People aged 50 and above who sleep for a maximum of five hours a day face a greater risk of developing multiple chronic conditions, such as heart disease, diabetes and cancer, a new study has said. The team of researchers, who published their findings in the peer-reviewed journal PLOS Medicine on October 18, analysed the data of 7,864 British civil servants at the ages of 50, 60 and 70. They measured the sleep duration of the participants over a span of 25 years and examined its association with multimorbidity, which the study defined as “the presence of 2 or more chronic diseases out of a predefined list of 13 chronic diseases.” The second objective was to determine whether sleep duration at age 50 shapes the natural course of a chronic disease - from a healthy state to chronic disease stage, multimorbidity, and death - using a multistate model. According to the findings, participants who slept for five hours or less at age 50 were associated with a 20 per cent increased risk of developing a chronic disease, and a similar increased risk of being diagnosed with two or more chronic diseases over 25 years, compared with those who slept for up to seven hours. The researchers found that sleeping for five hours or less at the age of 50, 60 and 70 was associated with 30 per cent to 40 per cent increased risk of multimorbidity. While the findings suggest that short sleep duration is associated with the onset of chronic disease and multimorbidity, “no consistent association was found with transition to mortality,” the study said. The authors also stated that they found no consistent link between short sleep duration with progression to death among those people with existing chronic diseases. This means that other studies that have reported associations with fewer hours of sleep and mortality, are “likely to be driven by the association of short sleep with onset of chronic diseases that are themselves associated with risk of mortality.” “As people get older, their sleep habits and sleep structure change. However, it is recommended to sleep for 7 to 8 hours a night - as sleep durations above or below this have previously been associated with individual chronic diseases,” said the study’s lead author Dr Severine Sabia (UCL Institute of Epidemiology & Health, and Inserm, Université Paris Cité). In order to get a better night’s sleep, Dr Sabia stressed on the importance of promoting good sleep hygiene — making sure the bedroom is quiet, dark and in a comfortable temperature. Electronic devices and large meals before bedtime should also be avoided, while physical exercise and exposure to light in the day can also promote sleep, she added.
