The authors are referring mainly to night-shift workers — doctors and nurses, for instance — who work in 24/7 industries. Data extraction Study quality was assessed with the Downs and Black scale for observational studies. However, there are problems with concluding from these studies that there really is a link between shift work and developing diabetes. When you start eating and sleeping at different times, it disrupts your body’s internal clock and affects blood glucose (sugar) control. SHOW is a population-based health examination survey that includes home- and clinic-based interviews and physical examinations. We included observational studies that reported OR with 95% CIs for the association between shift work and the risk of DM. Although the reason behind the increased risk for diabetes among male shift workers is not clear, it is believed that daytime levels of the main male sexual hormone testosterone is controlled by the body’s internal clock and research suggests an association between low testosterone levels, insulin resistance and diabetes.
Furthermore, by encouraging de-synchronized eating patterns in non-diabetics shift work disrupts the insulin-glucose equilibrium and thus may heighten contraction risk. It was also found that the study participants who worked a rotating shift, in which they began work at different times of a 24 hour cycle on a regular basis rather than a fixed shift, were associated with the highest risk of 42%. While they have been successful in getting in the papers, they have perhaps done the science a disservice. YL drafted the manuscript.