Evidence from:
B Karlsson et al. Occupational and Environmental Medicine. November (2001) Vol.58 # 11 p 747.
A study of known risk factors for heart disease and their association with shift work.
27,485 Swedish workers took part. Blood and build were analysed.
Obesity was found to be more prevalent among all ages of women shift workers, but only two age groups of men.
Increased triglycerides (>1.7 mmol/l) were found for two groups of shift working women but not men.
Impaired glucose tolerance was found among 60-year old women shift workers.
Comment
The authors conclude that shift work presents an increased risk of heart disease.
However, risk factors for disease are not indicators that disease will necessarily occur. Strengths of association reported here were very weak.
There was no information on the occupational /non-occupation origins of the associations found here.
The working time Directive was informed by debate about the health effects of shift work, but that debate was as inconclusive as this paper.