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1.
Int J Consum Stud ; 47(1): 59-73, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36718291

RESUMO

Many individuals have been reluctant to follow the COVID-19 prevention guidelines (e.g., wearing a mask, physical distancing, and vigilant handwashing) set forth by the U.S. Center for Disease Control to reduce the spread of COVID-19. In this research, we use reciprocal altruism theory to investigate the role of loneliness and its impact on compliance with these guidelines. Our findings indicate that lonely individuals are less willing to comply with COVID-19 prevention guidelines than non-lonely individuals. Process evidence suggests that this occurs as loneliness can inhibit an individual's sense of obligation to reciprocate to others. However, we demonstrate that framing information about COVID-19 through agentic (vs. communal) advertising messaging strategies can offset the negative impact of loneliness on compliance with COVID-19 prevention guidelines. Thus, marketers and policymakers may want to consider the important role of loneliness when tailoring messaging appeals that encourage compliance with COVID-19 prevention guidelines.

2.
J Bus Ethics ; : 1-20, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36187727

RESUMO

Sustainable products are engineered to reduce environmental, ecological, and human costs of consumption. Not all consumers value sustainable products, however, and this poses negative societal implications. Using self-expansion theory as a guide, we explore how an individual's general sense of belonging-or the perception that one is accepted and valued by others in the broader social world-alters their responses to sustainable products. Five experimental studies and a field study demonstrate that individuals lower in belonging respond less favorably to sustainable products in terms of evaluations and willingness to pay than individuals higher in belonging. Process evidence shows that the extent to which individuals low in belonging perceive that collective, sustainable choices will impact them personally drives this result and that belonging does not impact responses to conventional (i.e., non-sustainable) products. However, perceiving a shared human experience-or that individuals share some important, basic similarities with all people-attenuates the negative effect of low belonging on responses to sustainable products for consumers both low and high in belonging. This research has significant implications for businesses and society given the growing sense of disconnect in modern society. Supplementary Information: The online version contains supplementary material available at 10.1007/s10551-022-05257-0.

3.
Curr Heart Fail Rep ; 10(1): 36-45, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23114591

RESUMO

The symptoms and signs constituting the congestive heart failure (CHF) syndrome have their pathophysiologic origins rooted in a salt-avid renal state mediated by effector hormones of the renin-angiotensin-aldosterone and adrenergic nervous systems. Controlled clinical trials, conducted over the past decade in patients having minimally to markedly severe symptomatic heart failure, have demonstrated the efficacy of a pharmacologic regimen that interferes with these hormones, including aldosterone receptor binding with either spironolactone or eplerenone. Potential pathophysiologic mechanisms, which have not hitherto been considered involved for the salutary responses and cardioprotection provided by these mineralocorticoid receptor antagonists, are reviewed herein. In particular, we focus on the less well-recognized impact of catecholamines and aldosterone on monovalent and divalent cation dyshomeostasis, which leads to hypokalemia, hypomagnesemia, ionized hypocalcemia with secondary hyperparathyroidism and hypozincemia. Attendant adverse cardiac consequences include a delay in myocardial repolarization with increased propensity for supraventricular and ventricular arrhythmias, and compromised antioxidant defenses with increased susceptibility to nonischemic cardiomyocyte necrosis.


Assuntos
Cardiotônicos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Antioxidantes/fisiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Neurotransmissores/fisiologia , Estresse Oxidativo/fisiologia , Zinco/fisiologia
4.
Am J Med Sci ; 342(2): 129-34, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21747281

RESUMO

The progressive nature of heart failure is linked to multiple factors, including an ongoing loss of cardiomyocytes and necrosis. Necrotic cardiomyocytes leave behind several footprints: the spillage of their contents leading to elevations in serum troponins; and morphologic evidence of tissue repair with scarring. The pathophysiologic origins of cardiomyocyte necrosis relates to neurohormonal activation, including the adrenergic nervous system. Catecholamine-initiated excessive intracellular Ca accumulation and mitochondria Ca overloading in particular initiate a mitochondriocentric signal-transducer-effector pathway to necrosis and which includes the induction of oxidative stress and opening of their inner membrane permeability transition pore. Hypokalemia, ionized hypocalcemia and hypomagnesemia, where consequent elevations in parathyroid hormone further account for excessive intracellular Ca accumulation, hypozincemia and hyposelenemia each compromise metalloenzyme-based antioxidant defenses. The necrotic loss of cardiomyocytes and adverse structural remodeling of myocardium is related to the central role played by a mitochondriocentric pathway initiated by neurohormonal activation.


