The impact of angiotensin converting enzyme insertion/deletion gene polymorphism on diabetic kidney disease: A debatable issue.

Objective: The objective of this study was to evaluate the influence of ACE I/D gene polymorphisms on diabetic kidney disease (DKD) risk.

Methods: All eligible investigations were identified, the number of various genotype in the case and control group were reviewed. The pooled analysis was performed using Stata software.

Results: In overall subjects, 24,321 participants with 12,961 cases and 11,360 controls were included. the pooled analysis showed a significant link between D allele, DD or II genotype and DKD risk (D versus I: OR=1.316, 95% CI: 1.213-1.427, P=0.000; DD versus ID+II: OR=1.414, 95% CI: 1.253-1.595, P=0.000; II versus DD+ID: OR=0.750, 95% CI: 0.647-0.869, P=0.000). The subgroup pooled analysis showed that ACE I/D gene polymorphism was correlated with DKD both in Asian and in Chinese population. In addition, ACE I/D gene polymorphism was correlated with type 2 DKD (D versus I: OR=1.361, 95% CI: 1.243-1.490, P=0.000; DD versus ID+II: OR=1.503, 95% CI: 1.310-1.726, P=0.000; II versus DD+ID: OR=0.738, 95% CI: 0.626 -0.870, P=0.000). However, there was no obvious correlation in Caucasian subjects and type 1 diabetic patients.

Conclusion: ACE I/D polymorphisms were correlated with DKD in Asian and type 2 diabetic populations. ACE D allele/DD genotype might be a risk factor, while ACE II genotype might be a protective factor for DKD.