Impact of dietary protein and fat on postprandial glycemic response in adolescents with TYPE 1 diabetes and assessment of the management of this response through insulin regimen

This study was designed as a mono-center, randomized single-blind study with regards to insulin, and conducted on 11 participants aged between 12-18 with Type 1 diabetes using continuous subcutaneous insulin infusion (CSII) in order to determine the impact of dietary protein and fat taken on the postprandial blood glucose levels in adolescents with Type 1 diabetes, to assess the management of this impact through insulin regimen, and to analyze the effect of the dietary fat and protein on glucagon, glucagon-like peptide-1 (GLP-1) and free fatty acid (FFA) levels. Each volunteer was invited to the hospital on four different days and given four breakfast meals, one of which was a standard meal (SM) and three were high-fat-high-protein meals (HFHP). The insulin dose and its delivery method were based on carbohydrate counting in the SM and HFHP meal; additional fat counting and fat-protein counting were used to manage glucose in the HFHP-a and HFHP-b meals, respectively. The additional doses of insulin calculated by fat and fat-protein counting during the HFHP-a and HFHP-b meals, respectively were delivered via CSII as an extended bolus over 4 hours. The plasma glucagon, GLP-1 and FFA levels of the participants were assessed in venous blood samples drawn before and 30th, 60th, 90th, 120th, 240th, 360th minutes following the SM and HFHP meals. Whilst the effects of the meals on the glucose profile were assessed, the incremental area under the curve (iAUC) of 6 hours following the meals as well as glucose levels were compared. While the median age of the participants was 17.50 years. A significant difference between meals was found (p<0.05) after the 240th minute using the capillary glucose measurements, whereas a significant difference was present after the 60th minute in the interstitial glucose measurements. Capillary measurements revealed that the blood glucose level following the HFHP meal was significantly higher in the 240th, 300th and 360th minutes (p=0.003, p=0.002, p<0.001, respectively) than that of SM. On the other hand postprandial glucose levels in SM and HFHP-b meal were similar. Postprandial glycemic response was significantly lower in HFHP-b meal in comparison to the HFHP meal, both in the early (0-120 min iAUC) and late (120-360 min iAUC) period (p=0.001 and p<0.001, respectively). There was no difference between plasma glucagon, GLP-1 and FFA levels following the SM and HFHP meals (p<0.05). High-fat and high-protein meals cause an increase in glycemic response in participants with Type 1 diabetes particularly in the late postprandial period. This postprandial glycemic excursion can be improved using an insulin regimen based on fat-protein counting in addition to carbohydrate counting, instead of mere carbohydrate counting in mixed meals. However, recommendations should be individualized by evaluating the sensitivity of individuals to dietary fat and protein.