Association between inflammatory factor interleukin 6 and tumor necrosis factor α in type 2 diabetes: a Meta analysis

Wang Shuo; Liu Songfang; Ren Yan

doi:10.3760/cma.j.issn.1673-4777.2014.01.017

Abstract：Objective To research the association between inflammatory factor interleukin 6 (IL-6) and tumor necrosis factor α(TNF-α) in type 2 diabetes(T2DM) by a systematic review.Methods A systematic review according to the guideline of Cochrane review was performed.Prospective cohort studies concerning the association between IL-6,TNF-α and T2DM were searched from data base.IL-6 and TNF-α levels at baseline and endpoint (defined as development of clinical diabetes) were measured in all of these studies.Data of these studies was analyzed and combined to do meta analysis.The followings were used to assess the association between inflammatory factors and T2DM:risk ratio (RR)of T2DM according to quartiles of IL-6 or TNF-α and baseline level of IL-6 or TNF-α in T2DM population and non-T2DM population.Results All 6 studies about IL-6 including 10 111 subjects met the inclusion criteria.Meta analysis showed that after adjusting for confounding factors,the combined RR for diabetes comparing individuals in top vs bottom quartile of baseline IL-6 distribution was 2.33 [95％ confidence interval (1.89,2.87),P ＜0.00001].Baseline level of IL-6 in T2DM population was significantly higher than that in non-T2DM population(P ＜0.001).Five studies about TNF-oα including 7 803 subjects met the inclusion criteria.Meta analysis showed that after adjusting for confounding factors,the combined risk ratio for diabetes comparing individuals in top vs bottom quartile of baseline TNF-o distribution was 1.53 [95％ confidence interval (1.23,1.90),P =0.0002].Four studies of 5 showed that baseline level of TNF-o in T2DM population was significantly higher than that in non-T2DM population (P ＜ 0.001).Conclusions The levels of IL-6 and TNF-α may play roles in the development of T2DM,and may be risk factors of T2DM.Early screening and intervention are necessary in chronic inflammatory state with elevated IL-6 and TNF-c levels.