Prevention of Hypoglycemia During Exercise in Children With Type 1 Diabetes by Suspending Basal Insulin

Prevention of Hypoglycemia During Exercise in Children With Type 1 Diabetes by Suspending Basal Insulin the Diabetes Research in Children Network (DirecNet) Study Group * Address correspondence and reprint requests to Eva Tsalikian, MD, c/o DirecNet Coordinating Center, Jaeb Center for Health Research, 15310 Amberly Dr., Suite 350, Tampa, FL 33647. E-mail: direcnet{at}jaeb.org Abstract OBJECTIVE —Strategies for preventing hypoglycemia during exercise in children with type 1 diabetes have not been well studied. The Diabetes Research in Children Network (DirecNet) Study Group conducted a study to determine whether stopping basal insulin could reduce the frequency of hypoglycemia occurring during exercise. RESEARCH DESIGN AND METHODS —Using a randomized crossover design, 49 children 8–17 years of age with type 1 diabetes on insulin pump therapy were studied during structured exercise sessions on 2 days. On day 1, basal insulin was stopped during exercise, and on day 2 it was continued. Each exercise session, performed from ∼4:00–5:00 p.m. , consisted of four 15-min treadmill cycles at a target heart rate of 140 bpm (interspersed with three 5-min rest breaks over 75 min), followed by a 45-min observation period. Frequently sampled glucose concentrations (measured in the DirecNet Central Laboratory) were measured before, during, and after the exercise. RESULTS —Hypoglycemia (≤70 mg/dl) during exercise occurred less frequently when the basal insulin was discontinued than when it was continued (16 vs. 43%; P = 0.003). Hyperglycemia (increase from baseline of ≥20% to ≥200 mg/dl) 45 min after the completion of exercise was more frequent without basal insulin (27 vs. 4%; P = 0.002). There were no cases of abnormal blood ketone levels. CONCLUSIONS —Discontinuing basal insulin during exercise is an effective strategy for reducing hypoglycemia in children with type 1 diabetes, but the risk of hyperglycemia is increased. DirecNet, Diabetes Research in Children Network Footnotes * ↵ * A complete list of DirecNet Study Group members can be found in the appendix . ↵ A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances. 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 July 13, 2006. Received March 3, 2006. DIABET