Older adults who sleep for five or fewer hours per night are at 30% increased risk of having multiple chronic diseases than those who average seven hours of sleep, a large cohort study shows.

French researchers say their findings, published in PLOS Medicine, support the promotion of good sleep hygiene in both the primary and secondary prevention of multimorbidity in later life.

In the 25-year follow-up of the prospective UK-based Whitehall II cohort, the researchers examined data from nearly 7900 participants free of multimorbidity and who had data on sleep duration at 50 years of age.

A third of the cohort were diagnosed with at least two chronic diseases such as dementia, heart failure and COPD during the study period, and the mortality rate was about 10%.