CREATINE KINASE B-SUBUNIT GENE POLYMORPHISM ASSOCIATION WITH VO2MAX

This study examined the possible association between a CK B-subunit gene polymorphism and VO2max in the sedentary state, as well as its response (Δ) to 20 weeks of endurance training. Subjects were 199 (41 Blacks and 158 Whites) participants of the HERITAGE Family Study. The polymorphism was detected by PCR and digestion with Eco RI. This yielded two alleles: a wild type (W = 500bp) and a mutant (M = 400+100 bp). VO2max was determined by progressive exercise tests on a cycle ergometer. There were significant (p < 0.05) racial differences in genotype frequencies (Blacks; WW = 32%, WM = 58%, MM = 10% and Whites; WW = 61%, WM = 33%, MM = 6%). Although there was no evidence of association between genotype and sedentary state VO2max, the MM genotype was significantly associated with a lower VO2max training response (Δ) among Blacks but not among Whites. The same genotype was significantly associated with greater decrease in VO2 at a fixed work output (50 Watts) in response to training among White subjects. In conclusion, these results provide evidence in support of the hypothesis of association between the CK B-subunit gene and the VO2max training response and show that there are race-genotype interactions for this trait. Supported by multiple grants from NHLBI, NIH.