Objective: To qualitatively and quantitatively assess the evidence regarding the relation of ACE I/D polymorphism to coronary heart disease (CHD) risk.
Methods: Medline (January 1994 to February 2005) and China Hospital Knowledge Databases (January 1994 to May 2005) were retrieved for all publications relating to case-control studies reporting a link between CHD risk factors and the ACE I/D polymorphism. All 16 association studies were identified and a meta-analysis was conducted by using the RevMan 4.2 estimate for odds ratio (OR) to determine whether the DD genotype might predict the outcome in CHD.
Results: Sixteen out of 48 identified studies reporting data on 1345 CHD patients and 1286 matched controls fulfilled these inclusion criteria. The overall distribution of genotypes in the control subjects was 35.88% II, 40.86% ID, and 23.26% DD. The odds ratio for CHD for DD versus ID/II genotypes across all studies was 2.56 [95% CI, 2.09 - 3.13]. The relative CHD risk appeared to be increased with the D allele (chi(Trend)(2) = 97.12, P < 0.01).
Conclusions: ACE gene I/D polymorphism should be associated with susceptivity of coronary heart disease in China. The CHD risk is increased significantly in individuals with DD genotypes. The ACE D allele should be a risk factor for CHD.