Endothelial dysfunction in obesity and insulin resistance: a road to diabetes and heart disease

MicroRNA-126 attenuates palmitate-induced apoptosis by targeting TRAF7 in HUVECs

The aim of the present study was to explore the role of miR-126 in palmitate-induced HUVECs apoptosis and the possible mechanisms. Palmitate inhibited miR-126 expression in HUVECs, increased reactive oxygen species (ROS) production, and induced apoptosis as determined by up-regulation of caspase-3 activity and DNA fragmentation. Overexpression of miR-126 decreased ROS production, TNF-α expression, and apoptosis in palmitate-stimulated HUVECs. In contrast, miR-126 antagomir enhanced palmitate-induced ROS production, TNF-α expression, and apoptosis. The induction of miR-126 correlated with a reduction in TRAF7. We further showed that miR-126 targeted and inhibited TRAF7 expression through target sites located in the 3' untranslated region of TRAF7 mRNA. In concordance, miR-126 mimic reduced TRAF7 protein in HUVECs, whereas the inhibition of miR-126 increased it. This study demonstrates an anti-apoptotic role of miR-126 in HUVECs and identifies TRAF7 as a direct target of miR-126 in HUVECs.

Progression and reversal of coronary and mesenteric vascular dysfunction associated with obesity

OBJECTIVE

The purpose of this study was to examine progression and reversal of microvascular complications when rats were fed a high fat diet.

METHODS

Sprague-Dawley rats 10 weeks of age were fed a diet containing 45% kcal fat for up to 32 weeks. Blood pressure and heart rate was measured by telemetry. Vascular reactivity of aorta and small coronary and mesenteric vessels was determined after 8, 16, 24, and 32 weeks on diet.

RESULTS

There was a modest increase in weight and blood pressure in high fat fed rats. Sodium nitroprusside (SNP)-induced relaxation of coronary arteries was potentiated after 8 weeks on high fat diet, however, this enhanced response was not observed after 16, 24, or 32 weeks of diet. Acetylcholine (Ach) mediated relaxation was attenuated after 16, 24, and 32 weeks of high fat diet in coronary arteries; however, in aorta and mesenteric arteries, Ach-mediated response was not altered until 32 weeks on high fat diet. Reversing the high fat diet for 8 weeks resulted in partial recovery of metabolic parameters; however endothelial function in coronary arteries remained impaired.

CONCLUSIONS

These studies indicate that high fat diet promotes progressive impairment of coronary vascular function that is difficult to reverse.

The magnitude of obesity and its relationship to blood pressure among the residents of enugu metropolis in South East Nigeria

Background:

Obesity in developing nations is no longer as uncommon as it was thought to be decades ago however paucity of data on the burden of obesity from urban communities was observed by previous workers.

Aim:

To determine the magnitude of obesity and its relationship to blood pressure among urban adult residents in Enugu metropolis.

Subjects and Methods:

A cross-sectional community survey of adults who were not known to have diabetes or hypertension by self-report was carried out. Four parts of the metropolis selected by simple random sampling were used and consenting individuals aged 18-70 years were consecutively recruited. Anthropometric measurements were done using standard procedures as specified in the World Health Organization STEPs instrument. Obesity was determined using widely acknowledged body mass index (BMI) ≥30 kg/m². Descriptive and inferential statistical analyses was performed using SPSS with P value set at <0.05.

Results:

A high prevalence of obesity of 21.2% (95% confidence interval [CI]: 18.3-24.1) was found among the participants with significant female gender preponderance. The burden increased with age with the middle age group highly involved. Attainment of age of 40 years and above had an increased odd of developing obesity (odds ratio = 1.8; 95% CI: 1.3-2.6). There was a relationship between blood pressure and BMI as shown by positive correlation, higher BMI among hypertensive subjects and high burden of elevated blood pressure among obese subjects (91/164; 55.5%).

Conclusion:

A high magnitude of obesity existed among this apparently healthy unaware adults resident in an urban Nigerian city and obesity is associated with elevation in blood pressure.

Weight loss and progressive left ventricular remodelling: The Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

Impact of weight loss on cardiac structure has not been extensively investigated in large, multi-ethnic, community-based populations. We investigated the longitudinal impact of weight loss on cardiac structure by cardiac magnetic resonance (CMR).

METHODS AND RESULTS

2351 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent CMR at Exam 1 (2002) and Exam 5 (2011) were included. Primary outcomes were percentage change in LV mass (indexed to height) and LV mass-to-volume ratio (concentric LV remodelling). Multivariable linear regression was used to measure the association between outcomes and weight change. At median 9.4 years' follow-up, 639 individuals (27%) experienced >5% weight loss (median 6.9 kg) and 511 (22%) had >5% weight gain (median 6.4 kg). A >5% weight gain was associated with the greatest increase in LV mass (+5.4% median) and LV mass-to-volume ratio (+12.2% median). Adjusting for medications, hypertension/diabetes (and change in these risk factors), age, race and other risk factors, every 5% weight loss was associated with a 1.3% decrease in height-indexed LV mass and 1.3% decrease in LV mass-to-volume ratio (p<0.0001). There was no effect modification/confounding by age, race, gender or baseline BMI. Change in LV mass-to-volume ratio was roughly linear, specifically for modest degrees of weight loss (-10% to +10%). Change in LV mass was linear with weight loss, suggesting no threshold of weight loss is needed for LV mass regression.

CONCLUSIONS

In a large multi-ethnic population, weight loss is associated with beneficial effects on cardiac structure, independent of age, race, gender, BMI and obesity-related cardiometabolic risk. There is no threshold of weight loss required to produce these effects.

Rational use of antihypertensive medications in children

Hypertension has traditionally been regarded as an uncommon diagnosis in childhood and adolescence; however, there is compelling evidence to suggest that its prevalence is on the rise, particularly in those with obesity. As a result, pediatricians increasingly are asked to evaluate and manage patients with elevated blood pressure. An increased emphasis on conducting drug trials in children over the last 15 years has yielded important advances with respect to evidence-based data regarding the efficacy and safety of antihypertensive medications in children and adolescents. Unfortunately, data to definitively guide selection of initial agents is lacking. This article will present guidelines for the appropriate use of antihypertensive medications in the pediatric population, including the rational approach to selecting an appropriate medication with respect to pathophysiology, putative benefit, and likelihood for side effects.

Hydrogen peroxide mediates endothelium-dependent dilation of coronary arterioles in obese rats on a low-carbohydrate diet

OBJECTIVE

Endothelium-dependent vasodilation of coronary arterioles is impaired in obese rats and may be improved by a LCD. The aim of this study is to elucidate the mechanism by which this improvement occurs.

METHODS

We used four groups of male Zucker rats: lean and obese on either SD or LCD. Coronary arterioles were cannulated and pressurized for diameter measurements during administration of acetylcholine or sodium nitroprusside or during flow. Real-time PCR was performed to quantify mRNA expression of CuZnSOD and catalase.

RESULTS

The LCD significantly increased endothelium-dependent dilation in the obese rats. l-NAME and indomethacin reduced responses to flow and acetylcholine in the lean rats without any effect on the obese on either diet. In contrast, TEA and catalase blocked flow-dependent and acetylcholine-induced dilation in the obese on either diet, while no effect was observed on the lean. The LCD in the obese significantly up-regulated catalase mRNA expression and slightly increased CuZnSOD mRNA levels.

CONCLUSIONS

A LCD improves endothelium-dependent vasodilation of coronary arterioles in obese rats through the production of H2 O2 which acts as a hyperpolarizing factor, independent of nitric oxide and PGI2 .

