Preliminary report; Comparison of the circadian rest-activity rhythm of elderly Japanese community-dwellers according to sarcopenia status

ABSTRACT

We investigated in a preliminarily study the circadian rest-activity rhythm of elderly Japanese community-dwellers according to sarcopenia status based upon the 2019 updated classification criteria of the Asian Working Group for Sarcopenia. A total of 30 participants were recruited from a single rehabilitation center in northern Japan between July and November 2019. The rest-activity rhythm of those with and without sarcopenia was assessed for 7 consecutive 24 h spans by wrist actigraphy in free-living condition and gait performance in the clinic. As group phenomena, the circadian activity rhythm of the sarcopenia cohort (N = 11) was of significantly lower amplitude and more fragmented than the non-sarcopenia cohort (N = 19). The nonparametric circadian rest activity (RAR) parameters of intra-daily variability (IV), relative amplitude (RA), most active 10-h span (M10), and the least active 5-h span (L5), but not interdaily stability (IS), of the sarcopenia group, were all significantly worse than those of the non-sarcopenia group. Gait performance for the sarcopenia group correlated strongly with the fragmentation and altered amplitude of the RAR. These preliminary findings motivated future longitudinal investigation both to improve the detection of sarcopenia in community dwelling elderly and to inform novel preventive or rehabilitative strategies.