Hypertension at midlife and elevated midlife systolic blood pressure are associated with increased cognitive decline during a 20-year period, according to research published online ahead of print August 4 in JAMA Neurology. The decline is greater among Caucasians with high blood pressure than among African Americans with high blood pressure, said the authors.
Rebecca F. Gottesman, MD, PhD, Associate Professor of Neurology at Johns Hopkins University in Baltimore, and colleagues analyzed data for 13,476 African Americans and Caucasians in the Atherosclerosis Risk in Communities cohort. Baseline cognitive assessment was conducted from 1990 to 1992, and follow-up assessments occurred from 1996 to 1998 and from 2011 to 2013. A majority (58.0%) of living participants completed the 20-year cognitive follow-up.
During the follow-up, baseline hypertension was associated with an additional decline of 0.056 global z score points, and prehypertension was associated nonsignificantly with 0.040 additional global z score points of decline, compared with normal blood pressure. People with hypertension who took antihypertensives had less decline during the study period than untreated individuals with hypertension. Having an indication for initiating antihypertensive treatment at baseline (based on Eighth Joint National Committee hypertension guidelines) was associated with a greater 20-year decline than not having an indication.
The authors’ observations are important, but “they are not those of a randomized clinical trial representing a higher-level evidence-based medical decision-making source,” said Philip B. Gorelick, MD, Medical Director of Saint Mary’s Hauenstein Neuroscience Center in Grand Rapids, Michigan, in an accompanying editorial.
Lowering blood pressure is effective for reducing the risk of poststroke dementia in patients with a history of stroke, he added. Blood pressure lowering also can help prevent late-life dementia for people who are middle aged or for the younger elderly.
Given the current evidence, “on a case-by-case basis, the practitioner will need to balance the benefit of blood pressure lowering on cardiovascular disease risk reduction with the possible benefit or risk to cognition,” Dr. Gorelick concluded.
—Erik Greb