|Overview of biological circadian clock in humans. Biological clock affects the daily rhythm of many physiological processes. This diagram depicts the circadian patterns typical of someone who rises early in morning, eats lunch around noon, and sleeps at night (10 p.m.). Although circadian rhythms tend to be synchronized with cycles of light and dark, other factors - such as ambient temperature, meal times, stress and exercise - can influence the timing as well. (Photo credit: Wikipedia)|
Shift work, which disrupts the body clock (circadian rhythm), has long been associated with health problems including diabetes, high blood pressure, and high cholesterol, but its link with vascular disease has been less clear. But a new study published on bmj.com, found that shift work is associated with an increased risk of major vascular problems, such as heart attacks and strokes.
The study is the largest analysis of shift work and vascular risk to date, and it has implications for public policy and occupational medicine, say the authors.
In the study, a team of international researchers analyzed the results of 34 studies involving over 2 million individuals to investigate the association between shift work and major vascular events. Shift work was defined as evening shifts, irregular or unspecified shifts, mixed schedules, night shifts, and rotating shifts. Control groups were non-shift (day) workers or the general population.
Differences in study design and quality were taken into account to minimize bias.