Calcium channel blockers and risk of AD: the Baltimore Longitudinal Study of Aging

Objective: To investigate the association between use of calcium channel blockers (CCB), dihydropyridine (DHP) or nondihydropyridine (nonDHP) type CCB and risk of developing Alzheimer's Disease (AD) or mortality. There is evidence suggesting that calcium plays a key role in changes in the brain leading to AD. Previous reports suggest a possible role for CCB in the treatment of AD. However, there are some indications that CCB increase mortality in patients with cardiac disease. Methods: Subjects were 1092 participants in the Baltimore Longitudinal Study of Aging (BLSA) older than 60 years of age. Data on CCB use was collected prospectively for up to 19 years. Cox proportional hazards regression was used to estimate relative risks (RR) and confidence intervals (CI) of AD and mortality associated with use of CCB or use of only DHP or nonDHP-CCB. Analyses were adjusted for gender, education, smoking, blood pressure and history of heart problems. Results: Use of DHP-CCB was not associated with a significantly reduced risk of AD compared to non-users, although the estimate of the RR was low with DHP-CCB (RR = 0.30, 95% CI = 0.07-1.25, P = 0.10). Use of nonDHP-CCB was not associated with reduced risk of AD and the estimate of the RR risk was close to one (RR = 0.82, 95% CI = 0.37-1.83, P = 0.63). In addition, there was no increase in mortality among users of DHP-CCB (RR = 0.64, 95% CI = 0.32-1.29, P = 0.21) or nonDHP-CCB (RR = 1.10, 95% CI = 0.65-1.87, P = 0.72). Conclusion: Users of DHP-CCB and nonDHP-CCB in this study did not have a significantly reduced risk of AD. (C) 2004 Elsevier Inc. All rights reserved.