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A recent study funded by the National Institutes of Health (NIH) aimed to examine the link between chronic insufficient sleep and elevated insulin resistance in women, emphasizing the potential risk for type 2 diabetes. Published in Diabetes Care, the research highlighted the importance of adequate sleep in maintaining healthy blood sugar levels, particularly in postmenopausal women who exhibited more pronounced effects.
“Women report poorer sleep than men, so understanding how sleep disturbances impact their health across the lifespan is critical, especially for postmenopausal women,” Marishka Brown, PhD, director of the National Center on Sleep Disorder Research at the National Heart, Lung, and Blood Institute (NHLBI), said in a statement.
The findings revealed that restricting sleep to 6.2 hours or less per night over 6 weeks led to a 14.8% increase in insulin resistance in both pre- and postmenopausal women. Postmenopausal women experienced more severe effects, with a 20.1% increase in insulin resistance. Additionally, premenopausal women showed an increase in fasting insulin levels, while postmenopausal women exhibited rises in both fasting insulin and fasting glucose levels.
The study focused exclusively on women, aiming to investigate whether prolonged, mild sleep restriction (a reduction of 1.5 hours per night) could impact blood glucose and insulin levels. The research enrolled 40 women, aged 20-75, with healthy sleep patterns but increased risks for cardiometabolic diseases due to factors such as overweight or obesity, family history of type 2 diabetes, elevated blood lipids, or cardiovascular disease.
Participants underwent two 6-week study phases in random order—one with their regular sleep patterns (7.5 hours per night on average) and one with sleep restricted to 6.2 hours per night, mirroring the average sleep duration of U.S. adults with insufficient sleep. An oral glucose tolerance test and MRI scans were conducted at the beginning and end of each phase to measure glucose and insulin levels and body composition.
“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,” senior study author 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, stated. “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.”
The researchers explored whether changes in body weight could explain the observed alterations in insulin and glucose levels. However, the effects on insulin resistance were found to be largely independent of changes in body weight. Furthermore, upon returning to their typical 7-9 hours of sleep per night, participants' insulin and glucose levels returned to normal.
“This study provides new insight into the health effects of even small sleep deficits in women across all stages of adulthood and racial and ethnic backgrounds,” Corinne Silva, PhD, program director in the Division of Diabetes, Endocrinology, and Metabolic Diseases at NIDDK, said in a statement. “Researchers are planning additional studies to further understand how sleep deficiency affects metabolism in men and women, as well as explore sleep interventions as a tool in type 2 diabetes prevention efforts.”
Chronic sleep deficiency increases insulin resistance in women, especially postmenopausal women. News release. NHLBI News. Published November 13, 2023. Accessed November 17, 2023. https://www.nhlbi.nih.gov/news/2023/chronic-sleep-deficiency-increases-insulin-resistance-women-especially-postmenopausal