Sleep disturbance and cognitive trajectories among older adults with subjective cognitive decline: the roles of age and sleep treatment

Study Objectives Growing evidence indicates that subjective cognitive decline, characterized by self-reported cognitive deterioration without measurable cognitive impairment, may be an early indicator of Alzheimer’s Disease. This study investigated the association between baseline sleep disturbance and a 10-year trajectory of global cognitive performance in adults with subjective cognitive decline and examined if this association was moderated by age (50–64 years and≥65 years) and sleep treatment. Methods Using six waves (2010–2020) of the Health and Retirement Study, we included individuals aged ≥50 years who reported subjective cognitive decline but had no objective cognitive impairment at baseline (2010) and had the final wave of cognitive data (N =1372). Latent growth curve modeling was employed to examine the associations between self-reported sleep disturbance and cognitive trajectories from 2010 to 2020, controlling for sociodemographic and health-related factors. Results In the full sample, baseline sleep disturbance was not significantly associated with cognitive change. However, a significant interaction between sleep disturbance and age group was found (β=−0.04, 95% confidence interval [−0.08, −0.003]). Stratified analyses showed that poorer sleep was associated with faster cognitive decline in those aged ≥65 years (β=−0.04, 95% confidence interval [−0.07, −0.005]; n=558), and using sleep treatment was associated with a reduced impact of sleep disturbance on cognitive decline (β=0.31, 95% confidence interval [0.02, 0.60]). These associations were not significant in those aged 50–64 years (n = 814). Conclusions Sleep disturbance was an independent risk factor of future cognitive decline in older adults ≥65 years with subjective cognitive decline. Sleep treatment may mitigate this decline, offering a potential intervention strategy.