Impact of Gender on the Association of Epicardial Fat Thickness, Obesity, and Circadian Blood Pressure Pattern in Hypertensive Patients

Determinants of echocardiographic epicardial adipose tissue in a general middle-aged population - The Cardiovascular Risk in Young Finns Study

Epicardial adipose tissue (EAT) is the cardiac visceral fat depot proposed to play a role in the etiology of various cardiovascular disease outcomes. Little is known about EAT determinants in a general population. We examined cardiometabolic, dietary, lifestyle and socioeconomic determinants of echocardiograpghically measured EAT in early adulthood. Data on cardiometabolic, dietary, lifestyle and socioeconomic factors were collected from participants of the Cardiovascular Risk in Young Finns Study (YFS; N = 1667; age 34-49 years). EAT thickness was measured from parasternal long axis echocardiograms. Multivariable regression analysis was used to study potential EAT determinants. Possible effect modification of sex was addressed. Mean EAT thickness was 4.07 mm (95% CI 4.00-4.17). Multivariable analysis [β indicating percentage of change in EAT(mm) per one unit increase in determinant variable] indicated female sex (β = 11.0, P < 0.0001), type 2 diabetes (β = 14.0, P = 0.02), waist circumference (cm) (β = 0.38, P < 0.0001), systolic blood pressure (mmHg) (β = 0.18, P = 0.02) and red meat intake (g/day) (β = 0.02, P = 0.05) as EAT determinants. Sex-specific analysis revealed age (year) (β = 0.59, P = 0.01), alcohol intake (drinks/day) (β = 4.69, P = 0.006), heavy drinking (yes/no) (β = 30.4, P < 0.0001) as EAT determinants in women and fruit intake (g/day) (β = -1.0, P = 0.04) in men. In the YFS cohort, waist circumference, systolic blood pressure and red meat intake were directly associated with EAT among all participants. In women, age, alcohol intake, heavy drinking and type 2 diabetes associated directly with EAT, while an inverse association was observed between fruit intake and EAT in men.

Adverse association of epicardial adipose tissue accumulation with cardiac function and atrioventricular coupling in postmenopausal women assessed by cardiac magnetic resonance imaging

Background

This study aims to investigate the association of epicardial adipose tissue (EAT) accumulation with cardiac function and atrioventricular coupling in a cohort of postmenopausal women assessed by cardiac magnetic resonance imaging (CMR).

Materials and methods

Overall, 283 postmenopausal women (mean age 61.5 ± 9.1 years) who underwent CMR examination were enrolled. Participants were classified into four groups by the quartile of EAT volume. EAT volume was quantified on short-axis cine stacks covering the entire epicardium. CMR-derived cardiac structure and function, including left atrial (LA)- volume, emptying fraction, deformation, and left ventricular (LV)- mass, volume, ejection fraction, and deformation, were compared among the four groups of graded EAT volume.

Results

Left ventricular mass (LVM) and LV remodeling index were both increased in the group with the highest EAT volume, compared to those in the lowest quartile (p = 0.016 and p = 0.003). The LV global longitudinal strain (LV-GLS), circumferential strain (LV-GCS), and LA- reservoir strain (LA-RS), conduit strain (LA-CS), and booster strain (LA-BS), were all progressively decreased from the lowest quartile of EAT volume to the highest (all p &lt; 0.05). Multivariable linear regression analyses showed that EAT was independently associated with LV-GLS, LA-RS, LA-CS, and LA-BS after adjusting for body mass index and other clinical factors.

Conclusion

Epicardial adipose tissue accumulation is independently associated with subclinical LV and LA function in postmenopausal women. These associations support the role of EAT in mediating deleterious effects on cardiac structure and function.

Association between epicardial adipose tissue and blood pressure: A systematic review and meta-analysis

AIMS

Epicardial adipose tissue has been reported to be associated with the development of cardiometabolic disease. Whether this is true for hypertension and non-dipper blood pressure remains controversial. Here, we conducted a systemic review and meta-analysis to evaluate the association between EAT and blood pressure.

