The Association of Aldosterone With Obesity-Related Hypertension and the Metabolic Syndrome

The New Challenge of Obesity - Obesity-Associated Nephropathy

In recent years, obesity has become one of the major diseases that affect human health and consume human health resources, especially when it causes comorbidities such as hypertension, diabetes, cardiovascular disease and kidney disease. Many studies have demonstrated that obesity is associated with the development of chronic kidney disease and can exacerbate the progression of end-stage renal disease. This review described the mechanisms associated with the development of obesity-associated nephropathy and the current relevant therapeutic modalities, with the aim of finding new therapeutic targets for obesity-associated nephropathy. The mechanisms of obesity-induced renal injury include, in addition to the traditional alterations in renal hemodynamics, the involvement of various mechanisms such as macrophage infiltration in adipose tissue, alterations in adipokines (leptin and adiponectin), and ectopic deposition of lipids. At present, there is no "point-to-point" treatment for obesity-induced kidney injury. The renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-dependent glucose transporter 2 (SGLT-2) inhibitors and bariatric surgery described in this review can reduce urinary protein to varying degrees and delay the progression of kidney disease. In addition, recent studies on the therapeutic effects of intestinal flora on obesity may reduce the incidence of obesity-related kidney disease from the perspective of primary prevention. Both of these interventions have their own advantages and disadvantages, so the continuous search for the mechanism of obesity-induced related kidney disease will be extremely helpful for the future treatment of obesity-related kidney disease.

The Effect of Aldosterone on Cardiorenal and Metabolic Systems

Aldosterone, a vital hormone of the human body, has various pathophysiological roles. The excess of aldosterone, also known as primary aldosteronism, is the most common secondary cause of hypertension. Primary aldosteronism is associated with an increased risk of cardiovascular disease and kidney dysfunction compared to essential hypertension. Excess aldosterone can lead to harmful metabolic and other pathophysiological alterations, as well as cause inflammatory, oxidative, and fibrotic effects in the heart, kidney, and blood vessels. These alterations can result in coronary artery disease, including ischemia and myocardial infarction, left ventricular hypertrophy, heart failure, arterial fibrillation, intracarotid intima thickening, cerebrovascular disease, and chronic kidney disease. Thus, aldosterone affects several tissues, especially in the cardiovascular system, and the metabolic and pathophysiological alterations are related to severe diseases. Therefore, understanding the effects of aldosterone on the body is important for health maintenance in hypertensive patients. In this review, we focus on currently available evidence regarding the role of aldosterone in alterations of the cardiovascular and renal systems. We also describe the risk of cardiovascular events and renal dysfunction in hyperaldosteronism.

Change in Postprandial Level of Remnant Cholesterol After a Daily Breakfast in Chinese Patients With Hypertension

Background: Hypertension (HBP) is usually accompanied by hypertriglyceridemia that represents the increased triglyceride-rich lipoproteins and cholesterol content in remnant lipoproteins [i.e., remnant cholesterol (RC)]. According to the European Atherosclerosis Society (EAS), high RC (HRC) is defined as fasting RC ≥0.8 mmol/L and/or postprandial RC ≥0.9 mmol/L. However, little is known about postprandial change in RC level after a daily meal in Chinese patients with HBP. Methods: One hundred thirty-five subjects, including 90 hypertensive patients (HBP group) and 45 non-HBP controls (CON group), were recruited in this study. Serum levels of blood lipids, including calculated RC, were explored at 0, 2, and 4 h after a daily breakfast. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff point of postprandial HRC. Results: Fasting TG and RC levels were significantly higher in the HBP group (P < 0.05), both of which increased significantly after a daily meal in the two groups (P < 0.05). Moreover, postprandial RC level was significantly higher in the HBP group (P < 0.05). ROC curve analysis showed that the optimal cutoff point for RC after a daily meal to predict HRC corresponding to fasting RC of 0.8 mmol/L was 0.91 mmol/L, which was very close to that recommended by the EAS, i.e., 0.9 mmol/L. Fasting HRC was found in 31.1% of hypertensive patients but not in the controls. According to the postprandial cutoff point, postprandial HRC was found in approximately half of hypertensive patients and ~1-third of the controls. Conclusion: Postprandial RC level increased significantly after a daily meal, and hypertensive patients had higher percentage of HRC at both fasting and postprandial states. More importantly, the detection of postprandial lipids could be helpful to find HRC.