Obesity and cytokines in childhood-onset systemic lupus erythematosus

Background. In systemic lupus erythematosus (SLE), atherosclerosis is attributed to traditional and lupus related risk factors, including metabolic syndrome (MetS), obesity, and inflammation. Objective. To evaluate the association between obesity, measures of body fat content, serum tumor necrosis factor alpha (TNF-α), and interleukin (IL)-6 and -10 levels in childhood-onset SLE (cSLE). Methods. We screened consecutive cSLE patients followed up in the Pediatric Rheumatology Outpatient Clinic of the State University of Campinas. cSLE patients were assessed for disease and damage. Obesity was definite as body mass index (BMI) ≥30 kg/m². Serum TNF-α, IL-6, and IL-10 levels were measured by ELISA. Dual-energy X-ray absorptiometry was used to determine total fat mass, lean mass, and percent of body fat. Results. We included 52 cSLE patients and 52 controls. cSLE patients had higher serum TNF-α  (P = 0.004), IL-6 (P = 0.002), and IL-10 (P < 0.001) levels compared to controls. We observed higher serum TNF-α  (P = 0.036) levels in cSLE patients with obesity. An association between serum TNF-α levels and body fat percent (P = 0.046) and total fat mass on trunk region (P = 0.035) was observed. Conclusion. Serum TNF-α levels were associated with obesity and body fat content in cSLE. Our finding suggests that obesity may contribute to the increase of serum TNF-α levels in cSLE.

Insulin resistance is associated with lower acetylcholine-induced microvascular reactivity in nondiabetic women

BACKGROUND

The association between insulin resistance and microvascular dysfunction is well established in obese individuals with type 2 diabetes. It is unclear whether this relationship is dependent on obesity and body fat in insulin-resistant persons. This study investigated acetylcholine (ACh)-induced microvascular reactivity in apparently healthy women (n=37, 20-45 years), with and without insulin resistance.

METHODS

Body fat mass (dual X-ray absorptiometry), waist circumference (WC), blood pressure, fasting glucose, insulin, and free fatty acid concentrations were measured. Insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), and subjects were divided into insulin-resistant (IR, n=16) and insulin-sensitive (IS, n=21) groups. ACh-induced forearm microvascular reactivity was measured by laser Doppler imagery using iontophoresis of ACh and compared between groups adjusting for WC and skin resistance (SR).

RESULTS

The IR group had a higher body mass index (BMI) (30.7 ± 6.4 vs. 22.9 ± 7.3 kg/m(2), P < 0.01), fat mass (34.7 ± 11.9 vs. 19.7 ± 9.6 kg, P < 0.01), WC (89.9 ± 13.6 vs. 74.4 ± 9.7 cm, P < 0.01), and a lower SR (0.24 ± 0.08 vs. 0.32 ± 0.08 Ω, P < 0.05) than the IS group. Microvascular reactivity, expressed as percentage increase in perfusion from baseline, was significantly lower in IR subjects after adjusting for differences in WC and SR (420.9 ± 166.5 vs. 511.6 ± 214.8%, P < 0.05). There were associations between microvascular reactivity and SR (r=-0.34, P < 0.05) and systolic blood pressure (r=-0.36, P < 0.05), but not BMI, body fat mass, WC, or HOMA-IR.

CONCLUSION

ACh-induced microvascular reactivity was different between IR and IS apparently healthy, nondiabetic women once differences in WC and SR were accounted for.

Clinical evaluation of extracellular ADMA concentrations in human blood and adipose tissue

Circulating asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, has been proposed as a biomarker for clinical outcome. Dimethylarginine dimethylaminohydrolase (DDAH) is the main enzyme responsible for ADMA metabolism and elimination. Adipose tissue ADMA concentrations and DDAH activity and their role in diabetes and obesity have not yet been investigated. In this study, we evaluated clinical microdialysis in combination with a sensitive analytical method (GC-MS/MS) to measure ADMA concentrations in extracellular fluid. Adipose tissue ADMA concentrations were assessed before and during an oral glucose tolerance test in lean healthy subjects and subjects with diabetes (n = 4 each), and in morbidly obese subjects before and after weight loss of 30 kg (n = 7). DDAH activity was determined in subcutaneous and visceral adipose tissue obtained during laparoscopic surgery (n = 5 paired samples). Mean interstitial ADMA concentrations did not differ between study populations (healthy 0.17 ± 0.03 μM; diabetic 0.21 ± 0.03 μM; morbidly obese 0.16 ± 0.01 and 0.17 ± 0.01 μM before and after weight loss, respectively). We did not observe any response of interstitial ADMA concentrations to the oral glucose challenge. Adipose tissue DDAH activity was negligible compared to liver tissue. Thus, adipose tissue ADMA plays a minor role in NO-dependent regulation of adipose tissue blood flow and metabolism.

Alleviation of hyperglycemia induced vascular endothelial injury by exenatide might be related to the reduction of nitrooxidative stress

We will investigate the effects of exenatide on vascular endothelial injury and nitrooxidative stress in hyperglycemia both in vivo and in vitro and explore the role of nitrooxidative stress in endothelium-protective action of exenatide. Healthy male Wistar rats were randomly divided into 4 groups: control, diabetes mellitus (DM) model, low dose of exenatide treatment, and high dose of exenatide treatment. In vitro study showed that, compared with control group, the DM rats exhibited a lowered endothelium-dependent relaxation and damaged structural integrity of thoracic aortas, and there was a significant increase in plasma nitrotyrosine concentration. These parameters were improved after treatment with either low dose or high dose of exenatide for 45 days. In vitro study showed that exendin-4 (the active ingredient of exenatide) attenuated HUVECs injury induced by high glucose, with improving cell viability and attenuating cell apoptosis. Exendin-4 also significantly alleviated the increased malondialdehyde (MDA), nitrotyrosine content, and inducible nitric oxide synthase (iNOS) expression induced by high glucose in HUVECs. In conclusion, this study demonstrates that exenatide treatment can alleviate the vascular endothelial injury, as well as attenuating the nitrooxidative stress in hyperglycemia, implying that the endothelium-protective effect of exenatide might be related to the reduction of nitrooxidative stress.

Interaction between the NOS3 gene and obesity as a determinant of risk of type 2 diabetes: the Atherosclerosis Risk in Communities study

Endothelial nitric oxide synthase 3 (NOS3) catalyzes the production of nitric oxide from L-arginine in endothelial cells. Obesity is a modifiable risk factor for diabetes, and obese individuals have been reported to have reduced nitric oxide availability compared to controls whose weight is in the normal range. Since homozygous carriers of the NOS3 G894T variant are predicted to have decreased enzyme activity, the association between NOS3 genotype and type 2 diabetes, and possible effect modification by body mass index (BMI) were evaluated. The prevalence of diabetes and BMI was determined at baseline in 14,374 participants 45-66 years of age from the prospective biracial population-based Atherosclerosis Risk in Communities (ARIC) Study of the development of atherosclerosis in four communities in the United States. Individuals with a BMI ≥30 kg/m(2) were considered obese. Those subjects not meeting the case definition were the comparison groups for the 728 African American and 980 white participants with diabetes. Multivariable logistic regression models adjusted for age, sex, and field center were used to test for main genetic effects and interaction with obesity. Although the NOS3 G894T variant was not independently associated with diabetes in either African Americans or whites, significant interaction between BMI and the NOS3 polymorphism indicated that obesity was an effect modifier of diabetes risk for white individuals with the TT genotype (odds ratio (OR) for interaction = 1.65, p = 0.04). In stratified analyses, homozygosity for the NOS3 T allele in obese white participants but not in those whose BMI <30 kg/m(2) was associated with an elevated risk of diabetes (OR = 1.47, p = 0.02) when compared to the common GG genotype. These results suggest that interaction between obesity and NOS3 genotype may be a determinant of diabetes case status in whites in the ARIC cohort. Replication in other populations will be required to confirm these observations.

Renal vascular structure and rarefaction

An intact microcirculation is vital for diffusion of oxygen and nutrients and for removal of toxins of every organ and system in the human body. The functional and/or anatomical loss of microvessels is known as rarefaction, which can compromise the normal organ function and have been suggested as a possible starting point of several diseases. The purpose of this overview is to discuss the potential underlying mechanisms leading to renal microvascular rarefaction, and the potential consequences on renal function and on the progression of renal damage. Although the kidney is a special organ that receives much more blood than its metabolic needs, experimental and clinical evidence indicates that renal microvascular rarefaction is associated to prevalent cardiovascular diseases such as diabetes, hypertension, and atherosclerosis, either as cause or consequence. On the other hand, emerging experimental evidence using progenitor cells or angiogenic cytokines supports the feasibility of therapeutic interventions capable of modifying the progressive nature of microvascular rarefaction in the kidney. This overview will also attempt to discuss the potential renoprotective mechanisms of the therapeutic targeting of the renal microcirculation.

