NIH Researchers Identify Sleep Deficiency as a T2D Risk Factor

Yesterday, the National Institutes of Health (NIH) announced the results of a study that identified chronic sleep deficiency as a risk factor for type 2 diabetes (T2D). The study, published in Diabetes Care, indicated that a lack of sleep or continuous sleep insufficiency can increase insulin resistance in women, which increases the probability of T2D.

The NIH emphasized the importance of this study in women because, generally, more women report troubles with sleep.

With funding from the National Heart, Lung, and Blood Institute (NHLBI) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), investigators recruited 38 women ages 20–75.

For sleep measurements, researchers had participants wear a wrist sensor to monitor and record their sleep, identifying sleep patterns for two weeks. They were also asked to keep a sleep log.

Researchers excluded participants with cardiometabolic diseases or an actigraphy-confirmed habitual total sleep time (TST) outside the 7–9 hours/night range.

For the study's first phase, patients were asked to maintain adequate sleep (AS); however, in the second phase, participants experienced a mild sleep restriction (SR), which delayed their nightly sleep time by 1.5 hours. On average, the 1.5 hour/night sleep delay yielded a nightly sleep time of 6.2 hours.

Patient’s plasma glucose and insulin levels, homeostatic model assessment for insulin resistance (HOMA-IR) scores on fasting blood samples, total area under the curve for glucose and insulin, the Matsuda index, and oral glucose tolerance test disposition index were used to evaluate glucose metabolism in the patients at the start and end of each 6-week phase.

Based on these assessments, study leaders concluded that 6.2 hours or less of sleep nightly can increase the risk of insulin resistance by 14.8% in women, including premenopausal and postmenopausal women.

A closer look at the data from the 11 postmenopausal women in the study revealed that the impact of insufficient sleep was more significant in this population, increasing insulin resistance by as much as 20.1%.

However, they also noted that returning to their regular sleep schedule restored normal insulin and glucose levels.

“What we’re seeing is that more insulin is needed to normalize glucose levels in the women under conditions of sleep restriction, and even then, the insulin may not have been doing enough to counteract rising blood glucose levels of postmenopausal women. If that's sustained over time, it is possible that prolonged insufficient sleep among individuals with prediabetes could accelerate the progression to type 2 diabetes,” concluded Marie-Pierre St-Onge, PhD, associate professor of nutritional medicine and director of the Center of Excellence for Sleep and Circadian Research at Columbia University Vagelos College of Physicians and Surgeons, New York City, and senior author on the study, in the NIH press release.

Despite the evidence found in this study, additional research to validate these results is necessary. The sample size in this research was small and did not compare the impacts across different genders, races, and other sociodemographic factors.