Transitory Beneficial Effects of Professional Continuous Glucose Monitoring on the Metabolic Control of Patients with Type 1 Diabetes

Abstract

The benefit of professional continuous glucose monitoring (PCGM) in the metabolic control of patients with type 1 diabetes mellitus (T1DM) is uncertain. This was a retrospective study of all consecutive T1DM patients who underwent a 6-day PCGM in our Diabetes Unit over the course of 17 months. According to the indication, two groups were arbitrarily defined: "hyperglycemic" and "hypoglycemic." Data from medical files and sensor reports were reviewed. Glycated hemoglobin (HbA1c) was evaluated 2-4 weeks prior to PCGM, as well as 3-5 and 12 months after PCGM. In the hypoglycemic group, the number of self-reported mild hypoglycemic episodes (as defined by the American Diabetes Association) was collected. Of the 67 patients reviewed, 43 were in the hyperglycemic group, and 24 were in the hypoglycemic group. In the hyperglycemic group, the HbA1c level dropped at 3-5 months post-intervention from 8.45 ± 0.72% to 8.04 ± 0.9%, with the decline being statistically significant (-0.4%; P = 0.001) and positively correlated with the initial HbA1c value (0.366; P=0.016). One year after the PCGM study, the HbA1c level tended to return to the initial values: 8.20 ± 1.05% (-0.24%; P = 0.081). In the hypoglycemic group, HbA1c did not change either 3-5 or 12 months after PCGM, although the percentage of patients in whom the number of mild hypoglycemic episodes was significantly reduced was 86% (P=0.001). Although a transient phenomenon, PCGM can be useful in the short term in improving metabolic and clinical profile of suboptimally controlled T1DM subjects, including those with repeated hypoglycemia.