To investigate the interaction between leisure-time physical activity (LTPA) and sex on sleep quality among rural older adults in Chengdu.

Observational analysis was conducted based on data from a cluster randomized controlled trial. The Physical Activity Scale for the Elderly (PASE) was used to assess the level of LTPA; a higher PASE score indicates a higher level of LTPA. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality; a higher PSQI score indicates poorer sleep quality. A linear mixed model was used to analyze the interaction between LTPA and sex on sleep quality, and stratified and joint analyses were further conducted.

A total of 511 participants were included in this study, with a mean age of 70.94 years, of whom 284 were female. The interaction between LTPA and sex on sleep quality was significant (P=0.001). Stratified by LTPA level, female PSQI scores were significantly higher than those of males in the low, relatively low, and relatively high LTPA groups (low level: β=2.66, P=0.003; relatively low level: β=2.78, P<0.001; relatively high level: β=1.51, P=0.006). Stratified by sex, only in females did the relatively high and high LTPA groups have significantly lower PSQI scores compared with the low LTPA group (relatively high level: β=-0.61, P=0.050; high level: β=-0.98, P=0.003). Joint analysis showed that using the "low LTPA level + female" group as the reference, males had significantly lower PSQI scores than the reference group across all LTPA levels (all P<0.001), whereas females had significantly lower PSQI scores than the reference group only in the relatively high and high LTPA groups (relatively high level: β=-0.65, P=0.021; high level: β=-1.01, P<0.001).

There is a significant interaction between LTPA and sex on sleep quality among rural older adults in Chengdu. It is suggested that future sleep intervention programs should be tailored according to sex and LTPA level.