Significance of the suppression of blood glucose variability in acutely ill severe patients with glucose intolerance evaluated by means of bedside-type artificial pancreas

Introduction

We hereby report the usefulness of continuous use of an artificial pancreas (AP) to control blood glucose (BG) clinically. In this report we analyzed the significance of BG stability, or variability under strict control of BG, by the use of an AP.

Methods

BG control was performed by an AP, STG22. Patients were evaluated at early (E) phase and late (L) phase (1 week after the E phase). Based on the daily mean BG (BGm), basically calculated by 24 data obtained hourly, patients were classified into two groups. Patients with BGm <200 mg/dl and those with BGm >200 mg/dl were denoted as group B and group A, respectively. Each group was classified into two subgroups based on the daily BG difference (BGd), or 100 mg/dl, high and low variability subgroups. Group B patients with BGd <100 mg/dl were denoted BL, and group B patients with BGd >100 mg/d as BH. Subgroups AL and AH were classified similarly. The parameters studied were BGm, BGd, SOFA score and mortality.

Results

(1) Group A had BGm in the E phase and L phase of 231 ± 24 (n = 11) and 220 ± 19 (n = 7), respectively. Group B had BGm in the E phase and L phase of 175 ± 19 (n = 35) and 166 ± 21 (n = 42), respectively. (2) Relationship between BGm and BGd: (E phase) group A had the tendency of higher BGd as compared with group B (101 ± 60 vs 68 ± 46, P < 0.10); (L phase) group A had significantly higher BGd as compared with group B (109 ± 43 vs 66 ± 46, P < 0.025). (3) Relationships between BGd and SOFA score, mortality: (E phase) group AH had the tendency of higher mortality as compared with group AL (100%, n = 3 vs 50%, n = 8); (L phase) group BH had the tendency of higher SOFA score and mortality as compared with group BL (8.0 ± 6.7, 80%, n = 5 vs 6.7 ± 5.7, 38%, n = 37).

Conclusion

Although this is a preliminary study, based on the precise data measured by the AP, the following conclusions were suggested. High BG variability or unstability supported high morbidity and mortality. BG control aimed at the suppression of BG variability, or BGd lower than 100 mg/dl, may therefore improve the outcome as well as the improvement of BGm.