In a recent research article featured in Alzheimer’s and Dementia, a team of researchers delved into the impact of intense physical exercise (VPA) on the likelihood of developing mild cognitive impairment (MCI) and possible dementia in individuals with elevated hypertension risk.
Background
Hypertension, which affects around one-third of adults globally, significantly raises the chances of developing cardiovascular diseases (CVDs) and dementia, with a projected impact on over 175 million individuals by 2050. As a crucial alterable risk factor for cognitive issues such as MCI, Alzheimer’s, and vascular dementia, hypertension’s influence on cognitive well-being is substantial.
The Systolic Blood Pressure Intervention Trial Memory and Cognition in Decreased Hypertension (SPRINT MIND) research emphasized that rigorous blood pressure management can help prevent cognitive decline.
Although physical activity (PA) also aids in slowing cognitive deterioration, the ideal amount and intensity for maximal benefits remain uncertain. This underscores the need for further investigation to identify the most effective PA regimen for lowering the risk of cognitive impairment in high-risk individuals with hypertension.
About the study
In this retrospective analysis, data from the SPRINT MIND study, a component of the SPRINT trial (NCT01206062), were utilized. The study cohort consisted of 9361 nondiabetic adults aged 50 and above from the United States (U.S.) with hypertension and a high risk of cardiovascular disease (CVD).
The trial investigated the effects of intensive (target systolic blood pressure (SBP) <120 mm Hg) versus standard (target SBP <140 mm Hg) blood pressure management on various health outcomes, such as myocardial infarction, stroke, heart failure, and cognitive function. Due to the remarkable benefits observed in the intensive treatment group, the trial was prematurely discontinued.
This analysis specifically examined how intensive blood pressure control impacted the incidence of mild cognitive impairment (MCI) and likely dementia. Data originated from the National Heart, Lung, and Blood Institute, with all participants granting informed consent. Cognitive evaluations were carried out at baseline, 2 years, 4 years, and the conclusion of the study.
Participants were categorized into low (<1 session/week) and high (≥1 session/week) vigorous physical activity (VPA) groups. Individuals with significant physical restrictions or incomplete data were excluded, resulting in a final cohort of 7670 participants.
The statistical analysis employed Cox proportional hazards models to explore the relationship between VPA and cognitive outcomes, with sensitivity analyses adjusting for competing risks and additional underlying conditions. The analyses were performed using SAS and R software.
Study results
On the whole, the average age of the participants was 70.0 years (Standard deviation (SD) 9.2), with 34.5% being female and 59.4% identified as White. Notably, 59.3% of the participants reported engaging in vigorous physical activity at least once a week, categorizing them into the high VPA group.
Compared to individuals in the high VPA category, those in the low VPA group were more likely to be female, current smokers, less educated, have a higher body mass index (BMI), a higher incidence of chronic kidney disease (CKD), and require more antihypertensive medications.
During a maximum follow-up period of 7.4 years (median [25%, 75%] = 4.5 [3.6, 5.9] years), there were 570 confirmed cases of mild cognitive impairment (MCI), 273 cases of probable dementia, and 759 instances of the combined MCI/probable dementia outcome.
The rates of MCI, probable dementia, and the combined MCI/probable dementia outcome were lower in the high VPA group compared to the low VPA group, with percentages of 6.5% versus 8.8%, 3.1% versus 4.3%, and 8.7% versus 11.7%, respectively.
Similarly, the event rates per 1,000 person-years were lower for the high VPA group: 13.9 versus 19.7 for MCI, 6.3 versus 9.0 for probable dementia, and 18.5 versus 25.8 for the combined outcome.
The cumulative incidence (CI) rates of cognitive impairment were significantly higher in the low VPA group. After adjusting for sociodemographic factors, the high VPA group exhibited a notably reduced risk of MCI (Hazard ratio (HR) = 0.80, 95% CI: 0.67–0.95) and combined MCI/probable dementia (HR = 0.82, 95% CI: 0.70–0.94) compared to the low VPA group.
The link between higher VPA and a decreased risk of probable dementia approached significance (HR = 0.80, 95% CI: 0.63–1.02). Further adjustments for additional variables did not affect these associations. Notably, there was marked variability by age and race, with more pronounced correlations observed in individuals under 75 and Black participants.
The participants included in the analysis shared similarities in age, blood pressure, and randomization to the intensive SBP lowering trial arm when compared to those who were excluded. Excluded individuals were more inclined to be female, have lower educational attainment, be current smokers, and have a higher prevalence of depression, CKD, and CVD.
Even when considering the competing risk of mortality, the HR remained consistent with the main findings. Adjustments for additional comorbidities and excluding early MCI cases did not significantly alter the results, indicating a consistent association between different self-reported frequencies of VPA and a reduced risk of cognitive impairment outcomes.
Conclusions
In conclusion, individuals who participated in vigorous physical activity (VPA) exhibited a decreased risk of mild cognitive impairment (MCI) and probable dementia compared to those who engaged in VPA less frequently, irrespective of the intensity of systolic blood pressure (SBP) treatment.
The findings remained stable across different subcategories, although there were slight differences based on age and ethnicity. The research underscores VPA as a promising, low-risk strategy to safeguard cognitive abilities in individuals with hypertension.
Journal reference:
- Kazibwe R, Schaich CL, Muhammad AI, et al. (2024) Effect of vigorous-intensity physical activity on incident cognitive impairment in high-risk hypertension. Alzheimer’s Dement. doi:https://doi.org/10.1002/alz.13887. https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.13887
