Searching for a link between calcium-channel blockers and cognitive function.

U ntil recently, physicians tended not to treat hyper-tension in older people. Opinion held that high blood pressure was a useful adaptation to maintain flow in rigid arteriosclerotic arteries and that treatment with antihypertensive drugs would cause postural hypoten-sion and confusion. 1 Well-controlled trials have now demonstrated that treating hypertension in elderly patients reduces the risk of cardiovascular disease and death from this cause. 2-4 In fact, the largest reduction is among those at least 75 years of age. 5 Treatment of hypertension is the most important method available to reduce the incidence of stroke. 3,6 It has been estimated that a reduction in diastolic blood pressure of as little as 2 mm Hg would result in a 15% reduction in the risk of stroke and transient ischemic attacks. 7 Treatment of isolated systolic hypertension produces equally significant reductions in the incidence of stroke. 4 The reduction of death from cardiovascular disease in the past 20 years is due largely to better treatment 8 and may be improved further with attention to subgroups, such as those with hyperlipidemia. 9 But in spite of increasing public awareness and an expanding array of antihypertensive medications , hypertension remains a leading cause of cardiovas-cular disease and death. Studies relating to any aspect of this important health problem deserve close scrutiny. In this issue (page 501) Colleen J. Maxwell and colleagues 10 examine the effects that one class of drugs for the treatment of hypertension, the calcium-channel blockers (CCBs), might have on cognitive function in elderly patients. They were prompted to analyse data from the Cana-dian Study of Health and Aging (CSHA) by a report that patients using CCBs had worse cognitive function and greater leukoaraiosis than those using β-blockers. 11 The Canadian Study of Health and Aging is a population based prospective study of 10 623 people 65 years of age and older, who were initially interviewed between Feb-ruary 1991 and May 1992. Most lived in the community, and 1225 resided in institutions. All subjects underwent a standardized interview including a Modified Mini-Mental State (3MS) examination (scale 0 to 100). The subjects were classified as cognitively normal, cognitively impaired but not demented or demented (according to criteria of the Diagnostic and Statistical Manual of Mental Disorders). The subjects were reassessed in 1996/97. Maxwell and colleagues analysed data for the 509 subjects identified at baseline as not having dementia, who were using one or …