independent of the presence of cardiovascular disease (CVD) risk factors, new research shows.
“RHR is easy to measure and might be used to identify older people potentially at high risk of dementia and cognitive decline for early interventions,” Yume Imahori, MD, PhD, with the Aging Research Center, Karolinska Institutet, Stockholm, said in an interview.
“Health care professionals should be aware of potential cognitive consequences associated with elevated RHR in older people and may advise older people with high RHR to have a follow-up assessment of cognitive function,” Dr. Imahori said.
The study was published online Dec. 3, 2021, in Alzheimer’s & Dementia.
Heart-brain connection
The findings are based on 2,147 adults (62% women) aged 60 years and older (mean age, 70.6 years) from the population-based Swedish National Aging and Care in Kungsholmen (SNAC-K) study. All were free of dementia at baseline and were followed regularly from 2001-2004 to 2013-2016.
The average RHR at baseline was 65.7 bpm. Individuals in higher RHR groups were older, less educated, and were more likely to be smokers and sedentary and to have hypertension. There were no differences among RHR groups in the prevalence of CVD at baseline.
During a median follow-up of 11.4 years, 289 participants were diagnosed with dementia.
In the fully adjusted model, participants with RHR of 80 bpm or higher had a 55% increased risk of developing dementia, compared with peers with lower RHR of 60 to 69 bpm (hazard ratio, 1.55; 95% CI, 1.06-2.27).
“This association was not due to underlying cardiovascular diseases such as atrial fibrillation and heart failure, which is important because elevated RHR is often related to heart disease,” Dr. Imahori said in an interview.
Regarding cognitive function, Mini-Mental State Examination scores declined over time during the follow-up period in all RHR groups, but participants with RHR 70-79 and 80+ bpm had a greater decline, compared with those with lower RHR of 60-69 bpm.
Dr. Imahori said these findings are in line with data from the U.S. Atherosclerosis Risk in Communities study linking elevated RHR of 80+ bpm in midlife to dementia and cognitive decline in late life.
Public health implications
Reached for comment, Claire Sexton, DPhil, Alzheimer’s Association director of scientific programs and outreach, said this study adds to the “growing body of research showing the health of the heart and brain are closely connected. However, this study only shows a correlation between resting heart rate and cognition, not causation. More research is needed.
“Evidence shows that other risk factors for cardiovascular disease and stroke – obesity, high blood pressure, and diabetes – negatively impact your cognitive health,” Dr. Sexton said in an interview.
“The Alzheimer’s Association believes the conversation about heart health management is something everyone should be having with their doctor,” she said.
“There are things you can do today to lower your risk for cardiovascular disease, including regular exercise and maintaining a healthy diet. Improving your heart health is an important step to maintaining your brain health as you age,” Dr. Sexton added.
SNAC-K is supported by the Swedish Ministry of Health and Social Affairs and the participating county councils and municipalities and in part by additional grants from the Swedish Research Council and the Swedish Research Council for Health, Working Life and Welfare. Dr. Imahori and Dr. Sexton disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.