Antecedent caloric intake and glucose excursion following a subsequent meal in Type 1 diabetes

Abstract

Background: In the present study, we tested the hypothesis that calories consumed at a prior meal (lunch) may impair glycemic control after a subsequent meal (supper) even if the pre-supper glucose did not differ regardless of the size of the lunch meal.

Methods: Nine subjects with Type 1 diabetes using continuous subcutaneous (s.c.) insulin infusion (CSII) therapy were studied on two separate days. Lunch (1200 h) was randomly assigned as 25% or 50% of the usual daily intake on alternate study days. The CSII was stopped at 1000 h on the day of the study and glucose was controlled until supper by adjusting the rate of intravenous (i.v.) insulin based on glucose measurements every 15 min. The CSII was restarted 1 h before supper and i.v. insulin discontinued 15 min before the first bite of supper. An identical supper meal and pre-supper s.c. bolus of short-acting insulin were administered on both visits.

Results: Pre-supper glycemia was nearly identical on each of the two study days. However, the post-supper glucose area under the curve was 27.5% greater on the day of the antecedent large lunch compared with the small lunch (P = 0.0039).

Conclusions: For optimal postprandial glucose control, people with Type 1 diabetes may need to consider not only anticipated meal calories, but also prior food intake, a practice not commonly recommended based on currently used insulin dosing algorithms.

Keywords: blood glucose; diet; insulin; insulin infusion systems.

Figure 1

(a) Insulin infusion rates and (b) blood glucose concentrations prior to 1600 h indicated by clock time in subjects given a large (●) or small (○) lunch. Data are the mean ± SD.

Figure 2

Insulin and glucose infusion rates and post-supper glucose excursion plotted against time relative to the onset of supper (Time 0). (a) Insulin infusion rates and (b) blood glucose concentrations in subjects given a large (●) or small (○) lunch. (c) Glucose area under the post-supper curves (AUC) following the larger and smaller lunch. Because not all supper feedings were administered at exactly the same time, the values in (a) and (b) do not correspond precisely with the values in Fig. 1. Data are the mean ± SD (n = 9). *P < 0.05, **P < 0.01 compared with values on the day of the smaller lunch (Wilcoxon matched-pairs test with each subject as his or her own control).