Improved Insulin Sensitivity in Men after 'Catch-Up' Sleep

According to a recent randomized, two-period cross-over study, men who do not regularly sleep adequate amounts during the week may be able to improve their insulin sensitivity by “catching up” on sleep on the weekends.

Peter Y. Liu, MD, PhD, is a Visiting Professor and Senior Investigator at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center in Torrance. He reported his team’s findings at ENDO 2013: The Endocrine Society’s 95^th Annual Meeting & Expo in San Francisco on June 18, 2013.

A survey conducted by the National Sleep Foundation revealed that 40 to 50 percent of Americans report sleeping less on weekdays compared to weekends. According to Liu, many studies have examined the effects of sleep on insulin sensitivity and suggest that sleep restriction reduces insulin sensitivity by 15-25%. It has also been suggested that reduction or manipulation of slow-wave, or “deep” sleep, can affect insulin sensitivity. However, these studies have been performed in individuals who self-report normal sleep patterns. The research team aimed to investigate the effects of catch up sleep on insulin sensitivity in men with chronic, intermittent sleep restriction, as insulin resistance is a known risk factor for diabetes.

The study included 19 nondiabetic, Australian men with an average age of 28.6 years. On average, these men reported a chronic pattern (5.1 years) of sleeping for only 6.2 hours on weeknights and “catching up” on the weekends with 8.5 hours per night. Their reported sleep-wake cycles were verified by actigraphy. On two separate weekends under comparable conditions, the men slept for three nights in a sleep lab. Each subject was randomly assigned to two of three interventions: 10 hours of sleep (catch-up sleep), 6 hours of sleep (restricted sleep), or 10 hours of manipulated sleep. In this intervention, acoustic stimuli would be administered to prompt a change from deep sleep to shallow sleep without waking the subject. After the third night, an oral glucose tolerance test was performed and insulin levels were drawn. Food intake was standardized to eliminate possible dietary influence.

An increase in insulin sensitivity of 31% was seen after men received 3 nights of catch-up sleep when compared with those who got restricted sleep as measured by the oral glucose tolerance test. There was no effect on insulin sensitivity associated with sleep manipulated by acoustic stimuli. C-peptide, as a marker for insulin secretion, was found to be increased during catch up sleep.

The authors concluded that three nights of catch-up sleep improved insulin sensitivity in young men when compared with restricted sleep, and sleep extension could prevent development of insulin resistance and diabetes. Sleep is indeed important for metabolic health.

This study was funded by the National Institutes of Health’s National Center for Advancing Translational Sciences and Australia’s National Health and Medical Research Council.