Factors Responsible for Obesity-Related Hypertension

Central mechanisms in sympathetic nervous dysregulation in obesity

Cardiovascular and metabolic complications associated with excess adiposity are linked to chronic activation of the sympathetic nervous system, resulting in a high risk of mortality among obese individuals. Obesity-related positive energy balance underlies the progression of hypertension, end-organ damage, and insulin resistance, driven by increased sympathetic tone throughout the body. It is, therefore, important to understand the central network that drives and maintains sustained activation of the sympathetic nervous system in the obese state. Experimental and clinical studies have identified structural changes and altered dynamics in both grey and white matter regions in obesity. Aberrant activation in certain brain regions has been associated with altered reward circuitry and metabolic pathways including leptin and insulin signaling along with adiposity-driven systemic and central inflammation. The impact of these pathways on the brain via overactivity of the sympathetic nervous system has gained interest in the past decade. Primarily, the brainstem, hypothalamus, amygdala, hippocampus, and cortical structures including the insular, orbitofrontal, temporal, cingulate, and prefrontal cortices have been identified in this context. Although the central network involving these structures is much more intricate, this review highlights recent evidence identifying these regions in sympathetic overactivity in obesity.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Huoxue Qianyang Qutan Recipe Protects against Early Renal Damage Induced by Obesity-Related Hypertension via the SIRT1/NF-κB/IL-6 Pathway: Integrating Network Pharmacology and Experimental Validation-Based Strategy

Obesity is recognized as not only a major contributing factor to cardiovascular diseases but also an independent risk factor for end-stage renal disease. Previous studies have found that Huoxue Qianyang Qutan Recipe (HQQR) could reduce urinary microalbumin in patients with obesity-related hypertension (OBH). However, the renal protective activity of HQQR in OBH and its molecular targets involved remains ambiguous. In this work, we investigate the mechanism of HQQR against OBH-induced early renal damage using integrating network pharmacology and experimental validation-based strategy. First, via network pharmacology, IL-6 is identified as one of the key targets of HQQR against early renal damage in hypertension, and inhibition of inflammation is a crucial process. Second, in in vivo experiments, HQQR can lower blood pressure, lose weight, and restore metabolic abnormalities in OBH rats, which could be associated with the effects on protecting early renal damage. Finally, in the mechanism, HQQR increases SIRT1 mRNA and protein expression consistent with reduction of NF-κB acetylation and suppressed the p65-mediated inflammatory signaling pathway. As a result, HQQR robustly inhibits OBH-induced renal inflammation by reducing IL-6 mRNA and protein levels in the renal tissue and the release of IL-6 in serum of OBH rats. This study aims to provide a multimethod (network pharmacology-animal experiment) and multilevel (component-target-pathway) strategy for the prevention and treatment of OBH-induced target organ damage by traditional Chinese medicine.

Characteristics and molecular mechanisms through which SGLT2 inhibitors improve metabolic diseases: A mechanism review

Metabolic diseases, such as diabetes, gout and hyperlipidemia are global health challenges. Among them, diabetes has been extensively investigated. Type 2 diabetes mellitus (T2DM), which is characterized by hyperglycemia, is a complex metabolic disease that is associated with various metabolic disorders. The newly developed oral hypoglycemic agent, sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been associated with glucose-lowering effects and it affects metabolism in various ways. However, the potential mechanisms of SGLT2 inhibitors in metabolic diseases have not fully reviewed. Many of the effects beyond glycemic control must be considered off-target effects. Therefore, we reviewed the effects of SGLT2 inhibition on metabolic diseases such as obesity, hypertension, hyperlipidemia, hyperuricemia, fatty liver disease, insulin resistance, osteoporosis and fractures. Moreover, we elucidated their molecular mechanisms to provide a theoretical basis for metabolic disease treatment.

