise in humans. The present study investigated the contribution of heredity in the metabolic changes of adipose tissue to prolonged exercise in 11 monozygotic and 10 dizygotic pairs of male twins, 18 to 27 years of age, studied immediately before and after a 90 min bout of exercise. The sum of 7 skinfold thicknesses and percent of fat from underwater weighing were used as body fat indicators (BFI). Subcutaneous adipose tissue was excised and fat cell weight (FCW) determined. The activity of adipose tissue lipoprotein lipase (LPL) released with heparin was also measured. BFI and FCW were identical in both types of twins. As previously reported, LPL activity was increased by exercise (P less than 0.01) in both type of twins. The changes observed for LPL activity were more similar in monozygotic twins than in dizygotic twins resulting in a significant level of inheritance (P less than 0.05). A genetic component for LPL activity supports the hypothesis that adipose tissue LPL could be genetically determined not only in its basal activity but also in response to stresses such as exercise.