Lemon grass (Cymbopogon citratus (D.C) Stapf) polyphenols protect human umbilical vein endothelial cell (HUVECs) from oxidative damage induced by high glucose, hydrogen peroxide and oxidised low-density lipoprotein

The aromatic herb Cymbopogon citratus Stapf is widely used in tropical and subtropical countries in cooking, as a herbal tea, and in traditional medicine for hypertension and diabetes. Some of its properties have been associated with the in vitro antioxidant effect of polyphenols isolated from their aerial parts. However, little is known about C. citratus effects on endothelial cells oxidative injury. Using chromatographic procedures, a polyphenol-rich fraction was obtained from C. citratus (CCF) and their antioxidant properties were assessed by cooper-induced LDL oxidation assay. The main constituents of the active CCF, identified by high-performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD-MS), were chlorogenic acid, isoorientin and swertiajaponin. CCF 10 and 100 μg/ml diminishes reactive oxidative species (ROS) production in human umbilical vein endothelial cell (HUVECs), challenged with high D-glucose (60% inhibition), hydrogen peroxide (80% inhibition) or oxidised low-density lipoprotein (55% inhibition). CCF 10 or 100 μg/ml did not change nitric oxide (NO) production. However, CCF was able to inhibit vasoconstriction induced by the thromboxane A2 receptor agonist U46619, which suggest a NO-independent vasodilatador effect on blood vessels. Our results suggest that lemon grass antioxidant properties might prevent endothelial dysfunction associated to an oxidative imbalance promoted by different oxidative stimuli.

Effect of avocado soybean unsaponifiables on insulin secretion and insulin sensitivity in patients with obesity

AIM

To evaluate the effect of avocado soybean unsaponifiables (ASU) on insulin secretion and insulin sensitivity in patients with obesity.

METHODS

A randomized, double-blind, placebo-controlled, clinical trial was carried out in 14 obese adult volunteers. After random allocation of the intervention, 7 patients received 300 mg of ASU or placebo during a fasting state for 3 months. A metabolic profile including IL-6 and high-sensitivity C-reactive protein (hs-CRP) levels was carried out prior to the intervention. A hyperglycemic-hyperinsulinemic clamp technique was used to assess insulin secretion and insulin sensitivity phases. Mann-Whitney U test and Wilcoxon test were performed for statistical analyses. The study was approved by the local ethics committee of our institution.

RESULTS

At baseline, both groups were similar according to clinical and laboratory characteristics. There was no significant difference in insulin secretion and insulin sensitivity with ASU.

CONCLUSIONS

ASU administration for 3 months did not modify insulin secretion and insulin sensitivity in patients with obesity.

Effects of exercise training on chronic inflammation in obesity : current evidence and potential mechanisms

Chronic, systemic inflammation is an independent risk factor for several major clinical diseases. In obesity, circulating levels of inflammatory markers are elevated, possibly due to increased production of pro-inflammatory cytokines from several tissues/cells, including macrophages within adipose tissue, vascular endothelial cells and peripheral blood mononuclear cells. Recent evidence supports that adipose tissue hypoxia may be an important mechanism through which enlarged adipose tissue elicits local tissue inflammation and further contributes to systemic inflammation. Current evidence supports that exercise training, such as aerobic and resistance exercise, reduces chronic inflammation, especially in obese individuals with high levels of inflammatory biomarkers undergoing a longer-term intervention. Several studies have reported that this effect is independent of the exercise-induced weight loss. There are several mechanisms through which exercise training reduces chronic inflammation, including its effect on muscle tissue to generate muscle-derived, anti-inflammatory 'myokine', its effect on adipose tissue to improve hypoxia and reduce local adipose tissue inflammation, its effect on endothelial cells to reduce leukocyte adhesion and cytokine production systemically, and its effect on the immune system to lower the number of pro-inflammatory cells and reduce pro-inflammatory cytokine production per cell. Of these potential mechanisms, the effect of exercise training on adipose tissue oxygenation is worth further investigation, as it is very likely that exercise training stimulates adipose tissue angiogenesis and increases blood flow, thereby reducing hypoxia and the associated chronic inflammation in adipose tissue of obese individuals.

Direct cardiovascular effects of glucagon like peptide-1

Current gold standard therapeutic strategies for T2DM target insulin resistance or β cell dysfunction as their core mechanisms of action. However, the use of traditional anti-diabetic drugs, in most cases, does not significantly reduce macrovascular morbidity and mortality. Among emerging anti-diabetic candidates, glucagon like peptide-1 (GLP-1) based therapies carry special cardiovascular implications, exerting both direct as well as indirect effects. The direct cardiovascular effects of GLP-1 and its analogs remain the focus of this review.

Young Hispanics at risk of type 2 diabetes display endothelial activation, subclinical inflammation and alterations of coagulation and fibrinolysis

BACKGROUND

Hispanics have a high rate of diabetes that exposes them to an increased risk of cardiovascular disease. We hypothesized that many of the pathophysiological mechanisms that cause atherosclerotic disease may be present in young Hispanics who do not have clinical diabetes but are at increased risk of developing it.

METHODS

We studied 36 young Hispanic adults without diabetes (ages 18-40). Seventeen participants were at increased risk of developing type 2 diabetes given by overweight and a family history of diabetes on one or both parents (at risk group). Nineteen participants with normal body-mass index and no parental history of diabetes constituted the control group. We measured and compared plasma markers of endothelial dysfunction, disturbed coagulation and fibrinolysis, subclinical inflammation and adipose tissue dysfunction in the at risk and control groups.

RESULTS

Participants at risk of diabetes were more insulin-resistant according to different indicators, and had significantly higher levels of soluble intercellular adhesion molecule-1 (sICAM-1), tissue plasminogen activator (tPA), inhibitor of plasminogen activator-1 (PAi-1), high sensitivity C-reactive protein and free fatty acids, signaling the presence of multiple proatherogenic alterations despite the absence of overt diabetes. Levels of the prothrombotic molecule PAi-1 were most elevated in participants who were not only at risk of diabetes by the study definition, but also abdominally obese.

CONCLUSIONS

Young adult Hispanics at risk of type 2 diabetes but without overt disease already bear considerably high levels of markers reflecting processes that lead to the development of atherosclerotic cardiovascular disease.

Effects of a single bout of walking exercise on blood coagulation parameters in obese women

Obesity is associated with increased prevalence of thromboembolic events. We aimed to investigate whether obese women might benefit from vigorous aerobic exercise. Forty-two overweight and obese women performed a 30-min walking exercise test (treadmill ergometer) at an intensity of 70% of individual peak oxygen uptake. Blood samples were collected before and immediately after exercise. Thrombelastometry and platelet function measurements were performed on whole blood. Standard coagulation times, thrombin generation curves, markers of thrombin generation, fibrinolytic parameters, plasma levels of pro- and anticoagulatory factors, and microparticle procoagulant activity were determined in platelet-poor plasma samples. Thrombelastometry revealed a significant prolongation of clot formation time ( P = 0.037) and a significant deceleration of fibrin build up (alpha angle, P = 0.034) after exercise. Calibrated automated thrombography revealed a significant exercise-induced decrease in endogenous thrombin potential ( P = 0.039). Moreover, thrombin formation stopped earlier postexercise, reflected in shortened StartTail ( P = 0.046). Significantly elevated tissue-plasminogen activator levels ( P = 0.001) indicate an exercise-induced activation of the fibrinolytic system. White blood cell count increased significantly from pre- to postexercise ( P = 0.045), indicating a mild exercise-induced leukocytosis. The results of this study demonstrate that vigorous aerobic exercise might be a suitable tool to protect obese women from thrombotic events. We show that a single bout of vigorous aerobic exercise is clearly associated with an activation of the fibrinolytic system and a decreased readiness of the postexercise samples to form a clot and to generate thrombin, the pivotal enzyme of hemostasis.

