A comparison of serum cystatin C with traditional biomarkers of renal function in patients of essential hypertension in a tertiary care center of the Kumaun region

INTRODUCTION: In India, hypertensive renal disease, the second leading cause of chronic kidney failure, necessitates dialysis or renal transplantation. Most traditional renal function indicators, such as serum urea and creatinine, track disease progression and therapy response. Cystatin C, an excellent glomerular filtration rate (GFR) indicator, is freely filtered through the glomerular membrane, and its concentration is solely dictated by GFR. About 25%–40% of untreated hypertensives develop hyperuricemia. Microalbuminuria is a traditional renal function biomarker and outcome predictor in renal disease patients. This research compared blood cystatin C to standard renal function indicators (serum urea, serum creatinine [Scr], serum uric acid, urine microalbumin, and urinary total protein) in essential hypertension patients in a Kumaun tertiary care institution. MATERIAL AND METHODS: One hundred hypertensive individuals aged 30–60 years and 50 age- and sex-matched normotensive controls were studied. The fully computerized Roche Cobas C501 Analyzer assessed Scr and urea. Estimation of serum cystatin C was done by turbidimetric method using semiautomatic analyzer (MERCK Microlab 300). A urine sample taken over a 24-h period for total protein concentration and urinary microalbumin was taken in a clean plastic container. The preservative was 10% HCL. Using pyrogallol red and turbidimetric immunoassay, urine total protein and microalbumin were measured. RESULTS: In comparison to the control group and Stage II hypertension participants, hypertensive people exhibited substantially greater mean blood urea, creatinine, urine total protein, and urinary microalbumin levels. The difference was statistically significant (P < 0.0007). Only Stage II hypertensives had substantially lower mean estimated GFR (eGFR) and eGFR (Scr) levels than controls. These differences were statistically significant (P < 0.0001). Cases and Stage II hypertensives had considerably higher mean blood cystatin C levels than controls and Stage I hypertensives. Serum cystatin C correlated positively with urea, creatinine, and urine microalbumin, but negatively with uric acid (r = 0.004; P > 0.05). Linear connections were found between parameters. CONCLUSION: Our investigation found that cystatin C-based GFR equations beat Scr ones. Serum cystatin C is more sensitive than Scr for detecting early renal function deterioration in hypertensive individuals.