Insomnia, Metabolic Syndrome and Insulin Resistance

Insomnia symptoms are linked to metabolic syndrome (MetS), which includes abnormal glucose metabolism, insulin resistance (IR), and incidence of diabetes. In young healthy individuals, shortened sleep duration results in IR and elevated free fatty acid concentrations and has been associated with circadian misalignment. Additionally, individuals with type 2 diabetes (T2D) frequently have insufficient sleep or poor sleep quality, and greater sleep disturbances are associated with poorer glycemic control. Thus chronic sleep deficit is a major predictor of disease and early mortality. Further, insomnia is the most common sleep disorder in the United States, impacting at least 10% of the general population and ~40% of those with T2D. Although stress or changes in lifestyle habits often cause short-term insomnia, chronic insomnia (Insomnia Disorder) is defined as difficulty falling or staying asleep that causes daytime impairment 3 or more nights a week, lasts 3 or more months, and cannot be fully explained by another health problem.

The recommended first line of treatment for insomnia is Cognitive Behavioral Therapy for Insomnia (CBT-I). CBT-I is a multidimensional treatment that targets the thoughts and behaviors that perpetuate insomnia symptoms over time. The cognitive components of the therapy empower patients to challenge their automatic thoughts and reactions to poor sleep, and the behavioral components focus on matching time in bed to sleep ability in order to increase homeostatic sleep drive (or natural propensity for sleep). CBT-I improves insomnia in many populations (e.g., among those with psychological and physical comorbidities, chronic pain, etc). CBT-I has also demonstrated efficacy in reducing insomnia symptoms among those with IR in two pilot studies, but no studies have been powered to test CBT-I effects on metabolic outcomes within this population.

Obesity is a leading risk factor for impaired metabolic health. Given the impact of insomnia symptoms on MetS, effective treatment of insomnia may improve metabolic outcomes among those with obesity. This study aims to:

1. Demonstrate the feasibility of the proposed CBT-I protocol. Specifically, the investigators hypothesize that ≥85% of participants will complete all assigned treatment sessions and follow-ups.
2. Replicate previous findings that CBT-I reduces insomnia among obese adults with insomnia.
3. Explore CBT-I effects on MetS outcomes (ie. blood pressure, triglycerides, etc.).
4. Provide preliminary evidence that CBT-I impacts IR and fasting glucose concentrations within this population.

20 subjects with insomnia will be recruited. Participants will be randomly assigned to either CBT-i or sleep hygiene. The intervention is 5 wks. Pre and post intervention, the investigators will have participants fill out a number of questionnaires, a daily sleep diary, 2 weeks of actigraphy measuring sleep and physical activity and there will be a single blood draw at the beginning and the end of the study.