An additional bolus of rapid-acting insulin to normalise postprandial cardiovascular risk factors following a high-carbohydrate high-fat meal in patients with type 1 diabetes: A randomised controlled trial

Aim: To evaluate an additional rapid-acting insulin bolus on postprandial lipaemia, inflammation, and pro-coagulation following high-carbohydrate high-fat feeding in people with type 1 diabetes. Methods: Ten males with type 1 diabetes (HbA1c 52.5±5.9 mmol/mol [7.0±0.5%]) underwent three conditions: 1) a low-fat meal with normal bolus insulin (LF), 2), a high-fat meal with normal bolus insulin (HF), 3) a high-fat meal with normal bolus insulin with an additional 30% insulin bolus administered 3-hrs post-meal (HFA). Meals had identical carbohydrate and protein content and bolus insulin dose determined by carbohydrate-counting. Blood was sampled periodically for 6-hr post-meal and analysed for TG, NEFA, APOB48, glucagon, TNF-α, fibrinogen, HTF activity, and PAI-1. Continuous glucose monitoring captured interstitial glucose responses. Results: TG concentrations following LF remained similar to baseline, whereas TG levels following HF were significantly greater throughout the 6-hour observation period. The additional insulin bolus (HFA) normalised TG similarly to LF 3-6-hrs following the meal. HF was associated with late postprandial elevations in TNF-α, whereas LF and HFA was not. Fibrinogen, PAI-1, and TFP levels were similar between conditions. Conclusions: Additional bolus insulin 3-hrs following a high-carbohydrate high-fat meal prevents late rises in postprandial TGs and TNF-α, thus improving cardiovascular risk profile.