1. Division of Molecular Medicine (R.S.D., C.J.H., T.J.S.), Department of Medicine, Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, California 90502
2. Jules Stein Eye Institute (R.S.D., C.J.H., T.J.S.), Los Angeles, California 90095
3. Greater Los Angeles Veterans Hospital (R.S.D.), Los Angeles, California 90095
4. David Geffen School of Medicine at UCLA (R.S.D., T.J.S.), Los Angeles, California 90095
5. Department of Endocrinology and Metabolism (T.H.B., L.H.), Odense University Hospital, 5000 Odense, Denmark
6. The Danish Twin Registry (T.H.B., L.H.), Epidemiology, Institute of Public Health, University of Southern Denmark, 5230 Odense, Denmark