Adiponectin in coronary heart disease and newly diagnosed impaired glucose tolerance

Negative Correlation of Serum Adiponectin Level with Aortic Stiffness in Elderly Diabetic Persons

Adiponectin has anti-inflammatory activity against atherosclerosis. Aortic stiffness is a common manifestation of atherosclerosis in diabetes mellitus and elderly persons. This study aimed to evaluate whether low serum adiponectin levels were associated with aortic stiffness in geriatric diabetic patients. Blood samples were obtained from 130 diabetic participants aged ≥ 65 years. We defined high aortic stiffness based on a carotid−femoral pulse wave velocity (cfPWV) of >10 m/s. Circulating adiponectin concentrations were examined using enzyme-linked immunosorbent assays. Sixty-six participants (50.8%) had aortic stiffness. Patients with aortic stiffness had lower serum adiponectin concentrations than those in the control group (p < 0.001). Multivariate logistic regression analysis showed that the adiponectin level (odds ratio: 0.939, 95% confidence interval: 0.898−0.981, p = 0.005) was an independent predictor of aortic stiffness in elderly diabetic persons. Multivariate forward stepwise linear regression analysis also demonstrated that the adiponectin level (β = −0.256, adjusted R2 change = 0.100, p = 0.003) was negatively associated with cfPWV values in older diabetic patients. In conclusion, serum adiponectin is negatively correlated with cfPWV and is an independent predictor of aortic stiffness in elderly diabetic persons.

MORPHOLOGICAL AND FUNCTIONAL MYOCARDIAL ABNORMALITIES IN THE CHORNOBYL NPP ACCIDENT CLEAN-UP WORKERS OF «IODINE» PERIOD HAVING GOT TYPE 2 DIABETES MELLITUS

OBJECTIVE

Evaluation of morphological and functional myocardial abnormalities in the Chornobyl NPP (ChNPP)accident clean-up workers (ACUW) of the «iodine» period exposed to ionizing radiation at a young age and havinggot the type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

The ChNPP ACUW of «iodine» period (n=111) exposed to ionizing radiation (IR) at a young age(18-35 years) were involved in the study. Subjects having got the T2DM were included in study Group I (n = 66), per-sons with normal glucose challenge test were selected as a comparison Group II (n = 45). External radiation doses (ERD)ranged from 10 to 860 mSv. The Group III (clinical control) included persons having got the T2DM with no radiationexposure in a history (n=20). Group IV was the normative one. There was no statistical difference between the groups inage, sociodemographic characteristics and level of education. Echocardiography and cardiac Doppler sonography wereperformed in one- and two-dimensional regimens according to the recommendations of the European Association ofEchocardiography. Total adiponectin and proinflammatory cytokine (TNF-α and IL-6) concentrations were assayed by theimmunoenzyme method. Statistical processing of data was carried out using the Microsoft® Exel 2002 software.

RESULTS

Myocardial remodeling in the ChNPP ACUW of a «iodine» period having the T2DM occurred through a sig-nificant increase of its linear parameters. Volumetric parameters (EDV, ESV and their indexes) were within maximumpermissible limits significantly exceeding however the values in the Group IV. There was aт increase in myocardialmass of the left ventricle and its indices with the formation of structural-geometric abnormalities, mainly in theform of concentric hypertrophy with a decrease in the myocardial contractile capacity. There was no differences ofthe vast majority of key morphometric parameters of myocardium in the dose subgroups, while in persons with ERD> 500 mSv the incidence of serious left ventricular hypertrophy (LVMMI > 149 g/m2) significantly exceeded thisvalue in individuals with lower ERD. At a maximum ERD the more intense fibroplastic processes were observed inmyocardium [a significant increase in the interstitial collagen volumetric fraction (ICVF)] as compared to the caseswith ERD up to 50 mSv. Intensification of myocardial fibroblastic processes occurred in the comparizin group andgroup off clinical control. In combination with concentric myocardial hypertrophy this may lead to an increased riskof cardiovascular complications. Strong negative correlation was revealed between the parameters of left ventricu-lar structure in diastole and adiponectin level in the ChNPP ACUW of a «iodine» period with diagnosed T2DM, high-lighting its cardioprotective effect. At the same time, the content of FNP-α and IL-6 proinflammatory cytokines hada positive correlation with the main parameters of abnormal myocardial remodeling, indicating the possibility oftheir role in unfavorable cardiovascular modifications.

CONCLUSIONS

The decreased adiponectin level and elevated levels of TNF-α and IL-6 in the ChNPP ACUW of a«iodine» period having got the T2DM are the meaningful factors in progression of LV geometric remodeling. Togetherwith fibroplastic processes (a significant increase in ICVF) this may be a basis for the development of myocardialremodeling processes, namely a concentric hypertrophy, which is a prerequisite for the development of complica-tions in cardiovascular system.

Circulating levels of adiponectin and extent of coronary artery disease in patients undergoing elective coronary angiography

Adiponectin (APN), an adipose tissue-released adipokine with demonstrated anti-inflammatory and anti-atherogenic properties, is encoded by a gene whose polymorphisms are associated with presence of coronary artery disease (CAD). Serum APN levels are inversely related with presence and complexity of CAD. Within this context, we sought to compare levels of total APN and its high molecular weight form (HMW APN) according to clinical presentation and extent of CAD in patients undergoing elective cardiac catheterization. From March 2008 to June 2010, clinical data and blood samples for APN and HMW APN measurements were collected from 415 subjects undergoing cardiac catheterization at two tertiary centers. CAD extent was estimated by the number of coronary arteries with significant stenosis (≥70% obstruction in a major coronary artery) and by Duke Jeopardy Score (DJS). Serum APN levels were similar between groups with stable or unstable CAD (APN 9.20±5.88 vs 9.47±6.23 μg/mL, P=0.738, and HMW APN 5.31±3.72 vs 5.91±4.16 μg/mL, P=0.255), even after stratification by the number of arteries involved (single-vessel vs multivessel disease: APN 9.39±5.76 vs 9.26±6.27 μg/mL, P=0.871; HMW APN 5.29±3.79 vs 5.83±4.04 μg/mL, P=0.306) and DJS score (APN, P=0.718; HMW APN, P=0.276). We conclude that APN and HMW APN serum levels are similar across clinical presentations and different extents of CAD, despite being significantly lower in the presence of obstructive CAD.