DATA SYNTHESIS

Pubmed, Embase, and Web of Science were searched for relevant papers. Studies reported on the difference of EAT thickness between hypertensive and normotensive patients, or those recorded odds ratio (OR) between EAT and hypertension were included. The standard mean difference (SMD) and ORs were extracted and pooled using a random-effects model respectively. We further assessed the effect of EAT on circadian rhythm of blood pressure by combining multiple-adjusted ORs for non-dipper blood pressure. Seven studies with an overall sample of 1089 patients reported the mean difference of EAT thickness between hypertensive and normotensive patients, and the hypertensive patients had higher EAT (SMD = 1.07; 95% CI: 0.66-1.48; I2 = 89.2%) compared with controls. However, the pooled association between EAT and hypertension from two studies was not significant (OR = 1.65, 95%CI 0.62-4.68; I2 = 87.5%). The summary risk effect of EAT on non-dipper blood pressure from six studies comprising1208 patients showed that each 1 mm increment of EAT was associated with a 2.55-fold risk of non-dipper blood pressure.

CONCLUSION

Hypertensive patients tend to present higher EAT thickness near the right ventricular wall and increased EAT thickness might be associated with high risk of non-dipper blood pressure. Future researches are warranted to determine the causal link between EAT and hypertension and the underlying mechanism.

Increased epicardial adipose tissue thickness is associated with microalbuminuria in hypertensive patients with left ventricular hypertrophy

OBJECTIVE

Epicardial adipose tissue (EAT) is a cardiometabolic risk factor, and its possible relationship with hypertension has been previously reported. Microalbuminuria (MA) is associated with target-organ damage, especially in patients with hypertension with left ventricular hypertrophy (LVH) and suggest endothelial dysfunction. This study aimed to investigate the relationship between echocardiographic EAT thickness and presence of MA in patients with hypertension.

METHODS

A total of 297 newly diagnosed hypertension patients who applied to the outpatient clinic were enrolled consecutively in this study. Patients were divided into two groups regarding the presence of LVH in echocardiography. An age and gender matched control group was set including 156 healthy patients without HT. All subjects underwent transthoracic echocardiography for the measurement of EAT thickness. Spot urine samples were collected for the assessment of MA.

RESULTS

In hypertensive patients with LVH, the EAT thicknesses (6.6 ± 1.8 vs 5.3 ± 1.5 vs 5.1 ± 1.3, p < .001; respectively) and prevalence of MA (41.2 vs 20.1 vs 3.2%; p < .001 respectively) were significantly higher than the other two groups. In hypertensive patiens without LVH, no relationship was found between the presence of MA and EAT thickness. In multivariate regression analyses, EAT thickness (OR: 3.141, 95%CI: 2.425-6.123, p < .001) and left ventricular mass index (OR: 1.339, 95%CI: 1.145-2.143, p = .003) were determined as independent predictors for MA development in hypertensive patients with LVH.

CONCLUSION

Measurement of EAT thickness may help to identify high-risk hypertensive patients for target-organ damage especially among patients with LVH.

Characterization of the inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction: a hypothesis to explain influence of sex on the evolution and potential treatment of the disease

Accumulating evidence points to the existence of an inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction (HFpEF), which is characterized by biomarkers of inflammation, an expanded epicardial adipose tissue mass, microvascular endothelial dysfunction, normal-to-mildly increased left ventricular volumes and systolic blood pressures, and possibly, altered activity of adipocyte-associated inflammatory mediators. A broad range of adipogenic metabolic and systemic inflammatory disorders - e.g. obesity, diabetes and metabolic syndrome as well as rheumatoid arthritis and psoriasis - can cause this phenotype, independent of the presence of large vessel coronary artery disease. Interestingly, when compared with men, women are both at greater risk of and may suffer greater cardiac consequences from these systemic inflammatory and metabolic disorders. Women show disproportionate increases in left ventricular filling pressures following increases in central blood volume and have greater arterial stiffness than men. Additionally, they are particularly predisposed to epicardial and intramyocardial fat expansion and imbalances in adipocyte-associated proinflammatory mediators. The hormonal interrelationships seen in inflammatory-metabolic phenotype may explain why mineralocorticoid receptor antagonists and neprilysin inhibitors may be more effective in women than in men with HFpEF. Recognition of the inflammatory-metabolic phenotype may improve an understanding of the pathogenesis of HFpEF and enhance the ability to design clinical trials of interventions in this heterogeneous syndrome.

