Impact of adiponectin on left ventricular mass index in non-complicated obese subjects

Serum adiponectin level is positively associated with vascular reactivity index by digital thermal monitoring in patients with coronary artery disease

Objectives

Adiponectin has anti-inflammatory and antiatherogenic effects and is important in the pathogenesis of cardiovascular diseases. In this cross-sectional study, our objective was to study the potential correlation between serum adiponectin levels and endothelial function in participants with coronary artery disease (CAD).

Materials and Methods

We collected serum specimens from 125 fasting participants with CAD. The endothelial function was measured using the vascular reactivity index (VRI) determined by digital thermal monitoring, and VRI values of >2.0, 1.0-1.9, and <1.0 indicated good, intermediate, and poor vascular reactivity, respectively. A commercially available enzyme immunoassay kit was used to measure serum adiponectin levels.

Results

The cohort included 55, 57, and 13 patients with good, intermediate, and poor vascular reactivity, respectively. Poor vascular reactivity was shown to be associated with older age, higher levels of serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), C-reactive protein, and lower levels of serum albumin and adiponectin. The linear regression analysis with multivariable forward stepwise approach revealed that age (β = -0.232), serum LDL-C (β = -0.264), and serum adiponectin (β = 0.574) were correlated with the VRI in CAD patients significantly.

Conclusion

Fasting serum adiponectin levels were associated with good endothelial function determined using the VRI in patients with CAD.

Obesity related changes in cardiac structure and function: role of blood pressure and metabolic abnormalities

Background: It has been reported that changes in cardiac structure and ventricular function associated with obesity have to be attributable to hemodynamic and non-hemodynamic alterations. Accordingly, the aim of this was to evaluate left ventricular hypertrophy (LVH) prevalence and its effect on left ventricular systolic and diastolic function in a cohort of obese patients.Materials and Methods: LV internal diameter (LVID), left ventricular mass (LVM) and LVM/height^2.7(LVMI), relative wall thickness (RWT), LV ejection fraction (LVEF), E/A ratio, isovolumic relaxation time, deceleration time of E velocity by echocardiography and pulsed-wave Doppler and total circulating adiponectin (ADPN) by radioimmunoassay were measured in 319 obese subjects with and without LVH.Results: Increased values of BMI, WHR, SBP, DBP, MBP LVID, LVM, LVMI, IVST (p < .001), increased prevalence of subjects with LVEF< 50%,(p < .001), central fat distribution (p < .001), hypertension (p < .001), diabetes (p < .001), metabolic syndrome (p < .02), and reduced value of ADPN (p < .0001) and LVEF (p < .001) were detected in LVH obese subjects than controls without LVH. No significant differences in diastolic parameters were observed between the two groups. LVEF correlated directly with ADPN (p < .0001) and inversely with age (p < .01), BMI (p < .01), WHR (p < .001), MBP (p < .01) MetS (p < .02) and LVMI (p < .001). WHR, MBP, LVMI and ADPN were independently associated with LVEF.Conclusions: In conclusion, our data indicate that obese subjects with LVH might be considered a distinct phenotype of obesity, characterised by LVH, increased prevalence of cardiometabolic comorbidities, central fat distribution, hypoadiponectinemia and early left ventricular systolic dysfunction.

The Role of Secretory Activity Molecules of Visceral Adipocytes in Abdominal Obesity in the Development of Cardiovascular Disease: A Review

Adipose tissue is considered one of the endocrine organs in the body because of its ability to synthesize and release a large number of hormones, cytokines, and growth and vasoactive factors that influence a variety of physiological and pathophysiological processes, such as vascular tone, inflammation, vascular smooth muscle cell migration, endothelial function, and vascular redox state. Moreover, genetic factors substantially contribute to the risk of obesity. Research into the biochemical effects of molecules secreted by visceral adipocytes as well as their molecular genetic characteristics is actively conducted around the world mostly in relation to pathologies of the cardiovascular system, metabolic syndrome, and diabetes mellitus. Adipokines could be developed into biomarkers for diagnosis, prognosis, and therapeutic targets in different diseases. This review describes the relevance of secretory activity molecules of visceral adipocytes in cardiovascular disease associated abdominal obesity.

