美国约翰霍普金斯大学医学院Keenan A. Walker等研究人员，探讨了中年和老年血压模式与老年痴呆症的关系。2019年8月13日，知名学术期刊《美国医学会杂志》发表了这一成果。

这项前瞻性队列研究于1987至1989年间招募了4761名中年参与者，定期测量血压并随访至2017年12月31日。在第5次和第6次随访时对参与者进行详细的神经认知评估，共有516例参与者患上痴呆。中年和晚年血压都正常的参与者，痴呆发病率为每100人年1.31，中年血压正常晚年高血压的参与者为1.99，中年和晚年血压都高的参与者为2.83，中年血压正常晚年低血压的参与者为2.07，而中年高血压晚年低血压的参与者则高达4.26。

与血压始终正常的参与者相比，中年晚年血压都高的参与者和中年高血压晚年低血压的参与者患继发性痴呆的风险显著增加。即便不考虑晚年血压，中年高血压也与痴呆的风险显著相关。与血压始终正常的参与者相比，中年高血压晚年低血压的参与者患轻度认知功能障碍的风险亦显著增加。

据介绍，晚年血压（BP）与认知的关系可能依赖于是否有高血压史或慢性高血压。长期高血压造成的晚年血压下降或许会导致认知能力下降。

附：英文原文

Title: Association of Midlife to Late-Life Blood Pressure Patterns With Incident Dementia

Author: Keenan A. Walker; A. Richey Sharrett; Aozhou Wu; Andrea L. C. Schneider; Marilyn Albert; Pamela L. Lutsey; Karen Bandeen-Roche; Josef Coresh; Alden L. Gross; B. Gwen Windham; David S. Knopman; Melinda C. Power; Andreea M. Rawlings; Thomas H. Mosley; Rebecca F. Gottesman

Issue&Volume: Vol 322，No.6

Abstract:

Importance  The association between late-life blood pressure (BP) and cognition may depend on the presence and chronicity of past hypertension. Late-life declines in blood pressure following prolonged hypertension may be associated with poor cognitive outcomes.

Objective  To examine the association of midlife to late-life BP patterns with subsequent dementia, mild cognitive impairment, and cognitive decline.

Design, Setting, and Participants  The Atherosclerosis Risk in Communities prospective population-based cohort study enrolled 4761 participants during midlife (visit 1, 1987-1989) and followed-up over 6 visits through 2016-2017 (visit 6). BP was examined over 24 years at 5 in-person visits between visits 1 and 5 (2011-2013). During visits 5 and 6, participants underwent detailed neurocognitive evaluation. The setting was 4 US communities: Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis, Minnesota. Follow-up ended on December 31, 2017.

Exposures  Five groups based on longitudinal patterns of normotension, hypertension (>140/90 mm Hg), and hypotension (<90/60 mm Hg) at visits 1 to 5.

Main Outcomes and Measures  Primary outcome was dementia onset after visit 5, based on Ascertain Dementia-8 informant questionnaires, Six-Item Screener telephone assessments, hospital discharge and death certificate codes, and the visit 6 neurocognitive evaluation. Secondary outcome was mild cognitive impairment at visit 6, based on the neurocognitive evaluation.

Results  Among 4761 participants (2821 [59%] women; 979 [21%] black race; visit 5 mean [SD] age, 75 [5] years; visit 1 mean age range, 44-66 years; visit 5 mean age range, 66-90 years), there were 516 (11%) incident dementia cases between visits 5 and 6. The dementia incidence rate for participants with normotension in midlife (n = 833) and late life was 1.31 (95% CI, 1.00-1.72 per 100 person-years); for midlife normotension and late-life hypertension (n = 1559), 1.99 (95% CI, 1.69-2.32 per 100 person-years); for midlife and late-life hypertension (n = 1030), 2.83 (95% CI, 2.40-3.35 per 100 person-years); for midlife normotension and late-life hypotension (n = 927), 2.07 (95% CI, 1.68-2.54 per 100 person-years); and for midlife hypertension and late-life hypotension (n = 389), 4.26 (95% CI, 3.40-5.32 per 100 person-years). Participants in the midlife and late-life hypertension group (hazard ratio [HR], 1.49 [95% CI, 1.06-2.08]) and in the midlife hypertension and late-life hypotension group (HR, 1.62 [95% CI, 1.11-2.37]) had significantly increased risk of subsequent dementia compared with those who remained normotensive. Irrespective of late-life BP, sustained hypertension in midlife was associated with dementia risk (HR, 1.41 [95% CI, 1.17-1.71]). Compared with those who were normotensive in midlife and late life, only participants with midlife hypertension and late-life hypotension had higher risk of mild cognitive impairment (37 affected individuals (odds ratio, 1.65 [95% CI, 1.01-2.69]). There was no significant association of BP patterns with late-life cognitive change.

Conclusions and Relevance  In this community-based cohort with long-term follow-up, sustained hypertension in midlife to late life and a pattern of midlife hypertension and late-life hypotension, compared with midlife and late-life normal BP, were associated with increased risk for subsequent dementia.

DOI: 10.1001/jama.2019.10575

Source: https://jamanetwork.com/journals/jama/article-abstract/2747672