733-P: Postprandial Glucose Variability in People with Type 1 Diabetes Is Individual and Impacted by Physiological and Clinical Parameters

Aim: To assess whether postprandial glucose responses (PPGRs) are individual in people with type 1 diabetes (T1DM) and influenced by personal physiological and clinical parameters.

Methods: We assessed physiological and clinical parameters of one-hundred and twenty individuals with type 1 diabetes (mean±SD: Age 31±7years, BMI 26.9±2.3kg.m2, HbA_1c 7.6±0.8% [55.8±8.2mmol/moL]) and captured postprandial interstitial glucose responses via continuous glucose monitoring (CGM) in response to two carbohydrate-based standardised meals (shredded wheat [SW] or millet oat-porridge [OP]), twice, on four separate occasions. Each meal was matched for energy, fibre, and macronutrient composition, glycaemic index (GI), and insulin administration.

Results: Despite identical energy, fibre, and macronutrient content, GI, and prandial insulin administration, the average PPGR differed significantly between OP and SW, respectively (IG AUC: 1807±588 vs. 1678±533 mmol.L.min-¹; p=0.05). PPGRs to each meal type showed a high degree of reproducibility within individuals (OP r=0.994, p<0.001 vs. SW r=0.987 p<0.001), but large interpersonal variation within each meal type (CV%: OP 32.5% vs. SW 31.7%). Higher PPGR was positively associated with PPGR variability (r=0.698, p<0.001), HbA_1c (r=0.223, p=0.014), BMI (r=0.316, p<0.001), and age (r=0.277, p<0.001).

Conclusions: Using a total of 19,200 glucose measurements, we show that PPGR in individuals with type 1 diabetes is interpersonal and influenced by BMI, age, and HbA_1c. We show that identification of personal characteristics is a promising means for designing effective nutritional interventions to predict and control glycaemic responses to food in this population.