Subjects and Methods
We studied 17 patients with type 2 diabetes who were hospitalized for glycemic control at the Dokkyo Medical University Hospital (Mibu, Tochigi, Japan). Patients were eligible for enrollment if they had type 2 diabetes, were at least 20 years old and had a glycated hemoglobin (HbA1c) level of 6.0% to 12.0% on stable therapy with 1 to 3 oral antidiabetic drugs with or without insulin for at least 3 months. During hospitalization, all patients received an optimal diet therapy (25 to 30 kcal/kg of ideal body weight; 50% carbohydrate, 20% protein, and 30% fat). Tofogliflozin 20 mg/day was administered to 10 patients who were receiving DPP-4 inhibitors and to 7 patients who were not receiving these drugs.
During the last week of hospitalization, a CGM device (iPro2; Medtronic MiniMed. Inc., Northridge, CA, USA) was attached to each patient for 1 week. During the study period, no other anti-diabetic drugs were added and the dose of antidiabetic drugs and insulin remained unchanged. The starting day of CGM was defined as day 1. On day 4, treatment with tofogliflozin 20 mg/day was started. We compared the mean values of CGM parameters on day 2 and 3 (ie, before starting treatment with tofogliflozin) with those on day 5 and 6 (ie, after staring treatment with tofogliflozin). As indexes of glycemic variability, the 24-hour mean glucose level, standard deviation (SD) of the 24-hour glucose level, mean amplitude of glycemic excursions (MAGE), and mean of postprandial glucose excursion (MPPGE) were calculated from CGM. We evaluated postprandial glucose within 1 to 3 hours after each meal and the time in range as the percent time with a glucose level between 70 and 180 mg/dL. Time below range was defined as the percent of time with a glucose level less than 70 mg/dL, and time above range, as the percent of time with a glucose level above 180 mg/dL.
All participants gave written informed consent to participate in the study, which was approved by the Institutional Review Board of Dokkyo Medical University (approval no. 28150). The study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000025454).