Nephrin a biomarker of early glomerular injury in newly diagnosed untreated hypertensive subjects

Abstract

Introduction and Aim: Hypertension and proteinuria is known to cause renal and cardiovascular disease and mortality in patients irrespective of diabetes. It is beneficial to identify proteinuria and probable glomerular injury early to take preventive measures from cardiovascular event.  In our study, we aimed to evaluate whether a biomarker such as nephrin can detect early glomerular injury in treatment naïve hypertensive subjects.   Materials and Methods: Forty newly diagnosed, treatment naïve hypertensive subjects were recruited for the study along with 40 normotensive controls after obtaining informed consent and procuring approval from. Institutional Ethics Committee. The hypertensive group was classified as diabetic and non-diabetic hypertensives and compared with apparently healthy controls (normotensive). Urine sample was analyzed for microalbumin, creatinine and nephrin. Blood sample was analyzed for glycated hemoglobin, urea, creatinine, sodium, and potassium.  Statistical analysis was performed using ANOVA to compare the groups for various parameters. Odds ratio was calculated.   Results: Hypertensives were sub-grouped based on amount of microalbumin excreted. Urine nephrin excretion was significantly higher in hypertensive subjects than normotensive subjects (nephrin cut-off: 0.09 mg/g of creatinine). Urine nephrin (mg/g) was found to be elevated (median 0.15; interquartile range, 0.12 and 0.17) in hypertensives with normoalbuminuria and it was significantly higher than normotensive subjects (median 0.07; interquartile range, 0.04 and 0.09).     Conclusion: Urine nephrin may be used as a biomarker of early glomerular injury in hypertensive subjects even before microalbuminuria is detected.