1. Diabetes Centre, Ulster Hospital, South Eastern Health and Social Care Trust, Belfast, Northern Ireland.
2. Hygieia, Inc., Livonia, Michigan.
3. Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan.
4. Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan.