Sitagliptin reduces the urine albumin-to-creatinine ratio in type 2 diabetes through decreasing both blood pressure and estimated glomerular filtration rate

BackgroundWe investigated the change in the urine albumin-to-creatinine ratio (ACR) to examine the effect of sitagliptin on diabetic nephropathy. MethodsSitagliptin at a dose of 50mg was administered to 247 outpatients with type 2 diabetes. Data were collected on the patients' laboratory results (including the ACR), blood pressure, and body weight. Clinical data were compared before and after 3 months' administration of sitagliptin. ResultsThe ACR changed from 150.0538.6mg/gCre to 148.3764.6mg/gCre over 3 months. In the patients with micro- and macro-albuminuria, the ACR after 3 months significantly decreased compared with the baseline (P=0.04 and P=0.02, respectively). The subjects whose ACR decreased experienced significantly larger decreases over the 3-month period in blood pressure and estimated glomerular filtration rate (eGFR) than the other subjects. There was no significant correlation between change in ACR (ACR) and change in hemoglobin A1c (HbA1c) during 3 months (r=0.04, P=0.59), but there was a significant correlation between change in ACR and change in systolic blood pressure (r=0.16, P=0.03). Multiple regression analysis revealed that the significant predictors for ACR were change in systolic blood pressure (=0.21, P=0.016) and change in eGFR (=0.20, P=0.024) over 3 months (r=0.35, P=0.04). ConclusionsSitagliptin reduces the ACR through decreasing both blood pressure and eGFR, with no correlation with a decrease in HbA1c over a 3-month period. These results may reflect the direct action of sitagliptin on the kidneys.