Introduction: Visfatin is an adipokine secreted by visceral adipose tissue with insulin-mimetic properties. Higher circulating visfatin levels were reported in type 2 diabetes. The aim of this study was to analyse circulating visfatin and insulin levels and the visfatin/insulin ratio in obese women with and without metabolic syndrome (MetS).
Material and methods: The study involved 92 obese women. Subjects were diagnosed with MetS according to IDF 2005 criteria. The MetS group consisted of 71 subjects (age: 52.8 ±9.4 years, body mass index [BMI]: 39.1 ±5.6 kg/m(2), waist circumference: 109.6 ±11.4 cm and fat mass: 52.0 ±12.8 kg) while the non-MetS group consisted of 21 subjects (age: 51.7 ±9.5 years, BMI: 36.3 ±5.2 kg/m(2), waist circumference: 104.7 ±11.0 cm and fat mass: 45.2 ±10.7 kg). In addition to anthropometric measurements and assessment of serum glucose and lipids, plasma concentrations of visfatin were estimated by enzyme-linked immunosorbent assay (ELISA) and of insulin by radioimmunoassay (RIA). Homeostatic model assessment insulin resistance (HOMA-IR) and visfatin/insulin ratio were calculated.
Results: In the MetS group significantly higher (p < 0.01) plasma concentrations of insulin and HOMA-IR values but similar visfatin levels were observed than in the non-MetS group. As a consequence of the significantly higher plasma insulin concentration the visfatin/insulin ratio was significantly lower in the MetS group (p < 0.05). The visfatin/insulin ratio correlated inversely with anthropometric parameters such as body mass, BMI, body fat and waist circumference (r = -0.41, p = 0.0003; r = -0.42, p = 0.0002; r = -0.29, p = 0.01; r = -0.23, p = 0.04, respectively).
Conclusions: We conclude that the visfatin/insulin ratio declining with increasing visceral obesity may predispose to the development of insulin resistance.
Keywords: insulin; metabolic syndrome; obesity; visfatin.