Sleep controlled by the circadian rhythm is essential for many functions including energy conservation, memory consolidation and brain processing. Sleep duration and architecture changes with age. Sleep deprivation is very common in modern society and it has been identified as a major modifiable risk factor for many metabolic diseases.

A cross-sectional analysis was carried out on baseline data from the UK Biobank (n=82995). Sociodemographic, health-related and lifestyle information were collected using touch-screen questionnaires. Sleep and physical activity parameters were measured objectively using wrist-worn accelerometers (participants were aged 43–79 years). Sleep durations have been categorised into five groups. short sleepers: (1) <5 hours/night, (2) 5–6 hours/night, (3) 6–7 hours/night; normal sleepers: (4) 7–8 hours/night; long sleepers: (5) >8 hours/night.

Short objective sleep duration was associated with male gender, older age and lower social status. A greater proportion of males with a sleep duration <5 hours/night have very high risk waist circumference (>102cm) compared to normal and long sleepers (22.1%, 14.9%, 11.7%, 10.4% and 10.2%, respectively). A similar pattern was also seen in females (60.0%, 50.6% 43.9%, 41.3% and 40.6%, respectively). The percentage of participants with cardiometabolic diseases is significantly lower in those who sleep between 6–8 hours/night compared to other short and long sleepers (34.8%, 27.7%, 26.0%, 25.9% and 29.1%, respectively). They also have better health ratings and less likely to have hypertension, diabetes and cardiovascular disease. Finally, those who sleep 6–7 hours were most physically active compared to other sleep groups. In conclusion, 6–8 hours of sleep per night is associated with better metabolic health and higher physical activity level. Short sleep duration is associated with male gender and social deprivation. Although, no causal link can be established from this study, the results can help to develop interventions for targeted groups to reduce the adverse effects of poor sleep.