Pericardial adiposity versus body adiposity measured by BMI in the assessment of coronary atherosclerosis burden in patients with hypertension

OBJECTIVES

The link between obesity and hypertension with coronary atherosclerosis is complex. We aimed to assess the association of cardiac fat deposition measured by pericardial fat volume(PFV) using by multi-detector CT(MDCT) and general obesity measured by BMI with subclinical coronary atherosclerotic markers (coronary artery calcium score (CAC), coronary plaque and stenosis) in patients with hypertension and suspected coronary artery disease.

METHODS

Among 496 patients presenting with chest pain who underwent 64-slice MDCT angiography to exclude occlusive coronary disease, 261 patients with hypertension (age: 57 ± 8 years, 45% males) enrolled in the present study.

RESULTS

PFV showed a significant association with CAC(r = 0.2,P = .001),coronary stenosis severity(PFV median(IQR) 88(63-161) in patients with coronary stenosis<50% compared to PFV median(IQR) 125(85-140) in patients with coronary stenosis ≥ 50%, P = .001) and coronary plaque presence (PFV median (IQR) 89(65-128) in patients without plaque compared to PFV median (IQR) 115(74-150) in patients with plaque presence = 0.03).the significant association of PFV with CAC[odds ratio(95% confidence interval = 0.5(0.19-0.97),P = .001] and coronary stenosis severity [odds ratio(95% confidence interval = 1.1(1.00-1.01),P = .01]persisted after adjustment for conventional cardiac risk. BMI showed a significant association with significant coronary stenosis presence (P = .02).The association of BMI with significant coronary stenosis presence after adjustment for conventional cardiac risk factors (P = .03).BMI showed no significant association with CAC and coronary plaque presence (P > .05).

CONCLUSION

PFV showed a significant independent association with coronary calcification and significant coronary stenosis in patients with hypertension rather than BMI.

Epicardial Adipose Tissue Accumulation and Essential Hypertension in Non-Obese Adults

Background and Objectives: Epicardial adipose tissue (EAT) is shown to be an important factor in the development of coronary artery disease, but numerous pathophysiological mechanisms of its action are still only partially understood. There is a lack of studies on its association with different grades of essential hypertension (EH). Therefore, we aimed to evaluate the association between size of EAT depots and the risk of EH taking into account its grade. Materials and Methods: Non-obese adult patients with various cardiovascular diseases were investigated: 157 of them had essential hypertension and 101 did not. Hypertensive patients were assigned to three groups according to the grade of hypertension. EAT volume and thickness on ventricular free walls (6 locations) and grooves (5 locations) were measured using cardiac magnetic resonance imaging and compared between groups. A regression model for the prediction of EH was constructed. Results: In general, thickness (in all locations) and volume of EAT depots was greater among hypertensive patients than in normotensive (NORM) group. Mean EAT thickness in all 11 locations and EAT volume were lower in NORM than in grade 1 hypertension group; similarly, EAT volume was lower in grade 1 than in grade 2 hypertension group. EAT accumulation did not differ between grade 2 and severe hypertension groups. EAT volume, dyslipidaemia status, body mass index, and age were independent predictors for EH in regression model. Conclusions: EAT accumulation is larger among hypertensive than normotensive individuals. Measurement of EAT depots could be beneficial for identification of hypertensive patients and prediction of hypertension severity.

