Alcohol Consumption and Physical Inactivity Mediate the Link Between Sleep Disturbance and Psychological Wellbeing in Older Adults: A 10-Year Follow-Up From the English Longitudinal Study of Ageing

Abstract

Importance: The level of optimal sleep often decreases with age, yet the mechanisms explaining the links with psychological wellbeing and other outcomes remain poorly understood. Very few studies (none in the United Kingdom) explored these associations in large, well-characterised groups of community-dwelling individuals. \n \nObjective: To investigate the mediating role of various lifestyle behaviours in the relationship between sleep and subsequent psychological wellbeing. \n \nDesign: A longitudinal analysis of the English Longitudinal Study of Ageing spanning over 10 years from wave 4 (2008-09) to wave 9 (2018-19), and mediating factors investigated at wave 5 (2010-11). \n \nSetting: English population-based sample. \n \nParticipants: The sample was comprised of 4,110 men and women aged 50 years living in England. \n \nExposures: Sleep duration, sleep disturbance (insomnia, difficulty falling asleep) and covariates were assessed at wave 4. \n \nOutcomes: Lifestyle behaviours (alcohol, smoking, physical inactivity, and low fruit & vegetable consumption) were assessed at wave 5. Depressive symptoms, quality of life, and life satisfaction were measured with well-established scales at wave 9. \n \nResults: During a 10-year follow up, compared with optimal baseline sleep (7-8 hours), short sleep (<6 hours) predicted subsequent elevated depressive symptoms (odds ratios (OR) = 1.44, 95 % CI = 1.09, 1.90), independent of all covariates. In addition, compared with no sleep disturbance, some sleep disturbance and disturbed sleep were predictive of elevated depressive symptoms (OR = 1.33, 95 % CI = 1.01, 1.76 and OR = 1.77, 95 % CI = 1.31, 2.39) and poor quality of life (OR = 1.36, 95 % CI = 1.13, 1.64 and OR = 1.67, 95 % CI = 1.35, 2.07), respectively. Alcohol consumption and physical inactivity showed partial mediating effects in the relationship between sleep disturbance and poor quality of life with 7.8% and 5.2%, respectively. \n \nConclusions and Relevance: Too short sleep and sleep disturbance could adversely impact psychological wellbeing, while sleep disturbance could also impact the quality of life. Although some lifestyle behaviours such as alcohol consumption and physical inactivity partially mediate the relationship between some sleep disturbance and poor quality of life, they seem to play a very limited part in the causal process. \n \nFunding Information: This research was supported by the National Institute on Aging (grants R01AG7644-01A1 and R01AG017644). The English Longitudinal Study of Ageing is funded by the National Institute on Aging (Grant R01AG7644) and by a consortium of UK government departments coordinated by the Economic and Social Research Council (ESRC) and the Office for National Statistics. \n \nDeclaration of Interests: None. \n \nEthics Approval Statement: Ethical approval for each one of the ELSA waves was granted from the National Research Ethics Service (London Multicentre Research Ethics Committee (MREC/01/2/91) (http://www.nres.npsa.nhs.uk). All participants provided informed consent at every wave.