Unravelling the adiponectin paradox: novel roles of adiponectin in the regulation of cardiovascular disease

Adipose tissue (AT) has recently been identified as a dynamic endocrine organ secreting a wide range of adipokines. Adiponectin is one such hormone, exerting endocrine and paracrine effects on the cardiovascular system. At a cellular and molecular level, adiponectin has anti-inflammatory, antioxidant and anti-apoptotic roles, thereby mitigating key mechanisms underlying cardiovascular disease (CVD) pathogenesis. However, adiponectin expression in human AT as well as its circulating levels are increased in advanced CVD states, and it is actually considered by many as a 'rescue hormone'. Due to the complex mechanisms regulating adiponectin's biosynthesis in the human AT, measurement of its levels as a biomarker in CVD is highly controversial, given that adiponectin exerts protective effects on the cardiovascular system but at the same time its increased levels flag advanced CVD. In this review article, we present the involvement of adiponectin in CVD pathogenesis and we discuss its role as a clinical biomarker.