By Don Rauf

Going to sleep late at night could have a big negative impact in your health. A brand new study has found that “night owls” who head to bed late and wake late face a much greater likelihood of developing diabetes than “early birds.”

In an evaluation involving greater than 63,000 subjects published September 12 within the Annals of Internal Medicine, “evening people” had a 72 percent greater risk of diabetes. They were also more prone to drink alcohol in higher quantities, have a low-quality weight loss program, get fewer hours of sleep per night, and be current smokers. As well as, their weight, BMI, and physical activity rates were more prone to be in an unhealthy range.

“Overall, the night owls were 54 percent more prone to have an unhealthy lifestyle in comparison with the early birds,” says the lead study writer, Sina Kianersi, PhD, a postdoctoral research fellow at Brigham and Women’s Hospital and Harvard Medical School in Boston. “After we account for health aspects comparable to weight, physical activity and weight loss program, nonetheless, their diabetes risk drops from 72 percent to 19 percent. Which means much of the increased risk is as a result of their unhealthy habits.”

Sleep Habits Themselves May Affect Health Risks

The 19 percent greater diabetes risk as a result of unhealthy habits remains to be significant, nonetheless, in response to Dr. Kianersi. The result suggests that other aspects, comparable to sleep patterns themselves and their effect on metabolism and hormones, may contribute to diabetes risk.

For Sun Kim, MD, an endocrinologist and an associate professor of drugs at Stanford Medicine in California, the findings support previous research showing a link between sleep itself and health outcomes.

“Short sleep duration and/or sleep deprivation [for example] have been related to increased diabetes risk,” says Dr. Kim, who was not involved on this study. “Although mechanisms are still being investigated, short sleep may increase hormones for appetite and stress and increase inflammation, which may result in insulin resistance, a known mechanism to worsen glucose control.”

Kianersi adds that his team intends to explore how genetics may help explain this higher risk.

“Recent discoveries actually show that there are greater than 350 genetic markers or genetic signs in our DNA that could make us an evening owl or an early bird,” he says. “We really need to know what’s the mechanism that increases the danger amongst night owls even after accounting for his or her unhealthy habits.”

How Sleep Preferences Make a Difference

For this study, scientists sought to know how sleep preferences may influence diabetes risk. Every one has a natural inclination for once they prefer to sleep called a “chronotype.” Your chronotype could also be early-to-bed, early-to-rise; late-to-bed, late-to-rise; or somewhere in between.

Chronotypes are influenced by genetics and driven by circadian rhythms, the body’s natural processes which are guided by light and dark during a 24-hour period.

Kianersi and his team checked out data from 63,676 female nurses (ages 45 to 62) who self-reported their chronotype and health aspects, including weight loss program quality, weight and body mass index, sleep timing, smoking behaviors, alcohol use, physical activity, and family history of diabetes.

The participants, who were followed for eight years, had no history of cancer, heart problems, or diabetes on the study start line in 2009.

Just over 1 in 10 of the participants reported having a “definite evening” chronotype, and about 35 percent reported having a “definite morning” chronotype. The remaining population, around half, were labeled as “intermediate,” meaning they identified as neither a morning nor a night type or as being only barely more one than the opposite.

Study authors noted that amongst participants with the healthiest lifestyles, only 6 percent had evening chronotypes, while amongst those with the unhealthiest lifestyles, 25 percent were evening chronotypes.

In addition they found the association between evening chronotype and diabetes risk only in those nurses who worked day shifts and never those that worked overnight shifts.

The authors theorize that this association could also be as a result of work schedules that don’t align with an individual’s chronotype. The increased diabetes risk, then, could also be explained by a mismatch between chronotype and work timing moderately than the chronotype itself.

“A possible solution to this may very well be for people to work schedules that align with their personal chronotype to advertise a healthier lifestyle,” says Lauren Amaya, PhD, a teaching associate professor and diabetes specialist at Oklahoma State University in Stillwater.

If evening chronotypes are allowed to sleep and wake closer to their circadian clock — for instance, by working a night shift moderately than a morning shift — this will likely result in a more consistent schedule that higher matches their circadian sleep-wake timing, adds Fiona Barwick, PhD, an associate professor of psychiatry and behavioral sciences specializing in sleep medicine at Stanford Health Care in Redwood City, California.

“This will in turn result in less ‘shift work,’ more sleep, less need for sleep aids, more appropriate meal timing, and a healthier weight loss program — all of which would scale back risk to cardiometabolic health,” says Dr. Barwick.

Change Lifestyle Habits to Lower Risk

While people could also be genetically hardwired to be night owls or early birds, the researchers suggest that “evening people” can still take steps to enhance the unhealthy habits that raise diabetes risk, comparable to modifying their weight loss program, losing a few pounds, exercising more, reducing drinking, and quitting smoking.

Dr. Amaya, who was not involved on this research, points out that the study was limited in that it included primarily middle-aged white female nurses with a comparatively high level of education and socioeconomic status who did shift work in hospitals.

“It will be interesting to duplicate this study with other populations of people, comparable to men, nonwhite racial and ethnic groups, and people from lower socioeconomic statuses, all of that are aspects related to an elevated type 2 diabetes risk,” she says.