Importance of urinary NGAL, serum creatinine standardization and estimated glomerular filtration rate in resistant hypertension

In patients with resistant hypertension (RH) we investigated the importance of urinary neutrophil gelatinase-associated lipocalin (uNGAL- a chemiluminescent microparticle immunoassay (CMIA) method became using (Abbott Diagnostics) for the measurement of NGAL in urine samples) and incidence of chronic kidney disease using the Modification of Diet in Renal Disease Study (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in estimating glomerular filtration rate (eGFR) based on standardised serum creatinine method traceable to isotope dilution mass spectrometry (IDMS) method. It would have been difficult to predict that levels of these biomarker would perform better organ damage than traditional measurements of kidney function such as standardised serum creatinine, MDRD, or CKD-EPI equations in special population such as RH. Serum creatinine concentrations were measured in 50 patients (24M:26F from RH Registar in Clinical Hospital Merkur) by the kinetic Jaffe method. There were no significant differences between the GFR values derived by MDRD and CKD-EPI equations in the group of patients with RH. 62% of patients have eGFR > 60 mL/minl/1.73 m2, while a 38% of patients have eGFR < 60 mL/min/1.73 m2. The measurement of NGAL in urine samples of 40 patients with RH showed no difference and seems to be of no use in further determination of renal impairement. Higher value of uNGAL in some resistant hypertension patients could have link in the repair stage after AKI and would reveal pathways that could link AKI and CKD.