Modulation of Sirt1 and FoxO1 on Hypothalamic Leptin-Mediated Sympathetic Activation and Inflammation in Diet-Induced Obese Rats

Background Hypothalamic leptin-mediated signaling contributes to the exaggerated sympatho-excitation and increased blood pressure in obesity-associated hypertension. The aim of the study was to investigate the roles of energy-sensing enzyme sirtuin1 (Sirt1) and forkhead box protein O1 (FoxO1) on the hypothalamic leptin-mediated high sympathetic nerve activity and inflammation in obesity. Methods and Results Sprague Dawley rats were fed with high-fat diet (HFD) for 12 weeks. In vivo, the potential of Srit1 and FoxO1 in the sympathetic effects of leptin was investigated via siRNA injection to knockdown Sirt1 or FoxO1 gene in the arcuate nucleus (ARCN) of hypothalamus in rats. In vitro, the effects of Sirt1 or FoxO1 on leptin-mediated inflammation were observed in proopiomelanocortin (POMC) and microglial cells. Knockdown Sirt1 by siRNA significantly reduced the renal sympathetic nerve activity (RSNA) and blood pressure responses to leptin injection in the ARCN in the HFD rats. Conversely, knockdown FoxO1 significantly enhanced the RSNA and blood pressure responses to leptin injection in the HFD rats. Knockdown Sirt1 reduced the levels of pro-inflammatory cytokines interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), C1q/TNF-related protein-1 (CTRP1), and immune cell infiltration in the ARCN in the HFD rats. Knockdown FoxO1 significantly increased the level of IL-6 in the ARCN of HFD rats. In cultured hypothalamic POMC and microglial cells, knockdown Sirt1 significantly reduced leptin-induced IL-6 expression, affected the levels of AMP-activated protein kinase (AMPK) and serine/threonine-specific protein kinase (Akt). Knockdown FoxO1 significantly increased leptin-induced IL-6 in both POMC cells and microglial cells. Conclusions These data suggest that both Sirt1 and FoxO1 are the key modulators of leptin signaling in the hypothalamus contributed to the over sympathetic activation and inflammation in obesity.

An Overview of Similarities and Differences in Metabolic Actions and Effects of Central Nervous System Between Glucagon-Like Peptide-1 Receptor Agonists (GLP-1RAs) and Sodium Glucose Co-Transporter-2 Inhibitors (SGLT-2is)

GLP-1 receptor agonists (GLP-1RAs) and SGLT-2 inhibitors (SGLT-2is) are novel antidiabetic medications associated with considerable cardiovascular benefits therapying treatment of diabetic patients. GLP-1 exhibits atherosclerosis resistance, whereas SGLT-2i acts to ameliorate the neuroendocrine state in the patients with chronic heart failure. Despite their distinct modes of action, both factors share pathways by regulating the central nervous system (CNS). While numerous preclinical and clinical studies have demonstrated that GLP-1 can access various nuclei associated with energy homeostasis and hedonic eating in the CNS via blood-brain barrier (BBB), research on the activity of SGLT-2is remains limited. In our previous studies, we demonstrated that both GLP-1 receptor agonists (GLP-1RAs) liraglutide and exenatide, as well as an SGLT-2i, dapagliflozin, could activate various nuclei and pathways in the CNS of Sprague Dawley (SD) rats and C57BL/6 mice, respectively. Moreover, our results revealed similarities and differences in neural pathways, which possibly regulated different metabolic effects of GLP-1RA and SGLT-2i via sympathetic and parasympathetic systems in the CNS, such as feeding, blood glucose regulation and cardiovascular activities (arterial blood pressure and heart rate control). In the present article, we extensively discuss recent preclinical studies on the effects of GLP-1RAs and SGLT-2is on the CNS actions, with the aim of providing a theoretical explanation on their mechanism of action in improvement of the macro-cardiovascular risk and reducing incidence of diabetic complications. Overall, these findings are expected to guide future drug design approaches.

