[Benefits of subcutaneous continuous insulin infusion in type 1 diabetic patients with high glycemic variability]

Abstract

Background: Hypoglycemia limits the efficacy of intensive insulin therapy, especially in patients with great glucose variability. The extent to which continuous subcutaneous insulin infusion (CSII) overcomes this limitation is unclear. Our aim was to determine whether CSII is helpful for decreasing glucose variability and hypoglycemia, mainly in patients with the greatest variability.

Method: Twenty-four patients with type 1 diabetes wore a continuous glucose monitoring system sensor for three days before starting therapy with CSII and 6 months later. Glucose variability (SD, MAGE, M) and hypoglycemia duration (area under the curve (AUC) <70mg/dL) were compared in all patients and in those with the greatest MAGE (highest quartile).

Results: At 6 months, a decreased glucose variability was seen, as measured by MAGE, M, and SD (median: -28mg/dL (interquartile range, -48 to 1), p=0.03; -22(-40 to 0), p=0.04; -11(-23 to 0), p=0.009; respectively). Patients with the greatest initial glucose variability (MAGE quartile 4) showed a greater decrease in both MAGE (-47mg/dL (-103 to -34) vs -20 (-36 to 17), p=0.01) and AUC <70 (-10.7mg/dL x day (-15 to 0) vs -1.1 (-4.7 to 3.8), p=0.03) as compared to all others. Patients with longer initial hypoglycemia (AUC quartile 4) achieved a greater reduction in AUC <70 (-9.7mg/dL x day(-15 to -6.5) vs -0.08 (-2.9 to 3.8), p=0.003). A correlation was found between ΔMAGE-ΔAUC (r 0.4, p=0.03).

Conclusions: During CSII, glucose variability significantly decreased, especially in patients with the greatest initial variability. Hypoglycemia was also markedly less in patients with greater variability, with the greatest reduction occurring in those who experienced more marked hypoglycemia with CSII.