Serum Levels of Indoxyl Sulfate and P-cresol in Type II Diabetic Patients With and Without Nephropathy

Indoxyl sulfate (IS) and para-cresol (p-cresol) are uremic toxins with high protein bonding index that accumulate in the body with decreasing kidney function. The main purpose of the current investigation was to compare the concentration of p-cresol and IS in serum of the type II diabetic individuals with and without nephropathy.

Fifty-five patients with type II diabetes mellitus were divided into two groups: case and control. The case group consisted of 26 diabetic patients with nephropathy (proteinuria and serum creatinine below 1.5 mg/dL) without any other kidney diseases. The control group included 29 patients without diabetic nephropathy. Patients with advanced heart disease, cerebrovascular accident and other inflammatory or infectious diseases were excluded. Five mL of venous blood was taken from each patient in the morning fasting state. Then other laboratory tests including serum uric acid and creatinine levels, serum urea nitrogen, lipids and glucose were measured by standard methods. P-Cresol and IS levels were measured by the spectrofluorimetric method after extraction. We also filled out a checklist with information regarding the duration of their disease, medication history (oral or injectable), and other demographic information. There were no significant differences between the two groups regarding the investigated factors

There were no significant difference among the investigated factors between the two groups (P > .05) except for the serum creatinine, proteinuria and estimated glomerular filtration rate, where the mean values of cases were considerably higher than those of the controls. Serum IS and p-cresol levels were also significantly higher in the case group (P < .05).

According to the findings, it seems that IS, and p-cresol may play a role in the development of diabetic nephropathy and other complications of diabetes mellitus.