Relationship between Amount and Type of Dietary Fat, Postprandial Glycemia, and Insulin Requirements in Type 1 Diabetes

Abstract

ADA recommends individuals with type 1 diabetes (T1D) are taught to adjust insulin for dietary fat however optimal adjustments are not yet clear. This study aimed to determine 1) the relationship between the ‘amount’ and ‘type’ of dietary fat and glycemia and 2) the optimal insulin adjustments for dietary fat. Six adults with T1D using insulin pump therapy attended the research clinic on 9 to 12 occasions. On the first 6 visits, participants consumed meals containing 45g CHO with either 0g, 20g, 40g, or 60g fat and either saturated (SFA), monounsaturated (MUFA) or polyunsaturated (PUFA) fat. Insulin was dosed using individual insulin: carbohydrate ratio as a dual-wave 50/50% split over 2h. On subsequent visits, participants repeated the 20 to 60g fat meals with the insulin dose estimated using a model predictive bolus, with up to 2 repeats/meal until glycemic control achieved. With the same insulin dose, mean 5h incremental area under the curve (iAUC) was increased by 46%, 23% and 139% for the 3 fat loads relative to the 0g fat meal (0g: 509 ± 153; 20g: 742 ± 742; 40g: 626 ± 74; 60g: 1216 ± 434mmol/L.min; ns). The type of fat made small but non-significant differences to the 5h iAUC. To achieve glycemic control, on average, participants required 20-60% more insulin, delivered as a dual-wave over 1.25-2h. This study provides foundation for mealtime insulin dosing recommendations for dietary fat in T1D. Disclosure K. Bell: Other Relationship; Self; Novo Nordisk Inc.. S. Duke: None. K.M. Alexander: None. M. McGill: Advisory Panel; Self; Abbott. Speaker's Bureau; Self; AstraZeneca. Advisory Panel; Self; Merck Sharp & Dohme Corp.. Speaker's Bureau; Self; Merck Sharp & Dohme Corp. J. Wong: Speaker's Bureau; Self; Novo Nordisk A/S, AstraZeneca, Eli Lilly and Company. G. Fulcher: Other Relationship; Self; Novo Nordisk Inc., Janssen Scientific Affairs, LLC., Boehringer Ingelheim GmbH, Merck Sharp & Dohme Corp. S.M. Twigg: Advisory Panel; Self; Abbott. Consultant; Self; Abbott. Advisory Panel; Self; Novo Nordisk Inc., Sanofi-Aventis, AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company. Speaker's Bureau; Self; AstraZeneca, Merck Sharp & Dohme Corp.. Other Relationship; Self; Abbott. J. Brand-Miller: Board Member; Self; Glycemic Index Foundation. Other Relationship; Self; Hachette Australia. Stock/Shareholder; Spouse/Partner; Novo Nordisk A/S. Other Relationship; Self; Pam Krauss Books. G.M. Steil: Consultant; Self; Profusa, Eli Lilly and Company.