The purpose of this study was to determine the glycemic profiles of drug-naïve type 2 diabetes patients according to hemoglobin A1c (HbA1c) level using continuous glucose monitoring. We aimed to clarify factors associated with HbA1c and average blood glucose level. Patients were divided into three groups according to their HbA1c level (< 7.0% n=23, 7.0% ≤ HbA1c < 8.0% n=17 and ≥ 8.0% n=31), and the factors associated with HbA1c and average glucose of each group were evaluated. Pre-meal glucose levels were the highest before lunch, and the 2 hour postprandial blood glucose level was the lowest after lunch. The pre-meal and postprandial blood glucose levels increased after each meal with increases in HbA1c. Average glucose level was the most significant determinant of HbA1c, whereas pre-meal glucose level at dinner was the most significant determinant of average glucose level, and the range of increase in glucose from pre-meal at dinner was the most significant determinant of standard deviation (SD) of 24 hour glucose levels. HbA1c subgroup analysis indicated that pre-meal glucose level at lunch significantly correlated with average glucose level in the HbA1c < 8.0% group, while pre-meal glucose level at dinner significantly correlated with average glucose level in the HbA1c ≥ 8.0% group. The range of increase in glucose from pre-meal in the morning significantly correlated with SD of 24 hour glucose levels in the HbA1c < 8.0% group, and the postprandial peak glucose level at lunch significantly correlated with SD of 24 hour glucose levels in the HbA1c ≥ 8.0% group. The results suggest that improvement of the average glucose level is necessary to improve the HbA1c levels. For patients with HbA1c < 7.0%, it is important to improve blood glucose level after breakfast and before lunch to decrease the average glucose level. For patients with 7.0% ≤ HbA1c < 8.0%, it is important to improve blood glucose level before lunch and after dinner to decrease the average glucose level. For patients with HbA1c ≥ 8.0%, it is important to improve blood glucose levels after lunch and before dinner to decrease the average glucose level.
Keywords: continuous glucose monitoring; drug naïve; type 2 diabetes.