Sleep Extension and Insulin Sensitivity in Adolescents
Condition: Sleep
MeSH terms: Insulin Resistance
Study type: Interventional

Summary: 
      BACKGROUND: The influence of sleep extension on glucose homeostasis in adolescents at risk
      for type 2 diabetes is unknown. This issue is of high clinical relevance given the high
      prevalence of sleep deprivation in this population and the accumulating body of evidence
      indicating that having a good night's sleep is important for the prevention of chronic
      diseases including type 2 diabetes.

      OBJECTIVE: To determine if extending sleep duration improves insulin sensitivity in
      adolescents presenting with risk factors for type 2 diabetes.

      HYPOTHESIS: It was hypothesized that compared with decreasing sleep duration, increasing
      sleep duration by 1.5 hours over 1 week will improve insulin sensitivity.

      METHODS: Using a randomized, counterbalanced, 2-condition crossover design, 30 obese
      adolescents between 13 and 18 years of age who have insulin resistance will complete the
      study. Participants will sleep their typical amount at home for 1 week and will then be
      randomized to either increase or decrease their time in bed by 1.5 hours per night for 1
      week, completing the alternate schedule on the fourth week (washout period of at least 1 week
      between sleep conditions). This procedure will result in a targeted 3-hour time in bed
      difference between conditions. Sleep will be objectively measured using actigraphy
      (Actiwatch) and sleep schedule adherence will be promoted by providing fixed bedtimes and
      wake times during the experimental weeks, and will be monitored through phone calls to the
      research center. Participants will also be compensated for keeping the sleep schedule and
      daily calls to enhance adherence. The outcome measures will then be compared between both
      sleep conditions at the end (on day 8 of each study week). The primary outcome measure will
      be insulin sensitivity as measured by the Matsuda index (total body insulin sensitivity).
      Secondary outcomes will include the homeostasis model assessment of insulin resistance
      (HOMA-IR), blood lipids, food intake and physical activity. Repeated measures analysis using
      the mixed model will be used to assess the effect of the two sleep interventions on insulin
      sensitivity.

      RELEVANCE: The study will provide the first robust clinical evidence to determine if
      increasing sleep duration in youth at risk for type 2 diabetes improves insulin sensitivity.
      This information will be essential for clinical and public health guidelines for type 2
      diabetes prevention among adolescents.
    


Intervention name(s): Sleep manipulation
Intervention type(s): Behavioral
Intervention description(s): Participants will sleep their typical amount at home for 1 week and will then be randomized to either increase or decrease their time in bed by 1.5 hours per night for 1 week, completing the alternate schedule on the fourth week (washout period of 1 week between sleep conditions). This procedure will result in a targeted 3-hour time in bed difference between conditions. Sleep will be objectively measured using actigraphy (Actiwatch) and sleep schedule adherence will be promoted by providing fixed bedtimes and wake times during the experimental weeks, and will be monitored through phone calls to the research center.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Sleep restriction (-1.5 hours of sleep per day for 1 week) and Sleep extension (+1.5 hours of sleep per day for 1 week)
Masking: None (Open Label)
Primary purpose: Prevention