Adipokines and cardiovascular disease: A comprehensive review

Adipokines are peptides that signal the functional status of adipose tissue to the brain and other target organs. In adipose tissue dysfunction, adipokine secretion is altered, and this can contribute to a spectrum of obesity-associated conditions including cardiovascular disease. Some adipokines have anti-inflammatory and cardioprotective effects (omentin, apelin, adiponectin). Others are pro-inflammatory with negative impact on cardiovascular function (leptin, visfatin, resistin, adipocyte fatty-acid-binding protein). In the first part, this article reviews the endocrine functions of adipose tissue in general, effects of the distribution and composition of fat tissue, and the roles of cortisol and the renin-angiotensin-aldosterone system in the development of the inflammatory state of addipose tissue. In the second part, the known cardiovascular effects of different adipokines and their clinical potential are discussed in detail.

INTERACTING DISCIPLINES: Cardiac natriuretic peptides and obesity: perspectives from an endocrinologist and a cardiologist

Since their discovery in 1981, the cardiac natriuretic peptides (cNP) atrial natriuretic peptide (also referred to as atrial natriuretic factor) and brain natriuretic peptide have been well characterised in terms of their renal and cardiovascular actions. In addition, it has been shown that cNP plasma levels are strong predictors of cardiovascular events and mortality in populations with no apparent heart disease as well as in patients with established cardiac pathology. cNP secretion from the heart is increased by humoral and mechanical stimuli. The clinical significance of cNP plasma levels has been shown to differ in obese and non-obese subjects. Recent lines of evidence suggest important metabolic effects of the cNP system, which has been shown to activate lipolysis, enhance lipid oxidation and mitochondrial respiration. Clinically, these properties lead to browning of white adipose tissue and to increased muscular oxidative capacity. In human association studies in patients without heart disease higher cNP concentrations were observed in lean, insulin-sensitive subjects. Highly elevated cNP levels are generally observed in patients with systolic heart failure or high blood pressure, while obese and type-2 diabetics display reduced cNP levels. Together, these observations suggest that the cNP system plays a role in the pathophysiology of metabolic vascular disease. Understanding this role should help define novel principles in the treatment of cardiometabolic disease.

Serum lectin-like oxidized-low density lipoprotein receptor-1 and adiponectin levels are associated with coronary artery disease accompanied with metabolic syndrome

Background:

Coronary artery disease (CAD) is a major public health problem for developed and developing countries and is the single leading cause of death worldwide.

Objectives:

There is very few evidence regarding changes of both serum Lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and adiponectin in patients with CAD accompanied with metabolic syndrome (MS). Here we aimed to evaluate serum levels of LOX-1 and adiponectin in patients with CAD accompanied with MS.

Patients and Methods:

Thirty patients with coronary artery disease without metabolic syndrome, 30 patients with coronary artery disease and metabolic syndrome, 30 ones with metabolic syndrome and 30 healthy subjects were enrolled. For all subjects, a questionnaire was filled to collect data, and peripheral blood samples were collected aseptically from the antecubital vein to measure serum Lectin-like oxidized-low density lipoprotein receptor-1 and adiponectin levels by enzyme-linked immunosorbent assay.

Results:

Serum LOX-1 level was highest in CAD + MS group; the difference between control and disease groups was statistically significant (P < 0.001). Adiponectin level had the lowest value in CAD + MS group; the difference between control and disease groups was statistically significant (P < 0.05). No significant differences were observed in serum Lectin-like oxidized-low density lipoprotein receptor-1and adiponectin in patients with different ages and gender. Serum LOX-1 level was changed negatively and linearly (R2 = 0.721) correlated with adiponectin level in different groups.

Conclusions:

Patient with CAD and MS had higher risk than those with only CAD because of lipid and glucose metabolism abnormalities. Combination measurements of serum LOX-1 and adiponectin levels may be helpful to evaluate the severity of CAD together with MS.

Metabolic actions of natriuretic peptides and therapeutic potential in the metabolic syndrome

Natriuretic peptides (NPs) are a group of peptide-hormones mainly secreted from the heart, signaling via c-GMP coupled receptors. NP are well known for their renal and cardiovascular actions, reducing arterial blood pressure as well as sodium reabsorption. Novel physiological functions have been discovered in recent years, including activation of lipolysis, lipid oxidation, and mitochondrial respiration. Together, these responses promote white adipose tissue browning, increase muscular oxidative capacity, particularly during physical exercise, and protect against diet-induced obesity and insulin resistance. Exaggerated NP release is a common finding in congestive heart failure. In contrast, NP deficiency is observed in obesity and in type-2 diabetes, pointing to an involvement of NP in the pathophysiology of metabolic disease. Based upon these findings, the NP system holds the potential to be amenable to therapeutical intervention against pandemic diseases such as obesity, insulin resistance, and arterial hypertension. Various therapeutic approaches are currently under development. This paper reviews the current knowledge on the metabolic effects of the NP system and discusses potential therapeutic applications.