ESPE Abstracts

Background: Management of people with T1DM on intensive insulin therapy (IIT) uses algorithms based on the meal carbohydrate (CHO) content (MCC) to calculate prandial insulin dose. Typically, these calculations do not consider the meal content of fat or protein.

Objective: To determine if the postprandial blood glucose (BG) response to varying fat content is dose dependent when standard insulin bolus is given based on MCC.

Methods: Randomised repeat testing of 30 patients with T1DM >1 year duration, aged 8–18 years on IIT. A test drink was given on six consecutive nights, at 10 PM, in random order, without insulin, 4 hours after the regular evening meal; five test drinks varying in fat content (3, 13, 25, 38, 50 g), but without CHO/protein, and one 20 g CHO drink with no fat/protein. A continuous glucose monitoring system was used to assess BG levels at 10 minute intervals for 8 hours afterwards. Area under the BG excursion curve was calculated for each individual and analysed for each one-hour block after the drink. Generalised linear mixed models (GLM) with a random effect for the individual patients, were used to determine if there was a statistically significant difference between BG excursions after 20 g CHO drink compared to drinks containing fat. The dose response was estimated using similar GLM but excluding the CHO drink and treating the BG excursions as a continuous variable.

Results: There were thirty paritcipants of whom 17 (56.7%) were female, age 8–16 years, with median BMI 19.8 kg/m². The CHO drink increased average BG but this increase wasn’t seen with consumption of the drinks containing fat. Over the early postprandial period, patients who consumed the CHO drink had higher BG excursions than after consumption of the fat drinks (all P-values < 0.01). This remained statistically higher than some fat drinks at 3 hours after which the BG excursions of patients who had consumed the fat drinks tended to rise but did not reach significance until 6 hours. The dose response in AUC for fat became statistically significant between 6 and 7 hours (P=0.024), and 7 to 8 hours (P=0.015).

Conclusions: Fat lowers BGL in the first 4 hours after ingestion, in contrast with the increased glycaemia following a 20 g glucose ingestion without insulin. Fat increases BGL 6-8 hours after ingestion in a dose dependent manner. These observations may impact on insulin dosing for high-fat meals in intensive insulin therapy.