Sleep Extension or Regularity to Reduce Diabetes Risk

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 and Black 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 and Black 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 and Black adults.

Inclusion criteria

• African American or Black men and women
• Age 21-50 years old
• Overweight (BMI greater than or equal 25 kg/m2 and less than 35 kg/m2)
• Self-reported short sleep (less than 7hrs/night, sleep between 22:00-08:00, and who indicate they could sleep more if they had the opportunity)
• No previously diagnosed sleep disorders (including obstructive sleep apnea (OSA))
• No existing diagnosis of diabetes
• No history of endocrine dysfunction
• No history of psychiatric, cardiovascular, or eating disorders, not having a gastro-intestinal disease that requires dietary adjustment,
• Currently taking no medications (excluding statins and birth control)

Exclusion criteria

• Drug and nicotine use
• Habitual alcohol use of more than 2 drinks per day
• Caffeine intake of more than 500 mg per day
• Subjects who participated in medically managed weight loss program within the past year
• Subjects who have undergone bariatric surgery,
• Subjects who have dietary restrictions,
• Subjects who worked night shifts, or crossed any time zones in the month prior to the study.
• Sleep-disordered breathing (apnea-hypopnea index>15 events/hour) from an overnight at home sleep test (NOX)
• Peri- and post-menopausal women will not be included.