Cardiac hypertrophy with obesity is augmented after pregnancy in C57BL/6 mice

BACKGROUND

Over a third of reproductive-age women in the USA are obese, and the prevalence of cardiovascular disease (CVD) is rising in premenopausal women. Cardiac hypertrophy is an independent predictor of CVD. In contrast to pregnancy, where transiently increased left ventricular (LV) mass is not associated with cardiac damage, obesity-mediated cardiac hypertrophy is pathological. There is a paucity of data describing the effect of obesity during pregnancy on maternal cardiovascular health. The purpose of this study was to determine the long-term effect of obesity during pregnancy on cardiac function and structure in mice.

METHODS

Female C57BL/6 J mice were fed a high-fat (HF) or a low-fat (LF) diet for 20 weeks. After 4 weeks, LF- and HF-fed female mice were either crossed with males to become pregnant or remained non-pregnant controls. Following delivery, pups were euthanized, and females maintained on respective diets. After 20 weeks of diet feeding, cardiac function was quantified by echocardiography, and plasma leptin and adiponectin concentrations quantified in LF- and HF-fed postpartum and nulliparous females. mRNA abundance of genes regulating cardiac hypertrophy and remodeling was quantified from left ventricles using the NanoString nCounter Analysis System. Cardiac fibrosis was assessed from picrosirius red staining of left ventricles.

RESULTS

HF-fed postpartum mice had markedly greater weight gain and fat mass expansion with obesity, associated with significantly increased LV mass, cardiac output, and stroke volume compared with HF-fed nulliparous mice. Plasma leptin, but not adiponectin, concentrations were correlated with LV mass in HF-fed females. HF feeding increased LV posterior wall thickness; however, LV chamber diameter was only increased in HF-fed postpartum females. Despite the marked increase in LV mass in HF-fed postpartum mice, mRNA abundance of genes regulating fibrosis and interstitial collagen content was similar between HF-fed nulliparous and postpartum mice. In contrast, only HF-fed postpartum mice exhibited altered expression of genes regulating the extracellular matrix.

CONCLUSIONS

These results suggest that the combined effects of pregnancy and obesity augment cardiac hypertrophy and promote remodeling. The rising prevalence of CVD in premenopausal women may be attributed to an increased prevalence of women entering pregnancy with an overweight or obese BMI.

Determinants of Left Ventricular Characteristics Assessed by Cardiac Magnetic Resonance Imaging and Cardiovascular Biomarkers Related to Kidney Transplantation

Background:

Cardiac magnetic resonance (CMR) imaging accurately and precisely measures left ventricular (LV) mass and function. Identifying mechanisms by which LV mass change and functional improvement occur in some end-stage kidney disease (ESKD) patients may help to appropriately target kidney transplant (KT) recipients for further investigation and intervention. The concentration of serum adiponectin, a cardiovascular biomarker, increases in cardiac failure, its production being enhanced by B-type natriuretic peptide (BNP), and both serum adiponectin and BNP concentrations decline posttransplantation.

Objective:

We tested the hypothesis that kidney transplantation alters LV characteristics that relate to serum adiponectin concentrations.

Design:

Prospective and observational cohort study.

Setting:

The study was performed at 3 adult kidney transplant and dialysis centers in Ontario, Canada.

Patients:

A total of 82 KT candidate subjects were recruited (39 to the KT group and 43 to the dialysis group). Predialysis patients were excluded.

