1. Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, AL, USA
2. Veterans Affairs Medical Center, Birmingham, AL, USA
3. Department of Medicine, Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
4. Department of Molecular Genetics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
5. Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences, Little Rock, AR, USA