Circulating adiponectin levels and risk of endometrial cancer: the prospective Nurses' Health Study

OBJECTIVE: Adiponectin, a protein secreted by adipose cells, is inversely associated with endometrial cancer. Our objective was to assess prediagnostic adiponectin levels in relation to risk of endometrial cancer. STUDY DESIGN: This was a prospective nested case-control study within the Nurses' Health Study with 146 cases and 377 controls. Adiponectin was measured using enzyme-linked immunosorbent assay. Logistic regression analyses were performed adjusting for known endometrial cancer risk factors. RESULTS: Mean age at diagnosis was 64.6 years. Mean interval between blood draw and diagnosis was 7.4 years (range, 2-13). There was no difference in median adiponectin (cases 12.9 vs controls 12.9 mu g/mL; P = .97). Adiponectin >15 mu g/mL was not associated with endometrial cancer risk (relative risk = 0.86; 95% confidence interval, 0.53-1.39; P = .48), even among postmenopausal women (odds ratio, 0.66; 95% confidence interval, 0.29-1.5). Results did not vary by time from blood draw to diagnosis (P for heterogeneity = .18). CONCLUSION: Prediagnostic adiponectin was not predictive of endometrial cancer risk. Further study will better define the relationship between adiponectin and endometrial cancer.