Epidemiology Discipline/Disease Control Module, The University of Texas, School of Public Health, Houston, Texas, USA [B. C.]; Department of Internal Medicine, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA [C. G., I. deG.]; Departments of Pediatrics and Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [P. K., G. C.]; Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, USA [G. H., R. M.]; and Lipid Metabolism Branch, National Heart, Lung, and Blood Institute National Institutes of Health, Bethesda, Maryland, USA [I. T, B. R.]