AbstractObjectiveThe angiotensin converting enzyme insertion/deletion (ACE I/D) gene polymorphism is involved in a wide range of clinical outcomes. This makes ACE I/D an important genetic marker. Updating the genetic profile of ACE I/D and raising the evidence for its role in renal disease is therefore needed. Reported associations of ACE I/D with progressive renal failure (PRF) in autosomal dominant polycystic kidney disease (ADPKD) have been inconsistent, prompting a meta-analysis to obtain more precise estimates.MethodsMulti-database search yielded 18 articles for inclusion in the meta-analysis. Risks (odds ratios [ORs] and 95% confidence intervals) were estimated by comparing the ACE genotypes (heterozygote ID, homozygotes DD and II). Heterogeneous (random-effects) pooled associations were subjected to outlier treatment which yielded fixed-effects outcomes and split the findings into pre- (PRO) and post- (PSO) outlier status. Subgroup analysis was based on ethnicity (Asian/Caucasian) and minor allele frequency (maf). The ≥ 0.50 maf subgroup indicates higher frequency of the variant II genotype over that of the common DD genotype, otherwise, the subgroup is considered < 0.50 maf. Stability of the associative effects was assessed with sensitivity treatment. Temporal trend of association was examined with cumulative meta-analysis.ResultsIn the PSO analysis, overall effects were null (ORs 0.99-1.02) but not in the subgroups (Asian and ≥ 0.50 maf), where in presence of the D allele (DD/ID) and the I allele (II), increased (ORs 1.63-5.62) and reduced (OR 0.22) risks were observed, respectively. Of these pooled effects, the Asian and ≥ 0.50 maf homozygous DD genotypes had high ORs (5.01-5.63) indicating elevated magnitude of effects that were highly significant (Pa < 10−5) and homogeneous (I2 = 0%), in addition to their robustness. In contrast, the Caucasian and < 0.50 maf subgroup effects were: (i) non-heterogeneous (fixed-effects) at the outset, which did not require outlier treatment and (ii) non-significant (ORs 0.91-1.10, Pa = 0.15-0.79). Cumulative meta-analysis revealed increased precision of effects over time.ConclusionsPRF in ADPKD impacted the Asian and ≥ 0.50 maf subgroups where DD homozygote carriers were up to 6-fold susceptible. The high magnitude of these effects were highly significant, homogeneous and robust indicating strong evidence of association.
Evaluation of common polymorphisms of eNOS gene and ACE gene in autosomal dominant polycystic kidney disease patients and their association with hypertension and renal failure
