['Studies assessing plasma visfatin/nicotinamide phosphoribosyltransferase (NAMPT) concentrations in chronic kidney disease with the ELISA method are restricted mainly to subjects with end-stage kidney disease. Therefore, little is known about to what extent glomerular filtration rate (GFR) affects the plasma levels of visfatin/NAMPT. The aim of this study was to assess the relations between circulating visfatin/NAMPT levels and estimated GFR (eGFR), independently of potential confounders such as inflammation, nutritional status, and insulin resistance in the elderly population.', 'The analysis included 3023 elderly subjects (1076 with impaired kidney excretory function - eGFR <60 mL/min/1.73 m2) who were participants of the PolSenior study. Serum insulin, glucose, creatinine, C-reactive protein, interleukin-6, and plasma visfatin/NAMPT concentrations were measured by a highly specific ELISA method. Insulin resistance was assessed on the basis of homeostasis model assessment for insulin resistance, and kidney excretory function was assessed using the full MDRD formula.', 'Similar plasma visfatin/NAMPT levels were found in subjects with eGFR ≥60 and <60 mL/min/1.73 m2 (0.96 ng/mL in both groups), and even in those subjects with eGFR 15-30 mL/min/1.73 m2 (0.83 ng/mL). Additionally, there was no association between plasma visfatin/NAMPT concentrations and eGFR values in models of regression analysis including confounding factors.'] Is plasma visfatin/nicotinamide phosphoribosyltransferase ( visfatin/NAMPT ) concentration related to kidney function in elderly subjects?