Effect of meditation on endothelial function in Black Americans with metabolic syndrome: a randomized trial

OBJECTIVES

Psychological stress may play a role in metabolic syndrome. A consequence of metabolic syndrome is endothelial dysfunction, which is also influenced by psychological stress. We sought to compare the effect of consciously resting meditation (CRM), a sound based meditation, with a control intervention of health education (HE) on endothelial function in the setting of metabolic syndrome.

METHODS

Sixty-eight black Americans with metabolic syndrome risk factors (age, 30-65 years) were randomized to either CRM (n = 33) or HE (n = 35); interventions were matched for frequency and duration of sessions and lasted 12 months. Endothelial function was assessed by brachial artery flow-mediated dilation at baseline and at 6 and 12 months. Arterial elasticity, metabolic risk factors, and psychosocial and behavioral variables were secondary end points.

RESULTS

Although flow-mediated dilation improved in the CRM group for 12 months, this increase was not significantly higher than that in the HE group (p = .51 for the interaction between group and time). Non-endothelium-dependent dilation and arterial elasticity did not change in either group. Most metabolic syndrome risk factors showed beneficial trends in the CRM group only. A risk factor score counting the number of metabolic syndrome components decreased in the CRM group only (p = .049 for the interaction between treatment group and time).

CONCLUSIONS

Among black Americans with metabolic syndrome risk factors, CRM, did not improve endothelial function significantly more than a control intervention of HE. CRM resulted in favorable trends in metabolic syndrome risk factors, which were examined as secondary outcomes.

Palmitate induces apoptosis in mouse aortic endothelial cells and endothelial dysfunction in mice fed high-calorie and high-cholesterol diets

AIMS

Obesity is associated with hypertriglyceridemia and elevated circulating free fatty acids (FFA), resulting in endothelial dysfunction. Endoplasmic reticulum (ER) stress has been implicated in many of these processes. To determine if ER stress participates in palmitate-induced apoptosis, we investigated the effects of diet-induced obesity and palmitate on mouse aortic endothelial cells (MAEC) in vivo and in vitro.

MAIN METHODS

Male C57BL/6 mice were fed standard chow diets (SCD) or high-calorie and high-cholesterol diets (HCD) for 3 months. Insulin resistance was detected, and the serum, including proinflammatory indices and markers of endothelial function, was also analyzed. The ultrastructure and apoptosis of the endothelial cells in the thoracic aorta were observed. The primary MAEC were separated and treated with palmitate at different concentrations or different times respectively to observe any changes in cellular proliferation, intracellular reactive oxygen species (ROS) levels and apoptosis. Finally, the ER stress markers C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78) were analyzed.

KEY FINDINGS

HCD-fed obese mice became inflammation-activated and insulin-resistant. Swollen mitochondria, expanded ER and apoptosis in the endothelial cells of the thoracic aorta were observed in HCD-fed mice. Palmitate inhibited cell proliferation, increased production of ROS and induced apoptosis in MAEC. CHOP was overexpressed and shifted into the nucleus (mainly), while the expression of GRP78 was upregulated in the palmitate-treated MAEC.

SIGNIFICANCE

Our results indicate that diet-induced obesity results in endothelial dysfunction in vivo, and that oxidative and ER stress may be involved in apoptosis induced by the palmitate in vitro.

Pediatric post-transplant metabolic syndrome: new clouds on the horizon

Liver transplantation (LT) is a standard treatment for children with end-stage liver disease, standing at more than 90% survival rate after one yr, and at over a 70% survival rate after five yr. The majority of transplanted children enjoy an excellent quality of life but complications can occur in the long term, and can develop subclinically in otherwise well children; there are various underestimated nutritional and metabolic aspects, including the so-called post-transplant metabolic syndrome (PTMS). During the post-transplant period, the use of immunosuppressants, corticosteroids, calcineurin inhibitors, and the presence of risk factors, including non-alcoholic fatty liver disease (NAFLD), and kidney and bone complications have been largely implicated in PTMS development. Strategies to reduce the progression of PMTS should include careful screening of patients for diabetes, dyslipidemia, and obesity, and to support weight reduction with a carefully constructed program, particularly based on diet modification and exercise. With early identification and appropriate and aggressive management, excellent long-term health outcomes and acceptable graft survival can be achieved.

Resting IL-6 and TNF-α level in children of different weight and fitness status

Reports suggest children with high aerobic fitness (VO2max; mL/kg/min) have healthier profiles of TNF-α and IL-6; however, research has not accounted for differences in adiposity between high-fit and low-fit individuals. Thus, this study examined differences in inflammatory markers of obese and normal weight children of different fitness levels, using two different VO2max units: per unit of fat free mass (VO2FFM) or total body mass (VO2kg). Children (n = 124; ages 8-12) were divided into four matched groups; normal weight high-fit (NH), normal weight low- fit (NL), obese high-fit (OH), and obese low-fit (OL). Height, weight, skinfolds, body mass index (BMI), and predicted VO2max were measured and a morning, fasting blood sample taken. IL-6 was elevated in the NL and OL groups compared with the NH group, as well as the OL group compared with the OH group. No differences were found in TNF-α. The relationship between IL-6 or TNF-α and the two units of predicted VO2max did not differ suggesting that either VO2FM or VO2kg can be used to describe aerobic power when studying inflammation and exercise in youth. The relationship between IL-6 or TNF-α and predicted VO2max, whether expressed per mass or per fat-free mass was similar, suggesting that both can be used to describe aerobic power when studying inflammation and exercise in youth. Given the polar design of this study, this relationship should be confirmed including overweight subjects.

Metabolic hypertension: concept and practice

Hypertension is a serious public health problem worldwide. More than 60% of the risk factors for hypertension are associated with metabolic disturbances. Metabolic abnormalities increase the risk for hypertension and cause high blood pressure. Improving metabolic disturbances is beneficial for hypertension treatment. Due to the importance of metabolic abnormalities in the pathogenesis of hypertension, we propose a concept of metabolic hypertension. In this review, we discuss and review the clinical types, pathogenesis, risk evaluation and management of metabolic hypertension. Elucidation of the mechanism of metabolic hypertension should facilitate the design of novel pharmacotherapeutics and dedicated antihypertensive manipulations.

Obesity-related hypertension: pathogenesis, cardiovascular risk, and treatment--a position paper of the The Obesity Society and The American Society of Hypertension

In light of the worldwide epidemic of obesity, and in recognition of hypertension as a major factor in the cardiovascular morbidity and mortality associated with obesity, The Obesity Society and The American Society of Hypertension agreed to jointly sponsor a position paper on obesity-related hypertension to be published jointly in the journals of each society. The purpose is to inform the members of both societies, as well as practicing clinicians, with a timely review of the association between obesity and high blood pressure, the risk that this association entails, and the options for rational, evidenced-based treatment. The position paper is divided into six sections plus a summary as follows: pathophysiology, epidemiology and cardiovascular risk, the metabolic syndrome, lifestyle management in prevention and treatment, pharmacologic treatment of hypertension in the obese, and the medical and surgical treatment of obesity in obese hypertensive patients.

Obesity and inflammation: epidemiology, risk factors, and markers of inflammation

Obesity is a public health problem that has reached epidemic proportions with an increasing worldwide prevalence. The global emergence of obesity increases the risk of developing chronic metabolic disorders. Thus, it is an economic issue that increased the costs of the comorbidities associated. Moreover, in recent years, it has been demonstrated that obesity is associated with chronic systemic inflammation, this status is conditioned by the innate immune system activation in adipose tissue that promotes an increase in the production and release of pro-inflammatory cytokines that contribute to the triggering of the systemic acute-phase response which is characterized by elevation of acute-phase protein levels. On this regard, low-grade chronic inflammation is a characteristic of various chronic diseases such as metabolic syndrome, cardiovascular disease, diabetes, hypertension, non-alcoholic fatty liver disease, and some cancers, among others, which are also characterized by obesity condition. Thus, a growing body of evidence supports the important role that is played by the inflammatory response in obesity condition and the pathogenesis of chronic diseases related.

