The adipokines TNF-alpha and IL6 predicted incident cancer development in a Chnese community-based cohort

Abstract

Adipose tissue is recognized as an active endocrine organ. Cytokines released from adipocytes induce chronic low-grade inflammation, which is linked to the development of cardiovascular diseases and malignancy.In this study, we examined the relationship between baseline adipokines level and incident cancer risk in a community-based cohort of Chinese subjects. Subjects were recruited from the Hong Kong Cardiovascular Risk Factors Prevalence Study 2(CRISPS 2) cohort. Those with known malignancy were excluded. Fasting blood forglucose, insulin, lipids, the adipokines interleukin-6 (IL6), soluble tumor necrosis factor receptor 2 (sTNFR2, as a surrogate marker of tumor necrosis factor-alpha), adiponectin and adipocyte-fatty acid binding protein (A-FABP) levels was collected at baseline. Incident cancer cases were identified after a median follow up of 9.6 years. 1897 subjects were included in the final analysis. During the study period, 94 subjects developed cancers. Compared to subjects with no cancer, subjects who developed cancer were older at baseline (61.0±11.5 vs 51.9±11.8, P<0.001), had a higher proportion of males (59.6 vs 45.9%, P=0.009), central obesity (38.3 vs 29.6%, P=0.008), diabetes (27.7 vs 14.8%, P=0.036), hypertension (36.2 vs 26.7%, P=0.045) and dyslipidemia (71.9 vs 60.6%, P=0.013). They had a higher serum level of IL6 (0.78 vs 0.58 pg/ml in male, 0.65 vs 0.54 pg/ml in female, P<0.001), sTNFR2 (2419.2 vs 1991.7 ng/ml in male, 2051.7 vs 1816.0 ng/ml in female, P<0.001) and A-FABP (21.0 vs 19.0 ng/ml in male, 24.2 vs 27.9 ng/ml in female, P=0.02). Adiponectin level between the two groups was not significantly different. After adjustment for conventional risk factors, only baseline IL6 (HR 1.51, 95% CI 1.16–1.97) and sTNFR2 (HR 2.36, 95%CI 1.16–4.81) predicted incident cancer development. Our data supported the hypothesis that chronic low grade inflammation caused by obesity could increase the risk of malignancy.