I enjoyed reading the guidelines from the Canadian Consensus Conference on Dementia1 as well as the excellent physician's guide to using the recommendations.2 Having taken part in the conference, I can attest to the fact that the material published in your pages accurately reflects the deliberations at the meeting.
Despite my overall support for the guidelines, I must disagree with the statement that "the treatment of hypertension reduces the incidence of not only vascular dementia but also Alzheimer's disease" in scenario 4 of the physician's guide.2 The authors cite an article by Forette and colleagues,3 who make claims that are far too optimistic given the evidence they present. Forette and colleagues describe the Systolic Hypertension in Europe (Syst-Eur) trial, a secondary goal of which was to reduce the incidence of vascular dementia by the treatment of isolated systolic hypertension. Only 2 cases of vascular dementia occurred, far fewer than had been originally predicted. It was also found that treatment of hypertension apparently reduced the incidence of Alzheimer's disease and mixed and vascular dementias by 50%. Although this finding is interesting, it should be pointed out that the confidence interval around the estimate of a 50% reduction included 0. Thus, the data are also just as compatible with no treatment effect. Forette and colleagues' results constituted a post-hoc analysis, suggesting the possibility of false-positive results.
Of interest as well is the fact that the only comparable study (the Systolic Hypertension in the Elderly Program [SHEP]), while using different drugs than those used in the Syst-Eur trial, found no protection against dementia with control of systolic hypertension.4 A colleague and I have pointed out our objections to Forette and colleagues' overly optimistic claims in more detail elsewhere.5
Further trials are needed to determine whether treatment of hypertension will in fact reduce the incidence of vascular dementia and Alzheimer's disease, especially in the frail elderly suffering from comorbidity. In the meantime, we must continue to approach the decision to treat systolic hypertension in the very elderly with great care, lest we do more harm than good in treating them.
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