Abstract
Introduction: Irregular sleep is increasingly recognised as a correlate of adverse health outcomes, including cardiovascular disease, metabolic disorders, and all-cause mortality in large population-based studies. However, the association of irregular sleep, on quality of life (QoL) and mental health is yet to be established in large population-based studies particularly those that are representative of community populations. We aimed to address these associations in middle-aged adults from the Raine Study who are representative of the Australian community.
Method: Measures of sleep regularity, assessed by the sleep regularity index (SRI), were obtained from 808 middle-aged participants in the Raine Study (age [range], 57[42-82]; female=58%). SRI was calculated using actigraphy data from at least five consecutive 24-hour periods and SRI scores categorised by quartiles (lowest, irregular sleepers; middle two, mildly irregular sleepers; highest, regular sleepers). The relationships were determined between SRI; physical and mental component summary scores of QoL (Short Form Health Survey-12); depression symptoms (patient health questionnaire, PHQ9); and anxiety symptoms (generalised anxiety disorder, GAD7) using logistic regression adjusted for age, sex and shift work status. Specifically, adjusted logistic regression were used to examine associations between SRI groups with QoL (poor mental and physical component summary scores dichotomised by median) and depression (PHQ9 >9) and anxiety symptoms (GAD7 >9).
Results: Relative to regular sleepers, irregular sleepers had 1.6 (95%CI, 1.1-2.3) and 1.9-times (95%CI, 1.3-2.9) increased odds of poor mental and physical component summary scores of QoL, respectively. Irregular sleepers had increased risk of depression (3.9 (95%CI, 1.8-9.6)) and anxiety (2.84 (95%CI, 1.40-6.16)) symptoms relative to regular sleepers. There was no significant association of mildly irregular sleep with QoL and mental health outcomes relative to regular sleepers.
Conclusion: Behavioural interventions aimed at improving the regularity in sleep may be a feasible target to support improved QoL, depression, and anxiety symptoms in middle-aged adults.
Conflict of Interest: Yes- AJKP has received research funding from Delos and Versalux, and he is a director of Circadian Health Innovations PTY LTD.