More than half of adults over 65 suffer from at least two chronic diseases, which has an impact on life expectancy. However, by studying the link between sleep duration and the onset of chronic diseases (such as cancer or cardiovascular disease), Inserm researchers discovered that the presence of multiple chronic conditions in the same person (which called multimorbidity) was much higher among people over 50 who suffer from insomnia and short nights.
The recommendation: sleep more than 5 hours a night
The results of their study, which has just been published in the journal Plos one, show “that there is a robust association between a short duration of sleep, less than or equal to 5 hoursat the ages of 50, 60 and 70 years, and a higher risk of multimorbidity of the order of 30 to 40% depending on age” underline the researchers.
The authors also observed that short sleep duration at age 50 was associated with a 20% increased risk of developing a first chronic disease, and a similar increased risk of multimorbidity among people who had already developed a first chronic illness.
A risk of early death increased by 25%
For their study, the researchers used data from 7,000 Britons collected as part of University College London’s Whitehall II study (a large epidemiological study of civil servants in Britain).
Participants completed a self-report of their sleep duration multiple times between 1985 and 2019, which provided insights into their sleep duration at ages 50, 60, and 70. A group of participants (4,000 people) also wore a connected watch for a week, to have an accurate measurement of sleep duration and to check the accuracy of the estimates.
This data was then cross-referenced with their medical records. The researchers were thus able to verify the link between the duration of sleep at different ages and the occurrence of multimorbidities.
These results could explain the increased risk of death by around 25% observed in people aged 50 with a sleep duration less than or equal to five hours per night” explains Séverine Sabia, Inserm researcher and first author of the study.
Conversely, scientists did not find a robust association between having a longer sleep duration (greater than or equal to 9 hours) at age 50 and the risk of developing multimorbidity. during ageing.
Source : 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 studyPlos medicine, October 2022
