Interaction of renin-angiotensin system gene polymorphisms with hypertension in Chinese patients with type 1 diabetes and retinopathy

BACKGROUND: The objective of this research was to investigate the interaction of RAS gene polymorphisms in Chinese patients with type 1 diabetes mellitus (T1DM) and diabetic retinopathy (DR). METHODS: Genomic DNA was extracted from peripheral blood leukocytes and genotyping for the angiotensin converting enzyme (ACE) gene I/D and angiotensinogen (AGT) gene M/T polymorphisms was performed using the polymerase chain reaction method. 311 T1DM patients were recruited for the assessment of ACE and AGT polymorphisms relating to DR. RESULTS: Compared with the diabetic non-retinopathy (DNR) patients, DR patients had lower proportion of diabetic nephropathy (p<0.001) and M allele (p=0.013). Intriguingly, the frequency D allele (p=0.035) was lower in DR patients with hypertension, as well as DD (p=0.003) and DI genotype (p=0.012) in DR patients with normal blood pressure after multiple tests with Bonferroni correction, but D allele (p=0.025) displayed higher in normotensive patients with T1DM. Logistic regression analyses indicated that no significant relationship existed about the genotype and allele polymorphisms with the progress of DR after adjusting for confounding factors. CONCLUSIONS: Interaction of hypertension and the RAS gene polymorphisms might have a role in the DR development in Chinese T1DM patients.