Impact of Shift Work on Vascular Ailments
Shift work disturbs the body's natural clock (circadian rhythm), which in turn affects the work life equilibrium. This can result in a variety of health problems such as increased cholesterol and high blood pressure. Vascular ailments are caused by hardening of arteries (atherosclerosis) due to plaque deposition.
Recently, Manav and colleagues conducted a systemic review to assess the link between shift work and vascular events. For the review 34 observational studies in 2,011,935 individuals were identified. "Study quality was assessed with the Downs and Black scale for observational studies. The three primary outcomes were myocardial infarction, ischemic stroke, and any coronary event."
The scientists noticed that shift work is considerably linked with ischemic stroke and myocardial infarction. The risk ratio with myocardial infarction was 1.23 and with ischemic stroke was 1.05.
The scientists reported that in contrast to daytime workers, the shift workers had 24 percent high risk for coronary ailments, 5 percent high risk for stroke and 23 percent high risk for heart attack.
There was no association between raised mortality rates and shift work. Adjustment for socioeconomic status and smoking was not a cause of heterogeneity.
In Canada the occurrence of shift work is 32.8 percent and the risk for myocardial infarction were 7 percent, for ischemic stroke the risk was 6 percent and for coronary events the risk was 7.3 percent.
The researchers said, "The increased risk of vascular disease apparent in shift workers, regardless of its explanation, suggests that people who do shift work should be vigilant about risk factor modification."
They further added, "More work is needed to identify the most vulnerable subsets of shift workers and the effects of shift modifying strategies on overall vascular health."
The experts said that the relative risks were modest but because of the rising frequency of shift work among the general population, the consequences on the public health are not insignificant.
Scientists call for further researches to analyze the most affected shift workers and to assess how the overall vascular health is influenced by the pattern of shift.
Reference: Shift work and vascular events: systematic review and meta-analysis; Manav Vyas et al; BMJ 2012; 345 doi: 10.1136/bmj.e4800