Short sleep duration intensifies effects of frailty on depressive symptoms

Short sleep duration appeared to increase the effects of frailty on depressive symptoms, according to results of a prospective cohort study published in Journal of the American Geriatrics Society.

“Although sleep disturbance and frailty have been shown to exert independent effects on depression, little has been known about their combined effects on depression,” Huiying Liu, PhD, of the department of sociology at Central South University in China, and colleagues wrote. “Particularly in older adults, sleep disturbance and frailty often coexist and are interrelated, and there is evidence that the frailty-depression and sleep-depression associations could be explained by shared neural or physio mechanisms (eg, chronic inflammation, circadian rhythms and hypothalamic–pituitary–adrenal axis [HPA] dysregulation of hormones). While most research has evaluated the effect of either frailty or sleep duration on depression, it remains unclear that whether the combined effect of frailty and sleep duration is greater than the sum of its parts.”

The researchers sought to evaluate the effects of baseline and changes in frailty states on subsequent depressive symptoms and whether sleep duration affected these symptoms. They analyzed data of 5,026 community-dwelling adults aged 60 or older at baseline who participated in the 2011 and 2013 waves of the China Health and Retirement Longitudinal Study. Further, they used the physical frailty phenotype scale to measure frailty and the 10-item Center for Epidemiologic Studies Depression Scale to measure levels of depressive symptoms. They examined the effects of baseline and transitions in frailty states on subsequent depressive symptoms using the generalized estimating equations, adjusted for numerous confounding variables.

Results showed an association between baseline prefrail and frail states and higher subsequent level of depressive symptoms 2 years later. The researchers noted an association between transitioning into prefrail/frail and a higher subsequent level of depressive symptoms among individuals who were robust at baseline; short sleep duration accelerated this association. Transitioning into frail was linked to higher levels of depressive symptoms among individuals who were prefrail at baseline; those who reported short sleep duration exhibited this association more strongly.

“In accordance with the elevated levels of depression with worsening frailty, more clinical attention should be paid to the care of frail and prefrail older persons,” Liu and colleagues wrote. “The moderating effects of short sleep duration implied that several interventions that targeted on sleep disturbances, such as exercise training and mindfulness-based stress reduction, could be implemented to alleviate the effects of frailty on psychological well-being.”