Epicardial adipose tissue expression of adiponectin is lower in patients with hypertension

Abstract

Low plasma adiponectin levels are related to a higher risk of development of metabolic and cardiovascular disorders, including hypertension (HT). To date, there have been no studies supporting the relationship between epicardial adipose tissue (EAT) expression of adiponectin and HT. We collected samples of EAT from 116 patients undergoing elective cardiac surgery, mostly for coronary artery bypass grafting (n ¼ 54), valve surgery (n ¼ 49) or both (n ¼ 12). Samples of subcutaneous adipose tissue (SAT) were harvested from 85 patients. After RNA isolation, the expression of adiponectin was analysed by real-time retrotranscriptase (RT)-PCR. Baseline clinical data were obtained from medical records. The diagnosis of HT was established mostly by the patients' general physicians following current guidelines. We included 84 hypertensive and 32 non-hypertensive patients. Mean ( ± s.d.) age was 70.3±7.9 years. EAT expression levels of adiponectin were lower in hypertensives (14.0 ± 3.6 vs 15.3 ± 3.6 arbitrary units (a.u.), P ¼ 0.06). This difference was statistically significant (odds ratio (OR) 0.828 per a.u., P ¼ 0.020) after adjustment for age, gender, body mass index, diabetes mellitus, heart failure, coronary artery disease (CAD), total cholesterol and triglyceride levels. However, SAT adiponectin mRNA levels were similar in hypertensive and non-hypertensive patients (15.3 ± 4.2 vs 15.3 ± 5.0 a.u., P40.99). Adjustment for potential confounding factors hardly altered this result. Our findings indicate that EAT expression of adiponectin may be associated with HT status independently of CAD or other comorbidities, whereas SAT expression does not. These results support the hypothesis that EAT is actively implicated in global cardiovascular risk, describing its association with HT.

Receptor for advanced glycation end-products expression in subcutaneous adipose tissue is related to coronary artery disease

“…This tissue is a source of pro-inflammatory cytokines (6)(7)(8) and contains low levels of adiponectin, an anti-inflammatory adipokine, in patients with CAD (9,10). Moreover, adiponectin expression in EAT decreases in patients with hypertension (11); although its levels are not modified in diabetes (12). These findings suggest that EAT plays an important role in cardiovascular disease and some of its risk factors.…”

The diverse associations of uric acid with low-grade inflammation, adiponectin and arterial stiffness in never-treated hypertensives

“…Adiponectin is considered to be responsible for reduction in inflammation, stimulation of nitric oxide production and consequently for modulation of endothelial cell function. 20,21 Previous studies have demonstrated an independent negative association Abbreviations: c-f PWV, carotid-femoral pulse wave velocity; hs-CRP, high-sensitivity C-reactive protein; SUA, serum uric acid.…”

Proteomic analysis of epicardial and subcutaneous adipose tissue reveals differences in proteins involved in oxidative stress

“…Like other adipose tissues, EAT is now recognized as an endocrine organ, and its proximity to myocardium and coronary arteries suggests the possibility of paracrine action on these structures. In fact, in patients with coronary artery disease (CAD) (5,12) and hypertension (32), EAT produces lower levels of the anti-inflammatory adipokine adiponectin and higher levels of the proinflammatory cytokines IL-6 and leptin than does the EAT of non-CAD or nonhypertensive patients undergoing cardiac surgery, whereas the levels of adiponectin in SAT do not differ between hypertensive and nonhypertensive patients (32), and proinflammatory cytokines are higher in the EAT than the SAT of CAD patients (20).…”