Measurements:

Subjects underwent CMR with a 1.5-tesla whole-body magnetic resonance scanner using a phased-array cardiac coil and retrospective vectorographic gating. LV mass, LV ejection fraction (LVEF), LV end-systolic volume (LVESV), and LV end-diastolic volume (LVEDV) were measured by CMR pre-KT and again 12 months post-KT (N = 39), or 12 months later if still receiving dialysis (N = 43). LV mass, LVESV, and LVEDV were indexed for height (m^2.7) to calculate left ventricular mass index (LVMI), left ventricular end-systolic volume index (LVESVI), and left ventricular end-diastolic volume index (LVEDVI), respectively. Serum total adiponectin and N-terminal proBNP (NT-proBNP) concentrations were measured at baseline, 3 months, and 12 months.

Methods:

We performed a prospective 1:1 observational study comparing KT candidates with ESKD either receiving a living donor organ (KT group) or waiting for a deceased donor organ (dialysis group).

Results:

Left ventricular mass index change was −1.98 ± 5.5 and −0.36 ± 5.7 g/m^2.7 for KT versus dialysis subjects (P = .44). Left ventricular mass change was associated with systolic blood pressure (SBP) (P = .0008) and average LV mass (P = .0001). Left ventricular ejection fraction did not improve (2.9 ± 6.6 vs 0.7 ± 4.9 %, P = .09), while LVESVI and LVEDVI decreased more post-KT than with continued dialysis (−3.36 ± 5.6 vs −0.22 ± 4.4 mL/m^2.7, P < .01 and −4.9 ± 8.5 vs −0.3 ± 9.2 mL/m^2.7, P = .02). Both adiponectin (−7.1 ± 11.3 vs −0.11 ± 7.9 µg/mL, P < .0001) and NT-proBNP (−3811 ± 8130 vs 1665 ± 20013 pg/mL, P < .0001) declined post-KT. Post-KT adiponectin correlated with NT-proBNP (P = .001), but not estimated glomerular filtration rate (eGFR) (P = .13). Change in adiponectin did not correlate with change in LVEF in the KT group (Spearman ρ = 0.16, P = .31) or dialysis group (Spearman ρ = 0.19, P = .21).

Limitations:

Few biomarkers of cardiac function were measured to fully contextualize their role during changing kidney function. Limited intrapatient biomarker sampling and CMR measurements precluded constructing dose-response curves of biomarkers to LV mass and function. The CMR timing in relation to dialysis was not standardized.

Conclusions:

The LVESVI and LVEDVI but not LVMI or LVEF improve post-KT. LVMI and LVEF change is independent of renal function and adiponectin. As adiponectin correlates with NT-proBNP post-KT, improved renal function through KT restores the normal heart-endocrine axis.

Left-ventricular hypertrophy and obesity: a systematic review and meta-analysis of echocardiographic studies

AIM

Left-ventricular hypertrophy (LVH) is a frequent complication in obese individuals; an updated review and meta-analysis focusing on this issue is lacking. Thus, we analysed the literature in order to provide a comprehensive information on the left-ventricular structural changes, as assessed by echocardiography, associated to obesity.

DESIGN

A literature search using the keywords 'left ventricle', 'left-ventricular hypertrophy', 'cardiac hypertrophy', 'obesity', 'hypertension' and 'echocardiography' was performed in order to identify relevant papers. Full articles published in English language in the past 12 years reporting studies in adult obese individuals were considered.

RESULTS

A total of 22 studies including 5486 obese individuals were considered. Overall, in the pooled obese population, prevalence of LVH, defined by 12 criteria, was 56.0% (range 20.0-85.0%). Data provided by 15 studies (n = 4999 obese individuals), including 6623 non-obese controls, showed that the probability of having LVH was much higher in cases than in non-obese counterparts (odds ratio 4.19, 95% confidence interval 2.67-6.53, P < 0.01). A meta-regression analysis (n = 2214; 14 studies) showed a direct correlation between BMI and left-ventricular mass (P < 0.01). Among obese patients with LVH (n = 1930; 15 studies), eccentric hypertrophy was more frequent than the concentric phenotype (66 versus 34%; P < 0.01).

