Continuous Intraperitoneal Insulin Infusion Versus Subcutaneous Insulin Therapy in the Treatment of Type 1 Diabetes: Effects on Glycemic Variability

Introduction: As continuous intraperitoneal insulin infusion (CIPII) results in a more physiologic action of insulin than subcutaneous (SC) insulin administration, we hypothesized that CIPII would result in less glycemic variability (GV) than SC insulin therapy among type 1 diabetes mellitus (T1DM) patients. Materials and Methods: Data from 5-day blind continuous glucose monitoring (CGM) measurements performed during a 26-week, prospective, observational case-control study were analyzed. The coefficient of variation (CV) was the primary measure of GV. In addition, the SD of the mean glucose level, mean of daily differences, and mean amplitude of glycemic excursions were calculated. Results: In total, 176 patients (36% male; mean age, 49 [SD 13] years; median diabetes duration, 24 [interquartile range, 17, 35] years; glycated hemoglobin level, 63 [10] mmol/mmol), of which 37 used CIPII and 139 SC insulin therapy, were analyzed. CGM data were available for 169 patients at baseline (CIPII, n=35; SC, n=134) and for 164 patients at 26 weeks (CIPII, n=35; SC, n=129). After adjustment for baseline differences, the CV was 4.9% (95% confidence interval, 1.0, 8.8) lower with CIPII- compared with SC-treated patients, irrespective of the use of multiple daily injections or continuous SC insulin infusion. There were no differences in other indices of GV between groups. Conclusions: Despite higher blood glucose, the CV was slightly lower with CIPII compared with SC insulin therapy in T1DM patients, and other measures of GV were identical. Future studies are needed to confirm these findings and investigate whether this results in prevention of hypoglycemia and even perhaps (less) microvascular complications