A lower serum level of middle-molecular-weight adiponectin is a risk factor for endometrial cancer

The present study was undertaken to examine the correlation between serum levels of adiponectin isoforms and the risk for endometrial cancer. This retrospective case-control study included 43 Japanese women with endometrial cancer and 62 Japanese women with no history of cancer. Serum levels of total adiponectin and the respective isoforms were determined by enzyme-linked immunosorbent assay. Multivariate logistic regression analysis was performed on the serum levels of total adiponectin and its isoforms, high molecular weight, middle molecular weight, and low molecular weight adiponectins, after adjustment for confounders (age, body mass index, hypertension, and diabetes mellitus). The distribution of body mass index revealed a statistically significant difference between patients and controls (P = 0.001). A statistically significant difference (P < 0.01) was also found in the incidence of diabetes mellitus between the two groups, although there was no significant difference in the incidence of hypertension. In controls, an inverse correlation was observed between body mass index and serum adiponectin levels. However, in patients, an inverse correlation was found only between body mass index and serum middle molecular weight adiponectin level. After adjustment for confounding variables, the factor found to be most closely associated with endometrial cancer was a lower serum level of middle molecular weight adiponectin (adjusted odds ratio 4.89, 95 % confidence interval value 1.25-19.11, P = 0.022). Low serum level of middle molecular weight adiponectin was the only independent risk factor for endometrial cancer suggesting that the application of adiponectin might prevent or decrease the risk for endometrial cancer.