Neutrophil gelatinase-associated lipocalin: function, specificity, role in the diagnosis of renal dysfunction in hypertensive patients with concomitant type 2 diabetes and obesity

Abstract

Background. Neutrophil gelatinase-associated lipocalin (NGAL) belongs to the superfamily of lipocalins whose main function is the binding and transportation of hydrophobic molecules, si­derophores, as the most important ligands of NGAL. The diagnostic significance of NGAL as a marker of renal dysfunction, as well as its prognostic value in terms of the further prognosis of the course of renal pathology has now been confirmed. The purpose of the study: to determine the role of NGAL in the development of renal dysfunction in hypertensive patients with comorbid type 2 diabetes (T2D) and obesity. Materials and methods. One hundred and eleven patients with hypertension (50 men, 61 women) aged 54.37 ± 1.18 years and 20 controls were examined. During the examination, they were divi­ded into 4 groups depending on the presence of comorbid pathology: hypertension — the first group (n = 22); hypertension combined with obesity — the second group (n = 30); hypertension combined with T2D — the third group (n = 31); hypertension, T2D and obesity — the fourth group (n = 28). In all patients, body weight and height were measured, body mass index was calculated, levels of glycated hemoglobin, lipid metabolism, systolic and diastolic blood pressure were measured. The content of NGAL in blood serum was evaluated by the enzyme-linked immunosorbent assay. Results. The level of NGAL in all patients included in the study was significantly higher compared to the control group (p < 0.01). However, it was highest in comorbidity of hypertension, T2D and obesity, which, in turn, indicates a high risk of interstitial fibrosis in these patients. A significant correlation was found between the level of NGAL and the concentration of cardiotrophin (p < 0.032), catestatin (p < 0.001), β2-microglobulin (p < 0.001), cystatin (p < 0.021), atherogenic coefficient (p < 0.011), NT-proBNP (p < 0.014), vitamin D (p < 0.004). The obtained data demonstrate the significant role of NGAL in the development of early cardiovascular and renal complications in our patients. Conclusions. A significant increase in the level of NGAL was found in patients with hypertension, hypertension with T2D, hypertension with obesity, hypertension with T2DM and obesity compared to healthy individuals (p < 0.01). A significant correlation of the NGAL level with the serum concentration of cardiotrophin, catestatin, cystatin C, β2-microglobulin, atherogenic coefficient, NT-proBNP, and vitamin D in the exami­ned patients was proved.