A sizable fraction of sarcopenia, the loss of muscle mass and strength with age, is avoidable. Not all of it, of course, at least not without advances in therapies targeting the underlying mechanisms of aging. But it is in part the consequence of a lack of physical activity, with other contributions arising from diet, changes to the gut microbiome, and chronic inflammation. There is extensive data on the ability of structured exercise programs, such as strength training, to reverse measures of sarcopenia in older individuals. A more comprehensive set of lifestyle changes is assessed in this study, with varying outcomes. Physical activity still appears to come out ahead.
Few studies have comprehensively described changes in blood biomarkers of the physiological responses underlying sarcopenia reduction associated with lifestyle interventions. In this study, we performed secondary analyses of data in a randomized controlled trial of multi-domain lifestyle interventions (6-month duration physical exercise, nutritional enrichment, cognitive training, combination and standard care control) among 246 community-dwelling pre-frail and frail elderly, aged ≥65 years, with and without sarcopenia.
We observed that multi-domain physical, nutritional, and cognitive interventions among pre-frail and frail older adults were associated with favorable changes in sarcopenia and blood biomarkers underlying the muscle mass and physical functional response to intervention. As previously reported, the data are highly consistent with previous studies in showing that physical exercise alone or in combination with cognitive and nutritional intervention was most efficacious in improving muscle mass, lower limb strength, and gait speed. The physical exercise in this study was of moderate and gradually increasing intensity and well tolerated with high adherence rate (85%).
Perhaps unsurprisingly, there was limited effect observed with nutritional intervention delivered with a traditional oral nutrition supplement and not with a formulation with high content of leucine or whey protein or vitamin D, which have been shown in more recent studies to increase muscle mass and muscle function in sarcopenic and malnourished older patients.
Chronic low-grade inflammation associated with oxidative stress is believed to be a major underlying mechanism of aging and aging-related diseases including sarcopenia. Inflammatory markers such as CRP and IL-6 are reported to be associated with decreased muscle mass and strength, and the reduction of inflammation is believed to directly or indirectly ameliorate age-related muscle loss. In the present study, inflammatory levels are observed to be reduced especially by combined intervention, as evidenced by the significant drops in CRP and TNF-α levels. However, the levels of these inflammatory markers were not associated with sarcopenia status or reduction. Thus, the reduction of inflammation may not be the primary underlying mechanism of the response of sarcopenic elderly to lifestyle interventions.