Molecular determinants of obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized as recurrent episodes of obstruction in the upper airway during the period of sleep. The condition occurs in approximately 11% and 4% of middle-aged men and middle-aged women, respectively. Polysomnography is a diagnostic procedure that involves the constant observation of oxygen saturation and unsaturation during sleep. Usually, positive airway pressure is considered a benchmark treatment for OSA. This review summarizes the recent developments and emerging evidence from molecular biology-based research studies that show that genetic factors have an influence on OSA. The genetic aspects of OSA that have been identified include heritability and other phenotypic co-factors such as anatomical morphology. It also draws attention to the results of a polymorphic-based study that was conducted to determine the causative single nucleotide mutations associated with obesity and adverse cardiovascular risk in OSA. However, the role of such mutations and their linkage to OSA can not yet be established. Nonetheless, a large body of evidence supports a strong association between inflammatory cytokine polymorphism and obesity in the development of OSA. There are also probable intermediate factors with several gene-gene interactions. Therefore, advanced applications and modern techniques should be applied to facilitate new findings and to minimize the risk of developing OSA.

Obesity and hypertension

Obesity and in particular the excessive visceral fat distribution is accompanied by several alterations at hormonal, inflammatory and endothelial level. These alterations induce a stimulation of several other mechanisms that contribute to the hypertensive state and on the other side to increase the cardiovascular morbidity. In these chapter we will examine the main mechanisms of obesity and obesity-related hypertension and in particular the role of sympathetic nervous system, the alterations of the renal function and at the microvascular level. We will also depict the role of insulin resistance as factor stimulating and potentiating the other mechanisms. The second part will be focalized on the major target organ damage linked with obesity and obesity-related hypertension. We will finally describe the management and treatment of obesity and the antihypertensive drug therapies more effective in hypertensive obeses.

Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension

BACKGROUND

Hyperaldosteronism is well known cause of secondary hypertension. However, the importance of aldosterone for the much larger group of patients with primary hypertension is less clear. We hypothesized that in young subjects with primary hypertension, the rise of plasma aldosterone levels in response to head-up tilt testing as a stress stimulus is exaggerated.

METHODS

Hemodynamics (blood pressure (BP), heart rate (HR), cardiac index (CI), and total peripheral vascular resistance index (TPRI), all by TaskForce monitor) and hormones (plasma renin activity (PRA), angiotensin II (Ang II), aldosterone) were measured before and during 30 minutes of head-up tilt in 45 young hypertensive and 45 normotensive subjects.

RESULTS

BP, HR, CI, and TPRI all increased in response to head-up tilt, with no difference between groups. There was no difference in baseline PRA, Ang II, and aldosterone between groups. During head-up tilt, PRA, and Ang II levels increased similarly. However, aldosterone levels increased to a greater extent in the hypertensive vs. normotensive subjects (P = 0.0021).

CONCLUSIONS

Our data suggest that an increased release of aldosterone in response to orthostatic stress is a feature of early primary hypertension. The similar increase in PRA and Ang II suggests a potential role for secretagogues of aldosterone other than Ang II in this response. In addition to its established role in secondary hypertension, dysregulation of aldosterone release might contribute to the development of primary arterial hypertension.

Adipocytes, aldosterone and obesity-related hypertension

Understanding the mechanisms linking obesity with hypertension is important in the current obesity epidemic as it may improve therapeutic interventions. Plasma aldosterone levels are positively correlated with body mass index and weight loss in obese patients is reported to be accompanied by decreased aldosterone levels. This suggests a relationship between adipose tissue and the production/secretion of aldosterone. Aldosterone is synthesized principally by the adrenal glands, but its production may be regulated by many factors, including factors secreted by adipocytes. In addition, studies have reported local synthesis of aldosterone in extra-adrenal tissues, including adipose tissue. Experimental studies have highlighted a role for adipocyte-secreted aldosterone in the pathogenesis of obesity-related cardiovascular complications via the mineralocorticoid receptor. This review focuses on how aldosterone secretion may be influenced by adipose tissue and the importance of these mechanisms in the context of obesity-related hypertension.

