KCNJ11 AND KCNQ1 GENES INTERACTION IN VO2MAX

The inwardly rectifier ATP-sensitive K+ channel gene (KCNJ11) and the delayed rectifier K+ channel gene (KCNQ1) are modulators of cardiac cell action potentials. Both are encoded on chromosome 11p14–15. PURPOSE We examined the hypothesis of KCNJ11-KCNQ1 genes interaction in VO2max in the sedentary and trained states as well as in response (Δ) to a 20-wk endurance-training program (TP). METHODS KCNJ11 and KCNQ1 genotypes were determined in 241 Blacks and 449 Whites of the HERITAGE Family Study. VO2max was measured during maximal stationary cycle ergometer tests before and after the TP. AC → T transition in both the KCNJ11 (E23K) and KCNQ1 (S546S) genes were detected by PCR and digestion with BanII and MwoI, respectively. RESULTS χ2 revealed racial differences (p < 0.001) in allele and genotype frequencies in both genes. Presence of the T allele in both polymorphisms was frequent among Whites (n = 96; 21%) but rare in Blacks (n = 3; 1%). Among Blacks, for sedentary state VO2max, carriers of the T alleles in both genes were associated with the lowest values (P = 0.02). Although no statistically significant interactions were observed for trained state and (Δ) VO2max, carriers of the T allele tended to have the lowest values. The interaction effect was not evident among Whites. CONCLUSION These findings support the hypothesis of a KCNJ11 and KCNQ1 interaction effect for sedentary state VO2max in Blacks but not in Whites. Supported by CRC-RCMI UPR-MSC Grant #1P20RR11126, RCMI Basic Sciences #G12RR03051 and NIH #G12RR03051.