CONCLUSIONS

Our analysis shows that LVH is present in a consistent fraction of the obese population and that eccentric hypertrophy prevails over the concentric phenotype. As obesity-related LVH is a powerful risk factor for systolic/diastolic dysfunction, the prevention/treatment of obesity may have a strong, favourable impact on incident heart failure.

Longitudinal association of body mass index and waist circumference with left ventricular mass in hypertensive predialysis chronic kidney disease patients

Background

This study aimed to investigate the association of both body mass index (BMI) and waist circumference (WC) with left ventricular mass (LVM) in hypertensive predialysis chronic kidney disease (CKD) patients.

Methods

From 2004 to 2005, 206 consecutive incident adult patients from the outpatient CKD clinics of two hospitals in Greece were included. Inclusion criteria were the presence of CKD and hypertension. BMI (kg/m²), WC (cm) and LVM (g) were assessed annually for 3 years.

Results

The mean age was 68.1 years, mean BMI 29.1 kg/m² and mean WC was 103.7 cm. The median LVM was 245.7 g (n = 179). In the cross-sectional data, linear regression models showed that WC {β = 1.2 [95% confidence interval (CI) 0.15; 2.3]}, and not BMI [β = 2.1 (95% CI: −0.70; 4.8)], was significantly associated with LVM. After adjustment for age, sex, primary renal disease, smoking and history of cardiovascular disease, both BMI [β = 4.7 (95% CI: 2.0; 7.4] and WC [β = 1.2 (95% CI: 0.14; 2.3)] were significantly associated with LVM. These associations were pronounced in CKD stage 1–3, but not in CKD stage 4–5. In the longitudinal analysis, linear mixed models adjusting for confounders showed that both an increase in BMI [β = 2.9 (95% CI: 0.74; 5.1)] and an increase in WC [β = 1.1 (95% CI: 0.28; 1.8)] were significantly associated with an increase in LVM.

Conclusions

In hypertensive predialysis CKD patients, both BMI and WC were associated with LVM in CKD stage 1–3, but not in CKD stage 4–5. In the longitudinal analysis, both an increase in BMI and WC were associated with an increase in LVM. Future studies should focus on mechanisms responsible for the associations between anthropometric variables and LVM.

The relationship between adiponectin and left ventricular mass index varies with the risk of left ventricular hypertrophy

BACKGROUND

Adiponectin directly protects against cardiac remodeling. Despite this beneficial effect, most epidemiological studies have reported a negative relationship between adiponectin level and left ventricular mass index (LVMI). However, a positive relationship has also been reported in subjects at high risk of left ventricular hypertrophy (LVH). Based on these conflicting results, we hypothesized that the relationship between serum adiponectin level and LVMI varies with the risk of LVH.

METHODS

A community-based, cross-sectional study was performed on 1414 subjects. LVMI was measured by echocardiography. Log-transformed adiponectin levels (Log-ADPN) were used for the analysis.

RESULTS

Serum adiponectin level had a biphasic distribution (an increase after a decrease) with increasing LVMI. Although Log-ADPN did not correlate with LVMI, Log-ADPN was modestly associated with LVMI in the multivariate analysis (β = 0.079, p = 0.001). The relationship between adiponectin level and LVMI was bidirectional according to the risk of LVH. In normotensive subjects younger than 50 years, Log-ADPN negatively correlated with LVMI (r = -0.204, p = 0.005); however, Log-ADPN positively correlated with LVMI in ≥50-year-old obese subjects with high arterial stiffness (r = 0.189, p = 0.030). The correlation coefficient between Log-ADPN and LVMI gradually changed from negative to positive with increasing risk factors for LVH. The risk of LVH significantly interacted with the relationship between Log-ADPN and LVMI. In the multivariate analysis, Log-ADPN was associated with LVMI in the subjects at risk of LVH; however, Log-ADPN was either not associated or negatively associated with LVMI in subjects at low risk of LVH.

