Factors Beyond Carbs Might Influence Post Prandial Blood Glucose in T1DM Patients

A hybrid closed-loop system (HCLS) automatically delivers basal insulin according to an algorithm based on continuous glucose monitoring (CGM). However, there is very little information on the nutritional factors influencing postprandial glucose control in individuals with type 1 diabetes on HCLSs. Therefore, Dr Giovanni Annuzzi and his team conducted the first study to evaluate the relationship between meal nutrients and PGR in individuals with type 1 diabetes on an HCLS.

The researchers assessed the dietary composition of 1264 meals (398 breakfasts, 441 lunches and 425 dinners) was assessed by 7-day food records completed by 25 individuals with type 1 diabetes on HCLSs. For each meal, they evaluated the PGR (continuous glucose monitoring metrics, glucose incremental AUCs) and insulin doses (pre-meal boluses, post-meal micro boluses automatically delivered by the pump and adjustment boluses) over 6 hours.

Key findings of the study:

• Upon analysis, the researchers found that breakfast, lunch and dinner significantly differed with respect to energy and nutrient intake and insulin doses.
• They also found that the blood glucose postprandial profile showed an earlier peak after breakfast and a slow increase until 4 h after lunch and dinner.
• They noted that the mean ± SD postprandial time in range (TIR) was better at breakfast (79.3 ± 22.2%) than at lunch (71.3 ± 23.9%) or dinner (70.0 ± 25.9%).
• They observed significant negative predictors of TIR at breakfast on total energy intake, per cent intake of total protein and monounsaturated fatty acids, glycaemic load and absolute amounts of cholesterol, carbohydrates and simple sugars consumed.
• However, they observed no significant predictors for TIR at lunch.
• For TIR at dinner, they noted that the significant positive predictor was the per cent intake of plant proteins, while negative predictors were glycaemic load and intake amounts of simple sugars and carbohydrates.

The authors wrote, "A comprehensive nutritional education is a key factor to optimise blood glucose control in individuals with type 1 diabetes even in the era of advanced technologies. "

They concluded, "This study shows that nutritional factors other than the amount of carbohydrate significantly influence postprandial blood glucose control. These nutritional determinants vary between breakfast, lunch and dinner, with differing effects on postprandial blood glucose profile and insulin requirements, thus remaining a challenge to HCLSs."

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DOI: https://doi.org/10.1007/s00125-021-05587-0