The development of new-onset type 2 diabetes associated with choosing a calcium channel blocker compared to a diuretic or beta-blocker.
OBJECTIVE
It has been acknowledged that patients who receive a beta-blocker or diuretic based regimen are at increased risk of developing new-onset diabetes. Recently, angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have been shown to decrease patients' odds of developing new-onset type 2 diabetes. A number of large placebo-controlled multi-center trials in post-myocardial infarction and heart failure patients have shown the ability of renin-angiotensin-aldosterone system medications to reduce the onset of type 2 diabetes. Pharmacologic data has shown improved insulin sensitivity with ACEIs and ARBs. Controversy persists regarding the influence of calcium channel blockers on the development of new-onset diabetes.


METHODS
Two reviewers conducted a systematic literature search of Medline, EMBASE, CINAHL, and the Cochrane Library (1966 to December 2006) to extract a consensus of trial data involving calcium channel blockers versus diuretics or beta-blockers with an endpoint of new-onset type 2 diabetes. Studies were included if they were randomized controlled trials versus routine treatment, not observational studies of clinical practice. A random-effects model was utilized. Subgroup and sensitivity analyses were conducted.


RESULTS
Out of 1721 trials, six meeting inclusion criteria were identified, including 99 006 patients. Calcium channel blockers were associated with a reduced incidence of new-onset type 2 diabetes (odds ratio 0.81; 95% confidence interval [CI] 0.73-0.90; p = 0.0001) compared with diuretic or beta-blocker therapy. The reduction in new-onset type 2 diabetes was maintained when a calcium channel blocker was compared to only thiazide diuretics (OR 0.86; 95% CI 0.75-0.99; p = 0.0346). The meta-analysis was limited by the varying definition of new-onset type 2 diabetes mellitus, as well as the potential for publication bias, which is a limit of any meta-analysis.


CONCLUSIONS
Calcium channel blockers may be associated with reduced odds of developing new-onset type 2 diabetes compared to diuretics and beta-blockers.
Kuti
Effie L
EL
School of Pharmacy, University of Connecticut, Storrs, CT, USA.
Baker
William L
WL
White
C Michael
CM
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D002121:Calcium Channel Blockers / Q000009:adverse effects* / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology*; D004232:Diuretics / Q000009:adverse effects* / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000188:drug therapy; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
D000319:Adrenergic beta-Antagonists; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D002121:Calcium Channel Blockers; D004232:Diuretics