Association of resting heart rate with cognitive decline and dementia in older adults: A prospective population‐based study

Background Resting heart rate (RHR) is easily assessed and predicts future risk of cardiovascular (CV) events. However, large‐scale population‐based studies investigating the relationship of RHR with dementia and cognitive decline are scarce. Method We analysed data from baseline dementia‐free participants of the population‐based Swedish National study on Aging and Care in Kungsholmen (n=2423, age ≥60 years, mean age 71 years, female 61%) who were regularly followed from 2001‐2004 through 2013‐2016. RHR was assessed using a 12‐lead ECG at baseline. Incident dementia was diagnosed following the DSM‐IV criteria and global cognitive function was assessed using Mini‐Mental State Examination (MMSE). We used Cox proportional hazard models and linear mixed‐effects models with random intercepts and slopes to investigate the associations of RHR with incident dementia and cognitive decline, respectively, while controlling for demographics (age, sex, and education), smoking, physical activity, CV risk factors, and existing cardiovascular diseases. Result During the 12‐year follow up period, 332 participants developed dementia. As a continuous variable, per 10‐bpm increase in RHR was significantly associated with 12% increased risk of dementia (multi‐adjusted hazard ratio [HR] 1.12, 95% CI 1.02, 1.23). As a categorical variable, the multi‐adjusted HR (95% CI) of dementia associated with RHR (bpm) of <60, 60‐69 (reference), 70‐79, and ≥80 were 1.00 (0.75, 1.33), 1.00 (reference), 1.19 (0.89, 1.59), and 1.47 (1.04, 2.06), respectively. The multi‐adjusted β‐coefficients (95% CI) of MMSE score associated with the four categories of RHR were 0.01 (‐0.05, 0.07), 0.00 (reference), ‐0.10 (‐0.16, ‐0.03), and ‐0.16 (‐0.24, ‐0,08), respectively. There was no statistical interaction of RHR with gender and APOE ε4 allele on dementia risk (P for interaction >0.1). Conclusion Higher RHR is associated with increased risk for dementia and greater cognitive decline independent of CV risk factors and related diseases in a general population of older adults.