Reducing glucose variability with continuous subcutaneous insulin infusion increases endothelial progenitor cells in type 1 diabetes: an observational study

Circulating endothelial progenitor cells (EPCs) are involved in the repairing mechanisms of vascular damage. Glucose variability may contribute to the development of chronic vascular complications of diabetes. We evaluated whether reducing glucose variability with continuous subcutaneous insulin infusion (CSII) would increase circulating levels of EPCs in type 1 diabetes. The study population consisted of 106 type 1 diabetic patients: 41 subjects considered eligible for CSII completed a 6-month follow-up. Sixty-five patients on intensified insulin therapy with multiple daily injections served as control group. Seven EPCs phenotypes were assessed by flow cytometry, and glucose variability by mean amplitude of glycemic excursions (MAGE). Both CD34+KDR+ [difference between groups 32.0, 95 % CI (19.6–44.4) number/10⁶ cells, P < 0.001] and CD34+KDR+CD133+ [12.5 (5.5–19.5), P < 0.001)] cell count increased at endpoint in the CSII group, associated with a reduction of MAGE [−1.1 (−2.1 to −0.1), P = 0.026]. No changes occurred in the control group. In multivariate analyses, changes in MAGE were independently associated with changes in both CD34+KDR+ (P = 0.019) and CD34+KDR+CD133+ (P = 0.022) cell count. Reducing glucose variability with CSII in type 1 diabetes increases circulating EPCs levels, suggesting a novel mechanism of vascular damage by oscillating glucose.