Inverse association of leptin levels with renal cell carcinoma: Results from a case-control study

Leptin is primarily produced in adipose tissue and appears to play a modulatory role between metabolism and immunity. Given that obesity, a state of chronic inflammation, is an established risk factor for Renal Cell Carcinoma (RCC), we investigated the association between plasma leptin levels and RCC risk. DESIGN: This case-control study included 70 patients with newly diagnosed, histologically confirmed RCC and 280 age-, gender- and district of residence-matched controls. Anthropometric data, socio-demographic variables, medical history, lifestyle habits and dietary data were derived from a personal interview. Serum leptin and adiponectin levels were determined using standard commercial kits. Adjusted odds ratios for RCC risk were derived through multiple logistic analyses. RESULTS: Leptin levels were inversely controlling for potential confounding factors, such as Body Mass Index (BMI), recent weight change, history of diabets mellitus and other obesity related hormones, notably adiponectin. CONCLUSIONS: The precise mechanism linking obesity with RCC remains unclear; however, the inverse association of leptin with RCC might be attributed, at least in part, to hormonal cross-talk with complex neuron endocrine and immune circuits. These findings, if confirmed in prospective and interventional studies, might further elucidate the underlying mechanisms.