Plasma visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) concentration in elderly subjects with metabolic syndrome

INTRODUCTION Visceral adipose tissue is the main source of circulating proinflammatory adipokine, visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT), whose role in the pathogenesis of metabolic syndrome (MS) components such as hypertension and carbohydrate and lipid disturbances is still uncertain, due to commonly used low specific C-terminal immunoassays to determine visfatin/NAMPT levels. OBJECTIVES The aim of the study was to assess the association between the occurrence of MS components and circulating visfatin/NAMPT levels in elderly population. PATIENTS AND METHODS The analysis included 2174 elderly participants of the PolSenior study without heart failure, severe chronic kidney disease, cancer, and malnutrition. MS was defined according to the modified International Diabetes Federation criteria. Plasma visfatin/NAMPT concentrations were measured by a highly specific enzyme-linked immunosorbent assay. Additionally, high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), and insulin levels were assessed, and the homeostasis model assessment for insulin resistance was calculated. RESULTS Women were diagnosed with MS more often than men (71.2% vs 56.8%; P < 0.001) and had a greater prevalence of all MS components except for type 2 diabetes. Women with MS had higher concentrations of hsCRP and IL-6 than those without MS. Visfatin/NAMPT concentrations were higher in women with MS than in those without MS (1.06 ng/ml [0.65-1.87] vs 0.85 ng/ml [0.54-1.40]; P < 0.001), but no differences were observed in men (0.97 ng/ml [0.59-1.61] vs 0.90 ng/ml [0.56-1.60], respectively; P = 0.5). In women, there was a stronger association between the number of components of MS and increased plasma visfatin/NAMPT levels than in men. CONCLUSIONS Plasma visfatin/NAMPT levels are increased only in elderly women with MS. It is difficult to distinguish the components of MS specifically associated with increased visfatin/NAMPT levels.