Urine albumin-to-creatinine ratio and estimated glomerular filtration rate in matched groups of type 2 diabetes mellitus patients receiving metformin and metformin-sulfonylurea

Objective: Renal disease complications in type 2 diabetes mellitus patients are characterized by progressive urinary albumin excretion and decreased glomerular filtration. The drugs most commonly prescribed as antidiabetic therapy in Indonesia are metformin and sulfonylurea. It is still unclear whether the effect of metformin-sulfonylurea on kidney is different from that of metformin monotherapy. Methods: We compared the effectiveness of metformin monotherapy and metformin-sulfonylurea combination to the urine albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) as renal function parameters. Study subjects were patients on either of these drug regimens for at least 1 year. We collected 88 samples from type 2 diabetes mellitus patients (37 patients on metformin and 51 on metformin-sulfonylurea). The patients fasted for 8 h before urine and blood collection for UACR and eGFR analysis. We measured the eGFR using the chronic kidney disease epidemiology collaboration (CKD-EPI) equation, serum creatinine, and urine creatinine by colorimetric enzymatic assay, and urine albumin by immunoturbidimetry. Results: The eGFR level in the metformin and metformin-sulfonylurea groups was within the normal range, but lower in the metformin group (79.59±2.81) than in the metformin-sulfonylurea group (87.82±2.82) (p=0.018). In addition, hyperfiltration cases were more frequent in metformin-sulfonylurea group (p=0.029). The UACR in patients taking metformin-sulfonylurea (177.95±60.92) was higher than that in the metformin group (49.58±14.19) but the difference between them was not significant (p=0.099). Conclusion: Metformin monotherapy was associated with a lower frequency of hyperfiltration and lower UACR level compared to metformin-sulfonylurea combination.