The Loss of Postprandial Glycemic Control Precedes Stepwise Deterioration of Fasting With Worsening Diabetes

OBJECTIVE — The aim of the study was to determine whether the loss of fasting and post-prandial glycemic control occurs in parallel or sequentially in the evolution of type 2 diabetes. RESEARCHDESIGNANDMETHODS — In 130 type 2 diabetic patients, 24-h glucose profiles were obtained using a continuous glucose monitoring system. The individuals with type 2 diabetes were divided into five groups according to A1C levels: 1 (6.5%, n 30), 2 (6.5–6.9%, n 17), 3 (7–7.9%, n 32), 4 (8–8.9%, n 25), and 5 (9%, n 26). The glucose profiles between the groups were compared. The overall glucose concentrations for the diurnal, nocturnal, and morning periods, which represent the postprandial, fasting, and the dawn phe-nomenon states, respectively, were also compared. RESULTS — Glucose concentrations increased steadily from group 1 to 5 in a stepwise man-ner. The initial differences in mean glucose concentrations reaching statistical significance oc-curred 1) between groups 1 and 2 (6.4 vs. 7.7 mmol/l, P 0.0004) for daytime postprandial periods, followed by differences; 2) between groups 2 and 3 (7.5 vs. 9.3 mmol/l, P 0.0003) for the morning periods (dawn phenomenon); and finally 3) between groups 3 and 4 (6.3 vs. 8.4 mmol/l, P 0.0001) for nocturnal fasting periods