1. Epidemiologic Research and Information Center, VA Puget Sound Health Care System, Seattle, WA, USA.
2. Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
4. Division of Endocrinology and Metabolism, Department of Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea.
5. Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
6. Hospital and Specialty Medicine Service, VA Puget Sound Health Care System, Seattle, WA, USA.
7. Department of Anthropology, University of Washington, Seattle, WA, USA.