Bidirectional Relationships Between Sleep Quality and Cognitive Function in Older Chinese Adults: Observational Analysis of SAWA Trial

Purpose To examine the bidirectional relationships between sleep quality and cognitive function in older Chinese, and further examine the sex differences in the relationships using the random intercept cross-lagged panel model. Design A secondary observational analysis of a physical activity clustered randomized controlled trial (The Stay Active While Aging). Setting Eight villages in Sichuan, China. Subjects A total of 511 adults aged 60 or older. The response rate was 97.3%. Measures The Pittsburgh Sleep Quality Index was used to examine sleep quality. Cognitive function was assessed by the Telephone Interview for Cognitive Status. Results The mean age was 71.0 (SD, 5.710) years and 227 (44.4%) were men. Sleep quality in the previous wave was associated with cognitive function in the subsequent wave (β = −0.135, [95%CI -0.244 to −0.026], wave 2 to 3; β = −0.108, [95%CI -0.204 to −0.013], wave 4 to 5). Cognitive function in the previous wave was associated with sleep quality in the subsequent wave (β = −0.404, [95%CI -0.566 to −0.242], wave 3 to 4; β = −0.224, [95%CI -0.392 to −0.055], wave 4 to 5). Such relationships were significant only in women. Conclusions There were bidirectional relationships between sleep quality and cognitive function in older adults, especially in women. Future cognition interventions may find it helpful to improve sleep quality, and vice versa, particularly in women.