High blood pressure may prevent cognitive decline in a subset of older patients
By Megan Mayerle, PhD
September 5, 2019
High blood pressure in middle age has been associated with a wide variety of health issues including cardiovascular disease, cognitive decline, and mortality. However, the link between high blood pressure and cognitive decline is less clear in adults age 65 or older.
A team of researchers led by Stanford CVI member Dr. Michelle Odden had previously shown that the functional status of older adults, as measured by metrics such as grip strength or walking speed, impacted the association between blood pressure and health. Specifically, the scientists showed that high blood pressure was associated with worse health outcomes in higher functioning adults. Paradoxically however, low blood pressure was associated with worse outcomes in lower functioning adults.
In a study recently published in the Journal of Hypertension, researchers led by Dr. Odden set out to specifically determine if there is a relationship between systolic and/or diastolic blood pressure, functional status, and cognitive decline and dementia in older adults.
The scientists found that higher blood pressure was associated with improvements in cognitive function among persons with functional limitation. This association was attenuated or reversed among those without such limitations. A similar pattern was found with dementia. Why this association occurs is unknown, however it may be explained by insufficient organ perfusion among those with poor functioning and low blood pressure. In the case of dementia, the researchers suggested that low blood pressure may decrease the extent of blood perfusion to the brain, which could lead to hypoxia, which has been linked to an increased chance of cognitive decline and dementia.
Current clinical guidelines recommend interventions to lower blood pressure in older adults; these findings challenge the universality of such guidelines.
Lindsay M. Miller (Oregon State University), Carmen A. Peralta (UCSF), Annette L. Fitzpatrick (University of Washington), Chenkai Wu (Duke Kunshan University), Bruce M. Psaty (University of Washington and Kaiser Permanente Washington Health Research Institute), and Anne B. Newman (University of Pittsburgh) also contributed to these studies. Support was provided by contracts HHSN268201200036C, HHSN268200800007C, HHSN268201800001C, N01HC55222, N01HC85079, N01HC85080, N01HC85081, N01HC85082, N01HC85083, N01HC85086, and grants U01HL080295 and U01HL130114 from the National Heart, Lung, and Blood Institute (NHLBI), with additional contribution from the National Institute of Neurological Disorders and Stroke (NINDS), R01AG023629 from the National Institute on Aging (NIA), and R01-AG046206.