Metabolic disturbances in male workers with rotating three-shift work. Results of the WOLF study.
OBJECTIVE
The aim of the present study was to investigate the relationship between important metabolic risk factors for coronary heart disease (CHD) and type 2 diabetes in shift workers and day workers.


METHODS
Cross-sectional data from a sub-population in the WOLF study consisting of 665 day workers and 659 three-shift workers in two plants were analysed.


RESULTS
A higher proportion of shift workers than day workers had high triglyceride levels (> or =1.7 mmol/l), low levels of HDL-cholesterol (<0.9 mmol/l) and abdominal obesity (waist/hip ratio>0.9). The risk of low HDL-cholesterol was doubled in shift workers, (odds ratio (OR): 2.02, 95% confidence interval (95% CI): 1.24-3.28) after being adjusted for age, socio-economic factors, physical activity, current smoking, social support and job strain. High levels of triglycerides were also significantly associated with shift work (OR: 1.40, 95% CI: 1.08-1.83). The OR for abdominal obesity was 1.19, (95% CI: 0.92-1.56). The prevalence of hyperglycaemia (serum glucose > or =7.0 mmol/l) was similar in day and shift workers. No significant interaction was seen between shift work and abdominal obesity with regard to the associations with triglycerides and HDL-cholesterol.


CONCLUSIONS
We found a significant association between shift work and lipid disturbances (i.e. low HDL-cholesterol and high triglyceride levels). We did not find any association with hyperglycaemia.
Karlsson
Berndt H
BH
Occupational Medicine, Department of Public Health and Clinical Medicine, University of Umeå, 901 85 Umeå, Sweden.bernt.karlsson@vll.se
Knutsson
Anders K
AK
Lindahl
Bernt O
BO
Alfredsson
Lars S
LS
D000328:Adult; D001786:Blood Glucose; D008076:Cholesterol, HDL / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology; D003327:Coronary Disease / Q000150:complications / Q000378:metabolism*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D009784:Occupational Diseases / Q000150:complications / Q000378:metabolism; D012307:Risk Factors; D012959:Socioeconomic Factors; D014280:Triglycerides / Q000097:blood; D014940:Work Schedule Tolerance / Q000502:physiology*
D001786:Blood Glucose; D008076:Cholesterol, HDL; D014280:Triglycerides