Women who get less than the recommended eight hours? sleep a night are at higher risk of heart disease and heart-related problems than men with the same sleeping patterns, according to a UCL research published today in the journal SLEEP.
The study, which was conducted with the Sleep Medicine Unit at the University of Warwick, showed that women who reported sleeping eight hours had significantly lower levels of a marker related to coronary heart disease (Interleukin-6) than those who reported sleeping seven hours per night.
Women who reported sleeping five hours or fewer had significantly higher levels of another marker (High-sensitivity C-reactive protein), which is predictive of future cardiovascular problems.
However, the researchers found that levels of inflammatory markers do not vary significantly with sleep duration in men.
The study involved more than 4,600 participants from the UCL-based Whitehall II cohort study: a large-scale study of 10,308 civil servants that started more than 20 years ago.
Jane Ferrie (UCL Epidemiology and Public Health), is the lead researcher of the Whitehall II sleep research programme. She said: ’In one of the first studies to come out of this programme I and my co-authors showed that both short sleep (five hours or fewer per night) and a move from a normal sleep pattern (six to eight hours) into the short-sleep end of the spectrum was associated with an increased risk of cardiovascular mortality. Long sleep (nine hours or more) and a move to the long-sleep end of the spectrum were associated with an increased risk of early death from causes other than heart disease.
‘This new study shows that one of the mechanisms potentially underlying this additional risk of early death, at least in women, appears to be inflammatory processes.’
The Whitehall II study was set up by Professor Sir Michael Marmot to investigate the importance of social class, psychosocial factors and life style as determinants of disease by following a cohort of 10,308 men and women.
The study began by looking at the health of working people. It now seeks to answer questions about how previous and current circumstances affect health and quality of life in an ageing cohort. The study is currently funded by the Medical Research Council, the British Heart Foundation, the National Heart Lung and Blood Institute, USA and the National Institute of Ageing, USA.
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