Insomnia a risk factor for type 2 diabetes
JUN 29, 2018- Reuters Health News –
A new study provides more evidence that people who suffer from insomnia may be at increased risk for developing type 2 diabetes.
The study found that people with insomnia were 28% more likely to develop type 2 diabetes during the observation period than those without insomnia, after adjusting for potential confounding factors.
Dr. Erin S. LeBlanc, investigator at Kaiser Permanente Center for Health Research in Portland, Oregon, reported the findings June 23 at the American Diabetes Association (ADA) annual meeting in Orlando, Florida.
“Our findings are consistent with experimental work in which researchers disrupt sleep in healthy volunteers,” she told Reuters Health by email. “Such studies find that inadequate sleep duration (typically 4-5 hours per night for a 1- to 14-day period) and disruption of sleep architecture (by circadian misalignment with resultant changes in REM distribution) result in hyperglycemia and insulin resistance, which is reversed when sleep returns to normal.”
“Our study’s findings are also consistent with previous epidemiological studies, which have found a 28% to 84% increased risk of T2DM in those with short sleep duration or sleep difficulties. Our study adds to this existing literature by examining T2DM risk in participants with a clinical diagnosis of insomnia; previous cohorts have used sleep questionnaires and examined specific elements of sleep (ie, duration, sleep initiation),” she explained.
For the study, more than 79,000 people with prediabetes between 2007 and 2015 were followed for an average of 4 years. Almost 30% were classified as having insomnia (physician identified or insomnia medication dispense) during the observation period.
Those with insomnia were older and were more likely to be overweight, female, white, non-Hispanic, previous or current smokers and to have hypertension, low HDL cholesterol and elevated triglycerides compared with those without insomnia.
During follow up, 14,617 people (18%) developed T2DM. After adjustment for traditional risk factors, the hazard ratio for T2DM was 1.28 (95% confidence interval: 1.23-1.33) in those with insomnia. This estimate was essentially unchanged after adjusting for baseline hemoglobin A1C level and fasting plasma glucose values.
“The hazard ratio for insomnia was similar to more traditional risk factors such as hypertension, low HDL and high triglycerides,” the researchers report in their poster.
There are several possible reasons why poor sleep might increase the risk of type 2 diabetes, Dr. LeBlanc told Reuters Health.
“Experimental sleep deprivation and epidemiological studies suggest that disrupted or short duration sleep could impair the profile of peptides that mediate energy homeostasis (eg, leptin, ghrelin, adiponectin) leading to increased appetite, including cravings for calorie dense, high-carbohydrate food and, ultimately, insulin resistance,” she explained. “Other studies show that persons subjected to short-term experimental sleep deprivation and those with long-term short-sleep duration or sleep disturbances have elevated salivary and serum cortisol levels, particularly in the evening, when levels are normally quite low. Elevated cortisol levels are associated with increased central fat distribution, which is strongly associated with insulin resistance.”
“Increased inflammation and sympathetic activation could also contribute to the association between sleep disruption and diabetes risk. Both are activated with sleep disruption, and activation of both systems has been tied to insulin resistance and, eventually, type 2 diabetes. Insomnia has also been shown to accelerate loss of beta-cell function and increase beta-cell apoptosis with increased loss of beta-cell mass in laboratory models. Finally, the fatigue associated with sleep loss may be contributing to decreased amount and intensity of physical activity, which may contribute to the development of type 2 diabetes,” said Dr. LeBlanc.
Dr. Ronald Chervin, director of the University of Michigan Sleep Disorders Center, in Ann Arbor, said, “We’ve known for years now that obstructive sleep apnea appears to impair glucose control and increase risk for diabetes. This study suggests that chronic insomnia—another highly common sleep illnes—also may have a clinically significant impact.”
“A strength of this sizable study was its longitudinal design,” said Dr. Chervin, who is past president of the American Academy of Sleep Medicine (AASM) and was not…