[Antihypertensive treatment and prevention of dementia]

Hypertension is a risk factor for dementia, particularly vascular dementia. The objective of the "Vascular Dementia" project of the European multicentre Syst-Eur trial was to study the influence of antihypertensive therapy on the incidence of dementia in elderly patients with isolated systolic hypertension included in this trial. Patients were over the age of 60, with systolic blood pressure between 160 and 219 mmHg and diastolic blood pressure less than 95 mmHg in the sitting position and were not demented. After randomization, they were treated under double-blind conditions with nitrendipine associated with or replaced by enalapril or hydrochlorothiazide or an equivalent placebo. Cognitive functions were evaluated by the Mini-Mental State test (MMS) on inclusion then annually. When the MMS score was < or = 23, a complementary assessment was performed to establish the diagnosis of dementia according to DSM III-R criteria. The Modified Ischaemia score specified the aetiology of dementia. A total of 1180 and 1238 subjects were randomized to the placebo and active treatment groups, respectively. They presented comparable characteristics on inclusion. The median intent to treat duration of follow-up was 2.0 years. The incidence of dementia was decreased by 50%, from 7.7 per thousand patient-years in the placebo group to 3.8 per thousand patient-years in the active group (p = 0.05). There were 15 and 8 cases of dementia of the Alzheimer type, 4 and 3 cases of mixed dementia, 2 and 0 cases of vascular dementia in the placebo and active treatment groups, respectively. In conclusion, in subjects over the age of 60 years with isolated systolic HT, antihypertensive treatment initiated with nitrendipine can reduce the incidence of dementia.