Association of 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 gene polymorphism with diabetic retinopathy (DR). We compared gene insertion/deletion polymorphism between patients with and without DR in a middle-aged Indian population. The secondary outcome measure was the comparison of gene 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 gene polymorphism through primers flanking the polymorphic region of 287 bp Alu repeat sequence in intron 16.

RESULTS

Genotyping for the gene polymorphisms were done for 107 patients in each group. The presence of DR had no significant association with the prevalence of 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 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 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 gene polymorphism in these patients.