Predictors and consequences of subclinical renal impairment in patients with vascular disease

Abstract Aim: Estimated glomerular filtration rate (eGFR) is the most widely used biomarker of kidney function. More sensitive biomarkers may be required to detect additional predictors and consequences of kidney injury. We aimed to identify predictors and consequences of subclinical renal impairment, as reflected by the levels of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C. Methods: A cross-sectional study was performed in 71 patients with vascular disease. Demographic and anthropometric data, medical history, and ongoing drug therapy were recorded. Blood count, haemoglobin, plasma potassium, glucose, lipids, proteins, serum creatinine, uric acid, NGAL and cystatin C levels, and eGFR were evaluated. Potential predictors and consequences of increased NGAL and cystatin C levels were assessed. Results: Hypertension, diabetes, and diuretic therapy were the only independent predictors of decreased eGFR (all p<0.05). Meanwhile, increased white blood cell count and diuretic usage were independently associated with higher NGAL and cystatin C levels, respectively, and increased uric acid levels were independently associated with higher levels of both biomarkers of kidney injury (all p<0.05). At their turn, increased NGAL and cystatin C were independently associated with lower albumin and HDL-cholesterol levels, and increased cystatin C levels were also associated with higher serum potassium (all p<0.05). Conclusion: eGFR was associated with widely known risk factors for impaired renal function. Meanwhile, NGAL and cystatin C identified more subtle subclinical kidney injury-related hematologic and biochemical changes. These data reinforce the role of NGAL and cystatin C as biomarkers of subclinical kidney injury and predictors of subclinical kidney injury-related abnormalities.