Global assessment for quality and safety of control in type 2 diabetic patients

Background  HbA1c (glycated haemoglobin) suffers from obvious limitations in type 2 diabetic patients at risk of hypoglycaemia or requiring rapid therapeutic adjustments. This study was conducted to discern whether the monitoring of one particular plasma glucose (PG) value of the diurnal profile can be used in such situations. Design  Four diurnal PG concentrations (at 08:00, 11:00, 14:00 and 17:00 h) were measured in standardized conditions in 480 (246 men, 234 women) noninsulin‐using type 2 diabetic patients. Sensitivities for predicting treatment success, i.e. HbA1c < 7%, with a specificity ≥ 90% were calculated and compared using receiver‐operating characteristic (ROC) curves. Results  The probabilities (areas under ROC curves) for predicting HbA1c < 7% were significantly higher at 11:00, 14:00 and 17:00 h than at 08:00 h. The optimal PG cut‐off values for predicting treatment success were, respectively, 6, 9, 7 and 6 mmol L −1 at 08:00 h, 11:00, 14:00 and 17:00 h. In most patients the lowest PG values of the diurnal profile were at 17:00 h, and 17·5% of the patients with HbA1c < 7% (54·5% of them treated with sulphonylureas) exhibited a PG value less than 4·4 mmol L −1 at 17:00 h ( P =  0·0034 vs. the other timepoints). Conclusions  Glucose monitoring at 17:00 h, i.e. during the extended postlunch period, appears as a global marker of control in noninsulin‐using type 2 diabetic patients both for detecting patients at risk of hypoglycaemia and for assessing the short‐term quality of diabetic control.