Type 2 diabetes - unmet need, unresolved pathogenesis, mTORC1-centric paradigm

The current paradigm of type 2 diabetes (T2D) is gluco-centric, being exclusively categorized by glycemic characteristics. The gluco-centric paradigm views hyperglycemia as the primary target, being driven by resistance to insulin combined with progressive beta cells failure, and considers glycemic control its ultimate treatment goal. Most importantly, the gluco-centric paradigm considers the non-glycemic diseases associated with T2D, e.g., obesity, dyslipidemia, hypertension, macrovascular disease, microvascular disease and fatty liver as 'risk factors' and/or 'outcomes' and/or 'comorbidities', rather than primary inherent disease aspects of T2D. That is in spite of their high prevalence (60-90%) and major role in profiling T2D morbidity and mortality. Moreover, the gluco-centric paradigm fails to realize that the non-glycemic diseases of T2D are driven by insulin and, except for glycemic control, response to insulin in T2D is essentially the rule rather than the exception. Failure of the gluco-centric paradigm to offer an exhaustive unifying view of the glycemic and non-glycemic diseases of T2D may have contributed to T2D being still an unmet need. An mTORC1-centric paradigm maintains that hyperactive mTORC1 drives the glycemic and non-glycemic disease aspects of T2D. Hyperactive mTORC1 is proposed to act as double-edged agent, namely, to interfere with glycemic control by disrupting the insulin receptor-Akt transduction pathway, while concomitantly driving the non-glycemic diseases of T2D. The mTORC1-centric paradigm may offer a novel perspective for T2D in terms of pathogenesis, clinical focus and treatment strategy.

Molecular Mechanisms of SGLT2 Inhibitor on Cardiorenal Protection

The development of sodium-glucose transporter 2 inhibitor (SGLT2i) broadens the therapeutic strategies in treating diabetes mellitus. By inhibiting sodium and glucose reabsorption from the proximal tubules, the improvement in insulin resistance and natriuresis improved the cardiovascular mortality in diabetes mellitus (DM) patients. It has been known that SGLT2i also provided renoprotection by lowering the intraglomerular hypertension by modulating the pre- and post- glomerular vascular tone. The application of SGLT2i also provided metabolic and hemodynamic benefits in molecular aspects. The recent DAPA-CKD trial and EMPEROR-Reduced trial provided clinical evidence of renal and cardiac protection, even in non-DM patients. Therefore, the aim of the review is to clarify the hemodynamic and metabolic modulation of SGLT2i from the molecular mechanism.

Cerebrovascular function in hypertension: Does high blood pressure make you old?

The majority of individuals over an age of 60 have hypertension. Elevated blood pressure and older age are associated with very similar changes in brain structure and function. We review the parallel brain changes associated with increasing age and blood pressure. This review focuses on joint associations of aging and elevated blood pressure with neuropsychological function, regional cerebral blood flow responses to cognitive and metabolic challenges, white matter disruptions, grey matter volume, cortical thinning, and neurovascular coupling. Treatment of hypertension ameliorates many of these changes but fails to reverse them. Treatment of hypertension itself appears more successful with better initial brain function. We show evidence that sympathetic and renal influences known to increase blood pressure also impact brain integrity. Possible central mechanisms contributing to the course of hypertension and aging are then suggested. An emphasis is placed on psychologically relevant factors: stress, cardiovascular reactions to stress, and diet/obesity. The contribution of some of these factors to biological aging remains unclear and may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.

Sedentary behavior is more related with cardiovascular parameters in normal weight than overweight adolescents

This study analyzed the relationship between sedentary behavior and cardiovascular parameters in normal weight and overweight adolescents. The sample included 449 boys and 555 girls with mean age of 13 years from public schools, which were divided into five geographical regions, with data collections performed in one selected school from each region. Sedentary behavior was assessed by screen time on TV, computer, videogame and cell phone/tablet, with good reliability in adolescents. Physical activity was assessed by Baecke's questionnaire, validated for adolescents. Measures of body weight, height and waist circumference were collected. Adolescents were classified as overweight or normal weight by cut-off points of body mass index for age and sex. Cardiovascular parameters were evaluated by oscillometric device and heart rate by specific monitor. Computer use was positively related to systolic blood pressure (SBP) (β = 0.35; 95%CI = 0.07-0.62) and diastolic blood pressure (DBP) (β = 0.25; 95%CI = 0.05-0.44) in normal weight but not in overweight adolescents. Similar results were observed for cell phone/tablet in SBP (β = 0.46; 95%CI = 0.20-0.72) and DBP (β = 0.36; 95%CI = 0.18-0.54), only for normal weight. The cluster of screen time was related to SBP in normal weight (β = 0.44; 95%CI = 0.03-0.84) and overweight (β = 0.60; 95%CI = 0.01-1.19). Screen time in computer and cell phone/tablet was more related to cardiovascular parameters in normal weight than overweight adolescents.

