1. Division of Endocrinology and Metabolism, Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, U.S.A.
2. Medicine Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, U.S.A.
3. Knowledge and Evaluation Research Unit, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, Minnesota, U.S.A.