Frequency, intensity and duration of physical activity is associated with frailty in older adults with cardiac aging

While cardiovascular aging and frailty are strongly associated in older adults, their mechanistic relationship and how physical activity, through its frequency, intensity, and duration, may influence their association remains unclear. A prospective community cohort of older adults without cardiovascular disease were studied cross-sectionally for cardiac structure and function via echocardiogram, dynamometer-derived handgrip strength, skeletal muscle measurements and physical activity questionnaires. Based on handgrip strength and cardiac aging, we derived four phenotypic groups:¹ Normal², Physical frailty without cardiac aging³, Cardiac aging without physical frailty, and⁴ Physical frailty and cardiac aging. Multinomial logistic regression was used to examine factors associated with cardiac frailty phenotypes, adjusting for physical activity characteristics, physical measurements, demographics, and cardiovascular risk factors. Amongst 592 participants, the prevalence in the four groups were 44.9%, 20.6%, 18.8%, and 15.7% respectively. Participants in group 1 were the youngest (64, IQR 22), while those in group 4 were the oldest (75, IQR 4.7). Higher frequencies of physical activity (once a week: RRR = 8.922, 95%CI 1.799, 44.250, p = 0.007; and 2-3 times a week: RRR = 3.873, 95%CI 1.036, 14.478, p = 0.044) were associated with Group 4 category. Higher intensity of physical activity indicated by heavy breath and sweat or near exhaustion (RRR = 0.081, 95%CI 0.017, 0.380, p = 0.001), and longer duration (> 1 h: RRR = 0.261, 95%CI 0.079, 0.869, p = 0.029) were associated with Group 4 category as well. More than half of community older adults had physical frailty with or without cardiac aging. Higher intensity and longer physical activity duration were associated with lower risks of cardiac aging in the presence of physical frailty, although frequency of once and two to three times a week was associated with higher odds. Physical activity frequency showed no significant association with risks of isolated cardiac aging or physical frailty. These results highlight the importance of tailoring physical activity characteristics based on cardiac frailty phenotypes for developing individualized preventive interventions. Trial registration: ClinicalTrials.gov Identifier: NCT02791139 (06/06/2016).