Hypoglycemia in patients with type 2 diabetes treated with oral antihyperglycemic agents detected by continuous glucose monitoring: a multi-center prospective observational study in Croatia

BACKGROUND: Hypoglycemia in type 2 diabetes mellitus (T2DM) is still unsolved issue. The aim of this study was to investigate hypoglycemia in T2DM in participants treated with oral antihyperglycemic agents using different glucose cut-off values and to explore influence of different therapies. METHODS: This multi-center prospective observational study included participant with T2DM from primary care offices across Croatia treated with antihyperglycemic agents who were monitored using professional continuous glucose monitoring (CGM) device (iPro™2). Hypoglycemia was defined as at least 1% of the monitored period spent in the hypoglycemic range and/or area under the curve of glycemia registered ever under the defined cut-off value. The higher upper limit of blood glucose cut-off value was 3.9 mmol/L (70 mg/dL) and the lower one 3.0 mmol/L (54 mg/dL). RESULTS: Study included 94 participants. Median hemoglobin A1C levels, age, T2DM duration, body mass index, and CGM use duration were 7 (5.8–11.5) %, 65 (40–86) years, 7 (1–36) years, 30.4 (21.3–41.5) kg/m(2) and 6 (1–7) days, respectively. Fifty participants were treated with sulfonylurea, primarily gliclazide (84%). The percentage of participant with hypoglycemia based on the higher cut-off value was 42.6% vs. 16% based on the higher cut-off value. The percentage of participant with nocturnal hypoglycemia (23 PM to 06 AM) was significantly lower among participant with hypoglycemia based on the higher cut-off value compared to lower one (7.8% vs. 22.9%). Sulfonylurea treatment did not influence the occurrence of hypoglycemia. Analysis of the data from participants having hypoglycemia based on the lower cut-off value pointed to other possible risk factors for hypoglycemia like prolonged overnight fasting, physical activity, alcohol consumption, and concomitant therapy with angiotensin-converting enzyme inhibitors. CONCLUSIONS: In participant with T2DM treated with oral antihyperglycemic agents hypoglycemia based on the blood glucose cut-off value of 3.9 mmol/L was more prevalent, but with less nocturnal hypoglycemia. Sulfonylurea therapy was not risk factor for hypoglycemia regardless of cut-off value. In participants having hypoglycemia based on the blood glucose cut-off value of 3.0 mmol/L some other possible factors were identified related to concomitant therapy, nutrition and daily habits. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03253237.