Leptin and body mass index in relation to endometrial cancer risk

Because leptin is a hormone associated with obesity and reproduction, we attempted to examine whether there is a relationship between leptin and endometrial cancer.

Cases were 84 women with histologically confirmed incident endometrial cancer, whereas controls were 84 women admitted to the same hospital for small surgical operations. The serum leptin levels were determined in fasting morning blood samples by using radioimmunoassay. The mean values of leptin levels among cases and controls were compared with simple t test, and the data were further analyzed using multiple logistic regression procedures.

The serum leptin levels were 36.7 +/- (SD) 25.7 ng/ml among cases and 26.9 +/- 19.8 ng/ml among controls (p = 0.006). After adjustment for known risk factors of endometrial cancer, components of the insulin-like growth factor system did not confound the association of leptin with endometrial cancer, but this association was eliminated, when the body mass index was adjusted for. Thus, the odds ratio for an increment of 1 SD of blood leptin was 1.52 (p = 0.03) before adjustment for body mass index, but only 1.13 (p = 0.62) after adjustment for it.

In a case-control study of incident endometrial cancer in Greece, we found evidence that leptin is strongly positively associated with endometrial cancer. It cannot be conclusively inferred, however, whether leptin elevation, as a consequence of obesity, plays a role in endometrial carcinogenesis or whether it is a simple correlate of obesity.