IL-6 gene rs1800795 polymorphism and diabetes mellitus: a comprehensive analysis involving 42,150 participants from a meta-analysis

BACKGROUND: Over the past two decades, several studies have focused on the association between a common polymorphism (rs1800795) from interleukin-6 (IL-6) gene and Diabetes Mellitus (DM) risk. However, the results remain ambiguous and indefinite. METHODS: A comprehensive analysis was performed to explore this relationship. A search was conducted in the PubMed, Embase, Chinese (CNKI and Wanfang), and GWAS Catalog databases, covering all publications until February 10, 2022. Odds ratios (OR) with 95% confidence intervals (CI) were used to evaluate the strength of the association. Publication bias was assessed using both Begg and Egger tests. RESULTS: Overall, 34 case–control studies with 7257 T2DM patients and 15,598 controls, and 12 case–control studies (10,264 T1DM patients and 9031 health controls) were included in the analysis. A significantly lower association was observed between the rs1800795 polymorphism and T2DM risk in Asians, mixed population, and hospital-based (HB) subgroups (C-allele vs. G-allele: OR = 0.76, 95% CI 0.58–0.99, P = 0.039 for Asians; CG vs. GG: OR = 0.74, 95% CI 0.58–0.94, P = 0.014 for mixed population; CC vs. GG: OR = 0.61, 95% CI 0.41–0.90, P = 0.014 for HB). However, increased associations were found from total, mixed population, and HB subgroups between rs1800795 polymorphism and T1DM susceptibility (CG vs. GG: OR = 1.32, 95% CI 1.01–1.74, P = 0.043 for total population, CC vs. GG: OR = 2.45, 95% CI 1.18–5.07, P = 0.016 for mixed individuals; C-allele vs. G-allele: OR = 1.29, 95% CI 1.07–1.56, P = 0.0009 for HB subgroup). CONCLUSIONS: In summary, there is definite evidence to confirm that IL-6 rs1800795 polymorphism is associated with susceptibility to decreased T2DM and increased T1DM. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-022-00851-8.