Sleep Extension or Regularity to Reduce Diabetes Risk in African American Adults

Study Overview
=================
Brief Summary
-----------------
The goal of this study is to identify an intervention that improves sleep health and consequently metabolic health by examining whether sleep extension or enforced regularity in short sleepers will have beneficial effects on diabetes and obesity risk.

Detailed Description
-----------------
Numerous studies of restricted sleep have revealed insufficient sleep as a novel risk factor for metabolic disease. Specifically, it has been reported that insufficient sleep resulted in impairments in appetite regulation, energy intake, glucose tolerance, and insulin sensitivity. Further, recent studies have begun to reveal that the regularity of sleep timing may also impact metabolic health, in that increased sleep variability was associated with greater cardio-metabolic risk. Alternatively, only a few studies have explored whether sleep extension could be beneficial to metabolic outcomes, and no studies have focused on improved regularity or racial disparities. These studies have revealed improvements in glucose metabolism and caloric intake in predominantly non-Hispanic White individuals. Therefore, in this pilot study, we seek to examine whether sleep extension or enforced regularity can improve diabetes and obesity risk in a population known to be differentially impacted by sleep deficiency and metabolic disease, short sleeping African American adults. The investigator proposes to first assess sleep duration, food intake, ratings of hunger/appetite and reward-related eating, daily interstitial glucose, resting metabolic rate, insulin sensitivity, and glucose tolerance in short sleeping overweight African American adults during a baseline/habitual sleep assessment. Participants will then be randomized to one of two different 14-day sleep interventions: sleep extension or sleep regularity. Following the intervention, assessments of food intake, ratings of hunger/appetite and reward-related eating, daily interstitial glucose, resting metabolic rate, insulin sensitivity, and glucose tolerance will be repeated. The goal of this pilot project is to demonstrate feasibility of our study design, particularly effectively impacting sleep in the home. The aims of this pilot study are to demonstrate: that participants can extend sleep by  2 hours or adhere to sleep regularly within a 30min window at home for two weeks, changes in glucose metabolism following the interventions and changes in subjective hunger/appetite ratings and food intake This experimental approach is expected to reveal novel and important interventions that can have a beneficial impact on the risk of diabetes and obesity in an understudied population that suffers from increased risk, short sleeping overweight African American adults.

Official Title
-----------------
Sleep Extension or Regularity to Reduce Diabetes Risk in African American Adults

Conditions
-----------------
Overweight or Obesity

Intervention / Treatment
-----------------
* Behavioral: Sleep Extension
* Behavioral: Sleep Regularity


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: African American men and women Age: greater than 21 and no older than 50 years. Overweight [Body mass index (BMI) greater than or equal to 25 to 30 kg/m2] Self-reported short sleep (less than 7hrs /night, sleep between 22:00-08:00, could sleep more if time permitted) Exclusion Criteria: Anyone who does not meet the inclusion criteria will be excluded from the study.

Ages Eligible for Study
-----------------
Minimum Age: 21 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective, randomized and unblinded
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sleep Extension<br>Participants that are in the sleep extension group will have their time in bed extended by 2 hours. This can include going to bed earlier and/or waking up later. | Behavioral: Sleep Extension<br>* Extending time in bed by 2 hours (going to bed earlier and/or waking up later)<br>|
| Experimental: Sleep Regularity<br>Participants in the sleep regularity group will have consistent bedtimes (within 30min). | Behavioral: Sleep Regularity<br>* Consistent bedtimes (within 30min)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep outcome measures- Sleep time | A decrease in time to sleep onset from baseline to day 24 measured in time of day by Wrist Actigraphy Monitoring. | Baseline to Day 24 | 
| Sleep Outcome- Wake time | Change in wake time from baseline to day 24 measured in time of day by Wrist Actigraphy Monitoring. | Baseline to Day 24 | 
| Sleep outcome- Sleep duration | Change in Sleep duration from baseline to day 24 measured in minutes by Wrist Actigraphy Monitoring. | Baseline to Day 24 | 
| Sleep Outcome- Regularity of sleep | Change in regularity of sleep from baseline to day 24 measured by Wrist Actigraphy Monitoring. The value is from standard deviation of time of middle of the sleep period. | Baseline to Day 24 | 
| Sleep Outcome- Sleep Efficiency | Change in sleep efficiency from baseline to day 24 measure by a percentage of total sleep time/time in bed from Wrist Actigraphy Monitoring. | Baseline to Day 24 | 
| Change in glucose homeostasis after 24 days | The Matsuda Index of whole body insulin sensitivity, the homeostasis model assessment (HOMA) measures beta cell function and insulin resistance will be measured by Oral glucose tolerance test (OGTT). | Baseline to Day 24 | 
| Change in glucose homeostasis measured by Continuous Glucose Monitor (CGM) | Mean Absolute Glucose (MAG - mg/dl), Coefficient of Variation (CV - mg/dl), Standard Deviation (SD-mg/dl), Area Under the Curve (AUC - mg/dl), Time Spent in Range (TIR - minutes), Continuous Overall Net Glycemic Action (CONGA - (mg/dl) per minutes) will be measured by Continuous Glucose Monitor (CGM). | Baseline to Day 24 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes from baseline through day 24 of novel Patient Reported Outcome instrument | Detection of within-patient changes in sleep effects (sleepiness), appetite, mood, reported in a novel Patient-Reported Outcome instrument between baseline and Day 24. | Baseline to Day 24 | 
| Glucose Homeostasis-First phase insulin response | Changes in first phase insulin response (ARIg=mu.i^-1.min) from baseline to Day 24 measured by oral glucose tolerance test (OGTT). | Baseline to Day 24 | 
| Glucose Homeostasis-Oral disposition index (DIo) | Changes in oral disposition index (DIo) from baseline to Day 24 measured in (SI x ARIg = [(mu/l)^-1.min^-1] * [mu.l^-1.min]) by oral glucose tolerance test (OGTT). | Baseline to Day 24 | 
| Glucose Homeostasis- insulinogenic index | Changes in insulinogenic index (change in plasma insulin/change in plasma glucose from 0-30 minutes = (pmol/L)/(mg/dL)) from baseline to Day 24 measured by oral glucose tolerance test (OGTT). | Baseline to Day 24 | 
| Weight in kg, measured from screening through study completion. | The change in weight values will be measured by in laboratory anthropometrics measurements. | Screening to Day 24 |