This study builds upon our group's work where we characterized cardiovascular and skeletal muscle structure and function of community-based older adults. In this proposal, we will identify n=100 participants with cardio-sarcopenia phenotype. Comparing between participants with baseline low versus high levels of physical activity, we will investigate temporal changes in their cardiovascular, skeletal muscle, biomarkers and BMI data, over a six- to twelve month period. Physical activity will include subjective self-reported physical activities and objective measures of aerobic capacity. Their physical activity levels will be verified bi-monthly via physical activity and cardiac health application that measures these markers. Pertinent fluctuations in diet, lifestyle, risk factors and biomarkers will also be recorded.
The use of surrogate markers such as body mass index (BMI) as a target outcome of physical activity may not be appropriate in older adults who are at risk of muscle sarcopenia. In the presence of sarcopenia, reductions in body weight may lead to lower BMI values. We have previously found deleterious changes in cardiac structure and function among sarcopenic older adults, raising a possible biological syndrome of 'cardio-sarcopenia'. In this study, we will investigate the impact of physical activity on temporal changes in cardiac and skeletal muscle , and BMI, over six- to twelve month period, on older adults with this syndrome. By targeting the cardio-sarcopenic phenotype as a modifiable risk factor that may be altered by physical activity, the results will provide new knowledge into retarding deleterious consequences of cardiovascular ageing. This new target challenges the paradigm of using BMI as an anthropometric marker in health prevention. If proven, this will dramatically change primary prevention targets among older adults, justifying the use of cardio-sarcopenia as a rational anthropometric target.