Pioglitazone ameliorates endothelial dysfunction in those with impaired glucose regulation among the first-degree relatives of type 2 diabetes mellitus patients

OBJECTIVE

To study the effects of pioglitazone on endothelial dysfunction of subjects with impaired glucose regulation (IGR) among the first-degree relatives of patients with type 2 diabetes mellitus (T2DM).

SUBJECTS AND METHODS

The first-degree relatives of T2DM patients were screened with oral glucose test and IGR was diagnosed. IGR subjects whose blood glucose was still above the level after 1-month exercise were randomized to receive pioglitazone (15 mg/day) or vehicle for 12 weeks. Endothelial function was assessed as endothelium-dependent and -independent vasodilation. Blood nitric oxide (NO), blood pressure, body mass index, insulin and serum lipids were also measured. Area under the curve of glucose (AUC(glu)) and insulin (AUC(INS)), homeostasis model assessment of insulin resistance (HOMA-IR), HOMA of β-cell function (HOMA-β) and early insulin secretion index (ΔI(30)/ΔG(30)) were calculated.

RESULTS

After pioglitazone treatment, fasting plasma, 2-hour plasma glucose, triglyceride (TG), fasting insulin, AUC(glu), HOMA-β and HOMA-IR, 2-hour insulin, AUC(INS) and ΔI(30)/ΔG(30) decreased. Endothelium-dependent vasodilation and NO were significantly improved in the treatment group. Furthermore, the changes of endothelium-dependent vasodilation were negatively correlated with changes in AUC(INS) but positively with NO and HOMA-β. Stepwise multivariate regression analysis showed that changes in NO and HOMA-β were both independent parameters for improvement of endothelial dysfunction.

CONCLUSION

Pioglitazone decreased blood glucose and TG, increased insulin sensitivity, and ameliorated endothelial dysfunction of IGR subjects among the first-degree relatives of T2DM patients. Increased NO production may be associated with the improvement of endothelial dysfunction.

Obesity-related hypertension: pathogenesis, cardiovascular risk, and treatment: a position paper of The Obesity Society and the American Society of Hypertension

In light of the worldwide epidemic of obesity, and in recognition of hypertension as a major factor in the cardiovascular morbidity and mortality associated with obesity, The Obesity Society and the American Society of Hypertension agreed to jointly sponsor a position paper on obesity-related hypertension to be published jointly in the journals of each society. The purpose is to inform the members of both societies, as well as practicing clinicians, with a timely review of the association between obesity and high blood pressure, the risk that this association entails, and the options for rational, evidenced-based treatment. The position paper is divided into six sections plus a summary as follows: pathophysiology, epidemiology and cardiovascular risk, the metabolic syndrome, lifestyle management in prevention and treatment, pharmacologic treatment of hypertension in the obese, and the medical and surgical treatment of obesity in obese hypertensive patients.

Mild gestational hyperglycemia and the metabolic syndrome in later life

BACKGROUND

Diabetes and obesity, components of the metabolic syndrome, are common longterm complications in women with previous gestational diabetes (pGDM). Long-term follow-up of women with mild gestational hyperglycemia is lacking.

METHODS

Fifty women with previous positive oral glucose challenge test and negative oral glucose tolerance test (pOGCT+OGTT-), 161 with previous normal glucose tolerance (pNGT), and 182 pGDM were studied after 6.5 years from the index pregnancy.

RESULTS

Patients with pGDM showed a worse metabolic pattern than pNGT. Women with pOGCT+OGTT- had significantly higher levels of fasting glucose, homeostasis model assessment (HOMA), percentage of impaired fasting glucose, and low age and high-density lipoprotein (HDL)-cholesterol than pNGT subjects. Prevalence of the metabolic syndrome (MS) was, respectively, sixfold and twofold higher in pGDM and pOGCT+OGTT- than in pNGT. In a Cox proportional hazard model, after multiple adjustments, pGDM was significantly associated with subsequent hyperglycemia (hazard ratio [HR] = 4.2; 95% CI 1.6-11.1), low HDL-cholesterol (HR = 1.7, 1.1-2.8), hypertriglyceridemia (HR = 4.2, 1.2-14.9), hypertension (HR = 2.2, 1.3-3.6), MS (HR = 3.7, 1.3-10.8), while pOGCT+OGTT- was associated with subsequent hyperglycemia (HR = 4.3, 1.3-14.7), and low HDL-cholesterol (HR = 2.0, 1.0-3.8). The metabolic syndrome was present in 52.6% of obese pGDM, 50% of obese pOGCT+OGTT-, and 28.6% of obese pNGT women; the corresponding HRs were, respectively, HR = 2.20, 0.74-6.57 (pGDM), and HR = 3.56, 1.10-11.5 (pOGCT+OGTT-).

CONCLUSIONS

Women who failed the OGCT, but not the OGTT, showed a subsequent worse metabolic pattern than pNGT subjects, independently of confounding factors. In the presence of obesity, the prevalence of the metabolic syndrome was similar to that of obese pGDM women, and almost twofold higher than in obese pNGT controls.

Comparison of the effect of the metabolic syndrome and multiple traditional cardiovascular risk factors on vascular function

OBJECTIVE

To assess the effect of the metabolic syndrome (MetS) on endothelial function and compare these findings to those in individuals with a similar burden of traditional cardiovascular (CV) risk factors (≥ 3) without MetS.

PATIENTS AND METHODS

Both MetS and multiple CV risk factors were identified from 1103 individuals who underwent the evaluation of endothelial function at the Mayo Clinic, in Rochester, Minnesota, from July 1, 2000, through July 31, 2011. Endothelial function was measured using digital arterial tonometry by assessing reactive hyperemia-induced vasodilation in one arm and adjusting for changes in the contralateral arm (reactive hyperemia index [RHI]).

RESULTS

A total of 316 individuals with MetS and 210 with multiple risk factors were assessed. Endothelial dysfunction was more pronounced in the MetS group compared with the multiple risk factor group (mean ± SD natural logarithmic RHI, 0.61 ± 0.25 and 0.68 ± 0.28, respectively; P=.006). Leukocyte count (7.00 ± 1.89 × 10(9)/L vs 6.41 ± 1.76 × 10(9)/L, respectively; P=.001) and high-sensitivity C-reactive protein level (1.78 ± 1.53 mg/L vs 1.48 ± 1.42 mg/L, respectively; P=.01) were higher in the MetS group compared with the multiple risk factor group. After adjustment for covariates and 6 traditional CV risk factors in a multivariate regression model, MetS had a significant and independent influence on natural logarithmic RHI (β=-.11; P=.01).

CONCLUSION

The current study found that individuals with MetS have a higher degree of endothelial dysfunction and inflammation compared with individuals with multiple CV risk factors and may therefore have an increased CV risk beyond the contributions of multiple traditional risk factors.

Vascular disease in diabetic women: Why do they miss the female protection?

Gender plays a pivotal role in the onset as well as in the progression of the cardiovascular disease with a higher morbidity and mortality being detected in men with respect to women. Type 2 Diabetes Mellitus (T2DM) may reduce gender-related differences in the prevalence of cardiovascular disease by fading the vascular protective effects afforded by estrogen in females. This article will discuss the role of sex and sex hormones on the incidence and mechanisms involved in vascular dysfunction associated to T2DM, which might explain why women with T2DM lack the vascular protection.