Epicardial adipose tissue and its association with cardiovascular risk factors and mitral annular calcium deposits

Introduction

Epicardial fat is a variety of visceral adipose tissue that secretes pro-inflammatory cytokines that can lead to progression of atherosclerosis. Previous studies have shown a correlation between cardiovascular risk factors and severity of mitral annular calcification. The aim of our study was to assess the correlation between epicardial fat thickness and mitral annular calcification.

Methods

This study recruited 188 patients who were considered for coronary angiography and underwent echocardiography within 24 hours of admission. Epicardial fat thickness was measured in the parasternal long axis view at the end-systole. Mitral annular calcification was visualized in the parasternal short-axis view and was grade as none, mild, moderate, and severe. Furthermore, left atrial diameter, severity of mitral regurgitation, left ventricular ejection fraction, and early diastolic velocities (E wave) determined by transmitral pulsed Doppler, the early mitral annular velocities measured by tissue Doppler (e'), and E/e' were obtained.

Results

Patients with an epicardial fat thickness ≥7 mm had higher prevalence of hypertension and higher SYNTAX score (p value = 0.002 and 0.0014, respectively). Also, mitral annular calcification was both more prevalent and more extensive (p value = 0.007 and <0.001, respectively) and left atrial diameter was larger in these patients compared with patients with epicardial fat thickness <7 mm (p value = 0.001).

Conclusions

Our study showed significant association between increased epicardial fat thickness and calcium deposits in the mitral valve annulus that is a degenerative process associated with cardiovascular risk factors.

Epicardial fat, cardiovascular risk factors and calcifications in patients with chronic kidney disease

Background

Epicardial adipose tissue (EAT) exerts cardiopathogenic effects, but the independent association between EAT and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD) remains controversial. We therefore assessed the association between EAT, CV risk factors and CV calcifications.

Methods

257 patients with CKD Stage 3 and/or overt proteinuria underwent quantification of EAT, coronary artery calcification and aortic valve calcification by computed tomography. Framingham and American College of Cardiology and American Heart Association (ACC-AHA) 10-year CV event risk scores were calculated for each patient.

Results

Using multivariable regression analysis, higher EAT was significantly associated with the majority of investigated risk factors {higher age: odds ratio [OR] 1.05/year [95% confidence interval (CI) 1.02-1.08]; male sex: OR 4.03 [95% CI 2.22-7.31]; higher BMI: OR 1.28/kg/m² [95% CI 1.20-1.37]; former smoking: OR 1.84 [95% CI 1.07-3.17]; lower high-density lipoprotein cholesterol: OR 0.98/mg/dL [95% CI 0.96-1.00] and lower estimated glomerular filtration rate: OR 0.98/mL/min/1.73 m² [95% CI 0.97-0.99]; all P < 0.05} and was not associated with diabetes mellitus, hypertensive nephropathy, total cholesterol and albuminuria. EAT was positively associated with higher ACC-AHA and Framingham risk scores. EAT correlated with coronary artery calcification and aortic valve calcification [Spearman ρ = 0.388 (95% CI 0.287-0.532) and r _rb = 0.409 (95% CI 0.310-0.556), respectively], but these correlations were dependent on CV risk factors.

Conclusions

The increase of EAT can be explained by individual CV risk factors and kidney function and correlates with 10-year risk for CV event scores, suggesting that EAT is a modifiable risk factor in patients with CKD. Although EAT correlates with CV calcifications, these relations depend on CV risk factors.

Reduction of 24-h blood pressure variability in extreme obese patients 10 days and 6 months after bariatric surgery depending on pre-existing hypertension

Bariatric surgery is considered as a first line treatment in extreme obese patients to achieve a reduction in health risks. However, after surgical procedure obese patients with normal blood pressure (BP) levels still present residual risk, which may be partly related to lack of correction of BP profile and variability.

AIM

To evaluate short (10 days) and mid-term (6 months) changes of mean values, profile and variability of BP after bariatric surgery in extremely obese patients with and without hypertension.

