Systemic oxidative stress biomarkers in chronic periodontitis: a meta-analysis

Oxidative stress biomarkers have been observed in peripheral blood of chronic periodontitis patients; however, their associations with periodontitis were not consistent. This meta-analysis was performed to clarify the associations between chronic periodontitis and oxidative biomarkers in systemic circulation. Electronic searches of PubMed and Embase databases were performed until October 2014 and articles were selected to meet inclusion criteria. Data of oxidative biomarkers levels in peripheral blood of periodontitis patients and periodontal healthy controls were extracted to calculate standardized mean differences (SMDs) and 95% confidence intervals (CIs) by using random-effects model. Of 31 eligible articles, 16 articles with available data were included in meta-analysis. Our results showed that periodontitis patients had significantly lower levels of total antioxidant capacity (SMD = -2.02; 95% CI: -3.08, -0.96; P = 0.000) and higher levels of malondialdehyde (SMD = 0.99; 95% CI: 0.12, 1.86; P = 0.026) and nitric oxide (SMD = 4.98; 95% CI: 2.33, 7.63; P = 0.000) than periodontal healthy control. Superoxide dismutase levels between two groups were not significantly different (SMD = -1.72; 95% CI: -3.50, 0.07; P = 0.059). In conclusion, our meta-analysis showed that chronic periodontitis is significantly associated with circulating levels of three oxidative stress biomarkers, indicating a role of chronic periodontitis in systemic diseases.