Anti-Diabetic Atherosclerosis Effect of Prunella vulgaris in db/db Mice with Type 2 Diabetes

Diabetes mellitus is the leading cause of vascular complications such as atherosclerosis. This study was designed to investigate whether Prunella vulgaris (APV) would inhibit diabetic atherosclerosis in db/db mice with type 2 diabetes. The db/db mice were treated with high fat/high cholesterol (HFHC) diet and an aqueous extract of APV (100 and 200 mg/kg/day) for eight weeks to examine the long-term effect on metabolic abnormalities and diabetic atherosclerosis. APV treatment markedly lowered blood glucose and systolic blood pressure. The db/db mice experienced an increase in blood urea nitrogen as well as a decrease of creatinine clearance, the latter of which was restored by treatment with APV. Treatment with APV markedly decreased total plasma cholesterol, triglyceride, and LDL-cholesterol and also increased the HDL-cholesterol. In addition, malondialdehyde and TGF-β1 were decreased by treatment of APV. On the other hand, total NO level was decreased in db/db mice. However, the NO level was increased by treatment with APV, suggesting an association with vascular dysfunction. Vascular relaxation of aortic rings by acetylcholine or SNP-inducement was ameliorated by APV in a dose-dependent manner. Damage of vascular intima and hypertrophic of media were observed in db/db mice; however its dysfunction was improved by the treatment of APV. APV treatment significantly reduced the aortic expressions of ICAM-1, VCAM-1, ET-1, and nitrotyrosine. Furthermore, expression of eNOS in aortic was remarkably increased by APV treatment. Taken together, APV suppressed hyperglycemia and diabetic vascular dysfunction in HFHC diet-db/db mice. The present data suggest that Prunella vulgaris may prevent development of diabetic atherosclerosis.

Evaluation of metabolic syndrome after hematopoietic stem cell transplantation in children and adolescents

BACKGROUND

To determine the prevalence, characteristics, and risk factors associated with metabolic syndrome (MS) in patients undergoing hematopoietic stem cell transplantation (HSCT) in the Chilean National Program.

PROCEDURES

Descriptive and cross-sectional study including 69 patients was conducted. Body mass index, pubertal development, waist circumference, arterial pressure (AP), and triglycerides, HDL-cholesterol, and glucose levels were recorded at the time of study entry. The National Cholesterol Education Program (Adult Treatment Panel III, as modified by the American Heart Association) criteria are often used to diagnose MS in adults; however, for children and adolescents we followed criteria according to De Ferranti and American Diabetes Association. Statistical analyses were performed with a chi-square test or Fisher's exact test according to sample size.

RESULTS

Sixty-nine patients were studied. The median age at the time of diagnosis was 12.9 years, and the median time of follow-up post-transplant was 4 years. Forty-three patients were males, 54 patients had malignant diseases, and 59 patients received allogeneic transplants. Of the 69 patients, 32% had MS; the most common MS features were abdominal obesity (73%), hypertriglyceridemia (91%), and a low HDL-cholesterol level (96%). The most significant risk factor for MS was corticosteroid therapy use pre- (P < 0.03) and post-HSCT (P < 0.03), obesity and overweight associated with MS (P < 0.001). No patient developed cardiovascular complications.

CONCLUSIONS

The prevalence of MS was 32%, which was significantly higher than in a healthy pediatric population. We recommend prolonged follow-up for transplant recipients, coupled with enforcement of preventive measures, such as early diagnosis and encouragement of a healthy lifestyle.

Is obesity development associated with dietary sugar intake in the U.S.?

OBJECTIVE

In the public health arena, a single component of total dietary intake, such as sugar intake, has been questioned as the health risk of obesity. This study aimed to investigate if the uptrend of obesity prevalence in the USA is associated with dietary sugar intake when other dietary intakes are controlled.

METHODS

In this cross-sectional study, National Health and Nutrition Examination Surveys I (1971-1975, n = 20 195) and III (1988-1994, n = 28 663) were investigated. Multivariate predictive models were used to determine if body mass index was predicted by the daily intakes of total energy, carbohydrate (CHO), and total sugars and the percentages of energy from CHO, fat, total sugar, and added sugars.

RESULTS

From 1970 through 1990, the contribution of sugars to total CHO intake decreased in the 1 to 18 y and ≥19 y subgroups, and the contribution of added sugars to the total energy intake did not change. Multivariate predictive models identified energy intake as a positive predictor, CHO as a negative predictor, and total sugar intake as a non-predictor for body mass index in the 1 to 18 y and ≥19 y age subgroups. Daily energy intake was positively predicted by CHO and fat intakes but not with total and added sugar intakes in the two age subgroups.

CONCLUSION

Energy intake was the primary contributor to body mass index in all age groups in this study. The major energy sources of children and adolescents differed from those of adults. The implicated associations between energy and macronutrient intakes indicate that keeping energy balance is the primary strategy to avoid obesity.

Maternal obesity and venous thromboembolism

The incidence of obesity in pregnancy has increased rapidly in the last decade. Obesity is a risk factor for venous thromboembolism outside of pregnancy and previous studies of maternal death in the UK have identified obesity as a risk factor in pregnancy. As a result the Royal College of Obstetricians and Gynaecologists have targeted obesity as a risk factor in evaluation of the need for thromboprophylaxis in pregnancy. This article highlights the evidence that obesity increases the risk of venous thromboembolism in pregnancy and the puerperium, discusses thromboprophylaxis and appropriate dosing in obese parturients and details the anaesthetic implications of the 2009 Royal College of Obstetricians and Gynaecologists' guidelines. More clinical studies are required to clarify the appropriate dose of low-molecular-weight heparin in an obese parturient.

Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications.

Elevated serum C-reactive protein relates to increased cerebral myoinositol levels in middle-aged adults

C-reactive protein (CRP), a systemic marker of inflammation, is a risk factor for late life cognitive impairment and dementia, yet the mechanisms that link elevated CRP to cognitive decline are not fully understood. In this study we examined the relationship between CRP and markers of neuronal integrity and cerebral metabolism in middle-aged adults with intact cognitive function, using proton magnetic resonance spectrocospy. We hypothesized that increased levels of circulating CRP would correlate with changes in brain metabolites indicative of early brain vulnerability. Thirty-six individuals, aged 40 to 60, underwent neuropsychological assessment, a blood draw for CRP quantification, and ¹H MRS examining N-acetyl-aspartate, myo-inositol, creatine, choline, and glutamate concentrations in occipito-parietal grey matter. Independent of age, sex and education, serum CRP was significantly related to higher cerebral myo-inositol/creatine ratio (F(4,31) = 4.74, P = 0.004), a relationship which remained unchanged after adjustment for cardiovascular risk (F(5,30) = 4.356, CRP β = 0.322, P = 0.045). Because these biomarkers are detectable in midlife they may serve as useful indicators of brain vulnerability during the preclinical period when mitigating intervention is still possible.

T-cadherin attenuates insulin-dependent signalling, eNOS activation, and angiogenesis in vascular endothelial cells

AIMS

T-cadherin (T-cad) is a glycosylphosphatidylinositol-anchored cadherin family member. Experimental, clinical, and genomic studies suggest a role for T-cad in vascular disorders such as atherosclerosis and hypertension, which are associated with endothelial dysfunction and insulin resistance (InsRes). In endothelial cells (EC), T-cad and insulin activate similar signalling pathways [e.g. PI3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR)] and processes (e.g. angiogenesis). We hypothesize that T-cad is a regulatory component of insulin signalling in EC and therefore a determinant of the development of endothelial InsRes.

METHODS AND RESULTS

We investigated T-cad-dependent effects on insulin sensitivity using human EC stably transduced with respect to T-cad overexpression or T-cad silencing. Responsiveness to insulin was examined at the level of effectors of the insulin signalling cascade, EC nitric oxide synthase (eNOS) activation, and angiogenic behaviour. Overexpression and ligation of T-cad on EC attenuates insulin-dependent activation of the PI3K/Akt/mTOR signalling axis, eNOS, EC migration, and angiogenesis. Conversely, T-cad silencing enhances these actions of insulin. Attenuation of EC responsiveness to insulin results from T-cad-mediated chronic activation of the Akt/mTOR-dependent negative feedback loop of the insulin cascade and enhanced degradation of the insulin receptor (IR) substrate. Co-immunoprecipitation experiments revealed an association between T-cad and IR. Filipin abrogated inhibitory effects of T-cad on insulin signalling, demonstrating localization of T-cad-insulin cross-talk to lipid raft plasma membrane domains. Hyperinsulinaemia up-regulates T-cad mRNA and protein levels in EC.

CONCLUSION

T-cad expression modulates signalling and functional responses of EC to insulin. We have identified a novel signalling mechanism regulating insulin function in the endothelium and attribute a role for T-cad up-regulation in the pathogenesis of endothelial InsRes.

