Sleep Extension and Insulin Sensitivity in Adolescents

Study Overview
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Brief Summary
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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.

Official Title
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Effect of Increasing Sleep Duration on Insulin Sensitivity in Adolescents Having Risk Factors for Type 2 Diabetes

Conditions
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Sleep

Intervention / Treatment
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* Behavioral: Sleep manipulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adolescents between the ages of 13 and 18 with obesity (body mass index greater than the 95th percentile) and dyslipidemia (total cholesterol ≥ 200 mg/dL; low-density lipoprotein cholesterol ≥ 130 mg/dL; non-high-density lipoprotein ≥ 145 mg/dL; triglycerides ≥ 130 mg/dL; and high-density lipoprotein < 40 mg/dL) Adolescents who report between 6.5-8 hours of sleep per night will be eligible to ensure that adolescents can extend and restrict sleep duration without reaching a ceiling for what can be achieved (i.e. 8-10 hours/night of sleep is recommended at this age) while limiting excessive sleep deprivation Exclusion Criteria: History of a chronic medical or psychiatric condition Use of medications that could affect sleep or glucose homeostasis (e.g., metformin, thyroid medication, stimulant medication, etc.) History of sleep problems (e.g. sleep apnea).

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional 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)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sleep Extension<br>Increase in time in bed of 1.5 hours per night for one week | Behavioral: Sleep manipulation<br>* 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.<br>|
| Experimental: Sleep Restriction<br>Decrease in time in bed of 1.5 hours per night for one week | Behavioral: Sleep manipulation<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin sensitivity | Assessed by the Matsuda index during a 2-hour oral glucose tolerance test (OGTT) | On day 8 of each sleep condition (2 time points) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin sensitivity | HOMA-IR | On day 8 of each sleep condition (2 time points) | 
| Blood lipids | HDL-cholesterol, LDL-cholesterol, triglycerides, total cholesterol | On day 8 of each sleep condition (2 time points) | 
| Food intake | 3-day dietary record | On days 5, 6 and 7 of each sleep condition (2 time points) | 
| Physical activity level | Minutes per day of moderate-to-vigorous physical activity as assessed by accelerometry | During each 7-day sleep condition (2 time points) |