Type 2 diabetes mellitus (T2DM) is a common metabolic disorder that results from complex interactions of both environmental and genetic factors. Many single nucleotide polymorphisms (SNPs), including noncoding RNA genes, have been investigated for their association with susceptibility to T2DM and its complications, with little evidence available regarding Caucasians. The aim of the present study was to establish whether four miRNA SNPs (miR-27a rs895819 T>C, miR-146a rs2910164 G>C, miR-196a2 rs11614913 C>T, and miR-499a rs3746444 A>G) are correlated with susceptibility to T2DM and/or diabetic polyneuropathy (DPN) in a Romanian population. A total of 167 adult T2DM patients and 324 age- and sex-matched healthy controls were included in our study. miRNA SNPs were detected by real-time PCR using a TaqMan genotyping assay. A significant association with T2DM was observed only for the miR-499a rs3746444 A>G SNP in all the tested models, and the frequencies of both the miR-499a rs3746444 AG and the GG genotypes were higher in the T2DM patients compared to the controls. No correlation was observed for the miR-27a rs895819 T>C, miR-146a rs2910164 G>C, or miR-196a2 rs11614913 C>T SNPs in any genetic model. When we assessed the association of these SNPs with DPN separately, we found a positive association for the miR-499a rs3746444 SNP in both codominant and dominant models (OR 6.47, 95% CI: 1.71-24.47; OR 2.30, 95% CI: 1.23-4.29, respectively). In conclusion, this study shows that miR-499a rs3746444 A>G may influence both T2DM and DPN susceptibility, with carriers of the GG genotype and the G allele being at an increased risk in the Romanian population.
Keywords: diabetic polyneuropathy; genotype; microRNAs; single nucleotide polymorphism; type 2 diabetes mellitus.