Biochemical analysis

Fasting blood samples were placed on ice immediately after collection and centrifuged at 4 °C, and the resulting supernatants were stored at  −20 °C until assayed. low-density lipoprotein (LDL)-cholesterol levels were calculated using the Friedewald formula. Plasma adiponectin, high-sensitivity C-reactive protein (hs-CRP), glucagon, tumor necrosis factor alpha (TNF-α), N terminal prohormone of brain natriuretic peptide (NT-proBNP), and proinsulin were measured by latex agglutination, nephelometry, radioimmunoassay, enzyme-linked immunosorbent assay, electro-chemiluminescence immunoassay, and radioimmunoassay, respectively (SRL, Inc, Tokyo, Japan).