A study has found that sleep that is extremely disrupted or goes on for too long could result in a loss of nine months from an individual's working life after the age of 50. Those with moderate sleep disturbances could expect to work nearly five fewer months, while severe disturbances were linked to eight fewer months, irrespective of gender or job type.
The research, conducted by a team at the University of Turku in Finland, analysed data from the Finnish Public Sector (FPS) study and the Health and Social Support (HeSSup) study. It categorised nightly sleep length as short (under seven hours), mid-range (seven to 8.5 hours), or long (nine hours or more), and defined disturbances as difficulties falling or staying asleep, waking too early, and nonrestorative sleep over a four-week period.
The study observed that short and mid-range sleep lengths were associated with a working life expectancy of 13 years and two months after 50. However, long nightly sleep was linked to a shorter working life expectancy of 12 years and five months. The longest working life expectancy, almost 14 years, was seen in professional women without sleep disturbances, while the shortest, nearly 12 and a half years, was among men in routine jobs with severe sleep disturbances.
Dr Saana Myllyntausta, the lead investigator, noted that there were no differences found between short and mid-range sleep durations, which is considered optimal. She suggested that long sleep duration's association with shorter working life expectancy might be explained by its links to poorer health outcomes.