LAUSR

OBJECTIVE Poor sleep quality and reduced sleep duration impact over half of older adults and are associated with adverse health outcomes, such as multiple chronic conditions (multimorbidity) and reduced longevity. Our objective was to examine the relationship between sleep behaviours and multimorbidity in Canada. METHODS We analysed data from the Canadian Longitudinal Study on Aging (CLSA), a cross-sectional national health survey of community-dwelling adults over the age of 45 years. A total of 30,011 participants had physiological and psychosocial data collected at baseline. Sleep measures included self-reported sleep duration (short: <6 h; normal: 6-8 h; long: >8 h) and sleep quality (dissatisfied/very dissatisfied; neutral; satisfied/very satisfied). Multimorbidity was defined using two definitions (public health and primary care) and two cut-points (2 or more and 3 or more chronic conditions). RESULTS Approximately 70% were living with multimorbidity using the primary care definition (females: 67.9%; males 57.9%), whereas approximately 30% were living with multimorbidity using the public health definition (females: 30.9%; males: 24.0%). Adjusted analyses indicated that the odds of multimorbidity were higher for participants who selfreported either short or long sleep duration, as well as dissatisfaction with sleep quality. Associations were stronger among younger age groups (45-54 years and 55-64 years). CONCLUSIONS Disrupted sleep may be a risk factor for multimorbidity across sexes and age groups. It is necessary to understand the potential impact of sleep on the risk of multimorbidity to inform both clinical and public health guidelines for the prevention and management of this major health issue.