1. Clinical Center for Sleep and Breathing Disorders, UT Southwestern Medical Center, Dallas, Texas
2. Department of Quantitative Health Sciences
3. Sleep Disorders Center, Neurological Institute
4. Department of Endocrinology, Diabetes, and Metabolism
5. Department of General Surgery, and
6. Department of Pulmonary, Allergy, and Critical Care Medicine, Respiratory Institute, Cleveland Clinic, Cleveland, Ohio