The necessity and effectiveness of mineralocorticoid receptor antagonist in the treatment of diabetic nephropathy

Diabetes mellitus is a major cause of chronic kidney disease (CKD), and diabetic nephropathy is the most common primary disease necessitating dialysis treatment in the world including Japan. Major guidelines for treatment of hypertension in Japan, the United States and Europe recommend the use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, which suppress the renin-angiotensin system (RAS), as the antihypertensive drugs of first choice in patients with coexisting diabetes. However, even with the administration of RAS inhibitors, failure to achieve adequate anti-albuminuric, renoprotective effects and a reduction in cardiovascular events has also been reported. Inadequate blockade of aldosterone may be one of the reasons why long-term administration of RAS inhibitors may not be sufficiently effective in patients with diabetic nephropathy. This review focuses on treatment in diabetic nephropathy and discusses the significance of aldosterone blockade. In pre-nephropathy without overt nephropathy, a mineralocorticoid receptor antagonist can be used to enhance the blood pressure-lowering effects of RAS inhibitors, improve insulin resistance and prevent clinical progression of nephropathy. In CKD categories A2 and A3, the addition of a mineralocorticoid receptor antagonist to an RAS inhibitor can help to maintain 'long-term' antiproteinuric and anti-albuminuric effects. However, in category G3a and higher, sufficient attention must be paid to hyperkalemia. Mineralocorticoid receptor antagonists are not currently recommended as standard treatment in diabetic nephropathy. However, many studies have shown promise of better renoprotective effects if mineralocorticoid receptor antagonists are appropriately used.

Association between the body mass index and chronic kidney disease in men and women. A population-based study from Israel

BACKGROUND

Any association between the body mass index (BMI) and chronic kidney disease (CKD) has so far proved inconclusive. Most studies have estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) equation. This has recently been replaced by the more accurate Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

METHODS

In a cross-sectional study, data from a screening centre in Israel, n = 21880 (32% women) were used to assess the prevalence of CKD defined as eGFR < 60 mL/min/1.73 m(2) in relation to BMI categories. The CKD-EPI equation was used to assess the eGFR.

RESULTS

CKD was found in 167 men and 45 women. Subjects with a BMI of 25-29.9 kg/m(2), compared with those with a BMI of <25 kg/m(2), had an odds ratio (OR; 95% confidence intervals) for CKD of 1.8 (1.2-2.7) and 3.4 (1.5-7.7) for men and women, respectively. Subjects with a BMI of 30-35 kg/m(2) had an OR of 2.5 (1.6-4.0) and 4.5 (1.7-11.7) for men and women, respectively. In comparable data, for subjects with a BMI > 35 kg/m(2) the OR was 2.7 (1.3-5.5) and 15.4 (6.4-36.7) for men and women, respectively. After multivariate adjustment for age, hypertension and diabetes mellitus, no association was found in men yet it persisted for women. This correlation in women, between the BMI and CKD, was attributed to the subcategory of severely obese women with a BMI of >35 kg/m(2).

CONCLUSIONS

Our study is the first to suggest that morbid obesity may be an independent factor related to CKD in women.

