Effect of calcium channel blockers on incidence of diabetes: a meta-analysis

AIMS: Insulin resistance and the progressive loss of β-cell function are components of the fundamental pathophysiology of type II diabetes. A recent experimental study suggested that calcium channel blockers (CCBs) might inhibit β-cell apoptosis, enhance β-cell function, and prevent diabetes. The present meta-analysis examined the clinical effect of CCBs on the incidence of diabetes. METHODS: MEDLINE, EMBASE, ISI Web of Science, the Cochrane Library, and ClinicalTrials. gov were each searched for relevant articles published up to March 11, 2013. Randomized controlled trials (RCTs) with a follow-up period of at least 1-year were included. Identified articles were systematically reviewed, and those with pertinent data were selected for inclusion in a meta-analysis. RESULTS: We included ten RCTs in a meta-analysis. Of the 108,118 people with hypertension and no pre-existing diabetes, 7,073 (6.5%) cases of type II diabetes were reported. CCBs were associated with a higher incidence of diabetes than angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs; pooled risk ratios [95% confidence intervals]: 1.23 [1.01–1.51] and 1.27 [1.14–1.42], respectively) and a lower incidence compared with β blockers or diuretics (0.83 [0.73–0.94] and 0.82 [0.69–0.98], respectively). The overall risk of diabetes among subjects taking CCBs was not significant (0.99 [0.85–1.15]). CONCLUSION: The use of CCBs was not significantly associated with incident diabetes compared to other antihypertensive agents: the association with diabetes was lowest for ACEIs and ARBs, followed by CCBs, β blockers, and diuretics. Although CCBs can be safely used in hypertensive patients, it would be premature to advocate CCBs for the prevention or treatment of diabetes.