Blood pressure, dementia and Alzheimer's disease: the OPTIMA longitudinal study.
Razay G., Williams J., King E., Smith AD., Wilcock G.
BACKGROUND/AIMS: Studies on the relation between blood pressure (BP), dementia and Alzheimer's disease (AD) have yielded inconsistent results, showing an association with high or low BP, or no association with BP. The study was designed to look at the longitudinal effect of BP on cognitive function. METHODS: Participants were part of the OPTIMA longitudinal study of patients with dementia and agematched cognitively healthy controls. The Cambridge Cognitive Examination (CAMCOG) and BP were measured. We tested the dependence of CAMCOG scores on BP using generalised linear mixed models. RESULTS: A total of 235 were cognitively healthy controls, 42 had mild cognitive impairment (MCI), 141 had AD, and 59 had other dementia syndrome (ODS). In AD patients, the rate of decline of CAMCOG scores showed an inverted U-shaped (non-linear) dependence on diastolic BP. High (110 mm Hg) and low (60 mm Hg) levels of diastolic BP were related to faster cognitive decline over 5 years of follow-up (z = -2.51, p = 0.012). CAMCOG scores also showed an inverted U-shaped dependence on pulse pressure (z = -2.29, p = 0.022). CONCLUSION: High and low BP levels are related to faster cognitive decline in AD patients. This could have implications for the prevention and treatment of AD.