The association of circulating adiponectin levels with pancreatic cancer risk: a study within the prospective EPIC cohort.

Excess body weight and type 2 diabetes mellitus, risk factors of pancreatic cancer, are characterized by decreased levels of adiponectin. In addition to anti-inflammatory and anti-proliferative actions, adiponectin has an important role in regulating glucose metabolism, i.e., decreasing circulating blood glucose levels. Prospectively, hyperglycemia has been associated with risk of pancreatic cancer. The aim of this study was to investigate the association of pre-diagnostic adiponectin levels with pancreatic cancer risk. We conducted a case-control study nested within European Prospective Investigation into Cancer and Nutrition. Blood samples of 452 pancreatic cancer cases and 452 individually matched controls were analyzed by immunoassays. Multivariate conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Overall, adiponectin showed no association with pancreas cancer risk; however, among never smokers, higher circulating levels of adiponectin were associated with a reduction in pancreatic cancer risk (OR = 0.44 [95% CI 0.23-0.82] for highest vs. lowest quartile), whereas among current smokers there was no significant association (OR = 1.59 [95% CI 0.67-3.76] for highest vs. lowest quartile; p-trend = 0.530; p-interaction = 0.309). In our study, lower adiponectin concentrations may be associated with the development of pancreatic cancer among never smokers, whereas the only other prospective study being conducted so far showed a decrease in risk among male smokers. Therefore, further studies are needed to clarify the role of adiponectin in pancreatic cancer development.