Improved glycemic control with intraperitoneal versus subcutaneous insulin in type 1 diabetes: a randomized controlled trial

Abstract

OBJECTIVE Continuous intraperitoneal insulin infusion (CIPII) with an implantable pump has been available for the past 25 years. CIPII, with its specific pharmacodynamic properties, may be a viable treatment alternative to improve glycemic control in patients with type 1 diabetes for whom other therapies have failed. There have been few studies in which CIPII was compared with subcutaneous insulin treatment for patients with type 1 diabetes with poor glycemic control. RESEARCH DESIGN AND METHODS In an open-label, prospective, crossover, randomized, 16-month study, the effects of CIPII and subcutaneous insulin were compared in 24 patients. The primary outcome measure was the incidence of hypoglycemia. Secondary outcome measures were A1C, and glucose profile, including time in euglycemia, as measured by continuous glucose monitoring. RESULTS The incidence of grade 1 hypoglycemic events was 4.0 +/- 2.6 per week with subcutaneous insulin compared with 3.5 +/- 2.3 per week during CIPII (P = 0.13). The absolute mean difference in A1C with CIPII compared with subcutaneous treatment was -0.76% (95% CI -1.41 to -0.11) (P = 0.03). Baseline time spent in euglycemia was 45.2 +/- 12.6% and increased 10.9% (4.6-17.3) with CIPII compared with subcutaneous treatment (absolute value; P = 0.003). There were no differences in the occurrence rate for severe hypoglycemic events, daily insulin use, or BMI. No pump or catheter malfunction was observed during the study. CONCLUSIONS Although we did not observe a significant reduction in hypoglycemic events, improved glycemic control was achieved with the use of CIPII. We saw a 0.8% decrease in A1C and an 11% increase in the time spent in euglycemia.

Figure 1

Schematic view of the position of the insulin pump and catheter in vivo.

Figure 2

Mean A1C (percentage) at baseline and during subcutaneous insulin therapy (gray lines) and intraperitoneal insulin therapy (black lines). *P < 0.05 between therapy groups (solid lines). Dashed lines indicate A1C in the two treatment order groups; smallest dashes indicate subcutaneous insulin first and CIPII second group; larger dashes indicate CIPII first and subcutaneous insulin second. The I bars represent SEM.

Figure 3

Mean ± SEM time spent in different glucose ranges: time spent in the hypoglycemic range (A; <4.0 mmol/l), the euglycemic range (B; 4.0–;10.0 mmol/l), and the hyperglycemic range (C; >10.0 mmol/) at baseline (▧) and during subcutaneous insulin therapy (□), and intraperitoneal insulin therapy (■). *P < 0.05 between therapy groups.