Angiotensin-converting enzyme gene polymorphisms and T2DM in a case-control association study of the Bahraini population.

Bahrain has one of the highest incidence rates of type 2 diabetes mellitus (T2DM). Development of diabetic nephropathy (DN) as a complication was noticed in some patients while absent in others. This interesting observation raises the role of certain genetic risk factors for the development of DN. Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism was found to be associated with T2DM. While some patients have predisposition to DN in the population, others have negative association. The present case-control association study was designed to investigate the association of ACE I/D polymorphism in T2DM patients in Bahrain especially in those who developed DN. A total of 360 T2DM patients (110 with DN and 250 without DN) and 360 healthy (non-diabetic) age-matched subjects were recruited for this study for comparison. The presence (insertion)/absence (deletion) (I/D) polymorphism of a 287-bp Alu1 element inside intron 16 of the ACE gene was investigated using PCR-gel electrophoresis. The results show that the distribution of the homozygote DD genotype of the ACE gene was high among Bahraini T2DM patients compared to the healthy non-diabetic subjects. In addition, the distribution of the deletion (D) allele was high among Bahraini T2DM patients with DN when compared to the healthy non-diabetic subjects. However, there was no significant difference in the distribution of ACE I/D allele and genotypes between DN patients when compared to those T2DM patients without DN. The results obtained in this study are in closely agreement with some previous reports which show a strong association of ACE polymorphism with T2DM patients, yet not a risk factor for development of DN.