Assessment of Clinical Determinants of Glycemic Variability in Patients with Type 2 Diabetes

초록

Background Reducing glycemic variability (GV) has been an important target for glycemic control. However, there have been no studies considering various lifestyle habits. Aim We aimed to evaluate the clinical determinants of GV in patients with type 2 diabetes (T2DM) and to characterize the associated factors of adequate glycemic control in continuous glucose monitoring. Method We recruited Korean patients with T2DM treated with insulin between 2021 and 2022 at Korea University Ansan Hospital. All participants wore Dexcom G6 and Fitbit for 10 days. Dietary intake was investigated using a dietary record and taking pictures of food before and after eating. GV indices used were standard deviation (SD), coefficient of variation (CV), the mean of the interquartile range (IQR), and the mean of daily differences in glucose values (MODD). To explore the relationship between GV indices and clinical factors, multivariate regression analyses were conducted. The covariates included age, sex, BMI, eGFR, HbA1c, duration of diabetes, 2-hour postprandial C-peptide-to-glucose ratios (PCGR2), mean daily calorie, daytime step counts, and sleep duration. Adequate glycemic control was defined as co-achievement of time in range >70%, time above range (TAR) 180 mg/dL <25%, TAR 250 mg/dL <5%, time below range (TBR) 70 mg/dL <4%, and TBR 54 mg/dL <1%. Results A total of 97 patients were included in this analysis. The mean age was 53.9 ± 11.8 years, and about 70% of the participants used basal and prandial insulin. In the multivariate linear regression analysis, all GV indices showed an inverse association with eGFR and PCGR2 and a positive association with HbA1c except CV. The daytime step count was negatively associated with SD, IQR, and MODD. Multivariate-adjusted logistic regression analysis revealed that low HbA1c, high PCGR2, and women were associated with the concurrent achievement of the CGM-derived glucose target range. Conclusion We confirmed that renal function, and residual insulin secretion in addition to HbA1c are related to GV and the achievement of the expert-recommended glycemic targets.