Association of angiotensin converting enzyme gene insertion/deletion polymorphism with diabetic retinopathy in middle-aged Indians with type 2 diabetes mellitus

Objectives: There are conflicting reports regarding the association of angiotensin 1 converting enzyme (ACE) gene polymorphism with diabetic retinopathy (DR). We compared ACE gene insertion/deletion (I/D) polymorphism between patients with and without DR in a middle-aged Indian population. The secondary outcome measure was the comparison of ACE gene I/D polymorphism in different grades of DR severity. Methods: Institutional cross-sectional case-control study with middle-aged (45-64 years) type 2 diabetes patients from Eastern India with DR (DR group) and without DR (NODR group). Polymerase chain reaction (PCR) was used to determine the ACE gene I/D polymorphism through primers flanking the polymorphic region of 287 bp Alu repeat sequence in intron 16. Results: Genotyping for the ACE gene I/D polymorphisms were done for 107 patients in each group. The presence of DR had no significant association with the prevalence of ACE I/D genotype compared to those without DR either in the recessive model (p=0.588) or in the dominant model (p=0.891). The allele contrast was also similar between DR and NODR (p=0.837) groups. The severity of retinopathy was associated with the ACE I/D genotype in the recessive model (p=0.043) but not in the dominant model (p=0.136). However, the severity of retinopathy was associated with allele contrast (p=0.016). Conclusions: The ACE gene polymorphism was not associated with diabetic retinopathy in middle-aged Indian patients with type 2 diabetes in our study. However, the severity of DR was associated with the ACE gene polymorphism in these patients.