Circulating omentin-1 levels in women with polycystic ovary syndrome: a meta-analysis

To investigate the association between circulating omentin-1 levels and polycystic ovary syndrome (PCOS) in women, a meta-analysis was performed. A systematic literature search using PubMed, Embase and Web of Science was carried out. Ten articles with 13 studies were included in this meta-analysis, which included a total of 1264 subjects (733 patients with PCOS and 531 controls). The pooled standard mean difference (SMD) and 95% confidence interval (CI) were used to estimate the association between omentin-1 levels and PCOS. Circulating omentin-1 levels were lower in PCOS with an SMD (95% CI) of -0.67 (-0.91, -0.43) and p = 0.000 (random-effects). However, significant heterogeneity was detected across studies (I²=73.6% and p = 0.000). The subgroup analysis suggested that omentin-1 levels in PCOS patients were associated with HOMA-IR ratio. Meta-regression analysis indicated region was the main source of heterogeneity (p = 0.048). The results of this meta-analysis suggested that circulating omentin-1 levels are significantly lower in women with PCOS compared with controls, which indicated that omentin-1 may play a role in the pathologic processes of PCOS.