Association of I/D polymorphism in the ACE gene and the susceptibility of patients to diabetic neuropathy

Objective: We conducted a systematic review and meta-analysis to evaluate the association between polymorphisms in the ACE and ACE2 genes and the development of diabetic neuropathy (DN). Methods: We searched six databases (NCBI/PubMed, MEDLINE, Cochrane Library, Virtual Health Library, Scielo, and Embase) as well as grey literature (Google Scholar and citations). Two independent reviewers selected the articles according to predefined inclusion and exclusion criteria. Results: The systematic literature search identified 114 records across the databases. At the end of the selection process, 5 studies were included in the qualitative analysis, and 4 studies were included in the quantitative analysis. All included studies were case-control studies conducted in Iraqi, Pakistani, and Turkish populations. Conclusion: According to the meta-analysis, the ID+DD genotypes of the ACE gene I/D polymorphism are associated with an increased risk of developing DN (OR = 1.43, CI = 1.01–2.03, p = 0.0464). Our analysis also suggests that the D allele is a risk marker for DN (OR = 1.42, CI = 1.19–1.68, p < 0.0001), with similar findings previously reported. Further observational studies in diverse populations are needed to confirm this association.