Does the timing of insulin pump therapy initiation after type 1 diabetes onset have an impact on glycemic control?

Background: Continuous subcutaneous insulin infusion (CSII) mimics physiologic insulin release better than multiple daily injection (MDI) therapy and allows for greater flexibility in food intake and physical activity. Given these benefits, it raises the question "Is it required to wait to offer CSII to patients with type 1 diabetes (T1D) only after MDI therapy has failed"? This study sought to determine if starting CSII in patients with T1D within 1 year of diagnosis results in better long-term glycemic control than starting it later. Methods: This retrospective observational study was conducted in a tertiary-care medical center. The charts of 488 patients with T1D (273 females) 2.6-39 years old (mean, 19.9±7.7 years) who started CSII in 1998-2008 and used it for at least 1 year were reviewed for background, disease-related, and treatment-related variables. Study end points were glycosylated hemoglobin (HbA1c) level, rate of severe hypoglycemia, and diabetic ketoacidosis events during CSII use. Findings were compared between patients who started CSII within 1 year of diagnosis (Group 1, n=93) or later (Group 2, n=395). Results: Compared with Group 2, Group 1 patients were characterized by a significantly younger age at CSII initiation (10.7±5.7 vs. 16.4±7.0 years, P<0.001), more frequent blood glucose monitoring (5.4±1.8 vs. 3.9±1.5 times per day, P<0.001), and shorter total duration of diabetes (4.3±2.1 vs. 11.9±6.4 years, P<0.001) and of CSII therapy (3.6±2.1 vs. 4.7±2.5 years, P<0.001). There were no significant between-group differences in patient gender or ethnicity, indications for initiating CSII, mean HbA1c level, attainment of target HbA1c, or rates of severe hypoglycemia or ketoacidosis events after CSII initiation. Conclusions: Starting pump therapy at an early disease stage has no added benefit for glycemic control over time than starting later. The timing of CSII initiation should be tailored to the individual patient by the diabetes care team.