Calpain-10 gene polymorphisms in type 2 diabetes and its micro- and macrovascular complications

Genetic variations in the calpain 10 gene (CAPN10) were previously implicated with increased risk of type 2 diabetes (T2DM). We studied the association of single nucleotide polymorphisms in the CAPN10 gene, SNP - 43, SNP - 19 and SNP - 63, with T2DM and its complications. Overall, we examined 1440 individuals: 880 patients with diabetes and 560 healthy subjects, all Caucasians of Polish origin. All subjects were genotyped for the CAPN10 SNPs by polymerase chain reaction (PCR). The frequencies of alleles, genotypes and haplotypes at three studied loci were similar between the groups. However, the - 43 SNP was significantly more frequent in T2DM patients with coexisting cardiovascular disease (CVD) than in patients without CVD (p = 0.001). The - 43 SNP was still significantly associated with the risk of CVD after adjusting for potential risk factors including male gender, age, BMI, dyslipidemia and hypertension. The odds ratio for G allele for CVD + versus CVD- patients was 1.89, 95% CI 1.52–2.35. None of the studied SNPs was significantly associated with microvascular diabetic complications. There was a tendency to increased frequency of SNP - 43 1/1 homozygotes in patients with diabetic retinopathy (p = 0.057). The homozygous haplotype combination 121/121 was more frequent in T2DM patients than in non-diabetic controls (18.4% vs 10.5%, p = 0.019). In conclusion, the results of our study suggest the significant association of SNP - 43 with the risk of CVD coexisting with T2DM. We also observed that 121/121 haplotype was associated with T2DM in the studied population.