Impact of sex and age on metabolism, sympathetic activity, and hypertension

In this brief review, we summarize the current knowledge on the complex interplay between metabolism, sympathetic activity and hypertension with a focus on sex differences and changes with age in humans. Evidence suggests that in premenopausal women, sex hormones, particularly estrogen exerts a profound cardioprotective effect which may be associated with favorable metabolic profiles, as well as lower sympathetic activity and blood pressure at rest and any given physiological and environmental stimuli compared with men of a similar age. Along this line, premenopausal women seem to be generally protected from obesity-induced metabolic and cardiovascular complications. However, postmenopausal estrogen deprivation during midlife and older age has a detrimental impact on metabolism, may lead to adipose tissue redistribution from the subcutaneous to abdominal area, and augments sympathetic activity. All these changes could contribute significantly to the higher prevalence of hypertension and greater cardiometabolic risk in older women than older men. It is proposed that obesity-related hypertension has a neurogenic component which is characterized by sympathetic overactivity, but the impact of sex and age remains largely unknown. Understanding sex and age-specific differences in obesity and sympathetic neural control of blood pressure is important in the prevention and/or risk reduction of cardiometabolic disorders for both men and women.

Obesity, Hypertension, and Bariatric Surgery

PURPOSE OF REVIEW

Obesity increases the risk of hypertension. However, blood pressure decreases before any significant loss of body weight after bariatric surgery. We review the mechanisms of the temporal dissociation between blood pressure and body weight after bariatric surgery.

RECENT FINDINGS

Restrictive and bypass bariatric surgery lower blood pressure and plasma leptin levels within days of the procedure in both hypertensive and normotensive morbidly obese patients. Rapidly decreasing plasma leptin levels and minimal loss of body weight point to reduced sympathetic nervous system activity as the underlying mechanism of rapid blood pressure decline after bariatric surgery. After the early rapid decline, blood pressure does not decrease further in patients who, while still obese, experience a steady loss of body weight for the subsequent 12 months. The divergent effects of bariatric surgery on blood pressure and body weight query the role of excess body weight in the pathobiology of the obesity phenotype of hypertension. The decrease in blood pressure after bariatric surgery is moderate and independent of body weight. The lack of temporal relationship between blood pressure reduction and loss of body weight for 12 months after sleeve gastrectomy questions the nature of the mechanisms underlying obesity-associated hypertension.

Is the Brain an Early or Late Component of Essential Hypertension?

The brain's relationship to essential hypertension is primarily understood to be that of an end-organ, damaged late in life by stroke or dementia. Emerging evidence, however, shows that heightened blood pressure (BP) early in life and prior to traditionally defined hypertension, relates to altered brain structure, cerebrovascular function, and cognitive processing. Deficits in cognitive function, cerebral blood flow responsivity, volumes of brain areas, and white matter integrity all relate to increased but prehypertensive levels of BP. Such relationships may be observed as early as childhood. In this review, we consider the basis of these relationships by examining the emergence of putative causative factors for hypertension that would impact or involve brain function/structure, e.g., sympathetic nervous system activation and related endocrine and inflammatory activation. Currently, however, available evidence is not sufficient to fully explain the specific pattern of brain deficits related to heightened BP. Despite this uncertainty, the evidence reviewed suggests the value that early intervention may have, not only for reducing BP, but also for maintaining brain function.

A Metabolically Healthy Profile Is a Transient Stage When Exercise and Diet Are Not Supervised: Long-Term Effects in the EXERDIET-HTA Study

