Intensive blood pressure (BP) reduction may lower risk for all-cause dementia in patients with uncontrolled hypertension, according to study results published in Nature Medicine.

While recent meta-analyses have shown the role of antihypertensive treatment in reducing risk for dementia and mild cognitive impairment, there is insufficient evidence on prevention strategies for dementia in patients with hypertension.

In a cluster randomized trial (China Rural Hypertension Control Project Phase-3 [CRHCP-3]), researchers studied the effectiveness of an intensive BP intervention in lowering risk for dementia in real-world primary care settings. The original CRHCP study (ClinicalTrials.gov Identifier: NCT03527719) was designed to be a 2-phase effectiveness trial, with the primary outcome being BP control at 18 months.

Eligible participants of the extension study included residents in Chinese villages with a regular nonphysician community health care provider (NCHP) and aged 40 years and older with a mean untreated systolic BP (SBP) of 140 mm Hg or more and/or a diastolic BP (DBP) of 90 mm Hg or more.

This proven-effective intervention should be widely adopted and scaled up to reduce the global burden of dementia.

Participants were randomly assigned into 2 groups: the intervention group, where intensive hypertensive treatment was used to achieve a target SBP of less than 130 mm Hg and DBP of less than 80 mm Hg, and the usual-care group. All patients completed the Mini-Mental State Examination (MMSE), Functional Activities Questionnaire (FAQ), and Quick Dementia Rating System (QDRS) at the 48-month follow-up visit.

Primary outcome of the study was all-cause dementia, and secondary outcome was cognitive impairment no dementia (CIND).

A total of 33,995 participants were enrolled in the analysis, of whom 17,407 (mean age, 62.8 years; women, 60.8%) were in the intervention villages and 16,588 (mean age, 63.3 years; women, 61.6%) were in the usual-care villages.

The SBP reduced by approximately 30 mm Hg and DBP by 15 mm Hg and SBP by approximately 8 mm Hg and DBP by 6 mm Hg in the intervention vs usual-care group, respectively. At the 48-month follow-up, the researchers noted group differences in SBP reduction of -22.0 mm Hg (95% CI, -23.4 to -20.6 mm Hg) and DBP reduction of -9.3 mm Hg (95% CI, -10.0 to -8.7 mm Hg; P <.0001). Overall, 67.7% of the intervention group and 15.0% of the usual-care group achieved the target SBP and DBP at 48 months.

At the follow-up visit, 668 participants (4.59%) in the intervention group and 734 (5.40%) in the usual-care group had all-cause dementia. Risk ratio (RR) of all-cause dementia associated with the intervention was 0.85 (95% CI, 0.76-0.95; P =.0035).

A total of 2506 participants (17.2%) in the intervention group and 2808 (20.7%) in the usual-care group had CIND. The RR for composite outcome of dementia or CIND was 0.84 (95% CI, 0.81-0.87) and composite outcome of dementia or death was 0.86 (95% CI, 0.81-0.92; both P <.0001).

In terms of safety, serious adverse events occurred in 6201 participants (35.7%) in the intervention group and 6329 participants (38.2%) in usual-care group (RR, 0.94; 95% CI, 0.91-0.98; P =.0006).

Results of the sensitivity analysis, after adjusting for age, sex, and antihypertensives treatment, were consistent with results of the primary analysis, with risk reduction associated with the intervention remaining significant.

In the post hoc analysis, the researchers found that MMSE scores were higher while FAQ and QDRS scores were lower in the intervention vs usual-care group, at 48 months.

Further, a meta-analysis conducted by the researchers indicated a 15% reduction in dementia events with antihypertensives treatment (RR, 0.85; 95% CI, 0.78-0.92; P <.0001).

“This proven-effective intervention should be widely adopted and scaled up to reduce the global burden of dementia,” the researchers concluded.

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