CONCLUSION

Adiponectin level and LVMI are negatively associated in subjects at low risk of LVH and are positively associated in subjects at high risk of LVH. Therefore, the relationship between adiponectin and LVMI varies with the risk of LVH.

The malignant obesity hypoventilation syndrome (MOHS)

We have coined the term 'malignant obesity hypoventilation syndrome' (MOHS) to describe a severe multisystem disease due to the systemic effects of obesity. Patients with this syndrome have severe obesity-related hypoventilation together with systemic hypertension, diabetes and the metabolic syndrome, left ventricular hypertrophy with diastolic dysfunction, pulmonary hypertension and hepatic dysfunction. This syndrome is largely unrecognized as physicians do not make the association between the patients' multiple medical problems and obesity. Because of the delayed diagnosis and progressive morbidities of this condition, all patients with a body mass index of more than 40 kg m(-2) should be screened for MOHS. The management of patients with MOHS includes short-term measures to improve the patients' medical condition and long-term measures to achieve enduring weight loss. Bariatric surgery reverses or improves the multiple metabolic and organ dysfunctions associated with MOHS and should be strongly considered in these patients.

Relations of circulating resistin and adiponectin and cardiac structure and function: the Framingham Offspring Study

Obesity is associated with pathological cardiac remodeling and risk of heart failure (HF). Adipocytokines (ADKs) may mediate the increased risk of cardiovascular disease associated with excess adiposity. Yet data relating ADKs to cardiac remodeling phenotypes are sparse. We related two circulating ADKs, resistin and adiponectin, to three important echocardiographic markers of cardiac remodeling, left ventricular mass (LVM), left atrial diameter (LAD), and LV fractional shortening (LVFS) in 2,615 participants (mean age 61 years, 55% women) in the Framingham Offspring Study. Adiponectin concentrations were inversely related to LVM in multivariable linear regression models adjusting for key clinical correlates including BMI (regression coefficient per s.d.-increment in ln-adiponectin = -3.37, P = 0.02; P for trend across quartiles = 0.02). Adiponectin was not associated with LAD or LVFS (P > 0.56). Resistin concentrations were inversely related to LVFS (regression coefficient per s.d.-increment in ln-resistin = -0.01, P = 0.03; P for trend across quartiles = 0.04). Resistin was not associated with LVM or LAD (P > 0.05). In our moderate-sized, community-based sample, higher circulating concentrations of adiponectin and resistin were associated with lower LVM and lower LVFS, respectively. In conclusion, these associations identify potential mechanisms by which excess adiposity may mediate adverse cardiac remodeling and HF risk.

Adiponectin: anti-inflammatory and cardioprotective effects

Adipose tissue is an endocrine organ that plays an essential role in regulating several metabolic functions through the secretion of biological mediators called "adipokines". Dysregulation of adipokines plays a crucial role in obesity-related diseases. Adiponectin (APN) is the most abundant adipokine accounting for the 0.01% of total serum protein, and is involved in a wide variety of physiological processes including energy metabolism, inflammation, and vascular physiology. APN plasma levels are reduced in individuals with obesity, type 2 diabetes and coronary artery disease, all traits with low-grade chronic inflammation. It is has been suggested that the absence of APN anti-inflammatory effects may be a contributing factor to this inflammation. APN inhibits the expression of tumor necrosis factor-α-induced endothelial adhesion molecules, macrophage-to-foam cell transformation, tumor necrosis factor-α expression in macrophages and adipose tissue, and smooth muscle cell proliferation. It also has anti-apoptotic and anti-oxidant effects, which play a role in its cardioprotective action. This review will focus on APN as an anti-inflammatory, anti-atherogenic and cardioprotective plasma protein.

