Estimation of HbA1c response to sitagliptin by change in glycated albumin level for 2 weeks

Aims/Introduction: Since glycated albumin (GA) reflects shorter-term (about 2 weeks) control of plasma glucose levels compared with HbA1c, GA is thought to be a useful glycemic control indicator for the early period following commencement of the treatment of diabetes. In this study, we attempted to estimate HbA1c using the change in GA level before and after the first 2 weeks (Delta GA2w) of administration of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor. Materials and Methods: The study included 28 patients with type 2 diabetes who were administered sitagliptin at a dose of 50 mg/day for 12 weeks. Results: At 2 weeks after administration of sitagliptin, GA markedly decreased, while HbA1c had only slightly decreased. A significant positive correlation was observed between the Delta GA2w and the change in HbA1c before and after the first 12 weeks of administration of sitagliptin (Delta HbA1c12w) (R = 0.793, P < 0.0001). The latter was about 0.6 times the former. The estimated HbA1c after 12 weeks of therapy was calculated by adding Delta GA2w x 0.6 to the baseline HbA1c. A significant positive correlation was observed between the estimated HbA1c and the measured HbA1c after 12 weeks (R = 0.735, P < 0.0001) and both were similar levels. Conclusions: HbA1c in the first 12 weeks after administration of sitagliptin could be estimated from the formula using the Delta GA2w. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00167.x, 2012)