Independent and joint associations of cardiorespiratory fitness and lower-limb muscle strength with cardiometabolic risk in older adults

The aim of this study was to investigate the independent and joint associations of low cardiorespiratory fitness and lower-limb muscle strength with cardiometabolic risk in older adults. A total of 360 community-dwelling older adults aged 60-80 years participated in this cross-sectional study. Cardiometabolic risk was based on the diagnosis of Metabolic Syndrome and poor Ideal Cardiovascular Health according to the American Heart Association guidelines. Cardiorespiratory fitness and lower-limb muscle strength were estimated using the six-minute walk and the 30-second chair stand tests, respectively. Participants in the 20th percentile were defined as having low cardiorespiratory fitness and lower-limb muscle strength. Poisson's regression was used to determine the prevalence ratio (PR) and 95% confidence intervals (CI) of Metabolic Syndrome and poor Ideal Cardiovascular Health. Participants with low cardiorespiratory fitness alone and combined with low lower-limb muscle strength were similarly associated with a higher risk for Metabolic Syndrome (PR 1.27, 95% CI 1.09-1.48, and PR 1.32, 95% CI 1.10-1.58, respectively), and poor Ideal Cardiovascular Health (PR 1.76, 95% CI 1.25-2.47, and PR 1.65, 95% CI 1.19-2.28, respectively). Low lower-limb muscle strength alone was not associated with a higher risk for either Metabolic Syndrome or poor Ideal Cardiovascular Health (PR 1.23, 95% CI 0.81-1.87, and PR 1.11, 95% CI 0.89-1.37, respectively). Low cardiorespiratory fitness alone or combined with low lower-limb muscle strength, but not low lower-limb muscle strength alone, was associated with a higher cardiometabolic risk in older adults. The assessment of physical fitness may be a "window of opportunity" to identify youngest-old adults with a high cardiovascular disease risk.