Objective: To compare, in a long-term study, glycemic control by means of continuous subcutaneous insulin infusion (CSII or insulin pump therapy) versus multiple insulin injection therapy (MIIT) in routine clinical practice.
Methods: We identified, from a search of medical records, all active patients (N = 90) receiving CSII who had previously received MIIT. The primary objective was to compare the mean glycemic control, as documented by frequent measurements of glycosylated hemoglobin (HbA(1c)), during the 3-year period before initiation of CSII versus the mean glycemic control during the 3-year period after the first year of CSII. We included all patients for whom we had sufficient data for at least 1 year for both the pre- and post-CSII periods and only those patients who had received MIIT before CSII (N = 58). To eliminate potential biases, we excluded HbA(1c) values for the first year after initiation of CSII therapy.
Results: For the entire study group, the mean HbA(1c) +/- standard error for the 3-year period before insulin pump therapy (during MIIT) was 8.4 +/- 0.2% versus a mean HbA(1c) of 7.7 +/- 0.1% for the 3-year period after the first year of CSII. This 0.7% improvement in HbA(1c) was statistically significant (P = 0.001). Of the 34 patients with HbA(1c) values above 8.0% during MIIT, the mean HbA(1c) decreased from 9.2 +/- 0.2% with use of MIIT to 8.2 +/- 0.2% with CSII (P = 0.0006). In the 17 patients with HbA(1c) values above 9.0% during MIIT, the mean HbA(1c) declined from 10.0 +/- 0.3% with use of MIIT to 8.4 +/- 0.3% with CSII (P = 0.0006).
Conclusion: We conclude that implementation of intensive insulin therapy with CSII improves glycemic control, even in patients in whom MIIT has previously been used to its maximal effect.