0769 Sleep Quality in Midlife Is Associated with Mobility and Balance in Later Life in the Wisconsin Sleep Cohort

Abstract Introduction Cross-sectional studies suggest that poor sleep quality predicts worse performance on tests of mobility in older persons; however, little is known about how objectively-assessed sleep quality in midlife is associated with declines in mobility and balance later in life. We examined the association of three objectively-assessed sleep quality measures in midlife adults as predictors of measures of mobility and balance assessed, on average, 8 years later in participants of the Wisconsin Sleep Cohort study. Methods Wisconsin Sleep Cohort participants (n=576, 47% female) had sleep (in-laboratory polysomnography) studies to assess sleep quality at midlife and, on average 8 years later, Timed Up and Go (TUG) tests to assess mobility and balance. There were some participants with repeat visits (n=378) yielding a total data set of 945 data points. Mean age (SD) at the baseline sleep study visits was 61(8) years. Sleep quality variables include percent N3 and percent REM sleep and sleep efficiency. The Timed Up and GO (TUG) test measures time in seconds to complete a walking task with 4 different variations: walking only, walking with an obstacle at midpoint, walking while counting backwards by 3’s, and walking with both an obstacle and while counting backwards by 3’s. Models were adjusted for age, sex, body mass index, total sleep time, and self-reported habitual sleep time. PROC MIXED in SAS was used to account for repeated measures. Results Less percent N3 sleep at baseline was significantly associated with reduced performance (greater time to complete) on 3 of the 4 variations of the TUG test, performed on average, 8 years after sleep assessment (all p< 0.05 in adjusted models). A similar pattern of associations was observed with REM and sleep efficiency (less REM sleep and lower sleep efficiency were associated with reduced TUG performance), although these associations did not reach statistical significance. Conclusion Adequate sleep quality across midlife years may be an important modifiable contributor of improved mobility and balance in later life. Support (if any) This work was supported by the National Heart, Lung, and Blood Institute (R01HL62252) and the National Institute on Aging (R01AG058680) at the US National Institutes of Health.