Sleep disturbances in adults with frailty and sarcopenia

Purpose Several epidemiological studies have reported an age-related increase in the prevalence of sleep disturbances. This study aims to investigate the relationship between sleep and sarcopenia/frailty in older adults and clarify issues that remain to be addressed in future studies. Design/methodology/approach PubMed was searched for relevant studies with the following keywords in the title: "sleep" and "sarcopenia" or "sleep" and "frailty." A total of 15 studies published in English between 1998 and 2018 were reviewed. Findings Among the four studies that examined the relationship between sarcopenia and sleep, two reported that long or short sleep duration increased the risk of sarcopenia and this association was more pronounced in women than men. Among the seven studies examining the relationship between frailty and sleep, four reported that higher Pittsburgh Sleep Quality Index (PSQI) scores were associated with an increased risk of frailty. Practical implications Most previous studies have focused on interventions targeting a single area such as muscle strength or exercise habits, in older adults at risk for frailty. The results suggest that interventions targeting improved sleep may positively impact the maintenance of muscle strength. Originality/value The literature review revealed that too much or too little sleep increases the risk of sarcopenia in older adults. Further, sleep deprivation, greater night-time wakefulness and reduced sleep quality increase the risk of frailty. Interestingly, the risk of mortality is increased in individuals with daytime functional disorders such as excessive drowsiness or napping habits.