Feasibility of Automating Insulin Delivery for the Treatment of Type 1 Diabetes

• Published in: Diabetes (New York, N.Y.) Vol. 55; no. 12; pp. 3344 - 3350
• Main Authors: Steil, Garry M., Rebrin, Kerstin, Darwin, Christine, Hariri, Farzam, Saad, Mohammed F.
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.12.2006
• Subjects: Adult; Automation - methods; Biological and medical sciences; Blood Glucose - drug effects; Blood Glucose - metabolism; Body Mass Index; Diabetes Mellitus, Type 1 - blood; Diabetes Mellitus, Type 1 - drug therapy; Diabetes. Impaired glucose tolerance; Drug Administration Routes; Drug therapy; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Health aspects; Humans; Hypoglycemia; Hypoglycemic Agents - administration & dosage; Hypoglycemic Agents - pharmacokinetics; Hypoglycemic Agents - therapeutic use; Infusions, Parenteral - methods; Insulin; Insulin - administration & dosage; Insulin - pharmacokinetics; Insulin - therapeutic use; Male; Medical sciences; Middle Aged; Risk factors; Type 1 diabetes; Endocrinopathy; Immunopathology; Pancreatic hormone; Treatment; Type 1 diabetes; Autoimmune disease; Insulin
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/db06-0419

Feasibility of Automating Insulin Delivery for the Treatment of Type 1 Diabetes Garry M. Steil 1 , Kerstin Rebrin 1 , Christine Darwin 2 , Farzam Hariri 2 and Mohammed F. Saad 3 1 Medtronic MiniMed, Northridge, California 2 David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 3 Departments of Medicine and Preventative Medicine, Stony Brook University, Stony Brook, New York Address correspondence and reprint requests to Dr. Garry M. Steil, Medtronic MiniMed, 18000 Devonshire St., Northridge, CA 91325. E-mail: garry.steil{at}medtronic.com Abstract An automated closed-loop insulin delivery system based on subcutaneous glucose sensing and subcutaneous insulin delivery was evaluated in 10 subjects with type 1 diabetes (2 men, 8 women, mean [±SD] age 43.4 ± 11.4 years, duration of diabetes 18.2 ± 13.5 years). Closed-loop control was assessed over ∼30 h and compared with open-loop control assessed over 3 days. Closed-loop insulin delivery was calculated using a model of the β-cell’s multiphasic insulin response to glucose. Plasma glucose was 160 ± 66 mg/dl at the start of closed loop and was thereafter reduced to 71 ± 19 by 1:00 p.m. (preprandial lunch). Fasting glucose the subsequent morning on closed loop was not different from target (124 ± 25 vs. 120 mg/dl, respectively; P > 0.05). Mean glucose levels were not different between the open and closed loop (133 ± 63 vs. 133 ± 52 mg/dl, respectively; P > 0.65). However, glucose was within the range 70–180 mg/dl 75% of the time under closed loop versus 63% for open loop. Incidence of biochemical hypoglycemia (blood glucose <60 mg/dl) was similar under the two treatments. There were no episodes of severe hypoglycemia. The data provide proof of concept that glycemic control can be achieved by a completely automated external closed-loop insulin delivery system. CGMS, continuous glucose monitoring system CSII, continuous subcutaneous insulin infusion DIR, daily insulin requirement FFA, free fatty acid MAD, mean absolute difference SG, sensor glucose Footnotes The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted September 6, 2006. Received March 29, 2006. DIABETES