Adiponectin and cardiovascular health: an update

The global epidemic of obesity is accompanied by an increased prevalence of cardiovascular disease (CVD), in particular stroke and heart attack. Dysfunctional adipose tissue links obesity to CVD by secreting a multitude of bioactive lipids and pro-inflammatory factors (adipokines) with detrimental effects on the cardiovascular system. Adiponectin is one of the few adipokines that possesses multiple salutary effects on insulin sensitivity and cardiovascular health. Clinical investigations have identified adiponectin deficiency (hypoadiponectinaemia) as an independent risk factor for CVD. In animals, elevation of plasma adiponectin by either pharmacological or genetic approaches alleviates obesity-induced endothelial dysfunction and hypertension, and also prevents atherosclerosis, myocardial infarction and diabetic cardiomyopathy. Furthermore, many therapeutic benefits of the peroxisome-proliferator activated receptor gamma agonists, the thiazolidinediones, are mediated by induction of adiponectin. Adiponectin protects cardiovascular health through its vasodilator, anti-apoptotic, anti-inflammatory and anti-oxidative activities in both cardiac and vascular cells. This review summarizes recent findings in the understanding of the physiological role and clinical relevance of adiponectin in cardiovascular health, and in the identification of the receptor and postreceptor signalling events that mediate the cardiovascular actions of adiponectin. It also discusses adiponectin-targeted drug discovery strategies for treating obesity, diabetes and CVD.

LINKED ARTICLES

This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.

Characteristics of patients with the "malignant obesity hypoventilation syndrome" admitted to an ICU

BACKGROUND

The incidence of obesity in westernized nations is increasing at an alarming rate. We have noted an increasing number of patients admitted to our intensive care unit (ICU) with hypercapnic respiratory failure and multisystem organ dysfunction related to obesity. We have coined the term the malignant obesity hypoventilation syndrome (MOHS) to describe this entity.

METHODS

We reviewed the hospital records of all patients who were admitted to our ICU over an 8-month period, with a body mass index (BMI) greater than 40 kg/m² and a PaCO₂ greater than 45 mm Hg. We excluded patients with musculoskeletal disease, intrinsic lung disease, and those with >20 pack-year smoking history.

RESULTS

Sixty-one patients (8% of all admissions) met the inclusion criteria for our study. The patients' mean BMI was 48.9 ± 8.6 kg/m². The patients' mean age was 59 ± 11; 47 (77%) were female and 56 (92%) were black. All patients were admitted to the ICU with hypercapnic respiratory failure. The patients had been admitted to our hospital on average 6 times over the previous 2 years; 75% had been erroneously diagnosed and treated for chronic obstructive pulmonary disease (COPD)/asthma and 86% had been treated with diuretics for congestive cardiac failure. All patients had type 2 diabetes and the metabolic syndrome. Three patients had a tracheotomy in place at admission and required mechanical ventilation. All of the remaining patients were treated with noninvasive bilevel positive airway pressure (BiPAP), with 23 patients failing BiPAP and requiring mechanical ventilation. Seven patients had a tracheotomy performed. On the basis of unexplained abnormalities of liver function tests, 39 patients (64%) were presumptively diagnosed with nonalcoholic steatohepatitis (NASH). Pulmonary function tests were suggestive of a restrictive pattern in all patients tested. By echocardiography 43 (71%) patients had left ventricular hypertrophy and 37 (61%) patients had features of left ventricular diastolic dysfunction. Forty-seven (77%) patients had pulmonary hypertension, which was moderate to severe (pulmonary systolic pressure >45 mm Hg) in 25 cases. All patients had an elevated C-reactive protein (9.4 ± 6.9 mg/dL), and all but 1 were vitamin D deficient (13.5 ± 8.5 ng/mL). Eleven patients (18%) died during the index hospitalization.

CONCLUSIONS

MOHS is a serious multisystem disorder with a high mortality that appears to be relatively common, frequently misdiagnosed, and inadequately treated.

