Effects of Sleep Duration and Architecture on Insulin Sensitivity

Over the past 50 years, the incidence of diabetes has increased dramatically, while sleep duration in the US has decreased significantly. Epidemiological studies and small clinical trials suggest that these trends are causally related. In this study, our goal is to determine the mechanisms by which decreased sleep duration directly affects insulin sensitivity. The investigators will perform a clinical study in 20 healthy volunteers to determine whether 5 nights of sleep restriction decreases insulin sensitivity in the peripheral tissues (ie, skeletal muscle) or liver.

Peripheral insulin sensitivity will be measured by the hyperinsulinemic-euglycemic clamp, and hepatic insulin sensitivity will be quantified by measurement of hepatic glucose production, gluconeogenesis and glycogenolysis (using stable isotope tracer methods). Subjects will be randomized to an initial period of "normal sleep" or sleep restriction and will be admitted to the Clinical Research Center (CRC) for 9 days to undergo comprehensive metabolic studies and sleep assessments under the assigned sleep condition. After a 1-month washout period, subjects will be re-admitted to the CRC to undergo these same assessments under the opposite sleep condition.