Monitoring sarcopenia and frailty with wearable devices: findings from the PRO-EVA study
Sarcopenia. Physical Activity. Heart Rate Variability.
Introduction: Physical activity (PA) is associated with lower fat mass and increased muscle function, meaning it can significantly reduce the risk of sarcopenia and frailty syndrome. Physical impairment is a critical determinant of disability and death in the elderly, and autonomic dysfunction, which promotes changes in the behavior of cardiovascular variables, can further aggravate age-related decline in bodily capacity and function. Objective: To analyze how measures of physical activity and cardiovascular behavior, obtained through a wearable device (smartwatch), are related to sarcopenia and frailty syndrome in community-dwelling elderly people. Methods: Observational study, which included community-dwelling elderly people of both sexes, aged 60 years or over, duly registered in the Basic Health Units in the municipality of Parnamirim/Rio Grande do Norte. The elderly were initially assessed using the following instruments: Sociodemographic and clinical data form; Léganes Cognitive Test; Anthropometric assessment (Body Mass Index and calf circumference); Frailty investigation based on Fried's criteria; Handgrip dynamometry to define probable sarcopenia; and Skeletal Muscle Mass Index. Then, study participants received a Fitbit© smartwatch, model Inspire HR, and were instructed to use it for a period of 7 consecutive days on the non-dominant upper limb. Using remote monitoring, the following variables were evaluated: PA level, number of steps, calories, distance covered, average heart rate and heart rate variability (HRV). Preliminarily for this qualification, the data were analyzed using descriptive measures and for inferential statistics the Mann-Whitney test and the Kruscal-Wallis test were applied. Results: The sample consisted of 178 elderly people with a median age of 71 years (76-66), the majority of whom were female (60.1%). 40.3% of participants had probable sarcopenia, 71.2% were classified as pre-frail and 12.8% as frail. It was identified that the time spent in moderate PA (MPA) differed significantly between the sarcopenia and non-sarcopenic groups (p=0.02). Differences were also observed between the time involved in both light PA and MPA between the frail, pre-frail and non-frail groups, with p<0.001 for both classifications. Total HRV, measured using the SDNN index, differed significantly between the sarcopenia and non-sarcopenic groups (p=0.007) and frail, pre-frail and non-frail groups (p=0.02). Conclusions: PA and HRV measurements obtained from a wearable device were useful to identify differences between sarcopenic and non-sarcopenic individuals, as well as between frail, pre-frail and non-frail individuals. These findings may suggest that remote monitoring via a wearable device can support the diagnosis and monitoring of sarcopenia and frailty in community-dwelling elderly people.