Secretory units of islets in transplantation index is a useful clinical marker to evaluate the efficacy of sitagliptin in treatment of type 2 diabetes mellitus

We carried out a retrospective analysis of 40 Japanese patients with type 2 diabetes mellitus who received sitagliptin. Glycated hemoglobin (HbA(1c)) and fasting plasma glucose were significantly decreased from 7.53 +/- 0.65% and 155.2 +/- 29.4 mg/dL at baseline to 6.80 +/- 0.60% (P < 0.01) and 131.2 +/- 22.3 mg/dL (P < 0.01) at week 20, respectively. beta-Cell function was evaluated by the secretory units of islets in transplantation (SUIT) index, which was significantly increased from 28.5 +/- 14.0 at baseline to 38.6 +/- 17.0 at week 20 (P < 0.01). Multivariate analysis was carried out between Delta HbA(1c) and several parameters (age, the duration of diabetes, body mass index, triglyceride [TG], C-peptide [CPR], Delta CPR, HbA(1c) [baseline] and Delta SUIT), which showed HbA(1c) (baseline; beta = 0.580, P < 0.001) and Delta SUIT (beta = 0.308, P < 0.05) as significant independent determinants of Delta HbA(1c). These two variables explained 53% of the variance in HbA(1c) response. These results suggest that SUIT index can be a clinical marker for the efficacy of sitagliptin in treatment of diabetes mellitus. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00109.x, 2011)