Having low levels of melatonin, a hormone that regulates sleep, may put you at risk for type 2 diabetes, according to a new study.
By Amir Khan, Everyday Health Staff Writer
People with low levels of melatonin, a hormone that helps regulate sleep and circadian rhythm, may be at a higher risk for type 2 diabetes than people with high levels, according to a new study published in the Journal of the American Medical Association.
Researchers from Brigham and Women’s Hospital in Boston looked at 370 women who developed diabetes while taking part in the Nurses’ Health Study, a long-term study on women’s health, alongside 370 healthy controls, and found that study participants with low levels of melatonin were at approximately twice the risk of developing type 2 diabetes when compared to participants with high levels, even after the researchers adjusted for other diabetes risk factors such as smoking, diet, and exercise.
“This is the first time that an independent association has been established between nocturnal melatonin secretion and type 2 diabetes risk,” Ciaran McMullan, MD, study author and researcher in the renal division at Brigham and Women’s Hospital, said in a statement. “Hopefully this study will prompt future research to examine what influences a person’s melatonin secretion and what is melatonin’s role in altering a person’s glucose metabolism and risk of diabetes.”
Previous research done in rats has shown that taking a melatonin supplement protected them against diabetes, the researchers said, but they could not say for sure that it would have the same effect in humans.
Melatonin is produced in the pineal gland, which is located in the center of the brain, and can be measured through a blood, urine or saliva test. The hormone is only produced in the dark, and low levels have been linked to various conditions, including breast cancer, ovarian cancer, andinsomnia.
“Melatonin receptors have been found throughout the body in many tissues including pancreatic islet cells,” the researchers wrote in the study, “reflecting the widespread effects of melatonin on physiological functions such as energy metabolism and the regulation of body weight.”
While the researchers could not say for sure that there was a causal link between low melatonin levels and type 2 diabetes, they said previous research has shown that melatonin can play a role helping to regulate sugar levels in the body. When melatonin levels are low, the researchers continued, your blood sugar levels could be thrown off, raising your risk for diabetes.
In addition, they said that since melatonin helps regulate sleep and circadian rhythm, it’s possible that people with low melatonin levels wake up frequently during the night and sleep fewer hours, which could increase their risk.
“Sleep disruption may also be associated with diabetes,” the researchers wrote in the study. “For example, men who reported sleeping less than five hours per night were twice as likely to develop diabetes as those who reported sleeping seven hours per night.”
Although this is the first study to link melatonin to diabetes risk, some doctors use melatonin to treat patients who are already diagnosed with the condition. Michael Wald, MD, director of nutritional services at Integrated Medicine of Mount Kisco in Mount Kisco, NY, routinely gives his diabetic patients melatonin, and said it helps bring their blood sugar levels back into line.
“Several studies have noted that diabetes often have insomnia and it is this subgroup of diabetes that may benefit the most from melatonin supplementation,” said Dr. Wald. “In diabetics with low melatonin, taking slow-release melatonin seems to improve blood sugar levels. The diabetic blood sugar test, called hemoglobin A1c, is reduced in diabetics who take between 1 to 2 mg of melatonin two hours before bedtime.”
Giving patients melatonin, he added, not only helps their blood sugar levels, but also helps them sleep better, which can reduce the risks of other diseases as well.
“By improving sleep quality, melatonin may reduce the risk of many diseases that are associated with poor sleep quality,” Wald said, “including, but not limited to, cardiovascular disease, sleep apnea, nerve problems, depression and pain.”