ACE inhibitors may be better than other antihypertensives for diabetes patients

Angiotensin-converting enzyme (ACE) inhibitors were found to possibly improve outcomes for patients with diabetes more than other antihypertensives, a recent meta-analysis found.

In the systematic review and Bayesian network meta-analysis, researchers included 63 randomized, controlled trials with more than 36,000 participants who all had diabetes. All of the studies had follow-up of at least a year and reported outcomes of all-cause mortality, need for dialysis or doubling of serum creatinine. Studied drugs included ACE inhibitors, angiotensin receptor blockers (ARBs), alpha-blockers, beta-blockers, calcium channel blockers and diuretics. Results were published by BMJ on Oct. 24.

Of the studied drugs, only ACE inhibitors significantly reduced the risk of serum creatinine doubling compared to placebo (odds ratio, 0.58; 95% credible interval, 0.32 to 0.90). Only beta-blockers significantly increased patients' mortality risk (odds ratio, 7.13; 95% credible interval, 1.37 to 41.39). The researchers also looked at the drug classes compared to each other individually, and found that, although the differences were not statistically significant, ACE inhibitors had a probability of being superior to ARBs on all three outcomes.

The effect of combination therapy on mortality risk was also examined. Although no combination significantly outperformed placebo on this outcome, the analysis found that an ACE inhibitor plus a calcium channel blocker had the greatest probability (73.9%) of being the best treatment to reduce mortality, followed by ACE inhibitor plus diuretic at 12.5%, ACE inhibitors at 2.0%, calcium channel blockers at 1.2% and ARBs at 0.4%.

The results show superior effects with ACE inhibitors compared to other hypertension treatments for diabetic patients, the researchers concluded. Especially considering the lower cost of these drugs, they should be the first-line choice. If adequate control is not achieved with ACE inhibitors alone, adding a calcium channel blocker might be the preferred treatment, the authors recommended.

They cautioned that the number of patients in the trials prohibited evaluation of some other combination therapies (including ARBs plus any of the other drug classes), and that only 1.7% of the studied patients took an ACE inhibitor plus a calcium channel blocker, so the generalizability of that finding is uncertain. Future research should further compare ACE inhibitors and ARBs, they said, noting that some guidelines suggest that their effects are equivalent.