Sleep Deprivation Increases Diabetes Risk

Decreased sleep duration and quality may increase the risk of obesity and diabetes, according to Dr. Eve Van Cauter from the University of Chicago, US.

"Sleep curtailment has become common in industrialized countries, while simultaneously aging of population is associated with an increased prevalence of sleep disturbances," noted Van Cauter at her plenary lecture.

She reported studies in healthy volunteers demonstrating that sleep restriction to about 4-6 hours/day was associated with an adverse impact on glucose homeostasis. "Insulin sensitivity decrease rapidly and significantly without adequate compensation in beta-cell function, resulting in an elevated risk of diabetes," she said.

This adverse impact of sleep loss was shown to mediated by multiple mechanisms, including increased sympathetic nervous activity, decreased glucose uptake by the brain and elevated evening cortisol levels.

"Furthermore, reduced sleep quality, even without change in sleep duration, is also linked to an increased risk of diabetes," Van Cauter added. "We demonstrated that selective suppression of slow-wave sleep resulted in a rapid and marked reduction in insulin sensitivity. This was validated in prospective epidemiological studies in children and adults, which also indicate a role for sleep disturbances in an increased risk of dysglycemia."

In addition, sleep deprivation was also associated with dysregulation of the neuroendocrine control of appetite. Under conditions of controlled caloric intake and energy expenditure, a negative relationship was shown between sleep duration and leptin levels. "In a randomized crossover study design, where subjects had 2 days of 4 hours sleep per day followed by 2 days of 8 hours per day, leptin levels decreased and ghrelin levels increased during the short sleep days. The change in ghrelin to leptin ratio was strongly correlated to increased hunger," she reported.

The researches postulated that sleep loss alters the ability of leptin and ghrelin to accurately signal caloric need. Consistent with laboratory evidence, epidemiologic studies have also demonstrated that shorter sleep duration was associated with a higher BMI.

"Taken together, current evidence indicates that chronic sleep quality - a novel behavior that appears to have developed in our '24-hour society' - may play a role in the current epidemic of obesity and diabetes," concluded Van Cauter.