The pattern and quantity of insulin required for high protein high fat (HPHF) meals is not well understood.This study aimed to determine the amount and delivery pattern of insulin required to maintain euglycaemia for five hours after consuming a HPHF meal compared to a low protein low fat (LPLF) meal.Randomised cross-over clinical trial.Two Australian paediatric diabetes centres.12 - 21 year olds (n=10) with type 1 diabetes ≥1 year.Participants were randomised to HPHF meal (60g protein, 40g fat) or LPLF meal (5g protein, 5g fat) with identical carbohydrate content (30g). A modified insulin clamp technique was used to determine insulin requirements to maintain postprandial euglycaemia for five hours.Total mean insulin requirements over five hours.The total mean insulin requirements for the HPHF meal were significantly greater than for the LPLF meal [11.0 (CI 9.2,12.8) units vs 5.7 (CI 3.8,7.5) units; p=0.001]. Extra intravenous insulin was required for the HPHF meal; 0-2 hours (extra 1.2 (CI 0.6, 1.6) units/hr), 2-4 hours (extra 1.1 (CI 0.6,1.6) units/hr) and 4-5 hours (extra 0.6 (CI 0.1,1.1) units/hr) after the meal. There were marked inter-individual differences in the quantity of additional insulin (0.3 to 5 times more for HPHF) and the pattern of insulin delivery (0-85% of additional insulin required in the first two hours).The addition of protein and fat to a standardised carbohydrate meal almost doubled the mean insulin requirement, with most participants requiring half of the additional insulin in the first two hours.
Barbara Keating, Carmel E M Smart, Amelia J Harray, Nirubasini Paramalingam, Grant Smith, Timothy W Jones, Bruce R King, Elizabeth A Davis