Angiotensin I-converting enzyme insertion/deletion gene polymorphism and its association with diabetic nephropathy in type-2 diabetes mellitus patients: an Egyptian study

Samenvatting

Background Diabetic nephropathy (DN) is one of the most serious complications associated with type-2 diabetes mellitus (T2DM). With variable allele and genotype frequencies, the angiotensin I-converting enzyme (ACE) insertion–deletion (I/D) gene polymorphism has been suggested as a risk factor for DN. Objective The purpose of the study was to find whether ACE I/D polymorphism is associated with DN in Egyptian T2DM patients and its relation to ACE concentration and C-reactive protein quantitative level. Participants and methods A case–control study of 98 T2DM patients was divided into two groups: group 1, T2DM patients without DN, and group 2, T2DM patients with DN. The frequencies of the ACE I/D gene polymorphism (I, D allele and DD, ID, II genotype) were compared in the two groups. Results An association was found between D allele, combined II+DD genotype on comparing the two groups (odds ratio 2.029, 95% confidence interval: 1.379–2.985, P≤0.001 and odds ratio 2.039, 95% confidence interval: 1.027–4.048, P=0.042, respectively), ACE-activity level was the highest with DD and the lowest with II genotypes with P value less than 0.001 in all T2DM patients, while ACE I/D polymorphism did not show an association with C-reactive protein level. The multiple logistic-regression analysis revealed ACE-concentration level and combined ACE ID+DD genotype as independent risk factors for the development of DN. Conclusion The study showed a significant predisposing association of D allele and ACE ID+DD genotype with DN and the protective effect of II genotype, and that the DD genotype was associated with the highest ACE concentration.