MATERIALS & METHODS

A follow-up of cross-sectional study was conducted in 90 obese patients (aged 41.7 ± 11.3, BMI = 46.7 ± 5.7 kg/m2), who met the eligibility criteria and underwent bariatric surgery. Each patient underwent 24-h ambulatory BP monitoring with profile and variability estimation before, 10 days and 6 months after the intervention.

RESULTS

Sixty-seven (74.4%) patients had hypertension. Significant decrease from baseline in mean values of systolic and diastolic BP in 10 days (p < .005) and 6 months (p < .005) follow-up were observed only in patients with hypertension. Moreover, only hypertensive subjects revealed significant reduction (p < 0,05) from baseline in 24-h systolic and diastolic BP weighted standard deviation and average real variability after surgical procedure. No changes were found in dipping status.

CONCLUSIONS

Bariatric surgery not only decreased BP levels, but also contributed to reduction in BP variability in early period after intervention mainly in patients with pre-existing hypertension.

Sex differences in the vascular function and related mechanisms: role of 17β-estradiol

The incidence of cardiovascular disease (CVD) is lower in premenopausal women but increases with age and menopause compared with similarly aged men. Based on the prevalence of CVD in postmenopausal women, sex hormone-dependent mechanisms have been postulated to be the primary factors responsible for the protection from CVD in premenopausal women. Recent Women’s Health Initiative studies, Cochrane Review studies, the Early Versus Late Intervention Trial with Estradiol Study, and the Kronos Early Estrogen Prevention Study have suggested that beneficial effects of hormone replacement therapy (HRT) are seen in women of <60 yr of age and if initiated within <10 yr of menopause. In contrast, the beneficial effects of HRT are not seen in women of >60 yr of age and if commenced after 10 yr of menopause. The higher incidence of CVD and the failure of HRT in postmenopausal aged women could be partly associated with fundamental differences in the vascular structure and function between men and women and in between pre- and postmenopausal women, respectively. In this regard, previous studies from human and animal studies have identified several sex differences in vascular function and associated mechanisms. The female sex hormone 17β-estradiol regulates the majority of these mechanisms. In this review, we summarize the sex differences in vascular structure, myogenic properties, endothelium-dependent and -independent mechanisms, and the role of 17β-estradiol in the regulation of vascular function.

Epicardial Fat Thickness and Free Fatty Acid Level are Predictors of Acute Ischemic Stroke with Atrial Fibrillation

BACKGROUND

Increased epicardial fat is known to be associated with the presence and chronicity of atrial fibrillation (AF). Free fatty acids (FFAs) are major components of epicardial fat; however, their potential association with AF in ischemic stroke has not been investigated. We aimed to assess the performance of echocardiographic epicardial fat thickness (EFT) and plasma FFA level in identifying patients with ischemic stroke and AF.

METHODS

We enrolled a total of 214 consecutive patients (mean age, 66.8 ± 12.3 years; 39.7% women) diagnosed with acute ischemic stroke between March 2011 and June 2014. The patients were divided into two groups: ischemic stroke with AF (n = 35, 16.4%) and ischemic stroke without AF (n = 179, 83.6%).

RESULTS

The ischemic stroke with AF group showed significantly higher serum FFA level (1379.7 ± 717.5 vs. 757.8 ± 520.5 uEq/L, p < 0.0001) and EFT (6.5 ± 1.2 vs. 5.3 ± 1.2 mm, p < 0.001) than the group without AF. Multivariable logistic regression analysis demonstrated that age (odds ratio [OR], 1.112), serum FFA level (OR, 1.002), and EFT (OR, 1.740) were independently associated with the ischemic stroke group with AF. EFT and FFA significantly improved the goodness-of-fit and discriminability of the simple regression model including age as a covariate (log likelihood difference, 21.35; p < 0.001; c-index difference, 17.9%; p < 0.001).

CONCLUSIONS

High EFT and serum FFA level were associated with ischemic stroke in patients with AF. Echocardiographic EFT and serum FFA level can play a significant role in identifying ischemic stroke with AF.

