A recent study has found that lowering blood pressure may help protect the brain from small vessel disease, a condition that affects the small blood vessels and surrounding tissue in the brain. The study, conducted by researchers at Massachusetts General Hospital and the University of Texas Health in San Antonio, used magnetic resonance imaging (MRI) scans to compare the brains of participants in the SPRINT clinical trial. The trial involved over 9,300 people aged 50 and older with high blood pressure and increased risk of cardiovascular disease.
The SPRINT trial was stopped early in 2015 after the group targeting a lower blood pressure goal showed lower rates of heart attacks, strokes, heart failure, and other cardiovascular events, as well as reduced mortality from all causes. For the new analysis, researchers used three markers from MRI scans to create a composite index measuring the progression of small vessel disease in the brain. Of the 663 participants with complete initial measurements, 442 had follow-up scans, with an average age of around 68 and a 3.9-year interval between scans.
The study found that the group targeting a lower blood pressure goal of less than 120 mmHg had a 16.9% slower progression of small vessel disease compared to the group targeting a goal of less than 140 mmHg. Additionally, the actual reduction in blood pressure was associated with a greater slowing of brain changes. Compared to those with increased blood pressure, participants with a 10 mmHg reduction had a 21.2% slower disease progression, those with a 10-20 mmHg reduction had a 26.3% slower progression, and those with a 20 mmHg or greater reduction had a 39.4% slower progression.
The researchers emphasized that these percentages reflect a slowing of disease progression as seen on MRI scans and do not necessarily translate to a reversal of existing brain damage or a reduction in cognitive decline or stroke risk. The study excluded individuals with diabetes, previous stroke, dementia, or advanced kidney disease, so the generalizability of the findings to these populations is uncertain.
The study's findings suggest that lowering blood pressure may have a beneficial effect on small vessel disease in the brain. However, further research is needed to confirm these results and determine the optimal blood pressure goal for brain health. The researchers also noted that the study did not investigate the potential mechanisms by which lowering blood pressure may affect small vessel disease.
Small vessel disease is a major cause of cognitive decline and dementia, and the study's findings have important implications for the prevention and treatment of these conditions. The researchers suggested that the results may have significant public health implications, given the high prevalence of hypertension and small vessel disease in the population.
The study's lead author noted that the findings provide new evidence for the benefits of lowering blood pressure in protecting the brain. The researchers plan to conduct further studies to investigate the relationship between blood pressure and small vessel disease and to determine the optimal blood pressure goal for brain health.
Key points
- Lowering blood pressure may slow progression of small vessel disease in the brain
- Study used MRI scans to compare brain changes in participants with different blood pressure goals
- Findings have implications for prevention and treatment of cognitive decline and dementia
