Glutathione Peroxidase Level in Patients with Vitiligo: A Meta-Analysis.

Abnormality of glutathione peroxidase (GPx) is involved in the etiology and pathogenesis of vitiligo. However, the results were controversial. Aim. The purpose of this meta-analysis is to compare the levels of GPx between vitiligo patients and healthy controls. Methods. Relevant published articles were searched according to eligibility criteria. A meta-analysis was conducted to pool estimates of the standardized mean difference (SMD) with 95% confidence interval (CI). Results. Twenty-three studies with a total of 1076 vitiligo patients and 770 healthy controls were included. The pooled meta-analysis showed that patients with vitiligo had equivalent levels of GPx with the healthy controls (SMD = -0.47, 95% CI: -1.03 to 0.08, and p = 0.095). Further subgroup analysis showed that the GPx levels of Asian patients or segmental vitiligo patients were, respectively, lower than those of healthy controls (Asian: SMD = -0.47, 95% CI: -1.08 to 0.14, and p = 0.001; segmental: SMD = -3.59, 95% CI: -6.38 to -0.80, and p = 0.012). Furthermore, the GPx levels in serum/plasma were significantly decreased in either stable or active vitiligo patients, comparing to healthy controls (stable: SMD = -2.01, 95% CI: -3.52 to -0.49, and p = 0.009; active: SMD = -2.34, 95% CI: -4.07 to -0.61, and p = 0.008). Conclusion. This meta-analysis showed a significant association between low GPx level and vitiligo.