Polymorphism of angiotensin II receptor gene and microangiopathies in patients with insulin-dependent diabetes mellitus

Polymorphism A1166C of the AT1R gene encoding angiotensin vascular receptor [replacement of C (cytosine) for A (adenine)) at position 1166] was compar ed in patients with insulin-dependent diabetes mellitus (IDDM) with and wit hout diabetic nephropathy (DN) (n = 27 and n = 41, respectively) and also i n patients with IDDM with diabetic retinopathy (DR) and in corresponding in dividuals without DR (n = 30 and n = 44, respectively). The frequency of AT 1R gene alleles and genotypes in patients with IDDM complicated by DN did n ot differ significantly from that observed in patients with noncomplicated IDDM. In contrast, in patients with IDDM complicated by retinopathy, a sign ificant decrease in the content of A allele (68.3% versus 82.6%) and a sign ificant increase in the content of C allele (31.7% versus 17.4%) was found as compared with the control group. Thus, in the Moscow population, A1166C polymorphism of the AT1R gene is not associated with diabetic renal complic ations but indeed associated with diabetic retinal complications. C allele is a risk factor of DR (the relative risk, RR, is equal to 2.17), and A all ele is, in contrast, a protective factor against early retinopathy developm ent (RR is equal to 0.49).