Endothelial nitric oxide synthase single nucleotide polymorphisms and habitual physical activity among adult men and women

The purpose of this study was to examine possible genetic influences on voluntary physical activity (PA). Research suggests that 32 to 85% of the interindividual variation in PA levels is heritable; however evidence regarding specific genes influencing PA levels is limited. Endothelial nitric oxide synthase (NOS3) gene SNPs was chosen for analysis because of NOS3 single nucleotide polymorphisms (SNPs) association with health/fitness and exercise performance. Based in a conceptual framework of behavioral genetics, the relationship between variants in the NOS3 gene (-786T>C, rs1800779; -922A>G, rs2070744; 894G>T, rs1799983) and self-reported measures of PA were explored. Adults were genotyped and completed the Paffenbarger PA Questionnaire. PA phenotypes included hr/wk spent in light, moderate and vigorous intensity PA, and sitting. ANCOVA tested associations among NOS3 variants and PA with gender as a fixed factor and age and body mass index as covariates. Posthoc analyses with Bonferroni adjustments were performed. Those with the NOS3 +894 TT genotype reported spending more time in light and less time in vigorous intensity PA and sitting than those with the G allele, independent of gender. NOS3 +894 G>T is a missense mutation and likely to alter NOS3 function, in turn affecting NO bioavailability. Reasons for finding NOS3 +894 G>T associations with PA are not apparent and need to be further investigated. This research will contribute to positive social change by shedding light on the biological basis of PA, assisting researchers and clinicians in their efforts (a) to identify individuals who are less likely to engage in regular PA, and (b) to eventually design more effective exercise programs for individuals with the long-term goal of increasing PA levels to aid in improving overall health and quality of life of people residing in the US.