Diabetic and nondiabetic patients express similar adipose tissue adiponectin and leptin levels

Abstract

Objective: Epicardial adipose tissue (EAT) is an interesting visceral fat pad with a particular location. EAT and subcutaneous adipose tissue (SAT) produce a wide range of adipokines. Some of them, including adiponectin and leptin, can influence the risk of development of diabetes and other associated metabolic and cardiovascular conditions. We sought to assess whether EAT and SAT adiponectin and leptin expression levels are different in diabetic patients with respect to nondiabetic subjects. Subjects and methods: We collected samples of EAT from 120 patients and samples of SAT from 88 of the same group of patients undergoing elective cardiac surgery for coronary artery bypass grafting (n ¼ 69) or other procedures (n ¼ 51). After RNA isolation, adiponectin and leptin expression levels were analyzed by real-time reverse transcriptase PCR. Plasma levels were determined in small subsamples of subjects. Baseline clinical and treatment data were obtained from medical records. Results: A total of 45 diabetic and 75 nondiabetic subjects were included in the study. Mean (s.d.) age was 70.1 (7.8) years and there were 32% women. EAT and SAT adiponectin and leptin mRNA expression levels were similar in the diabetic and the nondiabetic groups (EAT adiponectin 14.4 (4.3) vs 14.6 (3.4) arbitrary units (a.u.), P ¼ 0.79; SAT adiponectin 15.6 (4.7) vs 15.1 (3.9), P ¼ 0.54; EAT leptin 9.3 (interquartile range 2.5) vs 9.5 (1.9) a.u., P ¼ 0.72; SAT leptin 9.9 (3.6) vs 10.0 (2.5) a.u., P ¼ 0.96). These findings persisted after stratification for sex and coronary artery disease. Logistic regression models including possible confounders and a combination of diabetes and impaired fasting glucose as a dependent variable led to similar results. Plasma adiponectin levels were lower in diabetic patients, whereas leptin levels showed a nonsignificant trend. Conclusion: Diabetic and nondiabetic subjects express similar EAT and SAT adiponectin and leptin levels. Counter-regulatory mechanisms of adiponectin and leptin expression in patients with established diabetes might partly account for these findings.

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.…”

“…Protein isolation from a series of SAT samples was performed as previously described (12). In brief, 100-150 mg of EAT and SAT were rinsed in 5 ml of phosphate saline solution containing 0.5 mM EDTA, 5 mM KCl, 10 mM HEPES acid, 2 mM MgCl 2 , 10 mM NaHCO 3 , 0.5 mM KH 2 PO 4 , 0.5 mM NaH 2 PO 4 , 10 mM glucose, 110 mM NaCl, and 0.16 mM CaCl 2 at pH 7.4, and then centrifuged at 300 g for 1 min to remove residual blood.…”

Transcriptome and Molecular Endocrinology Aspects of Epicardial Adipose Tissue in Cardiovascular Diseases: A Systematic Review and Meta-Analysis of Observational Studies

“…Two studies did not report the results of DEGs despite collecting EAT from CAD and non-CAD patients and using a case-control study design [ 19 , 44 ]. Several studies determined protein expression levels in EAT tissue in addition to the mRNA expression levels [ 17 , 29 , 32 , 34 , 39 , 40 , 46 , 53 ], while some others investigated the correlation of EAT mRNA expression with CAD markers such as C-reactive protein (CRP) [ 32 , 33 ]. The major obstacle in the quality assessment was the diversity in statistical procedures used to analyze the DEGs (normalization and analysis methods).…”

Epicardial fat and vascular risk

“…Of note, epicardial adipose tissue was associated with insulin resistance also in obese prepubertal and early pubertal children [25]. However, there are data reporting similar patterns of leptin and adiponectin gene expression in epicardial fat between diabetic and nondiabetic individuals undergoing CABG or other cardiac surgical procedures [26].…”