A single-nucleotide polymorphism in the interleukin-1 receptor-associated protein gene is associated with impaired glucose regulation and type 2 diabetes in a case-controlled study.

Impaired glucose regulation (IGR), containing prediabetes and diabetes, is an inflammatory disease. The interleukin-33 (IL-33)/IL-1 receptor-like 1 and IL-1/IL-1 receptor (IL-1R) pathways are involved and play opposite roles. While the IL-1R-associated protein (IL-1Rap) is indispensible for the two pathways, the association between the single-nucleotide polymorphisms (SNPs) of the IL-1Rap gene and IGR has not been determined. TaqMan probe quantitative polymerase chain reaction was used to genotype 11 SNPs in the regions of the IL-1Rap gene selected on the basis of linkage disequilibrium using the HapMap database in a study of 889 individuals (156 IGR patients in the case group and 733 non-diabetic patients in the control group). Logistic regression was applied to control the potential confounders in the multivariate analysis. Among 11 SNPs, IL-1Rap rs3773958 was associated with IGR. Further analysis showed that the odds ratios for GT and GT + GG carriers vs. TT carriers were 1.686 and 1.669, respectively, adjusted for gender, age, weight, waist, drinking, smoking, hypertension, alanine aminotransferase, total cholesterol and triglycerides. For rs3773958 in the non-smoking subgroup, GT and GT + GG carriers had a significantly higher risk of IGR compared to the TT carriers. The same conclusions were drawn using data from non-drinking and non-overweight subgroups. However, interactions between rs3773958 and smoking, drinking or being overweight were not significant. In conclusion, rs3773958 in the IL-1Rap gene region was associated with IGR.