Bariatric surgery to unload the stressed heart: a metabolic hypothesis

Obesity is an independent risk factor for cardiovascular disease. Data from the Framingham Study have reported a higher incidence of heart failure in obese individuals compared with a normal cohort. The body initially copes with the abundance of fuel present in an obese milieu by storing it in adipose tissue. However, when the storage capacity is exceeded, the excess energy is taken up and stored ectopically as fat in vital organs such as the heart. Indeed, intramyocardial lipid overload is present in hearts of obese patients, as well as in hearts of animal models of obesity, and is associated with a distinct gene expression profile and cardiac dysfunction. By imposing a metabolic stress on the heart, obesity causes it to hypertrophy and ultimately to fail. Conventional measures to treat obesity include diet, exercise, and drugs. More recently, weight loss surgery (WLS) has achieved increasing prominence because of its ability to reduce the neurohumoral load, normalize metabolic dysregulation, and improve overall survival. The effects of WLS on systemic metabolic, neurohumoral, and hemodynamic parameters are well described and include an early normalization of serum glucose and insulin levels as well as reduction in blood pressure. WLS is also associated with reverse cardiac remodeling, regression of left ventricular hypertrophy, and improved left ventricular and right ventricular function. By targeting the source of the excess energy, we hypothesize that WLS improves contractile function by limiting exogenous substrate availability to the metabolically overloaded heart. These changes have also been found to be associated with increased levels of adiponectin and improved insulin sensitivity. Taken together, the sustained beneficial effects of WLS on left ventricular mass and function highlight the need to better understand the mechanism by which obesity regulates cardiovascular physiology.

Association of adiponectin with left ventricular mass in blacks: the Jackson Heart Study

BACKGROUND

Blacks have a higher prevalence of left ventricular hypertrophy than whites. Several population-based studies have reported an inverse association between adiponectin and left ventricular mass (LVM); however, the relationship between adiponectin levels and LVM has yet to be defined in blacks. The Jackson Heart Study cohort provides an opportunity to test the hypothesis that the inverse association between adiponectin and LVM may be modified by risk factors common among blacks.

METHODS AND RESULTS

The study population included 2649 black Jackson Heart Study participants (mean age 51±12 years, 63% women, 51% obese, 54% with hypertension, and 16% with diabetes). Multiple linear and spline regression was used to assess the association, with adjustment for demographic, clinical, and behavioral covariates. Among all the participants, there was a statistically significant but modest inverse association between adiponectin and LVM index. Hypertension and insulin resistance emerged as statistically significant effect modifiers of this relationship. The inverse association present among the normotensive participants was explained by obesity measures such as the body mass index. Among participants with both hypertension and insulin resistance, there was a significant direct association between adiponectin and the LVM index after multivariable adjustment (β=1.55, P=0.04, per 1-SD increment in the adiponectin log value).

CONCLUSIONS

The association between serum adiponectin and LVM among blacks in the Jackson Heart Study cohort was dependent on hypertension and insulin resistance status. Normotensive blacks exhibited an inverse adiponectin-LVM association, whereas participants with hypertension and insulin resistance had a direct association.

Relations of circulating resistin and adiponectin and cardiac structure and function: the Framingham Offspring Study

