Optimized Mealtime Insulin Dosing for Fat and Protein in Type 1 Diabetes: Application of a Model-Based Approach to Derive Insulin Doses for Open-Loop Diabetes Management Diabetes Care 2016;39:1631–1634 | DOI: 10.2337/dc15-2855 OBJECTIVE To determine insulin dose adjustments required for coverage of high-fat, high- protein (HFHP) meals in type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS Ten adults with T1D received low-fat, low-protein (LFLP) and HFHP meals with identical carbohydrate content, covered with identical insulin doses. On subse- quent occasions, subjects repeated the HFHP meal with an adaptive model- predictive insulin bolus until target postprandial glycemic control was achieved. RESULTS With the same insulin dose, the HFHP increased the glucose incremental area under the curve over twofold (13,320 6 2,960 vs. 27,092 6 1,709 mg/dL · min; P = 0.0013). To achieve target glucose control following the HFHP, 65% more insulin was required (range 17%–124%) with a 30%/70% split over 2.4 h. CONCLUSIONS This study demonstrates that insulin dose calculations need to consider meal com- position in addition to carbohydrate content and provides the foundation for new insulin-dosing algorithms to cover meals of varying macronutrient composition. Studies have demonstrated that dietary fat and protein cause postprandial hyper- glycemia in patients with type 1 diabetes (T1D) (1), but definitive experimental data to guide clinical practice recommendations on how to adjust prandial insulin doses for higher fat and higher protein meals are lacking. The objective of the current study was to 1) determine the incremental differ- ences in postprandial glycemia following a high-fat, high-protein (HFHP) meal com- pared with a low-fat, low-protein (LFLP) meal with identical carbohydrate content and 2) determine how insulin doses should be adjusted to cover the HFHP meal. RESEARCH DESIGN AND METHODS Subjects Ten adults with T1D using insulin pump and continuous glucose monitoring, aged 18–75 years, with T1D for .3 years, using an insulin pump for .6 months, and with 1 Charles Perkins Centre and the School of Molecular Bioscience, The University of Sydney, Sydney, New South Wales, Australia 2 Joslin Diabetes Center, Boston, MA 3 Harvard Medical School, Boston, MA 4 Boston Children’s Hospital, Boston, MA Corresponding author: Howard A. Wolpert, howard.wolpert@joslin.harvard.edu. Received 31 December 2015 and accepted 24 May 2016. Clinical trial reg. no. NCT02248454, clinicaltrials .gov. This article contains Supplementary Data online at http://care.diabetesjournals.org/lookup/ suppl/doi:10.2337/dc15-2855/-/DC1. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More in- formation is available at http://diabetesjournals .org/site/license. Kirstine J. Bell, 1,2 Elena Toschi, 2,3 Garry M. Steil, 3,4 and Howard A. Wolpert 2,3 Diabetes Care Volume 39, September 2016 1631 NOVEL COMMUNICATIONS IN DIABETES Downloaded from http://diabetesjournals.org/care/article-pdf/39/9/1631/626278/dc152855.pdf by guest on 11 April 2024