Working that long crazy shift could make you sick. A new study finds that shift workers, and those with an inconsistent schedule, are more at risk of developing type 2 diabetes than workers with normal schedules.

"Physicians have long known that working shifts disrupts many key body chemicals, creating a ripple effect that can lead to ailments such as gastrointestinal disorders, cardiovascular disease, and even cancer," Dr. Alan Manevitz, a clinical psychiatrist at Lenox Hill Hospital in New York City, told HealthDay. "Now type 2 diabetes can be added to this considerable list."

The study, led by Zuxun Lu of Huazhong University of Science and Technology in Wuhan, China, focused on several key factors like a worker’s shift schedule, their body mass index, family history of diabetes, and their level of physical activity. Lu and his colleagues analyzed data from 12 international studies involving more than 226,500 people. Their results showed that shift workers had a nine percent greater chance of developing diabetes, and that their gender made a difference — men had a 37 percent higher risk of developing type 2 diabetes. The researchers said that men's levels of testosterone could help explain this difference, as lower levels have been linked to insulin resistance and diabetes. 

The researchers also concluded that shift workers with a shift that bounced from one part of the day to the next were more likely to develop diabetes than a typical 9-to-5 worker. These kinds of schedules make it very difficult to exercise and eat properly, putting a person at risk of gaining weight and becoming obese. Shift workers with these odd flip-flop shifts had a 42 percent chance of developing type 2 diabetes. "Growth hormone, known to elevate blood glucose when present in excess, peaks at 1 a.m.," Dr. Gerald Bernstein, director of the Diabetes Management Program at Friedman Diabetes Institute at the Beth Israel Medical Center in New York City, told HealthDay.

The Sleep Foundation defines a shift worker as anyone without a normal 9-to-5 schedule. These workers include doctors, nurses, pilots, bridge-builders, police officers, customer service representatives, and commercial drivers. Along with increasing their risk of type 2 diabetes, many of these shift workers are deprived of sleep leading to accidents, injuries, and fatalities. They are also more at risk for gastrointestinal illnesses, insomnia, and heart disease.

The odds seem to be against shift workers, but the researchers said that if the opportunity arises to work a shift job, there's no need to be afraid of getting diabetes. They recommend that all shift workers be screened for prediabetes in order to slow the progression of full blown diabetes.

Source: Young G, Chen Y, Xinyue T, et al. Shift work and diabetes mellitus: a meta-analysis of observational studies. Occupational & Environmental Medicine. 2014.