Resistance exercise improves cardiac function and mitochondrial efficiency in diabetic rat hearts

Metabolic disturbance and mitochondrial dysfunction are a hallmark of diabetic cardiomyopathy (DC). Resistance exercise (RE) not only enhances the condition of healthy individuals but could also improve the status of those with disease. However, the beneficial effects of RE in the prevention of DC and mitochondrial dysfunction are uncertain. Therefore, this study investigated whether RE attenuates DC by improving mitochondrial function using an in vivo rat model of diabetes. Fourteen Otsuka Long-Evans Tokushima Fatty rats were assigned to sedentary control (SC, n = 7) and RE (n = 7) groups at 28 weeks of age. Long-Evans Tokushima Otsuka rats were used as the non-diabetic control. The RE rats were trained by 20 repetitions of climbing a ladder 5 days per week. RE rats exhibited higher glucose uptake and lower lipid profiles, indicating changes in energy metabolism. RE rats significantly increased the ejection fraction and fractional shortening compared with the SC rats. Isolated mitochondria in RE rats showed increase in mitochondrial numbers, which were accompanied by higher expression of mitochondrial biogenesis proteins such as proliferator-activated receptor-γ coactivator-1α and TFAM. Moreover, RE rats reduced proton leakage and reactive oxygen species production, with higher membrane potential. These results were accompanied by higher superoxide dismutase 2 and lower uncoupling protein 2 (UCP2) and UCP3 levels in RE rats. These data suggest that RE is effective at ameliorating DC by improving mitochondrial function, which may contribute to the maintenance of diabetic cardiac contractility.

Epicardial Fat Thickness is Correlated with Vagal Hyperactivity in Patients with Neurally-Mediated Syncope

BACKGROUND

Epicardial fat tissue has unique endocrine and paracrine functions that affect the cardiac autonomic system. The head-up tilt test (HUTT) is a simple non-invasive measurement that assesses autonomic nervous system dysfunction. We investigated the association between epicardial fat thickness (EFT) and autonomic neural tone, such as vagal tone.

METHODS

A total of 797 consecutive patients (mean age 46.5 years, male: 45.7%) who underwent HUTT and echocardiography between March 2006 and June 2015 were enrolled. EFT was measured during the diastolic phase of the parasternal long axis view. We excluded patients with prior percutaneous coronary intervention, old age (* 70 years old), valvular heart disease, symptomatic arrhythmias and diabetes. We divided patients into two groups based on the HUTT (positive vs. negative).

RESULTS

There were 329 patients (41.3%) with a negative HUTT result and 468 patients (58.7%) with a positive result. The HUTT-positive patients showed a significantly lower waist circumference, body mass index and systolic and diastolic blood pressure, although a significantly higher EFT as compared to the HUTT-negative patients (HUTT-positive, 5.69 ± 1.76 mm vs. HUTT-negative, 5.24 ± 1.60 mm; p < 0.001). EFT > 5.4 mm was associated with a positive HUTT result with 51.7% sensitivity and 63.8% specificity (p < 0.001) on receiving operator characteristic analysis. Multivariate Cox regression analysis revealed that EFT (hazard ratio: 1.02, 95% confidence interval: 1.01-1.30, p = 0.004) was an independent predictor of HUTT-positivity.

CONCLSION

EFT was significantly correlated with positive HUTT, which suggests an association between EFT and autonomic dysregulation.

Epicardial Fat Thickness and Neutrophil to Lymphocyte Ratio are Increased in Non-Dipper Hypertensive Patients

Background

In this study, we aimed to investigate the relationship between echocardiographic epicardial fat thickness (EFT), neutrophil to lymphocyte ratio (NLR; an important inflammatory marker), and diurnal blood pressure (BP) changes in patients with recently diagnosed essential hypertension.

Methods

A total of 647 patients underwent echocardiography and 24 hours of ambulatory BP monitoring. EFT was measured by echocardiography, while NLR was measured by dividing the neutrophil count by the lymphocyte count. Patients were categorized into three groups according to BP pattern: the normotensive group, the dipper group, and the non-dipper group.

