Effect of PPARGC1A Gly428Ser (rs8192678) polymorphism on athletic sports performance: A meta-analysis
BackgroundGenetics plays a role in sports performance (SP) which, in this study, is measured by power and endurance activities as well as a mix between the two. However, variable results from genetic association studies warrant a meta-analysis to obtain more precise estimates of the association between PPARGC1A Gly482Ser polymorphism and SP.\n\nMethodsMulti-database literature search yielded 14 articles (16 studies) for inclusion. Pooled odds ratios (ORs) and 95% confidence intervals (CI) were used in estimating associations. Summary effects were modified based on statistical power. Subgroups were SP (power, endurance and mixed) and race (Caucasians and Asians). Heterogeneity was assessed with the I2 metric and its sources examined with outlier analysis.\n\nResultsGly allele effects significantly favoring SP (OR > 1.0, P < 0.05) form the core of our findings in: (i) the homogeneous overall effect at the post-modified, post-outlier level (OR 1.13, 95% CI 1.03-1.25, P = 0.01, I2 = 0%); (ii) initially homogeneous power SP (ORs 1.22-1.25, 95% CI 1.05-1.44, P = 0.003-0.008, I2 = 0%) which precluded outlier treatment; (iii) pre-outlier Caucasian outcomes (ORs 1.29-1.32, 95% CI 1.12-1.54, P = 0.0005) over that of Asians with a pooled null effect (OR 0.99, 95% CI 0.72-1.99, P = 0.53-0.92); (iv) homogeneous all > 80% (ORs 1.19-1.38, 95% CI 1.05-1.66, P = 0.0007-0.007, I2 = 0%) on account of high statistical power (both study-specific and combined). In contrast, none of the Ser allele effects significantly favored SP and no Ser-Gly genotype outcome favored SP. The core significant outcomes were robust and comparisons subjected to publication bias test showed no evidence of it.\n\nConclusionLines of evidence show that the Gly allele effects favor SP. These were observed in the overall, Caucasians and statistically powered comparisons which exhibited consistent significance, stability, robustness, precision and lack of bias, all of which provide good evidence of associations between the Gly allele and SP.\n\nList of abbreviations