Obstructive Sleep Apnea (OSA), Sleepiness, and Activity in Diabetes Management

Daily physical activity is important to achieve glucose control in persons with type 2 diabetes. The purpose of this study is to explore if obstructive sleep apnea and its daytime symptom, excessive sleepiness, act as barriers to physical activity. We will examine if treatment of obstructive sleep apnea with continuous positive airway pressure results in increased physical activity in persons with type 2 diabetes.

Obstructive sleep apnea (OSA) is a serious disorder characterized by episodic obstruction of the pharyngeal airway accompanied by cessation or reduction in airflow. Untreated OSA has a negative impact 24 hours a day, disrupting nighttime sleep and causing excessive daytime sleepiness that interferes with functioning. Recent studies suggest that OSA and type 2 diabetes (T2DM) not only co-exist but that OSA may adversely affect glucose homeostasis. While physical activity is recognized as beneficial to persons with T2DM, OSA severity or daytime sleepiness may act to hinder persons with T2DM from participating in physical activity. The primary aim of this pilot/feasibility study is to obtain preliminary data to facilitate further hypothesis development and enhance the feasibility of conducting a double blind, randomized, placebo-controlled study to examine physical activity in subjects with T2DM and OSA who are treated with CPAP compared to subjects on sham-CPAP. The secondary aims are to explore: 1) the interrelationships of OSA severity, daytime sleepiness, and physical activity on glucose variability at baseline; 2) average pre-post therapy changes in glucose variability in subjects treated with CPAP compared to subjects receiving sham-CPAP, and 3) pre to post therapy changes in weight, diet, residual sleepiness and mood in subjects treated with CPAP compared to subjects receiving sham-CPAP.

The primary endpoint of the study, physical activity, will be measured by the Bodymedia SenseWear Pro Armband® to determine activity counts. The endpoint for glucose variability will be measured by the Medtronic Continuous Glucose Monitoring System (CGMS). Adherence to CPAP will be measured by a Smart Card® inserted in subjects' CPAP machines. We will limit the sample of subjects who are randomized to CPAP or sham-CPAP to persons with an adequate sleep duration pre-treatment (\> 6 hours), with moderate or severe OSA and with EDS to have a more homogenous, profoundly affected sample for this pilot study. The information that will result from the proposed study on of the effect of OSA and EDS on glucose variability has the potential to lead to the development of improved behavioral interventions in persons with diabetes. In addition, this study contains measures of diet and mood to begin to elucidate the possible effects of OSA and EDS on diabetes management.

Eligibility Criteria:
Inclusion Criteria:

* T2DM (verified by primary care provider (PCP) or medication for T2DM)
* AHI (from PSG) greater than \> 15
* A1c \< 9.0%
* Epworth Sleepiness Sca;e \> 10 (Baseline Assessment)
* Able to ambulate independently or with a cane
* Age 40-65 years
* BMI\< 45
* No acute medical and psychiatric illness in past 3 months
* Self-reported sleep duration of at least 6 hours
* No changes in medications, including diabetic medications, in last 3 months
* Telephone access
* Able to perform study tests (e.g., speak, read and write in English)
* Willing to be randomized to CPAP or sham-CPAP

Exclusion Criteria:

* Diagnosis of another sleep disorder, in addition to OSA,
* Oxygen or Bi-level positive airway pressure required for treatment of OSA
* An oxygen saturation \<75% for \>10% of the diagnostic PSG or if subject has oxygen saturation \<75% for \>25% of the first 4 h of the diagnostic PSG
* Any individual in the household currently or with history of CPAP treatment
* Type 1 or gestational diabetes
* Prescribed insulin for treatment of type 2 diabetes
* Regular use (\> 3 times/week) of hypnotic or alerting medications
* History of a near-miss or automobile accident due to sleepiness
* Employed in transportation-related safety sensitive occupation such as an airline pilot, truck driver, or train engineer
* Currently working night or rotating shifts
* Routine consumption of alcohol as determined by \>2 drinks day
* Known allergy to medical adhesives or dermatological conditions that would preclude wearing CGMS
* Swim or water aerobics \>once a week
* Participation in contact sports or activity that may damage CGMS device or cause injury from monitor
* Claustrophobia that prevents wearing the CPAP mask
* Pregnancy