Effect of PPARGC1A Gly428Ser (rs8192678) polymorphism on athletic sports performance: A meta-analysis

Abstract

1 RESEARCH ARTICLE 2 Effect of PPARGC1A Gly428Ser (rs8192678) polymorphism on 3 athletic sports performance: A meta-analysis 4 5 Abstract 34 Background Genetics plays a role in sports performance (SP) which, in this study, is 35 measured by power and endurance activities as well as a mix between the two. However, 36 variable results from genetic association studies warrant a meta-analysis to obtain more precise 37 estimates of the association between PPARGC1A Gly482Ser polymorphism and SP.38 Methods Multi-database literature search yielded 14 articles (16 studies) for inclusion.39 Pooled odds ratios (ORs) and 95% confidence intervals (CI) were used in estimating 40 associations. Summary effects were modified based on statistical power. Subgroups were SP 41 (power, endurance and mixed) and race (Caucasians and Asians). Heterogeneity was 42 assessed with the I 2 metric and its sources examined with outlier analysis.43 Results Gly allele effects significantly favoring SP (OR > 1.0, P < 0.05) form the core of our 44 findings in: (i) the homogeneous overall effect at the post-modified, post-outlier level (OR 1.13, 45 95% CI 1.03-1.25, P = 0.01, I 2 = 0%); (ii) initially homogeneous power SP (ORs 1.22-1.25, 95% 46 CI 1.05-1.44, P = 0.003-0.008, I 2 = 0%) which precluded outlier treatment; (iii) pre-outlier 47 Caucasian outcomes (ORs 1.29-1.32, 95% CI 1.12-1.54, P = 0.0005) over that of Asians with a 48 pooled null effect (OR 0.99, 95% CI 0.72-1.99, P = 0.53-0.92); (iv) homogeneous all > 80% 49 (ORs 1.19-1.38, 95% CI 1.05-1.66, P = 0.0007-0.007, I 2 = 0%) on account of high statistical 50 power (both study-specific and combined). In contrast, none of the Ser allele effects 51 significantly favored SP and no Ser-Gly genotype outcome favored SP. The core significant 52 outcomes were robust and comparisons subjected to publication bias test showed no evidence 53 of it.54 Conclusion Lines of evidence show that the Gly allele effects favor SP. These were observed 55 in the overall, Caucasians and statistically powered comparisons which exhibited consistent 56 significance, stability, robustness, precision and lack of bias, all of which provide good evidence 57 of associations between the Gly allele and SP. 58 59