Association between adiponectin levels and endometrial carcinoma risk: evidence from a dose–response meta-analysis

OBJECTIVES Epidemiological studies evaluating the association between adiponectin levels and endometrial carcinoma risk have produced inconsistent results. Thus, a meta-analysis was conducted to assess the association between them. METHODS Pertinent studies were identified by a search of PubMed and Web of Knowledge through January of 2015. A random-effects model was used to combine the data for analysis. Dose-response relationship was assessed by restricted cubic spline and variance-weighted least squares regression analysis. RESULTS Twelve articles (5 prospective studies and 7 case-control studies) involving 1916 endometrial carcinoma cases were included in this meta-analysis. Pooled results suggested that highest adiponectin levels versus lowest levels were significantly associated with the risk of endometrial carcinoma (summary relative risk (RR)=0.525, 95% CI 0.388 to 0.712, I(2)=64.2%). The association was also found in postmenopausal women (summary RR=0.646, 95% CI 0.433 to 0.964), but not in premenopausal women. A linear dose-response relationship was found, with the risk of endometrial carcinoma decreasing by 3% for every 1 μg/mL increase in adiponectin levels (summary RR=0.97, 95% CI 0.96 to 0.98). No publication bias was found. CONCLUSIONS Our analysis suggested that the higher adiponectin levels might have a protective effect against endometrial carcinoma, especially in postmenopausal women.