Metabolic syndrome and polycystic ovary syndrome: an intriguing overlapping

Metabolic syndrome is an increasing pathology in adults and in children, due to a parallel rise of obesity. Sedentary lifestyle, food habits, cultural influences and also a genetic predisposition can cause dyslipidemia, hypertension, abdominal obesity and insulin resistance which are the two main features of metabolic syndrome. Polycystic ovary syndrome (PCOS) is a condition directly associated with obesity, insulin resistance (HOMA index) and metabolic syndrome, and it is very interesting for its relationship and overlap with the metabolic syndrome. The relationship between the two syndromes is mutual: PCOS women have a higher prevalence of metabolic syndrome and also women with metabolic syndrome commonly present the reproductive/endocrine trait of PCOS. Prevention and treatment of metabolic syndrome and PCOS are similar for various aspects. It is necessary to treat excess adiposity and insulin resistance, with the overall goals of preventing cardiovascular disease and type 2 diabetes and improving reproductive failure in young women with PCOS. First of all, lifestyle changes, then pharmacological therapy, bariatric surgery and laparoscopic ovarian surgery represent the pillars for PCOS treatment.

Role of aldosterone blockade in resistant hypertension

Apparent treatment-resistant hypertension (aTRH), defined as uncontrolled blood pressure using 3 or more antihypertensive medications or controlled using 4 or more antihypertensive medications, affects approximately 30% of uncontrolled and 12% of controlled blood pressure (BP) patients. aTRH is used when pseudoresistance cannot be excluded (eg, BP measurement artifacts, mainly office resistance, suboptimal adherence, suboptimal treatment regimens, and true TRH). True TRH comprises approximately 30% to 50% of TRH. Patients with TRH have a high prevalence of obesity, insulin resistance, sleep apnea, and volume expansion. Aldosterone, a mineralocorticoid, is an important contributor to TRH, with primary aldosteronism present in approximately 20% of patients. Spironolactone, a mineralocorticoid-receptor antagonist, as a fourth-line agent, decreases BP 20 to 25/10 to 12 mm Hg in TRH patients with and without primary aldosteronism. The BP response to spironolactone is roughly double that of other classes of antihypertensive medications in TRH. Although approximately 70% of patients with uncontrolled TRH have estimated glomerular filtration rate of 50 or greater and a serum potassium level of 4.5 or less, which are associated with a low risk for hyperkalemia, only a small percentage receive a mineralocorticoid-receptor antagonist. This review examines the clinical epidemiology and pharmacotherapy of controlled and uncontrolled hypertension with an emphasis on aTRH, the role of aldosterone in blood pressure regulation, and the potential benefits of mineralocorticoid-receptor antagonist in uncontrolled TRH.

Increased aldosterone: mechanism of hypertension in obesity

The prevalence of both obesity and hypertension are increasing worldwide. Hypertension is a common consequence of obesity. Increased central adiposity is associated with increased aldosterone levels and blood pressure in human beings. A number of small studies have shown an association between obesity-mediated hypertension and mechanisms directly linked to increased levels of aldosterone. These studies have shown a trend toward relatively greater blood pressure reduction using aldosterone-receptor blockers compared with other classes of antihypertensive agents. Other than treatment for weight loss, treatment of hypertension with specific antihypertensive medications that block or reduce aldosterone action are appropriate in obese patients. Further research is needed to understand the exact role of the adipocyte in obesity-mediated hypertension.

Management of pediatric obesity: a lifestyle modification approach

Over the last decades, pediatric obesity has become a global epidemic with worldwide estimates as high as 43 million children and adolescents affected, and this number is rising at an exponential rate. With pediatric obesity comes a host of co-morbidities including impaired glucose tolerance, dyslipidemia, hypertension, and impaired liver function. Treatment of this population has proven to be challenging for many reasons. For patients, a new baseline exists consisting of an increasingly sedentary lifestyle as well as a lack of availability of affordable healthy alternatives. In addition, there is an overwhelming presence of energy-dense foods. For physicians, there are many issues including lack of time, training, and reimbursement. The most efficacious and reliable way to treat this population and its co-morbidities is with a healthy, balanced lifestyle consisting of a realistic diet plan and exercise regimen. The is the cornerstone of therapy in the Center for Obesity And its Complications in Health (COACH) clinic which is Children's Medical Center's (Dallas, TX) strategy to combat and treat pediatric overweight and obesity. Lifestyle changes of diet and exercise plans are tailored to each individual's interests and metabolic needs in COACH which is a multi-disciplinary clinic. Additionally, co-morbidities are screened for and treated aggressively to help prevent long-term complications of overweight and obesity. If others do similar interventions in their communities, this global epidemic has the possibility of more positive outcomes than those currently projected.

