Novel adipokines: links between obesity and atherosclerosis

Today, cardiovascular diseases (CVD) remain the principal cause of death in industrialized countries and are linked to obesity and metabolic syndrome. Metabolic syndrome is characterized by changes in arterial blood pressure, glucose metabolism, lipid and lipoprotein profiles in addition to inflammation. Adipose tissue produces many cytokines and secretory factors termed adipokines. Intra-abdominal (visceral) adipose tissue in particular, rather than peripheral, appears to be associated with global cardiometabolic risk. The present article summarizes information on five recently discovered adipokines: vaspin, visfatin, apelin, acylation stimulating protein (ASP) and retinol-binding protein 4 (RBP4) and their potential beneficial or deleterious roles in obesity and atherosclerosis. Vaspin may have antiatherogenic effects through its potential insulin-sensitizing properties. Similarly, visfatin has been suggested to enhance insulin sensitivity, but its potential role in plaque destabilization may counteract this. Apelin, via inhibition of food intake, and increases in physical activity and body temperature, may promote weight loss, resulting in a beneficial antiatherogenic effect. Further, favourable effects on vasodilatation and blood pressure add to this positive effect. Considering its increased levels in subjects with demonstrated atherosclerosis, RBP4 may constitute a biomarker. Lastly, ASP, often increased in obesity and metabolic disorders, may be contributing to efficient lipid storage, and decreasing or blocking ASP may provide a potential antiobesity target. Adipokines may further contribute to obesity-atherosclerosis relationships, the full understanding of which will require further research.