The role of adiponectin in metabolic and vascular disease: a review.

Adiponectin is a protein secreted by adipose tissue. Unlike other adipocytokines produced by adipose tissue, adiponectin appears to have anti-inflammatory, anti-diabetic, and anti-atherogenic properties. Although secreted solely by adipose tissue, plasma levels of adiponectin are generally negatively related to total adipose mass; with higher plasma adiponectin levels in lean individuals and lower adiponectin levels in obese individuals. Plasma concentrations of adiponectin are lower in patients with insulin resistance compared to insulin sensitive patients; and lower in patients with diabetes compared to non-diabetics. A similar inverse relationship of plasma adiponectin level has been reported with hypertension (HTN), blood pressure level, and albuminuria. However, in chronic kidney disease (CKD) marked elevations in plasma adiponectin concentrations have been described. Plasma adiponectin levels are markedly elevated among patients with end-stage renal disease and are lower following kidney transplantation. Considering the inverse relationship of plasma adiponectin with renal function, the cardiovascular protective role of adiponectin in patients with CKD remains controversial. Further research on the distribution and function of different circulating fractions of adiponectin in patients with CKD will be needed in order to determine if adiponectin is a useful biomarker in patients with CKD.