Calcium-channel blockers and cognitive function in elderly people: resultsfrom the Canadian Study of Health and Aging

Background: Concern has been raised about the potential for adverse cogniti ve effects associated with the use of calcium-channel blockers (CCBs) in ol der people. This study was undertaken to examine prospectively the associat ion between the use of these and other antihypertensive drugs and cognitive function. Methods: The authors examined data from the Canadian Study of Health and Ag ing (CSHA], a population-based, prospective 5-year investigation of the epi demiology of dementia and other health problems in Canadians 65 years of ag e and older. The risk of cognitive decline, as indicated by a decline in pe rformance on the Modified Mini-Mental State (3MS) examination over the 5-ye ar period, was assessed in relation to the use of antihypertensive and diur etic drugs by 205 subjects with a history of hypertension and no evidence o f dementia at baseline. Results: The proportion of subjects whose cognitive performance declined ov er the study period was significantly higher in the group using CCBs than i n the group using other antihypertensive agents (75% v. 59%). The adjusted odds ratio (OR) for a significant decline in cognitive performance (defined as a decrease in 3MS score of 10 points or more) was 2.28 (95% confidence interval [CI] 1.12-4.66) for subjects using CCBs. The adjusted ORs land 95% CIs) for cognitive decline in subjects using selected antihypertensive age nts or diuretics relative to those exposed to P-blockers were as follows: a ngiotensin-converting-enzyme inhibitor, OR 1.36 (95% CI 0.41-4.55); diureti c or other antihypertensive drug, OR 1.45 (95% CI 0.51-4.14); dihydropyridi ne CCB (nifedipine), OR 1.94 (95% CI 0.52-7.27) and non dihydropyridine CCB (diltiazem or verapamil), OR 3.72 (95% CI 1.22-11.36). Interpretation: Older people taking CCBs were significantly more likely tha n those using other agents to experience cognitive decline. These findings are consistent with the results of previous cross-sectional research and em phasize the need for further trials to examine the associations between CCB use, blood pressure and cognitive impairment in elderly patients.