Influence of serum high-molecular-weight and total adiponectin on arteriosclerosis in IgA nephropathy patients

Adiponectin has attracted a great deal of attention because of its antiatherogenic properties. Previous studies have reported that high-molecular-weight (HMW) adiponectin may be the active form of this protein, but there have been no reports on the relationship between serum adiponectin and arteriosclerosis. The aim of our study was to determine whether HMW or total adiponectin levels are associated with arteriosclerosis in patients with IgA nephropathy.

We enrolled 72 patients aged 34.3 +/- 12.7 years, from whom interlobular arteries were obtained by renal biopsy in our hospital between 2003 and 2006 and who were confirmed to have IgA nephropathy. We assessed them in relation to age, gender, body mass index, presence of hypertension, serum total cholesterol, triglyceride, uric acid, high-sensitive C-reactive protein and HMW adiponectin and total adiponectin levels, creatinine clearance, and urinary protein excretion. The severity of arteriosclerosis was semiquantitatively evaluated and classified into the following four grades: 0 = none; 1 = mild; 2 = moderate, and 3 = severe.

Multiple stepwise regression analysis showed associations between arteriosclerosis grade and age [standard regression coefficient (st beta) = 0.560, p < 0.001], total adiponectin (st beta = -0.218, p = 0.026), triglyceride (st beta = 0.222, p = 0.033), and presence of hypertension (yes = 1, no = 0; st beta = 0.182, p = 0.036) in the IgA nephropathy patients as a whole and associations between arteriosclerosis grade and age (st beta = 0.708, p < 0.001), HMW adiponectin (st beta = -0.321, p = 0.035), and triglyceride (st beta = 0.292, p = 0.038) in the male IgA nephropathy patients.

Serum total adiponectin levels are an independent determinant of arteriosclerosis in IgA nephropathy patients. It was noteworthy that in males the serum HMW adiponectin levels correlated more strongly with arteriosclerosis grade than the total adiponectin levels did. Adiponectin may prevent renal arteriosclerosis.