Alarming Diabetes Danger: Insufficient Sleep Raises Insulin Resistance in Women

The study, funded by the National Institutes of Health (NIH), has revealed a concerning connection between insufficient sleep and insulin resistance in women, particularly among postmenopausal women, potentially elevating the risk of type 2 diabetes. This underscores the crucial role that adequate sleep plays in preserving women’s health and preventing diabetes.

The research findings emphasize that insufficient sleep can be regarded as a modifiable risk factor for the development of type 2 diabetes.

According to the study, chronic insufficient sleep can lead to increased insulin resistance, even in otherwise healthy women, with more pronounced effects observed in postmenopausal women. The study, published in the scientific journal Diabetes Care, underscores the significance of ensuring sufficient sleep to mitigate the risk of type 2 diabetes, a condition that arises when the body’s utilization of insulin, a vital hormone for regulating blood sugar levels, becomes inefficient.

Marishka Brown, Ph.D., who serves as the director of the National Center on Sleep Disorder Research at the National Heart, Lung, and Blood Institute (NHLBI) and co-funded the study with the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), both components of the NIH, stressed the importance of comprehending the impact of sleep disturbances on women’s health, particularly postmenopausal women. Women tend to report poorer sleep compared to men, making it imperative to assess how sleep quality influences their overall well-being.

Previous studies have already indicated that sleep restriction can elevate the risk of conditions such as cardiovascular disease, hypertension, and disrupted glucose metabolism, which can subsequently lead to insulin resistance and type 2 diabetes. However, many of these studies were primarily conducted in men or focused on severe, short-term sleep deprivation.

The current study exclusively enrolled women and aimed to determine if a prolonged but mild reduction in sleep duration – specifically, a nightly reduction of just 1.5 hours – would result in elevated blood glucose and insulin levels in women. Insulin plays a crucial role in regulating glucose within the body, and when the body’s cells become resistant to insulin, their ability to utilize it effectively diminishes, significantly increasing the risk of prediabetes and type 2 diabetes.

To conduct the study, 40 women aged 20-75, who had healthy sleep patterns (averaging 7-9 hours of sleep per night) and normal fasting glucose levels but were at increased risk for cardiometabolic diseases due to factors such as overweight or obesity, family history of type 2 diabetes, elevated blood lipids, or cardiovascular disease, were recruited. The participants wore wrist sensors to record their sleep patterns and maintain sleep logs for two weeks to establish a baseline. Subsequently, they underwent two six-week study phases in random order: one phase where they continued their regular sleep patterns and another phase with sleep restriction. A six-week break was taken between these phases for recalibration. During the phase with adequate sleep, participants adhered to their usual sleep and wake times, averaging 7.5 hours of sleep per night. In the sleep-restricted phase, participants delayed their bedtime by 1.5 hours each night while maintaining their regular wake time, resulting in an average sleep duration of 6.2 hours per night, a figure that approximates the average sleep duration of adults in the United States who suffer from insufficient sleep. At the start and conclusion of each study phase, participants underwent an oral glucose tolerance test to measure their blood glucose and insulin levels, as well as an MRI scan to assess body composition.

The study’s findings indicated that restricting sleep to 6.2 hours or less per night over six weeks led to a 14.8% increase in insulin resistance among both premenopausal and postmenopausal women, with even more substantial effects observed in postmenopausal women, reaching as high as 20.1%. In premenopausal women, fasting insulin levels increased in response to sleep restriction, while postmenopausal women exhibited increases in both fasting insulin and fasting glucose levels.

Marie-Pierre St-Onge, Ph.D., the senior author of the study and an associate professor of nutritional medicine, as well as the director of the Center of Excellence for Sleep and Circadian Research at Columbia University Vagelos College of Physicians and Surgeons in New York City, noted that the study’s results suggest that more insulin is required to normalize glucose levels in women experiencing sleep restriction. However, in some cases, even increased insulin levels may not adequately counteract the rising blood glucose levels in postmenopausal women. This raises concerns that sustained insufficient sleep among individuals with prediabetes could potentially accelerate the progression to type 2 diabetes.

The researchers also investigated whether changes in body weight could account for the observed alterations in insulin and glucose levels, as sleep-restricted individuals tend to consume more calories. However, they determined that the effects on insulin resistance were largely independent of changes in body weight. Moreover, once the women returned to their typical sleep duration of 7-9 hours per night, their insulin and glucose levels reverted to normal.

In conclusion, this study provides valuable insights into the health consequences of even minor sleep deficits in women of all age groups and various racial and ethnic backgrounds. Corinne Silva, Ph.D., a Program Director in the Division of Diabetes, Endocrinology, & Metabolic Diseases at NIDDK, highlighted the significance of these findings and mentioned that researchers plan to conduct further studies to deepen their understanding of how sleep deficiency affects metabolism in both men and women. Additionally, they intend to explore the potential use of sleep interventions as a preventive tool in addressing type 2 diabetes.

Reference:
“Chronic Insufficient Sleep in Women Impairs Insulin Sensitivity Independent of Adiposity Changes: Results of a Randomized Trial” by Faris M. Zuraikat; Blandine Laferrère; Bin Cheng; Samantha E. Scaccia; Zuoqiao Cui; Brooke Aggarwal; Sanja Jelic and Marie-Pierre St-Onge, 13 November 2023, Diabetes Care.
DOI: 10.2337/dc23-1156

Funding for this study was provided by NHLBI (R01HL128226, R35HL155670, T32HL007343, R01HL106041, R01HL137234) and NIDDK (R01DK128154, R01DK128154, P30DK063608, R01DK128154), with clinical trial support from the National Center for Advancing Translational Sciences (NCATS; UL1TR001873).

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• NIH – National Heart, Lung, and Blood Institute
• NIDDK – National Institute of Diabetes and Digestive and Kidney Diseases
• Diabetes Care Journal
• Columbia University Vagelos College of Physicians and Surgeons
• National Center for Advancing Translational Sciences (NCATS)