Blood pressure trajectories from midlife to late life in relation to dementia in women followed for 37 years.

Higher midlife blood pressure increases risk for dementia. To further understand the relation between blood pressure and dementia, it is necessary to examine evolution of blood pressure from midlife to late life. We examined blood pressure trajectories using linear mixed models in a representative sample of middle-aged women (N=1462) who were followed from 1968-1969 until 2005-2006 with comprehensive medical and neuropsychiatric examinations. Dementia was diagnosed according to established criteria. Among those not treated with antihypertensives, higher systolic blood pressure at baseline but not blood pressure trajectories from 1968 to 1992 was associated with dementia and Alzheimer disease. Those with history of antihypertensive treatment had higher baseline systolic blood pressure than those who were never treated. In this group, those who developed dementia and Alzheimer disease had lower baseline systolic blood pressure and steeper increase in systolic blood pressure from 1968 to 1992 than those who did not. A steeper decline in systolic blood pressure during the later part of the study was observed in those who developed dementia regardless of antihypertensive treatment. The latter association was attenuated or disappeared when adjusting for body mass index. The association between blood pressure and dementia is complex and influenced by antihypertensive treatment. The findings emphasize the importance of detecting increased blood pressure in midlife and controlling blood pressure in those treated. Whether the trajectory of blood pressure is a risk factor or part of the clinical course of dementia needs to be elucidated.