Results

The mean EFT was highest in the non-dipper group (non-dipper group, 7.3 ± 3.0 mm; dipper group, 6.1 ± 2.0 mm; control group, 5.6 ± 2.0 mm; p < 0.001). NLR was also highest in the non-dipper group (non-dipper, 2.75 ± 2.81; dipper, 2.01 ± 1.32; control, 1.92 ± 1.11; p < 0.001). EFT was significantly correlated with age (r = 0.160, p < 0.001) and NLR (r = 0.353, p < 0.001). Furthermore, an EFT ≥ 7.0 mm was associated with the non-dipper BP pattern with 51.3% sensitivity and 71.6% specificity [95% confidence interval (CI) = 0.56–0.65, p < 0.001]. In a multivariate analysis, EFT [adjusted odds ratio (OR) = 3.99, 95% CI = 1.22–13.10, p = 0.022] and NLR (OR = 1.34, 95% CI = 1.05–1.71, p = 0.018) were independent parameters that distinguished a non-dipper pattern after adjustment for cardiovascular risk factors.

Conclusion

EFT and NLR are independently associated with impaired diurnal BP profiles in hypertensive individuals. EFT (as measured by echocardiography) and NLR appear to be helpful in stratifying cardiometabolic risk.

Sexual dimorphism in obesity-related genes in the epicardial fat during aging

Aging increases the risk of cardiovascular disease and metabolic syndrome. Alterations in epicardial fat play an important pathophysiological role in coronary artery disease and hypertension. We investigated the impact of normal aging on obesity-related genes in epicardial fat. Sex-specific changes in obesity-related genes with aging in epicardial fat (EF) were determined in young (6 months) and old (30/36 months) female and male, Fischer 344 × Brown Norway hybrid (FBN) rats, using a rat obesity RT² PCR Array. Circulating sex hormone levels, body and heart weights were determined. Statistical significance was determined using two-tailed Student's t test and Pearson's correlation. Our results revealed sex-specific differences in obesity-related genes with aging. Dramatic changes in the expression profile of obesity-related genes in EF with aging in female, but not in male, FBN rats were observed. The older (30 months) female rats had more significant variations in the abundance of obesity-related genes in the EF compared to that seen in younger female rats or both age groups in male rats. A correlation of changes in obesity-related genes in EF to heart weights was observed in female rats, but not in male rats with aging. No correlation was observed to circulating sex hormone levels. Our findings indicate a dysfunctional EF in female rats with aging compared to male rats. These findings, with further functional validation, might help explain the sex differences in cardiovascular risk and mortality associated with aging observed in humans.

Sex differences in obesity-induced hypertension and vascular dysfunction: a protective role for estrogen in adipose tissue inflammation?

Obesity is a potent predictor of cardiovascular disease and associated risk factors, including hypertension. Systemic inflammation has been suggested by a number of studies to be an important link between excess adiposity and hypertension, yet the majority of the studies have been conducted exclusively in males. This is problematic since women represent ∼53% of hypertensive cases and are more likely than men to be obese. There is a growing body of literature supporting a central role for immune cell activation in numerous experimental models of hypertension, and both the sex of the subject and the sex of the T cell have been shown to impact blood pressure (BP) responses to hypertensive stimuli. Moreover, sex steroid hormones play an important role in energy homeostasis, as well as in the regulation of immune responses; estrogen, in particular, has a well-known impact on both cardiovascular and metabolic disorders. Therefore, the purpose of this review is to examine whether sex or sex hormones regulate the role of the immune system in the development of hypertension and related vascular dysfunction in response to metabolic changes and stimuli, including a high-fat diet.

Effect of Gender on the Total Abdominal Fat, Intra-Abdominal Adipose Tissue and Abdominal Sub-Cutaneous Adipose Tissue among Indian Hypertensive Patients

INTRODUCTION

Abdominal obesity is a better marker of adverse metabolic profile than generalized obesity in hypertensive subjects. Further, gender has effect on adiposity and its distribution.

