Angiotensin-converting enzyme gene insertion/deletion polymorphism and high-altitude pulmonary edema: An updated meta-analysis

OBJECTIVE: The purpose of the study was to investigate the association between angiotensin-converting enzyme gene insertion/deletion polymorphism and high-altitude pulmonary edema. METHODS: A systematic search for relevant literature was performed in MEDLINE, CNKI, and EMBASE. The pooled odds ratios and their corresponding 95% confidence intervals were calculated in STATA 12.0 software. RESULTS: Seven studies, with a total of 304 patients and 564 controls, qualified for the inclusion in the analysis. There was no significant association between angiotensin-converting enzyme insertion/deletion polymorphism and high-altitude pulmonary edema risk in the total population (DD vs II: odds ratio=1.07, 95% confidence interval 0.52-2.24; DI vs II: odds ratio=1.12, 0.85-1.49; dominant model: odds ratio=1.07, 0.83-1.40; recessive model: odds ratio=0.96, 0.53-1.77). Subgroup analysis according to race also revealed no significant correlation between angiotensin-converting enzyme gene insertion/deletion polymorphism and high-altitude pulmonary edema. CONCLUSIONS: Our findings suggest that angiotensin-converting enzyme insertion/deletion polymorphism does not contribute to the risk of high-altitude pulmonary edema. Larger, well-designed studies are required to further validate these results.