Association Between Sleep Disturbances and Frailty: Evidence From a Population-Based Study

Objective To explore the association between both self-reported quality and quantity sleep characteristics and frailty status in a large non–sex-specific population of older individuals in Greece. Design Cross-sectional study. Setting and Participants In total, 1984 older individuals (≥65 years old) were drawn from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). Measures Frailty was assessed using 3 different definitions, the Frailty Index (FI), the Tilburg Frailty Indicator (TFI), and the Groningen Frailty Indicator (GFI). Sleep quality was evaluated through the Sleep Index II, which includes 9 of the 12 self-reported items of the Medical Outcomes Study-Sleep Scale. To examine sleep duration, participants were asked to report on how many hours they slept each night during the past 4 weeks. Logistic regression models adjusted for multiple covariates were explored. Additional analyses, stratified by gender, adjusting for sleep-related medications and excluding participants diagnosed with dementia, were also performed. Results In total, 389 (20%), 619 (31.9%), and 608 (31.3%) participants were categorized as frail according to the FI, the TFI, and the GFI respectively. Sleep quality was significantly associated with frailty in all models. Even after adjusting for subjective sleep duration, compared with participants who subjectively reported high sleep quality, those with low sleep quality had 3.7, 2.6, and 2.5 more times to be frail as measured with FI, TFI, and GFI respectively. Regarding the associations between frailty and self-reported sleep duration, sex-specific associations were observed: prolonged sleep duration was associated with frailty in the subsample of male participants. Conclusions and Implications The present study shows a strong correlation between subjective sleep quality and frailty status, contributing substantial information to the growing literature demonstrating that sleep is associated with older people's overall health. Sleep complaints should not be underestimated, and older individuals who self-report sleep disorders should be further assessed for frailty.