Metabolically unhealthy obesity (MUO) is a regular state in people with primary hypertension (HTN), obesity, and who are physically inactive. To achieve and maintain a metabolically healthy overweight/obese (MHO) state should be a main treatment goal. The aims of the study were (1) to determine differences in metabolic profiles of overweight/obese, physically inactive individuals with HTN following a 16-week (POST) supervised aerobic exercise training (SupExT) intervention with an attentional control (AC) group, and (2) to determine whether the changes observed were maintained following six months (6 M) of unsupervised time. Participants (n = 219) were randomly assigned into AC or SupExT groups. All participants underwent a hypocaloric diet. At POST, all participants received diet and physical activity advice for the following 6 M, with no supervision. All measurements were assessed pre-intervention (PRE), POST, and after 6 M. From PRE to POST, MUO participants became MHO with improved (p < 0.05) total cholesterol (TC, ∆ = -12.1 mg/dL), alanine aminotransferase (∆ = -8.3 U/L), glucose (∆ = -5.5 mg/dL), C-reactive protein (∆ = -1.4 mg/dL), systolic blood pressure (SBP), and cardiorespiratory fitness (CRF) compared to unhealthy optimal cut-off values. However, after 6 M, TC, glucose, and SBP returned to unhealthy values (p < 0.05). In a non-physically active population with obesity and HTN, a 16-week SupExT and diet intervention significantly improves cardiometabolic profile from MUO to MHO. However, after 6 M of no supervision, participants returned to MUO. The findings of this study highlight the need for regular, systematic, and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.

Sympathetic Nervous System Contributions to Hypertension: Updates and Therapeutic Relevance

The sympathetic nervous system plays a pivotal role in the long-term regulation of arterial blood pressure through the ability of the central nervous system to integrate neurohumoral signals and differentially regulate sympathetic neural input to specific end organs. Part 1 of this review will discuss neural mechanisms of salt-sensitive hypertension, obesity-induced hypertension, and the ability of prior experiences to sensitize autonomic networks. Part 2 of this review focuses on new therapeutic advances to treat resistant hypertension including renal denervation and carotid baroactivation. Both advances lower arterial blood pressure by reducing sympathetic outflow. We discuss potential mechanisms and areas of future investigation to target the sympathetic nervous system.

Obesity, kidney dysfunction and hypertension: mechanistic links

Excessive adiposity raises blood pressure and accounts for 65-75% of primary hypertension, which is a major driver of cardiovascular and kidney diseases. In obesity, abnormal kidney function and associated increases in tubular sodium reabsorption initiate hypertension, which is often mild before the development of target organ injury. Factors that contribute to increased sodium reabsorption in obesity include kidney compression by visceral, perirenal and renal sinus fat; increased renal sympathetic nerve activity (RSNA); increased levels of anti-natriuretic hormones, such as angiotensin II and aldosterone; and adipokines, particularly leptin. The renal and neurohormonal pathways of obesity and hypertension are intertwined. For example, leptin increases RSNA by stimulating the central nervous system proopiomelanocortin-melanocortin 4 receptor pathway, and kidney compression and RSNA contribute to renin-angiotensin-aldosterone system activation. Glucocorticoids and/or oxidative stress may also contribute to mineralocorticoid receptor activation in obesity. Prolonged obesity and progressive renal injury often lead to the development of treatment-resistant hypertension. Patient management therefore often requires multiple antihypertensive drugs and concurrent treatment of dyslipidaemia, insulin resistance, diabetes and inflammation. If more effective strategies for the prevention and control of obesity are not developed, cardiorenal, metabolic and other obesity-associated diseases could overwhelm health-care systems in the future.

Intermedin in Paraventricular Nucleus Attenuates Ang II-Induced Sympathoexcitation through the Inhibition of NADPH Oxidase-Dependent ROS Generation in Obese Rats with Hypertension

