In the study, researchers included individuals from the population-based Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Data of demographics, physical activity, medication use, serum total cholesterol, APOE alleles, and diagnosis of hypertension, diabetes, and cardiovascular diseases were collected.
RHR was obtained through echocardiogram (ECG) and categorized into less than 60, 60-69, 70-79, and more than 80 beats per minute. Researchers assessed global cognitive function and dementia diagnosis at each visit using the Mini-Mental State Examination (MMSE) and the DSM-IV, respectively. The study excluded individuals without dementia. Researchers conducted follow-ups with individuals for 2001-2004 to 2014-2016.
Mean MMSE score of participants (n=2147 aged 70.6±8.9 years 62% women) was 29.0±1.2 and average RHR was 65.7±10.9 beats per minute.
Participants with a RHR exceeding 80 beats per minute had a 55% increased risk of developing dementia in follow-up (mean 11.4 years per person, 289 individuals diagnosed with dementia) compared with those with a RHR of 60 to 69 beats per minute.
Participants with an RHR of at least 70 had a greater decline in MMSE compared with patients with RHR 60 to 69 bpm. These associations remained following exclusion of patients with cardiovascular disease (CVD) at baseline. Patients with CVD experienced a quicker cognitive decline in MMSE scores compared with other patients.
In sensitivity analyses, patients with an RHR lower than 50 beats per minutes had a higher risk of dementia in Model 1 (adjusted for age, sex, and education) and Model 2, which further adjusted for the behavioral risk factors of smoking, physical activity, and body mass index (BMI).
Limitations of this study include, among others, that while investigators could adjust for a range of potential confounders, residual confounding might still play a role due to imperfect measurements of confounders.
“While our findings merit further confirmation in different cohorts, future intervention studies to manage high RHR may result in novel preventive strategies of cognitive aging,” researchers said.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Imahori Y, Vetrano DL, Xia X, et al. Association of resting heart rate with cognitive decline and dementia in older adults: a population-based cohort study. Alzheimer’s & Dementia. Published online December 3, 2021. doi:10.1002/alz.12495