Forget bad guys and gunfire: Being a police officer can be hazardous to your health in other ways.

Researchers at the University of Iowa have found that police officers who sleep fewer than six hours per night are more susceptible to chronic fatigue and health problems, such as being overweight or obese, and contracting diabetes or heart disease. The study found that officers working the evening or night shifts were 14 times more likely to get less restful sleep than day-shift officers, and also were subjected to more back-to-back shifts, exacerbating their sleep deficit.

The study is the first peer-reviewed look at differences in duration and quality of sleep in the context of shift work and health risks in the police force, the authors noted.

"This study further confirmed the impact of shift work on law enforcement officers and the importance of sleep as a modifiable risk factor for police," wrote Sandra Ramey, assistant professor in the College of Nursing at the UI and the lead author on the paper published in Workplace Health & Safety. "The good news is this is correctable. There are approaches we can take to break the cascade of poor sleep for police officers."

The research is important because getting fewer than six hours of sleep could affect officers' ability to do their jobs, which could affect public safety. It also boosts the risk for health problems, which could affect staffing and could lead to higher health costs borne by taxpayers.

The researchers recommend putting practices in place to ensure officers get proper sleep. For example, 83 percent of police on the evening or night shift reported having to report to duty early the next morning at least occasionally. One idea from the UI team is to change the morning time that evening or night-shift officers may need to appear in court, to ensure that they get full rest. They also recommend that law enforcement and nurses partner more closely, to encourage officers to get 7-8 hours of sleep per night.

The researchers surveyed 85 male police officers ranging in age from 22 to 63 years old from three police departments in eastern Iowa. The respondents were equally divided between those who worked the day shift and those who worked the evening or night shifts. The officers, who worked on average 46 hours per week, were queried on their levels of stress and fatigue, while their height, weight, and C-reactive protein levels (marks inflammation levels in the blood) were measured.

While officers working the evening or night shifts were more likely to get fewer than six hours of sleep, the researchers also found that police who slept fewer than six hours were twice as likely to sleep poorly. That finding is important, because poor sleep can lead to "vital exhaustion," or chronic fatigue, the authors noted, which can trigger additional health problems.

The UI study builds on other studies that show a possible link between sleep deprivation and ill health and chronic fatigue in police officers. "This finding is supported by other studies that suggested poor sleep and short sleep (with resultant fatigue) may be related to psychological stress," they wrote.

Somewhat surprisingly, the researchers did not find a strong tie between lack of sleep and the onset of health complications, although they said a larger statistical sample may be needed to more fully understand the relationship.

The study, titled "The effect of work shift and sleep duration on various aspects of police officers' health," was published in the May edition of the journal. M. Kathleen Clark, Yelena Perhounkova, and Hui-Chen Tseng from the UI College of Nursing are co-authors on the study. Laura Budde, from Mercy Hospital in Iowa City, and Mikyung Moon, from Keimyung University in South Korea, are contributing authors on the paper.

The Prevention Research Center for Rural Heath at the UI College of Public Health funded the research. Ramey has a secondary appointment in the College of Public Health.