Increased reactive oxygen species (ROS) induced by angiotensin II (Ang II) in the paraventricular nucleus (PVN) play a critical role in sympathetic overdrive in hypertension (OH). Intermedin (IMD), a bioactive peptide, has extensive clinically prospects in preventing and treating cardiovascular diseases. The study was designed to test the hypothesis that IMD in the PVN can inhibit the generation of ROS caused by Ang II for attenuating sympathetic nerve activity (SNA) and blood pressure (BP) in rats with obesity-related hypertension (OH). Male Sprague-Dawley rats (160-180 g) were used to induce OH by feeding of a high-fat diet (42% kcal as fat) for 12 weeks. The dynamic changes of sympathetic outflow were evaluated as the alterations of renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) responses to certain chemicals. The results showed that the protein expressions of Ang II type 1 receptor (AT1R), calcitonin receptor-like receptor (CRLR) and receptor activity-modifying protein 2 (RAMP2) and RAMP3 were markedly increased, but IMD was much lower in OH rats when compared to control rats. IMD itself microinjection into PVN not only lowered SNA, NADPH oxidase activity and ROS level, but also decreased Ang II-caused sympathetic overdrive, and increased NADPH oxidase activity, ROS levels and mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) activation in OH rats. However, those effects were mostly blocked by the adrenomedullin (AM) receptor antagonist AM22-52 pretreatment. The enhancement of SNA caused by Ang II can be significantly attenuated by the pretreatment of AT1R antagonist lorsatan, superoxide scavenger Tempol and NADPH oxidase inhibitor apocynin (Apo) in OH rats. ERK activation inhibitor U0126 in the PVN reversed Ang II-induced enhancement of SNA, and Apo and IMD pretreatment in the PVN decreased Ang II-induced ERK activation. Chronic IMD administration in the PVN resulted in significant reductions in basal SNA and BP in OH rats. Moreover, IMD lowered NADPH oxidase activity and ROS level in the PVN; reduced the protein expressions of AT1R and NADPH oxidase subunits NOX2 and NOX4, and ERK activation in the PVN; and decreased Ang II levels-inducing sympathetic overactivation. These results indicated that IMD via AM receptors in the PVN attenuates SNA and hypertension, and decreases Ang II-induced enhancement of SNA through the inhibition of NADPH oxidase activity and ERK activation.

Sex differences in sympathetic activity in obesity and its related hypertension

The prevalence of obesity is rapidly increasing in the United States, particularly among women. Approximately 60-70% of hypertension in adults may be directly attributed to obesity. In addition, maternal obesity is a major risk factor for hypertensive disorders during pregnancy. The underlying mechanisms for the association between obesity and cardiovascular risk are multifactorial, but activation of the sympathetic nervous system is one significant contributing factor. This brief review summarizes the current knowledge on sex differences in sympathetic activity in obesity and its related hypertension, with a focus on studies in humans. Evidence suggests that abdominal visceral fat, rather than subcutaneous fat, is related to augmented sympathetic activity regardless of sex. Race/ethnicity may affect the relationship between obesity and sympathetic activity. Obesity-related hypertension has an important neurogenic component, which is characterized by sympathetic overactivity. However, sex may influence the association between hypertension and sympathetic overactivity in obese people. Finally, both body weight and sympathetic overactivity seem to be involved in the development of gestational hypertensive disorders in women. Chronic hyperinsulinemia due to insulin resistance, high plasma levels of leptin, and/or obstructive sleep apnea may be responsible for sympathetic overactivity in obesity-related hypertension.

Sex Differences in Renal Inflammation and Injury in High-Fat Diet-Fed Dahl Salt-Sensitive Rats

We examined the impact of sex on high-fat diet (HFD)-induced renal alterations in Dahl salt-sensitive and Sprague Dawley rats. In Dahl rats, HFD (60% kcal from fat for 24-26 weeks starting at weaning) significantly and equally increased blood pressure in males and females when compared with rats fed a control diet (10% kcal from fat). Male Dahl rats on HFD exhibited progressive renal histological injury and moderately increased renal macrophage infiltration at 10 and 24 weeks of feeding when compared with males on control diet. Female Dahl rats had lower grade renal injury and less macrophage infiltration (except at 17 weeks) than males regardless of diet. Male Dahl rats on both diets showed progressively increasing numbers of renal T-cells, a pattern not observed in females. HFD per se did not significantly affect renal T-cell number. Male Dahl rats had lower renal regulatory T-cells cell ratio than females at 24 weeks. Renal macrophage and T-cell infiltrations were highly correlated to final mean arterial pressure levels in males but not in females. Sprague Dawley rats fed HFD were normotensive without significant renal injury/inflammation after 24 weeks of feeding. In summary, HFD feeding fails to increase arterial blood pressure in Sprague Dawley rats but strongly promotes hypertension in both male and female Dahl salt-sensitive rats. Only Dahl males, however, exhibited blood pressure-associated renal inflammation and injury. Maintenance of regulatory T-cells ratio may protect against hypertension-associated renal injury/inflammation but not HFD-induced hypertension.

The QardioArm Blood Pressure App for Self-Measurement in an Obese Population: Validation Study Using the European Society of Hypertension International Protocol Revision 2010

Background

Obesity and high blood pressure (HBP) pose high cardiovascular risks, and they are frequent causes of cardiovascular disease.

