The polymorphism in the let-7 targeted region of the Lin28 gene is associated with increased risk of type 2 diabetes mellitus

•This is the first study about the association between miRNA associated polymorphisms and T2DM risk in Chinese population.•rs3811463 polymorphism of Lin28 was associated with increased risk of T2DM, especially in females.•Differences were observed in the clinical features for different genotype of rs3811463 in T2DM.•rs3811464 polymorphism of Lin28 is lack of association with T2DM risk. Genetic polymorphisms in the miRNAs pathway of the pathogenesis of disease might contribute to the risk of disease. However, it is unclear whether these polymorphisms about miRNAs are associated with the risk of type 2 diabetes mellitus (T2DM). We performed a case-control study to investigate two polymorphisms in the let-7/Lin28 pathway based on 588 T2DM patients and 588 age and sex matched controls. The results showed that the rs3811463 polymorphism was associated with increased risk of T2DM (odds ratio (OR)=1.47, 95% confidence inference (95%CI)=1.13–1.93, P=0.005), while the rs3811464 not (OR=1.04, 95%CI=0.79–1.36, P=0.78). For the rs3811463 polymorphism, the variant genotypes were associated with increased risk of disease in females; statistically differences were observed in the clinical features of age at diagnosis, hypertension and peripheral neuropathy for the variant and wild genotype of the rs3811463 in T2DM. In summary, the results indicated that the rs3811463 polymorphism in the let-7/Lin28 pathway could significantly increase the risk of T2DM.