Dietary protein increases the postprandial glycemic response and insulin requirements in people with type 1 diabetes (T1D). The aim of this study was to determine the appropriate amount of additional insulin required for the protein content of a meal to prevent postprandial hyperglycemia. Twenty-nine subjects (12 male) with T1D using CSII (HbA1c<8.1%/65mmol/mol) aged 10-40 years consumed 5 test meals containing 50g protein, 0g fat and 30g CHO. Insulin doses were calculated based on the individual insulin:CHO ratio with 0 (standard), 15, 30, 45 and 60% additional insulin added to the dose and delivered over 3 hours using a dual/combination bolus. Postprandial glycemia was assessed by 4 hours of CGM. Standard insulin dosing resulted in delayed and sustained postprandial hyperglycemia. From 150 minutes, additional insulin doses of 30% resulted in significantly lower postprandial glycemic excursions, returning to baseline by 4 hours; compared with 0-15% additional insulin (p<0.05). Additional insulin doses of 45 and 60% resulted in increased episodes of hypoglycemia in 50% (n=15) and 80% (n=23) of participants respectively. This study demonstrates that adding 30% more insulin to a standard meal-time dose for a high protein meal, delivered using a dual/combination bolus, improves postprandial glycemia in individuals with T1D using CSII.
M.A. Paterson: None. C.E. Smart: None. J. Rafferty: None. B. Fenton: None. D. Price: None. D.C. Foskett: None. A. Maher: None. P. Howley: None. B.R. King: None.
John Hunter Children's Hospital; Dexcom External Research Program
