Adiponectin: A Promising Marker for Cardiovascular Disease (Editorials‪)‬

Obesity is a major risk factor for coronary heart disease (CHD). Obese persons have an ~1.5- to 2.0-fold increased risk for CHD, and between 15% and 20% of all cases of CHD can be attributed to overweight and obesity (1). Although hypertension, dyslipidemia, insulin resistance, and type 2 diabetes are core components of the metabolic syndrome and are probably key elements in the causal pathway from obesity to CHD, the underlying mechanisms are only poorly understood. It is known that adipose tissue itself is capable of producing a variety of cytokines and hormones (called adipokines or adipocytokines) that may be relevant for CHD development. Among others, these include pro-inflammatory cytokines, such as tumor necrosis factor-[alpha] (TNF-[alpha]) and interleukin-6; hormones involved in blood pressure regulation, such as those of the renin-angiotensin system; factors that affect hemostasis and angiogenesis, such as plasminogen activator inhibitor-1 and vascular endothelial growth factor; and hormones involved in energy metabolism, such as leptin (2). Adiponectin may be the most relevant and promising adipokine with respect to a better understanding of the link between obesity and CHD. Adiponectin (also called ARCP30, AdipoQ, apM1, and GBP28) is a 247-amino acid peptide hormone discovered in 1995 (3). It is induced early in the differentiation of fat cells (adipocytes), consists of an N-terminal collagenous and a C-terminal globular domain, and shares homology with subunits of complement factor C1q. Contrary to other adipose-derived hormones, adiponectin circulates at relatively high concentrations in the blood stream, accounting for 0.05% of total serum proteins, and is inversely associated with obesity, insulin resistance, type 2 diabetes, and cardiovascular disease (CVD) (3-10). Data from animal studies suggest that administration of adiponectin improves insulin sensitivity and may have antiatherogenic and antiinflammatory properties (3).