Obesity is associated with pathological cardiac remodeling and risk of heart failure (HF). Adipocytokines (ADKs) may mediate the increased risk of cardiovascular disease associated with excess adiposity. Yet data relating ADKs to cardiac remodeling phenotypes are sparse. We related two circulating ADKs, resistin and adiponectin, to three important echocardiographic markers of cardiac remodeling, left ventricular mass (LVM), left atrial diameter (LAD), and LV fractional shortening (LVFS) in 2,615 participants (mean age 61 years, 55% women) in the Framingham Offspring Study. Adiponectin concentrations were inversely related to LVM in multivariable linear regression models adjusting for key clinical correlates including BMI (regression coefficient per s.d.-increment in ln-adiponectin = -3.37, P = 0.02; P for trend across quartiles = 0.02). Adiponectin was not associated with LAD or LVFS (P > 0.56). Resistin concentrations were inversely related to LVFS (regression coefficient per s.d.-increment in ln-resistin = -0.01, P = 0.03; P for trend across quartiles = 0.04). Resistin was not associated with LVM or LAD (P > 0.05). In our moderate-sized, community-based sample, higher circulating concentrations of adiponectin and resistin were associated with lower LVM and lower LVFS, respectively. In conclusion, these associations identify potential mechanisms by which excess adiposity may mediate adverse cardiac remodeling and HF risk.

Plasma adiponectin levels are associated with left ventricular hypertrophy in a random sample of middle-aged subjects

BACKGROUND

A low adiponectin level is associated with high blood pressure which, in turn, often results in left ventricular hypertrophy. We evaluated the association between plasma adiponectin concentrations and echocardiographic measurements, including left ventricular mass index (LVMI), in 933 middle-aged subjects consisting of 453 hypertensives and 480 controls.

METHODS

Plasma adiponectin concentrations were measured with an enzyme-linked immunosorbent assay (ELISA) method. One experienced cardiologist performed echocardiographic examinations, and LVMI was calculated according to Devereux's method.

RESULTS

Low plasma adiponectin levels were independently associated with increased intraventricular septum thickness, posterior ventricular wall thickness, and left ventricular mass index (P<0.001) in the whole cohort. In the subgroup analysis, the association between these echocardiographic parameters and adiponectin concentrations was observed only in the hypertensive cohort although fractional shortening revealed an association with adiponectin levels also in the control cohort (P=0.021). Findings remained significant after adjustment for the major risk factors for LVMI, such as age, sex, smoking, and systolic blood pressure.

CONCLUSIONS

This study in a large population sample detected an association between low plasma adiponectin concentration and LVMI, a marker of left ventricular hypertrophy. This association may be one of the factors that could explain the reported increased cardiovascular risk in subjects with low adiponectin levels.

Relationship between adiponectin and left atrium size in uncomplicated obese patients: adiponectin, a link between fat and heart

BACKGROUND

It is well known that obesity is a risk factor for severe cardiovascular complications, such as coronary heart disease, heart failure, stroke, venous thromboembolic disease, and atrial fibrillation. Left ventricle (LV) and left atrium (LA) enlargement is a characteristic feature of these patients with the consequent cardiovascular risk. Factors other than hemodynamic may influence LA remodeling. The aim of the study is to evaluate the relationship between adiponectin and LA size in uncomplicated obese patients.

METHODS

Seventy-four asymptomatic obese patients and an age- and sex-matched control group (N = 70) were recruited. A detailed clinical, echocardiographic, and analytical study was performed. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance (HOMA-IR) method. Insulin sensitivity was assessed measuring serum total adiponectin concentrations.

RESULTS

Adiponectin levels were lower in the obese group (P < 0.001) and particularly so in those obese participants with enlarged LA (32%; P < 0.0005). LA sizes were higher in the obese group (P < 0.0005). Adiponectin displayed significant correlations with body mass index, glucose, insulin, high-density lipoprotein cholesterol, and triglyceride concentrations as well as HOMA-IR (P < 0.001 for all). Adiponectin displayed significant correlations with LV mass and LA size, diastolic and systolic cardiac volumes and diameters, and cardiac output (P < 0.001 for all). Adiponectin correlations with LA size (r = -0.429; P < 0.001) persisted after adjustment for HOMA-IR, age, sex, and LV mass.

CONCLUSIONS

A novel inverse relationship between adiponectin and LA size independent of age, sex, insulin resistance, and LV mass appears in our series. Adiponectin could be a link between adipose tissue and the heart, having an influence on cardiac remodeling.