Objective

The aim of this study was to validate the mobile app QardioArm for high blood pressure monitoring in obese subjects (body mass index ≥30 kg/m²) according to guidelines in the European Society of Hypertension-International Protocol 2 (ESH-IP2).

Methods

We recruited 33 obese subjects and measured their blood pressure using QardioArm (test device) and Omron M3 Intellisense (Omron Healthcare, Kyoto, Japan; standard device). We compared systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) according to the ESH-IP2.

Results

A total of 95 of 99 differences for SBP and 91 of 99 for DBP displayed absolute differences within 10 mm Hg. A total of 98 of 99 differences for SBP and 98 of 99 for DBP exhibited absolute differences within 15 mm Hg. This result satisfied requirements for part 1 of the ESH-IP2. A total of 27 out of 33 individuals for SBP and 30 out of 33 individuals for DBP had a minimum of 2 of 3 comparisons within 5 mm Hg difference. None of the subjects had 3 differences outside 5 mm Hg for SBP and DBP, satisfying part 2 of the ESH-IP2. For HR measurements, a total of 90 of 99 differences had absolute differences within 3 beats per minute (bpm), and a total of 94 or 99 differences had absolute differences within 5 bpm. A total of 98 of 99 differences had absolute differences within 8 bpm. Therefore, the test device satisfied part 1 of ESH-IP2 criteria for HR. For part 2 of ESH-IP2, 31 of 33 individuals had a minimum of 2 of 3 comparisons within 3 bpm difference for HR. Only 1 of 33 subjects had 3 differences outside 3 bpm.

Conclusions

To the best of our knowledge, this was the first study to show that an app that measures blood pressure and HR meets the requirements of the ESH-IP2 in an obese population. We believe the ESH-IP2 should publish explicit criteria for validation of blood pressure devices in specific populations.

OBESITY IN RUSSIAN POPULATION — PREVALENCE AND ASSOCIATION WITH THE NON-COMMUNICABLE DISEASES RISK FACTORS

Aim. Evaluation of the prevalence of obesity and association with the risk factors of chronic non-communicable diseases of the inhabitants of selected regions of Russia, by the data from ESSE-RF study.

Material and methods. Representative selections investigated, of the inhabitants of 13 regions of Russia, totally 21768 participants, males n=8 304, females n=13 464, age 25-64 y. o., under the circumstances of the study “Epidemiology of cardiovascular diseases (ESSE-RF)”, with response ~80%. Standard questionnaire, consisting 12 modules, was developed based upon adapted international methods. For the risk factors prevalence assessment, the standard epidemiological methods were applied. Body mass (BM) was evaluated in the categories of body mass index (BMI) (Ketle index: BMI — Body mass, kg / height, m2). BM as BMI was evaluated as insufficient (BMI <18,5), normal (18,5≤ BMI ≤24,9), overweight (25,0≤ BMI ≤29,9), obesity grade I (30,0 ≤BMI ≤34,9), obesity grade II (35,0 ≤BMI ≤39,9) and obesity grade III (BMI ≥40,0). Abdominal obesity (AO) was assessed with the criteria: for males waist circumference (WC) ≥102 cm and for females ≥88 cm.

Results. Mean BMI value among the participants was 27,6 kg/m2, with no gender difference. BMI increases with the age only in women. WC — 87,8 cm ±0,1, among males it was significantly higher than in females (92,9 cm vs 84,1 cm, p<0,001), increasing with age. The prevalence of obesity was higher among females comparing to males: by BMI — 30,8% vs 26,9%, p<0,001; by AO — 38,4% vs 24,3%, p<0,001. The prevalence of obesity in female inhabitants of rural regions was significantly higher comparing to citizens (p<0,001), and in the group of higher education, there was no difference among males wither by BMI (p<0,005), or by AO (p<0,001). There was no clear geographic gradient of the risk factors. The prevalence of obesity increases linearly with the age, in males from 14,3% to 36,3%, p<0,001, and in females from 10,7% to 52,3%, p<0,001. AO was more prevalent in women comparing to men in every of analyzed age group, and with the age this difference gets more profound. In the multifactorial model the associations of risk factors were analyzed, with any type of obesity. Close relation was found for obesity and raised levels of glucose and triglycerides, with alcohol overconsumption. Most significant associations were found for obesity and AH in both genders — OR: 2,71 and 2,52 in men and women, respectively. There was linear increase of AH prevalence with mean SBP and DBP, together with BM.

