Circulating chemerin levels and gestational diabetes mellitus: a systematic review and meta-analysis

Background: Chemerin is a novel adipokine which is associated with metabolic syndrome and type 2 diabetes mellitus. However, recent investigations regarding circulating chemerin levels in gestational diabetes mellitus (GDM) are conflicting. This meta-analysis is to evaluate and determine their associations. Methods: A systematic literature search was performed in PubMed, EMBASE and Web of Science up to 13 December 2017. Pooled standardized mean differences (SMD) and 95% confidence interval (CI) were calculated using a random-effect model. Results: Eleven studies comprising 742 GDM patients and 840 normal pregnant women were included. Circulating chemerin levels were increased in GDM patients compared with healthy pregnant women (SMD: 1.16; 95% CI: 0.29, 2. 04; P = 0.009). Subgroup analyses revealed such difference was especially available in the groups of the second trimester (SMD: 1.47; 95% CI: 0.28, 2.67) and mean age < 30 years (SMD: 2.30; 95% CI: 0.69, 3.91) of GDM patients. There was significant heterogeneity among studies (I-2 = 98.0%, P < 0.001); however, heterogeneity disappeared or markedly decreased in the subgroups of European populations (I-2 = 0.0%, P = 0.531), age >= 30 years (I-2 = 28.2%, P = 0.223) and WHO diagnostic criteria (I-2 = 0.0%, P = 0.490) when stratifying by study location, trimester of chemerin measurement and the diagnostic criteria of GDM. Conclusions: The elevated levels of circulating chemerin were associated with GDM, which suggests it might play an important role in the pathogenetic mechanism of GDM.