Objectives-To explore how metabolic risk factors for cardiovascular disease (CVD) diVer between shift workers and day workers in a defined population. Shift work has been associated with an increased risk of CVD. Risk factors and causal pathways for this association are only partly known. Methods-A working population of 27 485 people from the Västerbotten intervention program (VIP) has been analysed. Cross sectional data, including blood sampling and questionnaires were collected in a health survey. Results-Obesity was more prevalent among shift workers in all age strata of women, but only in two out of four age groups in men. Increased triglycerides (>1.7 mmol/l) were more common among two age groups of shift working women but not among men. Low concentrations of high density lipoprotein (HDL) cholesterol (men<0.9 and women<1.0 mmol/l) were present in the youngest age group of shift workers in both men and women. Impaired glucose tolerance was more often found among 60 year old women shift workers. Obesity and high triglycerides persisted as risk factors in shift working men and women after adjusting for age and socioeconomic factors, with an OR of 1.4 for obesity and 1.1 for high triglyceride concentrations. The relative risks for women working shifts versus days with one, two, and three metabolic variables were 1.06, 1.20, and 1.71, respectively. The corresponding relative risks for men were 0.99, 1.30, and 1.63, respectively. Conclusions-In this study, obesity, high triglycerides, and low concentrations of HDL cholesterol seem to cluster together more often in shift workers than in day workers, which might indicate an association between shift work and the metabolic syndrome. (Occup Environ Med 2001;58:747-752)

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.

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This cohort study showed that shift work with night shifts is associated with increased risk of breast cancer, but not shift work without night shifts. Research on the disease mechanisms needs to be intensified. Original article Scand J Work Environ Health. 2013;39(2):170-177. doi:10.5271/sjweh.3323 Breast cancer among shift workers: results of the WOLF longitudinal cohort study Objective The aim of this study was to investigate whether shift work (with or without night work) is associated with increased risk of breast cancer. Affiliation MethodsThe population consisted of 4036 women. Data were obtained from WOLF (Work, Lipids, and Fibrinogen), a longitudinal cohort study. Information about baseline characteristics was based on questionnaire responses and medical examination. Cancer incidence from baseline to follow-up was obtained from the national cancer registry. Two exposure groups were identified: shift work with and without night work. The group with day work only was used as the reference group in the analysis. Cox regression analysis was used to calculate relative risk. ResultsIn total, 94 women developed breast cancer during follow-up. The average follow-up time was 12.4 years. The hazard ratio for breast cancer was 1.23 [95% confidence interval (95% CI) 0.70-2.17] for shifts without night work and 2.02 (95% CI 1.03-3.95) for shifts with night work. When including only women <60 years of age, the risk estimates were 1.18 (95% CI 0.67-2.07) for shifts without night work, and 2.15 (95% CI 1.10-4.21) for shifts with night work. ConclusionsOur results indicate an increased risk for breast cancer among women who work shifts that includes night work.

For workers in a heavy job like construction work, occupational factors are of great importance for disability pension. The majority of years lost are caused by pensions granted at ages 50 years and older.Measures to decrease disability pension should be initiated at earlier stages of work life to decrease effects of negative exposures and increase employability.