Correlation between serum interleukin-6 level and type 1 diabetes mellitus: A systematic review and meta-analysis.

OBJECTIVE: This report aimed to explore the association between the change of circulating interleukin-6 (IL-6) in patients and the development of type 1 diabetes mellitus (T1DM). METHODS: Four databases (PubMed, CNKI, WanFang and Civip) were used to search and list all clinical case-control studies about serum IL-6 level in T1DM patients between Jan 1, 2000 and Aug 31, 2016. RESULTS: A total of 20 case-control studies with 1238 T1DM patients and 742 healthy controls were included in this study. Compared to healthy controls, the serum content of IL-6 in patients with T1DM was significantly greater (overall: SMD, 1.49; 95% CI, 1.04 to 1.93; p<0.001), and notably increased in all subgroup with different age, ethnic and disease duration (all p<0.001). Furthermore, the analysis in subgroup exhibited that serum levels of IL-6 in the age greater than 20-year old (SMD, 1.64; 95% CI, 0.57-2.71; p<0.001), the diseased duration among 0-10years (SMD, 2.43; 95% CI, 1.42-3.44; p<0.001) and the sorted American group (SMD, 1.68; 95% CI, 0.85-2.51; p<0.001) were higher than those in control groups. CONCLUSIONS: Patients with T1DM were found to be linked to elevated level of serum IL-6, which the age, ethnic and disease durations in T1DM patients had no effect on the serum IL-6 levels for promoting diabetes mellitus.