Conclusion. In Russian population, obesity is associated most closely with alcohol overconsumption, increased glucose level, lipid disorders and especially strongly — with systemic hypertension, the factors that increase prevalence with age. Burden of this closely interrelated factors on healthcare system will increase with the portion of elderly inhabitants of the country. State of affairs demand for a complex approach based on the governmental politics on the control of populational levels of bodyweight, beginning at elementary school, with mass-media involvement, as the groceries manufacturers, regional governments.

Anti-Inflammatory Effects of Melatonin in Obesity and Hypertension

PURPOSE OF REVIEW

Here, we review the known relations between hypertension and obesity to inflammation and postulate the endogenous protective effect of melatonin and its potential as a therapeutic agent. We will describe the multiple effects of melatonin on blood pressure, adiposity, body weight, and focus on mitochondrial-related anti-inflammatory and antioxidant protective effects.

RECENT FINDINGS

Hypertension and obesity are usually associated with systemic and tissular inflammation. The progressive affection of target-organs involves multiple mediators of inflammation, most of them redundant, which make anti-inflammatory strategies ineffective. Melatonin reduces blood pressure, body weight, and inflammation. The mechanisms of action of this ancient molecule of protection involve multiple levels of action, from subcellular to intercellular. Mitochondria is a key inflammatory element in vascular and adipose tissue and a potential pharmacological target. Melatonin protects against mitochondrial dysfunction. Melatonin reduces blood pressure and adipose tissue dysfunction by multiple anti-inflammatory/antioxidant actions and provides potent protection against mitochondria-mediated injury in hypertension and obesity. This inexpensive and multitarget molecule has great therapeutic potential against both epidemic diseases.

Monitoring and management of hypertension with obesity in adolescents

Largely due to the childhood obesity epidemic, there has been an increase in the prevalence of hypertension in children and adolescents. Obesity associated hypertension is the most common hypertension phenotype among adolescents. Approximately 30% of obese adolescents have elevated blood pressure (BP) or hypertension. Updated definitions of elevated BP and hypertension in adolescents are now similar to definitions of BP status in adults. For adolescents ≥13 years of age, elevated BP is 120 to 129/<80 mm Hg. Hypertension, stage 1, is ≥130 to 139/80 to 89 mm Hg, and hypertension, stage 2, is ≥140/90 mm Hg. BP measurements over separate clinic visits are necessary to verify the diagnosis of elevated BP or hypertension. Ambulatory BP monitoring, when available, provides confirmatory data on BP status. Causal mechanisms for obesity associated hypertension include increased sympathetic nervous system activity, increased renal sodium retention secondary to insulin resistance/hyperinsulinemia, and obesity mediated inflammation. The primary treatment for obesity associated hypertension is weight reduction with lifestyle changes in diet and physical activity. Although difficult to achieve, even modest weight reduction can be beneficial. The diet should be rich in fruits, vegetables, fiber, and low-fat dairy with reduction in salt intake. When lifestyle changes are insufficient to achieve BP control, pharmacologic therapy is indicated to achieve a goal BP of <130/80 mm Hg or <90th percentile, whichever is lower. Regular BP monitoring is necessary for ongoing management of obesity associated hypertension in adolescents.

Recent Advances in Neurogenic Hypertension: Dietary Salt, Obesity, and Inflammation

Neurally-mediated hypertension results from a dysregulation of sympathetic and/or neuroendocrine mechanisms to increase ABP. Multiple factors may exert multiple central effects to alter neural circuits and produce unique sympathetic signatures and elevate ABP. In this brief review, we have discussed novel observations regarding three contributing factors: dietary salt intake, obesity, and inflammation. However, the interaction among these and other factors is likely much more complex; recent studies suggest a prior exposure to one stimulus may sensitize the response to a subsequent hypertensive stimulus. Insight into the central mechanisms by which these factors selectively alter SNA or cooperatively interact to impact hypertension may represent a platform for novel therapeutic treatment strategies.