Urinary Hydrogen Peroxide and Renal Function Parameter of Type 2 Diabetes Mellitus Patients Consuming Metformin and Metformin-Sulfonylurea

Abstract

Objective: Diabetes is one of the primary causes of kidney failure. About 40% people with diabetes will get Chronic Kidney Disease (CKD). The previous study reported that oxidative stress played an important role in diabetic patients with kidney damage. However, the study did not take consideration for the therapeutic treatment of the patients. This study purpose to determine urinary hydrogen peroxide concentration as a biomarker of oxidative stress in type 2 diabetes patients consuming metformin and metformin-sulfonylurea and to know its correlation with estimated Glomerular Filtration Rate (eGFR) and Urine Albumin to Creatinine Ratio (UACR) as a parameter of the renal function. Methods: Blood and urine were collected from 114 type 2 diabetes outpatients in Pasar Minggu Community Health Center. The concentration of urinary hydrogen peroxide (H2O2) was measured using Ferrous Ion Oxidation Xylenol Orange 1 (FOX-1) method and was normalized with urine creatinine measured with kinetic Jaffe method. The value of eGFR was calculated based on serum creatinine using Cockroft-gault, MDRD, dan CKD-EPI equation. Results: There were no significant difference in concentration of urinary H2O2 (p = 0.228), eGFR (Cockroft-Gault p = 0.936; MDRD p = 0.779; dan CKD-EPI p= 0.671), and UACR (p = 0.838) between the two groups of treatment. There was no correlation between urinary H2O2 with eGFR in all equations and between urinary H2O2 and UACR. In the other hand, moderate positive correlation showed in analysis between urinary H2O2 and UACR in patients with albuminuria (r=0.457; p=0.001). Results of linear regression analysis showed that H2O2 was the most and the only significant factor for increased UACR, even after controlled by age, gender, IMT, systolic blood pressure, HbA1c, hypertension status, smoking habit, exercise habit, and medicine. Conclusion: There was no significant difference in concentration of urinary H2O2 in type 2 diabetes patients consuming metformin and metformin-sulfonylurea. Urinary presumably will increase significantly together with the present of albuminuria, so it can not be used in early detection of renal function in patients without albuminuria. Key words: Metformin, Sulfonylurea, Diabetes Mellitus, Estimated Glomerular Filtration Rate, Urine Albumin to Creatinine Ratio, Urinary Hydrogen Peroxide.