Adiposity and insulin resistance in humans: the role of the different tissue and cellular lipid depots

Human adiposity has long been associated with insulin resistance and increased cardiovascular risk, and abdominal adiposity is considered particularly adverse. Intra-abdominal fat is associated with insulin resistance, possibly mediated by greater lipolytic activity, lower adiponectin levels, resistance to leptin, and increased inflammatory cytokines, although the latter contribution is less clear. Liver lipid is also closely associated with, and likely to be an important contributor to, insulin resistance, but it may also be in part the consequence of the lipogenic pathway of insulin action being up-regulated by hyperinsulinemia and unimpaired signaling. Again, intramyocellular triglyceride is associated with muscle insulin resistance, but anomalies include higher intramyocellular triglyceride in insulin-sensitive athletes and women (vs men). Such issues could be explained if the "culprits" were active lipid moieties such as diacylglycerol and ceramide species, dependent more on lipid metabolism and partitioning than triglyceride amount. Subcutaneous fat, especially gluteofemoral, appears metabolically protective, illustrated by insulin resistance and dyslipidemia in patients with lipodystrophy. However, some studies suggest that deep sc abdominal fat may have adverse properties. Pericardial and perivascular fat relate to atheromatous disease, but not clearly to insulin resistance. There has been recent interest in recognizable brown adipose tissue in adult humans and its possible augmentation by a hormone, irisin, from exercising muscle. Brown adipose tissue is metabolically active, oxidizes fatty acids, and generates heat but, because of its small and variable quantities, its metabolic importance in humans under usual living conditions is still unclear. Further understanding of specific roles of different lipid depots may help new approaches to control obesity and its metabolic sequelae.

Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice

BACKGROUND

Obesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice.

METHODS AND RESULTS

Eight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all p<0.001). Inflammation measured by mRNA expressions of IL-6, MMP-9, PAI-1 and leptin and protein expression of NF-κB was higher, whereas anti-inflammation measured by mRNA expressions of adiponectin and INF-γ was lower in obesity than in control and OR (all p<0.003). Oxidative protein expressions of NOX-1, NOX-2 and oxidized protein were higher, whereas expression of anti-oxidant markers HO-1 and NQO-1 were lower (all p<0.01); and apoptosis measured by Bax and caspase 3 was higher, whereas anti-apoptotic Bcl-2 was lower in obesity as compared with control and OR (all p<0.001). The expressions of fibrotic markers phosphorylated Smad3 and TGF-β were higher, whereas expression of anti-fibrotic phosphorylated Smad1/5 and BMP-2 were lower (all p<0.02); and LVEF was lower, whereas the LV remodeling was higher in obesity than in control and OR (all p<0.001).

CONCLUSION

Impaired LVEF, enhanced LV remodeling, inflammation, fibrosis, oxidative stress and apoptosis were reversed by reduction in mouse obesity.

[Renal consequences of obesity]

The steady increase in the prevalence of obesity contributes to the increase in the prevalence of chronic kidney disease, through renal damages associated with type-2 diabetes and hypertension. Obesity is also an independent risk factor for the kidney, since it is associated with an increased risk of albuminuria and glomerulosclerosis, and worsens the course of chronic kidney disease regardless of the primary renal disease. The existence of a metabolic syndrome, constant in type-2 diabetes, and associated with abdominal obesity, is not the only requirement for renal anomalies of which the translation is a functional hyperfiltration, a clinical microalbuminuria and histologically a glomerulomegaly and glomerulosclerosis. The estimated glomerular filtration rate (GFR) in obese patients is strongly influenced by the weight or indexation to body surface area, and it is logical to take into account the value of non-indexed GFR to assess renal risk and treatment effects, especially if they lead to weight loss. Hypertension is promoted by salt sensitivity, potentially reversible, and overactivity of the renin-angiotensin system (RAS) in part due to adipose tissue. The cytokines secreted by adipose tissue (adipokines), induce sympathetic hyperactivity through leptin, and low-grade inflammatory state that contributes to the development of glomerular sclerosis lesions, especially because a resistance to adiponectin. The treatment relies on weight loss, possibly through bariatric surgery, and antagonists of the RAS.

