Association of angiotensin-converting enzyme insertion/deletion polymorphism with type 1 diabetic nephropathy: a meta-analysis

Objective: This study aimed to systematically evaluate the effect of an angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism on type 1 diabetic nephropathy (DN).Methods: Cochrane Library, Embase, PubMed, Science Direct, Web of science, Wanfang data, VIP database, China Knowledge Resource Integrated Database, and SinoMed were searched. A total of 17 case-control studies analyzing ACE I/D polymorphism and type 1 DN risk were included in the present meta-analysis.Results: Overall, a significant increased risk was found in allele comparison (OR=1.16, 95% CI=1.05-1.28, p=0.04), dominant comparison (OR=1.56, 95% CI=1.14-2.15, p=0.006) and homozygote comparison (OR=1.52, 95% CI=1.06-2.19, p=0.02). In subgroup analyses according to ethnicity, the risk of type 1 DN in Asian population was increased in allele comparison (OR=1.98, 95% CI=1.15-3.42, p=0.01), recessive comparison (OR=2.48, 95% CI=1.51-4.10, p=0.0004), dominant comparison (OR=3.15, 95% CI=1.90-5.23, p<0.00001), and homozygote comparison (OR=2.87, 95% CI=1.02-8.06, p=0.05). However, there was no association between the ACE I/D genetic variants and type 1 DN in Caucasian populations.Conclusions: Our meta-analysis results indicate that the ACE I/D polymorphism may contribute to type 1 DN development, especially in the Asian groups with type 1 diabetes. The current findings need to be confirmed by future well-designed and larger sample size primary studies in populations with different ethnicities.