Longitudinal relationship between sleep deficiency and pain symptoms among community-dwelling older adults in Japan and Singapore.

The association of sleep with pain is well documented among adult populations. Even though both sleep problems and pain are prevalent in older adults, the longitudinal and bidirectional relationship between sleep deficiency (i.e. insufficient and poor sleep) and pain is less well established. This study investigated the association between sleep deficiency and pain among community-dwelling adults aged 65 years and older across a 2- to 3-year period. We analyzed cross-country data from the Nihon University Japanese Longitudinal Study of Aging (N = 2888) and the Panel on Health and Aging of Singaporean Elderly (N = 2111). Sleep deficiency was operationalized as self-reported short sleep duration (<6 hours), frequent restlessness during the night, and/or non-restorative sleep. Pain was characterized in terms of any pain, multiple pain locations, and pain-related disability. Demographics, smoking, nap duration, depressive symptoms, chronic conditions, and body mass index were included as covariates. Baseline sleep deficiency was associated with any pain, multiple pain locations, and pain-related disability among older adults at follow-up, although differences by country of residence were observed. In Singaporeans, sleep deficiency predicted the new onset of any pain, and any pain also predicted the new emergence of sleep deficiency. Improving sleep of older adults may improve pain-related symptoms and help intervene on the vicious cycle of pain and sleep deficiency.