Efficacy of renin-angiotensin system inhibitors, calcium channel blockers, and diuretics in hypertensive patients with diabetes: subgroup analysis based on albuminuria in a systematic review and meta-analysis

In hypertensive patients with diabetes, the effectiveness of renin-angiotensin system (RAS) inhibitors in improving mortality, cardiovascular events, and renal outcomes, compared to other antihypertensive drugs such as calcium channel blockers (CCBs) and diuretics, remains uncertain, particularly in the context of albuminuria. A comprehensive literature search was conducted using PubMed, the Cochrane Library, and the Japan Medical Abstracts Society databases up to October 2024. A meta-analysis of 12 randomized controlled trials, including 14,163 patients, was performed. RAS inhibitors showed no significant advantage over CCBs or diuretics for all-cause mortality (relative risk [RR]: 1.00, 95% confidence interval [CI]: 0.92–1.08, p = 0.98), myocardial infarction (RR: 0.64, 95% CI: 0.32–1.31, p = 0.22), stroke (RR: 1.14, 95% CI: 1.00–1.31, p = 0.05), composite cardiovascular events (RR: 0.93, 95% CI: 0.81–1.07, p = 0.45), or end-stage renal disease (RR: 0.88, 95% CI: 0.72–1.08, p = 0.21). Subgroup analyses stratified by albuminuria status revealed no significant benefits of RAS inhibitors, regardless of albuminuria presence. The findings emphasize the need for cautious interpretation due to limited sample sizes, wide confidence intervals, and low precision. These results highlight the importance of considering not only RAS inhibitors but also other antihypertensive drugs as the first-line choice for blood pressure control in diabetic patients, with careful attention to side effects and other relevant factors.