Obesity-related hypertension: epidemiology, pathophysiology, and clinical management

The prevalence of obesity, including childhood obesity, is increasing worldwide. Weight gain is associated with increases in arterial pressure, and it has been estimated that 60-70% of hypertension in adults is attributable to adiposity. Centrally located body fat, associated with insulin resistance and dyslipidemia, is a more potent determinant of blood pressure elevation than peripheral body fat. Obesity-related hypertension may be a distinct hypertensive phenotype with distinct genetic determinants. Mechanisms of obesity-related hypertension include insulin resistance, sodium retention, increased sympathetic nervous system activity, activation of renin-angiotensin-aldosterone, and altered vascular function. In overweight individuals, weight loss results in a reduction of blood pressure, however, this effect may be attenuated in the long term. An increasing number of community-based programs (including school programs and worksite programs) are being developed for the prevention and treatment of obesity. Assessment and treatment of the obese hypertensive patient should address overall cardiovascular disease (CVD) risk. There are no compelling clinical trial data to indicate that any one class of antihypertensive agents is superior to others, and in general the principles of pharmacotherapy for obese hypertensive patients are not different from nonobese patients. Future research directions might include: (i) development of effective, culturally sensitive strategies for the prevention and treatment of obesity; (ii) clinical trials to identify the most effective drug therapies for reducing CVD in obese, hypertensive patients; (iii) continued search for the genetic determinants of the obese, hypertensive phenotype.

Primary aldosteronism with right-dominant heart failure

A 48 year-old obese male with hypertension was admitted to our department because of severe right-dominant heart failure. His heart rhythm was 2:1 atrial flutter and the left ventricle was diffusely hypertrophic and hypokinetic. Primary aldosteronism was diagnosed based on severe hypokalemia (2.6 mEq/L) and a low renin-high aldosterone state with hypertension despite the use of an angiotensin-II receptor blocker, but its etiology could not be clarified with computed tomography, adrenal scintigraphy, and adrenal vein sampling. Ascites and edema rapidly worsened. Ascites aspiration was performed daily, until serum potassium was normalized by a full dose of an aldosterone receptor blocker (spironolactone 100 mg/day). A diuretic (furosemide) was then added. Rate control of atrial flutter was obtained with a beta-adrenergic blocker, and anticoagulation therapy was started. His heart failure was successfully controlled. Coronary arteries were normal on coronary arteriograms, and an endomyocardial biopsy sample obtained from the left ventricle did not show any specific pathological findings. Blood pressure was well controlled with the full dose of the aldosterone receptor blocker, but he died one year later due to intracerebral hemorrhage. As his heart failure was right dominant, we believe that its etiology may have been hyperaldosteronism-induced cardiomyopathy, and not advanced hypertensive heart disease.

Progression of normotensive adolescents to hypertensive adults: a study of 26,980 teenagers

Although prehypertension at adolescence is accepted to indicate increased future risk of hypertension, large-scale/long follow-up studies are required to better understand how adolescent blood pressure (BP) tracks into young adulthood. We studied 23 191 male and 3789 female adolescents from the Metabolic Lifestyle and Nutrition Assessment in Young Adults cohort (mean age: 17.4 years) with BP <140/90 mm Hg at enrollment or categorized by current criteria for pediatric BP and body mass index (BMI) values. Participants were prospectively followed up with repeated BP measurements between ages 25 and 42 years and retrospectively between ages 17 and 25 years for the incidence of hypertension. We identified 3810 new cases of hypertension between ages 17 and 42 years. In survival analyses, the cumulative risk of hypertension between ages 17 and 42 years was 3 to 4 times higher in men than in women. Using Cox regression models adjusted for age, BMI, and stratified by baseline BP, the hazard ratio of hypertension increased gradually across BP groups within the normotensive range at age 17 years, without a discernible threshold effect, reaching a hazard ratio of 2.50 (95% CI: 1.75 to 3.57) for boys and 2.31 (95% CI: 0.71 to 7.60) for girls in the group with BP at 130 to 139/85 to 89 mm Hg. BMI at age 17 years was strongly associated with future risk of hypertension even when adjusted to BP at age 17 years, particularly in boys. Yet, BMI at age 30 years attenuated this association, more evidently in girls. In conclusion, BP at adolescence, even in the low-normotensive range, linearly predicts progression to hypertension in young adulthood. This progression and the apparent interaction between BP at age 17 years and BMI at adolescence and at adulthood are sex dependent.

