Effects of cholinesterase inhibitors appear greater in patients on established antihypertensive therapy

Introduction: There is increasing evidence that hypertension may contribute to development of dementia. Studies show that blood pressure lowering therapy might protect against cognitive deterioration and that antihypertensive treatment reduce the incidence of dementia. Aim: We hypothesize that administration of cholinesterase inhibitors (AChEis) to patients with Alzheimer's Disease (AD) receiving antihypertensive medications therapy would result in clinical benefits for a period of 40 weeks in routine clinical practice. Methods and materials: Patients with possible or probable AD were enrolled from 16 Alzheimer evaluation units (UVA) of Brescia and Cremona (Northern Italy). Patients treated with donepezil, rivastigmine and galantamine for 40 weeks independently of dosages were selected. Patients were evaluated at baseline (T0), 4 weeks (T1), 16 weeks (T2) and 40 weeks (T3). Results: 416 patients completed the study at 40 weeks; of these 255 were 'non users' while 161 utilized antihypertensive drugs ('users'). The mean change in MMSE score from baseline to week 40 demonstrate that antihypertensive-treated patients improved by 0.7 points while patients receiving only AChEis remain stables. Analyzing separately patients (n = 183) that ameliorate (responders) on cognition at T3 (≥ 1 point MMSE score increase) a significant differences in favor of 'users' antihypertensive drugs over 'non users' on cognition at weeks 16 and 40 has been demonstrated. In particular, at T2 the mean change of MMSE from baseline in 'users' was 3.2 ± 2.6 vs 'non users' 2.2 ± 2.3 (p = 0.016) and at T3 was 3.5 ± 2.5 vs 'non users' 2.0.2.7 ± 1.6 (p = 0.018). Antihypertensive drugs were independently associated with cognitive improvement in responder patients treated with AChEis (95% CI: 0.41-1.79; p = 0.002). Conclusion: Antihypertensive medications in AD patients treated with AChEis are associated with an independent improvement on cognition after 40 weeks of treatment.