RBP4 and metabolic syndrome: Serum RBP4 level is alsocorrelated with visceral adiposity, body mass index (BMI), dyslipidemia,inflammation, and incipient nephropathy in patients with DM [10, 13, 14].Interestingly, clinical observations showed that increased circulating RBP4 wasassociated with chronic heart failure (CHF), and elevated serum RBP4 wascorrelated with a worse outcome in elderly patients with CHF [15, 16].