Lipocalin-2 deficiency prevents endothelial dysfunction associated with dietary obesity: role of cytochrome P450 2C inhibition

BACKGROUND AND PURPOSE

Lipocalin-2 is a pro-inflammatory adipokine up-regulated in obese human subjects and animal models. Its circulating levels are positively correlated with the unfavourable lipid profiles, elevated blood pressure and insulin resistance index. Augmented lipocalin-2 has been found in patients with cardiovascular abnormalities.The present study was designed to investigate the role of lipocalin-2 in regulating endothelial function and vascular reactivity.

EXPERIMENTAL APPROACH

Wild-type and lipocalin-2 knockout (Lcn2-KO) mice were fed with either a standard chow or a high-fat diet. Blood pressures and endothelium-dependent relaxations/contractions were monitored at 2 week intervals.

RESULTS

Systolic blood pressure was elevated by high-fat diet in wild-type mice but not in Lcn2-KO mice. Endothelial dysfunction, reflected by the impaired endothelium-dependent relaxations to insulin and augmented endothelium-dependent contractions to ACh, was induced by high-fat diet in wild-type mice. In contrast, Lcn2-KO mice were largely protected from the deterioration of endothelial function caused by dietary challenges. The eNOS dimer/monomer ratio, NO bioavailability, basal and insulin-stimulated PKB/eNOS phosphorylation responses were higher in aortae of Lcn2-KO mice. Administration of lipocalin-2 attenuated endothelium-dependent relaxations to insulin and promoted endothelium-dependent contractions to ACh. It induced eNOS uncoupling and elevated COX expression in the arteries. Treatment with sulphaphenazole, a selective inhibitor of cytochrome P450 2C9, improved endothelial function in wild-type mice and blocked the effects of lipocalin-2 on both endothelium-dependent relaxations to insulin and endothelium-dependent contractions to ACh, as well as eNOS uncoupling.

CONCLUSIONS

Lipocalin-2, by modulating cytochrome P450 2C9 activity, is critically involved in diet-induced endothelial dysfunction.

Evaluation of microalbuminuria in obese children and its relation to metabolic syndrome

Several epidemiologic studies have clearly demonstrated that obesity increases the risk of kidney diseases. We have attempted to evaluate the association of obesity with albuminuria, an early marker of kidney disease, among obese children and its relation to metabolic syndrome. This study included 150 obese children. Blood pressure, fasting blood glucose, plasma insulin and the lipid profile were assessed. The homeostasis model assessment of insulin resistance (HOMA-IR) was used to calculate in vivo insulin resistance. Urinary albumin and creatinine were estimated. Microalbuminuria was detected in 22 (14.7%) of the obese children. Waist circumference, blood pressure, triglyceride, low-density lipoprotein (LDL), insulin resistance and fasting blood glucose were significantly higher in obese children with microalbuminuria than in those with normoalbuminuria and showed significant positive correlations with microalbuminuria. High-density lipoprotein (HDL) was significantly lower in obese children with microalbuminuria than in those with normoalbuminuria, with a significant negative correlation with microalbuminuria. We found that body mass index, abdominal obesity, hypertension, impaired fasting glucose level and insulin resistance significantly increased the odds of microalbuminuria in the obese children enrolled in this study. Moreover, high triglyceride, high LDL and low HDL were significantly associated with microalbuminuria. In our patient group, childhood obesity was a risk factor for the development of microalbuminuria, which in turn was significantly associated with metabolic syndrome and its different constituents.

Exercise Training Prevents Coronary Endothelial Dysfunction in Type 2 Diabetic Mice

Type 2 diabetes (T2D) is a leading risk factor for cardiovascular diseases including atherosclerosis and coronary heart disease. Exercise training (ET) is thought to have a beneficial effect on these disorders, but the basis for this effect is not fully understood. Because endothelial dysfunction plays a key role in the pathological events leading to cardiovascular complications in T2D, we hypothesized that the effects of ET will be evidenced by improvements in coronary endothelial function. To test this hypothesis, we assessed the effects of ET on vascular function of diabetic (db/db, Lepr(db)) mice by evaluating endothelial function of isolated coronary arterioles of wild-type (WT) and db/db mice with/without ET. Although dilation of vessels to the endothelial-independent vasodilator, sodium nitroprusside was not different between db/db and WT, dilation to the endothelial-dependent agonist, acetylcholine (ACh), was impaired in db/db compared to WT mice. Vasodilation to ACh was restored in db/db with ET and insulin sensitivity was improved in the db/db after ET. Exercise did not change body weight of db/db, but superoxide dismutase (SOD1 and SOD2) and phosphorylated- eNOS protein (Ser1177) expression in heart tissue was up-regulated whereas tumor necrosis factor-alpha (TNF-α) protein level was decreased by ET. Serum level of interleukin-6 (IL-6) was higher in db/db mice but ET decreased IL-6. This suggests that ET may improve endothelial function by increasing nitric oxide bioavailability as well as decreasing chronic inflammation. We suggest this connection may be the basis for the benefit of ET in T2D.

Unmet needs in Hispanic/Latino patients with type 2 diabetes mellitus

In the United States, the prevalence of adults who are overweight or obese is higher in Hispanics/Latinos compared with non-Hispanic whites. In addition, data from the National Health and Nutrition Examination Survey (NHANES) indicate that the prevalence of type 2 diabetes mellitus is consistently greater in racial/ethnic minority groups, such as Hispanics/Latinos, compared with non-Hispanic whites. In fact, data from the Centers for Disease Control and Prevention (CDC) from 2007 to 2009 suggest that the prevalence of type 2 diabetes is almost twice as high in Hispanics/Latinos compared with non-Hispanic whites (11.8% vs. 7.1%, respectively). Although genetics plays a role in the increased prevalence of type 2 diabetes in Hispanics/Latinos, cultural and environmental factors also contribute. In addition to the increased prevalence of type 2 diabetes in Hispanics/Latinos, evidence suggests that the patients in this population are often undertreated and, therefore, less likely to achieve control of their glucose, blood pressure, and lipid levels. Because individuals with type 2 diabetes have a 2- to 4-fold increased risk of cardiovascular disease compared with individuals with normal glucose levels, there is consensus that targeting environmental factors, particularly the development of obesity at an early age, is the most cost-effective approach to prevent the development of type 2 diabetes and its broad spectrum of complications, including cardiovascular disease. Cultural and socioeconomic barriers, such as language, cost, and access to goods and services, must be overcome to improve management of type 2 diabetes in this high-risk population. By increasing healthcare provider awareness and the availability of programs tailored to Hispanic/Latino individuals, the current treatment gap among ethnic minorities in the United States will progressively narrow, and eventually, disappear.

Effects of Aerobic Exercise vs. Resistance Training on Endothelial Function in Women with Type 2 Diabetes Mellitus

BACKGROUND

There is controversy over whether aerobic or resistance exercise is more effective for improving endothelial function in type 2 diabetes mellitus (T2DM). This study was aimed to investigate the effects of an aerobic and resistance training program on endothelial function, and the influences of glycemic control, body weight changes, and aerobic capacity in T2DM.

METHODS

Total 40 overweight women with T2DM were assigned into 3 groups: an aerobic exercise group (AEG, n=13), resistance exercise group (REG, n=12), and control group (CG, n=15), and followed either brisk walking for the AEG or resistance band training for the REG, 60 minutes per day, 5 days per week for 12 weeks with monitoring daily activity using accelerometers. We assessed endothelial function by flow-mediated dilation (FMD), and aerobic capacity by oxygen uptake at anaerobic threshold (AT_VO(2)) at baseline and following training program.

RESULTS

The mean participants' age was 57.0±6.8 years, and body mass index (BMI) was 27.0±2.3 kg/m(2). After intervention, FMD increased by 2.2±1.9% in AEG, which differed from REG and CG (P=0.002), despite of decreased body weight (BW) in both AG and RG (2.8±2.5%, P=0.002; 1.6±2.0%, P=0.017, respectively). A significant increased AT_VO(2) and decreased HbA1c were found only in AEG. In all participants, FMD was changed with the significant relations to the AT_VO(2) (r=0.348, P=0.035), but not to HbA1c levels or BW.

