Editorial den Ruijter et al Adiponectin Regulation in CVD 2181 proof of concept was further substantiated in healthy individuals, where induction of low-grade inflammation resulted in reduced adiponectin levels, independent of BNP. Despite the novel and interesting concept, some limitations of the study should be taken into account. Different patient groups have been studied, patients undergoing percutaneous coronary intervention or coronary artery bypass grafting, who may differ in syntax scores, risk factor profiles, and stability of CVD, all affecting circulating adiponectin levels. In addition, the model resembling mild inflammation, Salmonella Typhi vaccination, was administered in healthy patients who were on average 30 years younger than the patients with CAD. Besides, the model most likely does not reflect the chronic inflammatory process involved in atherosclerosis. Still, the study by Antonopoulos et al12 provides the reader with an interesting novel concept of variability in adipocyte responsiveness in healthy and diseased adipose tissue. Furthermore, it is clearly established that cardiac-derived BNP is the critical denominator of adiponectin responses in patients with severe CVD (Figure). It is intriguing to speculate that in CVD BNP may affect fat composition by browning of adipocytes, thereby possibly altering adiponectin release. In fact, it has been established that natriuretic peptides can promote a favorable fat distribution profile (with decreased visceral fat, increased lower body fat, and improved insulin sensitivity) 14 and induce the browning of adipocytes. 15 It is of high interest to determine whether the diseased adipose tissue from patients with CVD contains brown fat deposits, either consisting of classical or inducible brown fat, that may directly affect morphological and functional differences compared with healthy adipose tissue.

Whether or not adiponectin is a valuable biomarker for the prognosis of CVD remains elusive because this study provides circulating adiponectin levels at a single time point only. As mentioned earlier, adiponectin circulates in different isoforms, depends on type of CVD, stability of CVD, and other