A 25-year-long observational study, recently published in the journal, PLOS Medicine, reported that less than 5 hours of sleep at night is associated with ≥30% increased risk of multiple chronic diseases such as diabetes, coronary heart disease, heart failure, stroke, chronic kidney disease, etc., in the middle-aged and elderly individuals.
This study included participants from the Whitehall II cohort study. Sleep duration data on 7,864 individuals at age 50, 60, and 70 years were analyzed over a follow-up period of 25 years to determine the association between the duration of sleep and the incident risk of first chronic condition, multimorbidity, and death. The study results are summarized below (see graphic):
- Short duration of sleep (≤5 h):544 (6.9%) subjects reported sleeping for ≤5 h; this was associated with 30% higher incident risk of multiple chronic conditions at age 50, which increased to 40% at age 70, compared to those who reported 7 h of sleep (n = 3,589; 45.9%).
- Longer duration of sleep (≥9 h): This was associated with more than 50% increased risk of multimorbidity at age 60 and 70 but not at age 50.
- Individuals who were free of any disease at age 50 and who reported sleeping for ≤5 h were at a 20% higher incident risk for first chronic disease and further multimorbidity. There was no link between shorter sleep duration and mortality in individuals with chronic conditions.
Clinical implication: This long-term study reported that short sleep duration, indicative of poor sleep quality, was linked with an increased risk of onset of first chronic disease and subsequent multimorbidity, but not mortality. These findings highlight the importance of sleep duration and quality of sleep in the middle-aged and elderly individuals for primary and secondary prevention of chronic illnesses.
(Reference: Sabia S, Dugravot A, Léger D, et al. Association of sleep duration at age 50, 60, and 70 years with risk of multimorbidity in the UK: 25-year follow-up of the Whitehall II cohort study. PLoS Med. 2022;19(10):e1004109. Doi: 10.1371/journal.pmed.1004109)