AIM

Effect of gender on obesity and the distribution of fat in different sub-compartments of abdomen among Indian hypertensive subjects.

MATERIALS AND METHODS

This observational study included 278 adult subjects (Males-149 & Females-129) with essential hypertension from a tertiary care centre in north India over one year. A detailed history taking and physical examination including anthropometry were performed in all patients. Total Abdominal Fat (TAF) and abdominal adipose tissue sub-compartments like Intra-Abdominal Adipose Tissue (IAAT) and Sub-Cutaneous Adipose Tissue (SCAT) were measured using the predictive equations developed for Asian Indians.

RESULTS

Female hypertensive subjects had higher Body Mass Index (BMI) with more overweight (BMI ≥ 23kg/m(2)), and obesity (BMI≥ 25 kg/m(2)). Additionally, they had higher prevalence of central obesity based on both Waist Circumference (WC) criteria (WC≥ 90 cm in males and WC≥ 80 cm in females) and TAF criteria {≥245.6 cm(2) (males) and ≥203.46 cm(2) (females)} than male patients. But there was no difference in the prevalence of central obesity based on Waist Hip Ratio (WHR) criteria (WHR ≥0.90 in males and WHR ≥ 0.85 in females) between two genders. High TAF & IAAT were present in more females although there was no difference in the distribution of high SCAT between two genders.

CONCLUSION

Female hypertensive subjects were more obese with higher abnormal TAF & IAAT compared to male patients. However, there was no difference in the distribution of high SCAT among them.

Association among epicardial fat, heart rate recovery and circadian blood pressure variability in patients with hypertension

Background

Epicardial fat tissue is known to have an unique endocrine function which affect the cardiac autonomic system. Heart rate recovery (HRR) is a simple non-invasive measurement that assesses autonomic nervous system dysfunction. We aimed to investigate the association among epicardial fat thickness (EFT), HRR and circadian blood pressure (BP) variation in patients with hypertension.

Methods

A total of 358 consecutive patients who underwent both 24-hour ambulatory BP monitoring (ABPM) and a treadmill test were enrolled. Echocardiographic EFT and HRR, defined as peak heart rate minus heart rate after a 1-min recovery time, were measured. Patients were classified according to the ABPM; 147 patients with hypertension with a dipping pattern at night (dippers), 140 patients with hypertension with a non-dipping pattern at night (non-dippers) and 71 normotensive controls.

Results

EFT was significantly higher in hypertensive patients, especially in the non-dipper group, compared to the controls (non-dippers, 7.5 ± 2.9 mm; dippers, 6.6 ± 1.6 mm; controls, 5.5 ± 2.1 mm; p < 0.001). HRR was significantly lower in both hypertensive groups as compared to the control group and was the lowest in the non-dipper group (non-dipper, 26.6 ± 18.6; dipper, 29.5 ± 21.5; control, 71.4 ± 19.8; p < 0.001). EFT was significantly correlated with age, body mass index, 24-hour mean systolic BP and 24 h mean BP variability, whereas exercise duration, metabolic equivalents (METs) and HRR were inversely correlated with EFT. Furthermore, EFT > 6.7 mm was associated with a blunted HRR with 76 % sensitivity and 61 % specificity (ROC area under curve: 0.71, 95 % confidence interval, CI = 0.65–0.76, p < 0.001). In a multivariate analysis, EFT (odds ratio, OR = 3.53, 95 % CI = 1.20–10.37, p = 0.022) and 24-hour mean BP variability (OR = 1.09, 95 % CI = 1.03–1.16, p = 0.005) were independent predictors of a blunted HRR defined as HRR ≤ 12 beats (n = 63) in patients with hypertension.

Conclusion

EFT and HRR were significantly correlated with circadian BP variability in patients with hypertension. EFT and circadian BP variability were independent predictors of blunted HRR, which suggests a link between epicardial fat and autonomic dysregulation in hypertension.