Obesity and chronic kidney disease

This article summarizes the current hypotheses that link visceral obesity and kidney malfunction and provides information on the epidemiology and renal pathology resulting from visceral obesity.

Interaction of aldosterone and extracellular volume in the pathogenesis of obesity-associated kidney disease: a narrative review

Obesity and obesity-associated kidney injuries have played an important role in the rising prevalence of chronic kidney disease (CKD). The link between obesity and kidney disease begins with obesity's well-known associations with diabetes and hypertension, the two leading etiologies of CKD. However, a growing body of evidence suggests that elevated aldosterone levels and expanded extracellular volume are key components of obesity-induced renal disease via aldosterone's non-epithelial effects on the kidney. Highlighting these blood pressure- and diabetes-independent mechanisms of kidney injury in obesity allows an exploration of whether mineralocorticoid receptor blockade, coupled with weight loss and salt restriction, is an optimal treatment for overweight CKD patients.

The metabolic syndrome

The "metabolic syndrome" (MetS) is a clustering of components that reflect overnutrition, sedentary lifestyles, and resultant excess adiposity. The MetS includes the clustering of abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure and is associated with other comorbidities including the prothrombotic state, proinflammatory state, nonalcoholic fatty liver disease, and reproductive disorders. Because the MetS is a cluster of different conditions, and not a single disease, the development of multiple concurrent definitions has resulted. The prevalence of the MetS is increasing to epidemic proportions not only in the United States and the remainder of the urbanized world but also in developing nations. Most studies show that the MetS is associated with an approximate doubling of cardiovascular disease risk and a 5-fold increased risk for incident type 2 diabetes mellitus. Although it is unclear whether there is a unifying pathophysiological mechanism resulting in the MetS, abdominal adiposity and insulin resistance appear to be central to the MetS and its individual components. Lifestyle modification and weight loss should, therefore, be at the core of treating or preventing the MetS and its components. In addition, there is a general consensus that other cardiac risk factors should be aggressively managed in individuals with the MetS. Finally, in 2008 the MetS is an evolving concept that continues to be data driven and evidence based with revisions forthcoming.

Asthma, environmental risk factors, and hypertension among Arab Americans in metro Detroit

Asthma and obesity-related health problems disproportionately impact low-income ethnic minority communities residing in urban areas. Environmental risk factors, particularly those related to housing and indoor air, may impact the development or exacerbation of asthma. There is increasing evidence to suggest a link between obesity-related health problems and asthma. Previous studies have also reported that immigrant status may influence myriad risk factors and health outcomes among immigrant populations. The Arab American Environmental Health Project (AAEHP) was the first study to explore environmental health problems among Arab Americans. This paper examined whether hypertensive status modified the relationship between environmental risk factors and asthma among Arab Americans in metro Detroit. An environmental risk index (ERI) was used to quantify household environmental risk factors associated with asthma. Physician diagnosed hypertension was self-reported, and asthma status was determined using responses to a validated symptoms checklist and self-reported diagnosis by a physician. Hypertension significantly modified the relationship between ERI and asthma in this study population. The positive association between household environmental risk factors and asthma was stronger among participants diagnosed with hypertension. Effect modification of the relationship between environmental risk factors and asthma could have serious implications among high-risk communities. However, further research is needed to elucidate the relationships between hypertension, environmental risk factors, and asthma.