A Genetic Variant In Il-15r Alpha Correlates With Physical Activity Among European-American Adults

BackgroundInterleukin-15 (IL-15) is a myokine associated with muscle strength, possibly by attenuating protein breakdown. A variant in the alpha-receptor (IL-15R 1775 A>C, rs2228059) partially modulates the muscle strength and size response to resistance training. We examined if this polymorphism associated with habitual physical activity among European-American adults.MethodsMen (n=240, 23.70.3year, body mass index [BMI] 25.30.3 kg/m(2)) and women (n=292, 23.2 +/- 0.3year, 24.0 +/- 0.3kg/m(2)) were genotyped. Physical activity phenotypes were derived from the Paffenbarger Physical Activity Questionnaire. Analysis of covariance (ancova) tested log-transformed differences between the IL-15R genotype and physical activity phenotypes by gender with age and BMI as covariates.ResultsMen with the IL-15R 1775AA genotype spent more time in light intensity physical activity (39.4 +/- 2.4hr/week) than men with the CC genotype (28.6 +/- 2.3hr/week, (p=.009).ConclusionFurther research is needed to confirm our finding and determine the possible mechanisms by which the IL-15R variant modulates light intensity physical activity.