Angiotensin Converting Enzyme Insertion/Deletion Olymorphism And Risk Of Pregnancy Hypertensive Disorders: A Meta-analysis

Background: The angiotensin-converting enzyme (ACE) geneinsertion/deletion (I/D) polymorphism has been reported inconsistently asbeing associated with risk of pregnancy hypertensive disorders (PHDs).Studies based on different countries, ethnicities, disease definitions cometo different conclusions. In order to identify if there exists this correlation,we examined these associations by performing a meta-analysis.Methods: Two investigators independently consulted the Medline,Embase, CNKI, and Chinese Biomedicine databases using certain keywords. Researches were included according to inclusion/exclusion criteria,data of the included researches were extracted. Odds ratios (ORs) and95%confidence intervals (95%CIs) were calculated in fixed-andrandom-effects models when appropriate. Subgroup analyses wereperformed by ethnicity, types of PHD (gestational hypertension,pre-eclampsia and eclampsia), country and Hardy–Weinberg equilibrium(HWE) in controls.Results: This meta-analysis included30case–control studies with 3523cases and4817controls. Overall, we found that the DD variant ofthe ACE I/D polymorphism was associated with a significantly increasedPHD risk. In the subgroup analysis by ethnicity, the results suggested thatthe DD genotype was significantly associated with risk of PHD devel-opment among Asians and Caucasians. Moreover, when stratifying bytypes of PHD, a significantly increased risk was observed forpre-eclampsia. Interestingly, when stratifying by country, a significantlyelevated risk was found among ‘others’ countries (those that were notChina or Korea). Limiting the analysis to the studies within HWE, theresults were persistent and robust.Conclusion: This meta-analysis suggests that the I/D polymorphismof ACE may be associated with PHD risk, especially among Asians andCaucasians.