NADPH oxidase p22phox C242T polymorphism is associated with macroalbuminuria in diabetic patients: A meta-analysis

Aims Previous studies suggested an association between C242T polymorphism in NADPH Oxidase p22phox and diabetic nephropathy (DN) risk, but the results were inconsistent. To obtain a more precise estimation, we carried out a meta-analysis to analyze the effect of C242T polymorphism in NADPH Oxidase p22phox on DN risk. Methods We searched PubMed, ISI Web of Science, and China National Knowledge Infrastructure for all eligible case–control studies through May 2016. The odds ratios (ORs), together with the 95% confidence intervals (CIs), were calculated to evaluate the strength of association between C242T SNP in NADPH Oxidase p22phox on DN risk. Results Overall, ten eligible studies involving a total of 1894 cases and 1746 controls were included in our meta-analysis. The results showed that there was no statistical evidence of association between NADPH oxidase p22phox C242T polymorphism and DN in all genetic models (T vs. C: OR 1.16, 95% CI 0.85–1.59, p=0.34; TT vs. CC: OR 1.49, 95% CI 0.80–2.76, p=0.21; TT/CT vs. CC: OR 1.18, 95% CI 0.81–1.72, p=0.40; TT vs. CT/CC: OR 1.31, 95% CI 0.82–2.11, p=0.26). However, significant association was found in diabetic patients with macroalbuminuria. Conclusion This meta-analysis indicates that NADPH oxidase p22phox C242T polymorphism is associated with macroalbuminuria in diabetic patients. However, this conclusion should be interpreted with caution due to the small sample size. Larger sample-size studies with homogeneous patients and well-matched controls are required.