Key Points:
- Intensive blood pressure (BP) lowering intervention was tested on hypertensive patients in rural China.
- In this four year blood pressure intervention program in rural China, the intervention, led by non-physician community health-care providers, significantly reduced systolic blood pressure and the risk of all-cause dementia.
- Serious adverse events were less frequent in the intervention group, indicating the safety of the approach.
The study conducted a cluster-randomized effectiveness trial to assess the impact of an intensive blood pressure (BP) lowering intervention on the risk of dementia among hypertensive patients in rural China. The research addressed a critical need in the medical community, given that dementia ranks as a leading cause of deaths and disability worldwide, yet effective interventions to prevent or delay its onset are currently lacking.
The study was conducted in 326 villages in rural China and included a total of 33,995 participants aged 40 years and older with untreated BP levels of 140/90 mmHg or higher (130/80 mmHg for those at high risk for cardiovascular disease or already taking antihypertensive medication) were recruited. The participants were divided into two groups: the intervention group, where non-physician community health-care providers led the initiative, and the control group receiving usual care. The intervention involved a stepped-care protocol implemented by trained nonphysician providers to achieve a systolic BP goal of <130 mmHg and diastolic BP goal of <80 mmHg, with supervision from primary care physicians.
The analysis followed an intention-to-treat approach, employing Poisson regression with robust error variance to determine the relative risk and associated 95% confidence intervals for dementia and secondary outcomes associated with the intervention. Stratification by village, town, county, and province was applied. At the end of the four-year study period, trained and certified neurologists, who were blinded to randomization assignments, conducted cognitive function assessments or screenings. The final diagnosis of all-cause dementia or cognitive impairment, no dementia was made by an expert adjudication panel, who were also blinded to which intervention the study participants were assigned.
After 48 months, the results demonstrated a significant reduction in both systolic and diastolic blood pressures in the intervention group compared to the usual care group. The net change in systolic BP was -22.0 mmHg, and the net change in diastolic BP was -9.3 mmHg, both statistically significant. Importantly, the primary outcome of dementia showed a significant decrease in the intervention group compared to the usual care group (1.12% vs. 1.31% per year). Additional cognitive outcomes, including adjudicated cognitive impairment, a composite outcome of dementia or cognitive impairment, and all-cause mortality, were also notably lower in the intervention group.
The study’s findings mark a milestone as the first large cluster-randomized trial demonstrating the effectiveness of BP lowering in reducing the risk of dementia in hypertensive patients. Furthermore, serious adverse events, such as deaths or hospitalizations, were less frequent in the intervention group, underscoring the safety of the approach.
The evidence supporting the effectiveness of intensive BP lowering in reducing the risk of dementia not only addresses a critical gap in current medical knowledge but also provides a practical and scalable intervention strategy. The involvement of non-physician community health-care providers adds a dimension of feasibility to the implementation of this approach. This study’s implications extend beyond hypertension management, offering a potential avenue for reducing the global burden of dementia through proactive cardiovascular care strategies. Further research and widespread implementation of this proven-effective intervention hold promise for transformative changes in both cardiology and neurology practices.
