7. Patients with risk factors of diabetes mellitus may be enrolled in the study, provided that the patient's disease is stable and that there have been no recent (within 3 months) admissions for diabetic ketoacidosis, hyperosmolar coma, or hypoglycemia. Patients with non-insulin-dependent diabetes may enroll in the study if controlled on diet or oral medications. All diabetic patients must have a HbA1c concentration of <=10% and a plasma glucose concentration of <= 250 mg/dL.