Sustained efficacy of continuous subcutaneous insulin infusion in type 1 diabetes subjects with recurrent non-severe and severe hypoglycemia and hypoglycemia unawareness: a pilot study

Abstract

Background: This study evaluated the effect of CSII on hypoglycemia awareness and on glucose profile in type 1 diabetes (T1D) subjects with repeated non-severe or severe hypoglycemia (NS or SH, respectively).

Methods: We included subjects (1) older than 18 years, (2) with T1D duration of >5 years, (3) on multiple doses of insulin, and (4) without micro- or macrovascular complications and more than four NS events per week (in the last 8 weeks) and more than two SH events (in the last 2 years). NS/SH episodes and hypoglycemia awareness were evaluated. A 72-h continuous glucose monitoring (CGM) was performed before continuous subcutaneous insulin infusion (CSII). A hypoglycemia-induced test was used to evaluate each patient's symptoms in euglycemia/hypoglycemia. Quality of life (QoL) was also evaluated. After 6, 12, and 24 months, all the subjects were reevaluated.

Results: Twenty subjects were included (34.0 +/- 7.5 years old, 12 women, A1c 6.7 +/- 1.1%, 16.2 +/- 6.6 years of diabetes' duration). At baseline, 19 out of 20 subjects displayed hypoglycemia unawareness, which diminished significantly during the follow-up (3 out of 20). NH episodes per week diminished from 5.40 +/- 2.09 at baseline to 2.75 +/- 1.74 at the end of the follow-up (P < 0.001). SH episodes fell from 1.25 +/- 0.44 per subject-year to 0.05 +/- 0.22 after 24 months (P < 0.001). Hemoglobin A1c remained unaltered. With CGM, the percentage of values within 70-180 mg/dL increased (53.2 +/- 11.0% to 60.3 +/- 17.1%, P = 0.13), and the percentage of values <70 mg/dL decreased (13.7 +/- 9.4% to 9.1 +/- 5.2%, P = 0.07), after 24 months. Mean amplitude of glycemic excursions diminished after 24 months of CSII (136 +/- 28 mg/dL to 115 +/- 19 mg/dL; P < 0.02). An improvement in all the aspects of QoL was observed. The basal alteration in symptom response to an induced hypoglycemia improved after 24 months of initiating CSII leading to a response indistiguishable from that observed in a control group of subjects with T1D without repeated NH and SH.

Conclusions: CSII prevents hypoglycemic episodes, improves hypoglycemia awareness, and ameliorates glycemic profile in T1D subjects with repeated NS/SH. Its use is also associated with an improvement in diabetes QoL.