CONCLUSION

Aerobic exercise appears to be more beneficial than resistance exercise for improving endothelial function in T2DM. In addition, aerobic capacity could be a better predictor of changes in FMD than BW and glycemic control.

Is the risk for cardiovascular disease increased in all phenotypes of the polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is a common disorder in women of reproductive age, affecting around 10% of them. Polycystic ovary syndrome is considered to be related to increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). There are 2 definitions for PCOS: one adopted in 1990 (classical PCOS with phenotypes A and B) and the other in 2003 (Rotterdam criteria with 4 phenotypes A to D). The latter is a wider definition including the 1990 phenotypes. There is mounting data suggesting that phenotypes C and D are not actually related to increased CVD risk, and thus screening for CVD risk factors of intervening for primary CVD prevention in young women is not cost-effective. There is an increasing number of suggestions to return to the 1990 criteria plus some metabolic parameters to identify real CVD risk in this population. However, such a strategy needs verification by large, prospective studies.

Adiponectin and sE-selectin Concentrations in Relation to Inflammation in Obese Type 2 Diabetic Patients With Coronary Heart Disease

Adipose tissue can release proinflammatory mediators, namely C-reactive protein (CRP), interleukin 1β (IL-1β), and monocyte chemotactic protein 1 (MCP-1), contributing to vascular injury and insulin resistance (IR). Other mediators namely, adiponectin and nitric oxide (NO) are protective. We enrolled type 2 diabetes mellitus (T2DM) obese male patients without coronary heart disease ([CHD] group II, n = 25) and T2DM obese patients with CHD (group III, n = 25). They were compared with 20 age- and body mass index (BMI)-matched nondiabetic control males (group I). Fasting blood glucose (FBG), glycated hemoglobin (HbA1c%), lipids, insulin, malondialdehyde ([MDA]; lipid peroxidation product), NO, high-sensitivity CRP (hsCRP), IL-1β, MCP-1, adiponectin as well as sE-selectin concentration were significantly different in patients with T2DM and CHD compared with patients without CHD and nondiabetic controls ( P = .01). There was a significant negative correlation between adiponectin and E-selectin ( P = .0001). Adipose tissue in T2DM obese patients may contribute to the pathogenesis of CHD.

Effect of obesity on cardiovascular disease risk factors in African American women

Obesity is a growing health care concern with implications for cardiovascular disease (CVD). Obesity and CVD morbidity and mortality are highly prevalent among African American women. This pilot study examined the association between obesity and the traditional and emerging CVD risk factors in a sample of African American women. Participants comprised 48 women (27 obese, 21 normal weight) aged 18-45. with no known history of CVD. The women completed demographic and 7-day physical activity recall questionnaires. Height and weight were used to determine body mass index (BMI). Hypertension risk was assessed using the average of two resting blood pressure (BP) measurements. Lipid profile, blood glucose, fibrinogen, high-sensitivity C-reactive protein (hs-CRP), plasminogen activator inhibitor-1 (PAI-1), soluble intercellular adhesion molecule-1 (sICAM-1), and E-selectin (eSel) levels were assessed using fasting blood samples. Laboratory findings were interpreted using the American Diabetes Association (ADA) and Adult Treatment Panel (ATP) III reference guidelines as well as manufacturers' reference ranges for the novel CVD risk factors. The most common traditional risk factors were physical inactivity (72.9%), positive family history of CVD (58.3%), and obesity (56.3%). Obese individuals had elevated systolic BP (p = .0002), diastolic BP (p = .0007) and HDL-cholesterol (p = .01), triglyceride (p = .02), hs-CRP (p = .002), and fibrinogen (p = .01), when compared with normal-weight women. The findings suggest an association between obesity and higher prevalence of both traditional and emerging CVD risk factors in young African American women.

Astragaloside IV improves metabolic syndrome and endothelium dysfunction in fructose-fed rats

The prevalence of metabolic syndrome has increased in modern society and the condition is proving to be a common precursor of cardiovascular disease. The aim of the present study was to investigate whether astragaloside IV, a major active constituent of Astragalus membranaceus (Fisch) Bge., is able to prevent the development of hypertension and endothelial dysfunction in fructose-fed rats. Rats were fed with 10% fructose in their drinking water for 8 weeks. From the beginning of week 5, two groups of fructose-fed rats were treated with 0.5 or 2 mg/kg, i.p., astragaloside IV. Another group of fructose-fed rats, injected with the same volume of vehicle (dimethylsulfoxide, DMSO) from week 5, served as the control group. At the end of the treatment period, blood pressure, blood glucose, glucose tolerance, blood insulin and lipids were determined. In addition, in vitro experiments were conducted at the end of the eight week treatment period to evaluate endothelium-dependent aortic vasorelaxation, as well as myocardial and aortic tissue levels of nitrate and nitrite (NOx) and cGMP. Fructose-fed rats developed clustering signs of metabolic syndrome, such as increased bodyweight, mild hypertension, hyperinsulinaemia, hypertriglyceridaemia, impaired glucose tolerance and impaired endothelium-dependent vasorelaxation. Administration of astragaloside IV reduced blood pressure and triglyceride levels in fructose-fed rats and high dose of astragaloside IV also improved glucose tolerance and endothelium-dependent vasorelaxation. The astragaloside IV-induced improvement in vasorelaxation was associated with increased levels of aortic NOx and cGMP and was abrogated by blockade of nitric oxide synthase with NG-nitro-l-arginine methyl ester (l-NAME). On the basis of its favourable effects on lipid metabolism, endothelium-dependent vasorelaxation and the nitric oxide–cGMP-related pathway, astragaloside IV may be useful in ameliorating food-induced metabolic syndrome.

Dysfunction of human subcutaneous fat arterioles in obesity alone or obesity associated with Type 2 diabetes

The aim of the present study was to examine the effects of obesity alone and obesity associated with Type 2 diabetes on the structure, vascular reactivity and response to insulin of isolated human subcutaneous fat arterioles; these effects were correlated with the expression of insulin signalling proteins. Periumbilical subcutaneous adipose tissue was explanted during surgery, small arterioles (internal diameter 220 ± 40 μm) were dissected out and investigated by electron microscopy, myography and immunoblotting. Compared with the subcutaneous arterioles of lean subjects, obesity activated the endothelium, enhanced the accumulation of collagen within vascular wall and increased the sensitivity of adrenergic response; obesity also diminished eNOS (endothelial NO synthase) protein expression, NO production, and endothelium-dependent and insulin-induced vasodilatation, as well as the protein expression of both IRS (insulin receptor substrates)-1 and IRS-2 and of the downstream molecules in the insulin signalling pathway, such as PI3K (phosphoinositide 3-kinase), phospho-Akt and Akt. When obesity was associated with Type 2 diabetes, these changes were significantly augmented. In conclusion, obesity alone or obesity associated with Type 2 diabetes alters human periumbilical adipose tissue arterioles in terms of structure, function and biochemsitry, including diminished eNOS expression and reduced levels of IRS-1, IRS-2, PI3K and Akt in the insulin signalling pathway.

Metabolic syndrome, chronic kidney, and cardiovascular diseases: role of adipokines

Obesity is a chronic disease, whose incidence is alarmingly growing. It is associated with metabolic abnormalities and cardiovascular complications. These complications are clustered in the metabolic syndrome (MetS) leading to high cardiovascular morbidity and mortality. Obesity predisposes to diabetic nephropathy, hypertensive nephrosclerosis, and focal and segmental glomerular sclerosis and represents an independent risk factor for the development and progression of chronic kidney disease (CKD). Albuminuria is a major risk factor for cardiovascular diseases (CVDs). Microalbuminuria has been described as early manifestation of MetS-associated kidney damage and diabetic nephropathy. Obesity and MetS affect renal physiology and metabolism through mechanisms which include altered levels of adipokines such as leptin and adiponectin, oxidative stress, and inflammation. Secretory products of adipose tissue also deeply and negatively influence endothelial function. A better understanding of these interactions will help in designing more effective treatments aimed to protect both renal and cardiovascular systems.