Assuntos
Miócitos Cardíacos/metabolismo , Estresse Oxidativo/fisiologia , Troponina/sangue , Animais , Fibrose , Humanos , Hiperparatireoidismo Secundário/metabolismo , Hiperparatireoidismo Secundário/fisiopatologia , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Necrose , Troponina/metabolismo , Troponina/fisiologia
5.
Hypertens Res ; 33(11): 1091-101, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20827279

RESUMO

Inappropriately (relative to dietary Na(+)) elevated plasma aldosterone concentrations (PAC), or aldosteronism, have been incriminated in both the appearance of the cardiometabolic syndrome (CMS) and its progressive nature. The deleterious dual consequences of elevated PAC and dietary Na(+) have been linked to several components of the CMS, including salt-sensitive hypertension. Moreover, their adverse consequences are considered to be synergistic, culminating in a pro-oxidant phenotype with oxidative injury involving the heart and systemic tissues, including peripheral blood mononuclear cells (PBMC). Our experimental studies in rats receiving aldosterone/salt treatment have identified a common pathogenic event that links aldosteronism to the induction of oxidative stress. Herein, we review these findings and the important role of excessive intracellular Ca(2+) accumulation (EICA), or intracellular Ca(2+) overloading, which occurs in the heart and PBMC, leading to, respectively, cardiomyocyte necrosis with a replacement fibrosis and an immunostimulatory state with consequent coronary vasculopathy. The origin of EICA is based on elevations in plasma parathyroid hormone, which are integral to the genesis of secondary hyperparathyroidism that accompanies aldosteronism and occurs in response to plasma-ionized hypocalcemia and hypomagnesemia whose appearance is the consequence of marked urinary and fecal excretory losses of Ca(2+) and Mg(2+). In addition, we found intracellular Ca(2+) overloading to be intrinsically coupled to a dyshomeostasis of intracellular Zn(2+), which together regulate the redox state of cardiac myocytes and mitochondria via the induction of oxidative stress and generation of antioxidant defenses, respectively. To validate our hypothesis, a series of site-directed, sequential pharmacological and/or nutriceutical interventions targeted along cellular-molecular cascades were carried out to either block downstream events leading to the pro-oxidant phenotype or to enhance antioxidant defenses. In each case, the interventions were found to be cardioprotective. These cumulative salutary responses raise the prospect that pharmacological agents and nutriceuticals capable of influencing extra- and intracellular Ca(2+) and Zn(2+) equilibrium could prevent adverse cardiac remodeling and thereby enhance the management of aldosteronism.


Assuntos
Aldosterona/metabolismo , Cálcio/metabolismo , Hiperaldosteronismo/metabolismo , Estresse Oxidativo , Animais , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Modelos Animais de Doenças , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Necrose , Ratos , Sódio/metabolismo , Vasculite/metabolismo , Vasculite/patologia , Zinco/metabolismo
6.
Am J Med Sci ; 339(1): 31-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20057275

RESUMO

BACKGROUND: In patients hospitalized with decompensated biventricular failure having hypoalbuminemia and lymphocytopenia without underlying hepatic or renal disease, we addressed the presence of a protein-losing enteropathy (PLE). METHODS: We studied 78 patients having a dilated cardiomyopathy, who were hospitalized with congestive heart failure (CHF) and hypoalbuminemia of uncertain origin. In the first 19 patients, we investigated the presence of PLE using Tc-Dex scintigraphy together with serum albumin 2 to 4 weeks later when compensation had been restored. In the next 59 patients, presenting with reduced serum albumin and relative lymphocyte count at admission, these parameters were again monitored (2-4 weeks) later when symptoms and signs of CHF had resolved. RESULTS: PLE, documented by Tc-Dex(70) scintigraphy, was found in 10 of 19 patients and whose hypoalbuminemia (2.7 +/- 0.1 g/dL, mean +/- standard error of mean) were corrected (3.3 +/- 0.1 g/dL; P < 0.05) with the resolution of CHF, whereas in the 9 patients without a PLE, reduced baseline serum albumin (2.6 +/- 0.1 g/dL) failed to improve on follow-up (2.6 +/- 0.2 g/dL) in keeping with malnutrition. Relative lymphocyte count was reduced (14.6 +/- 1.5%) in patients with PLE but was normal (21.4 +/- 3.3%; P < 0.05) in those without PLE. Serum albumin and relative lymphocyte count were each reduced at admission (2.8 +/- 0.1 g/dL and 14.4 +/- 1.0%, respectively) in 59 patients and increased (P < 0.05) to normal values (3.5 +/- 0.1 g/dL and 24.9 +/- 1.0%) 2 to 4 weeks after they were compensated. CONCLUSIONS: Enteral losses of albumin and lymphocytes account for the reversible hypoalbuminemia and lymphocytopenia found in patients hospitalized with CHF having splanchnic congestion.


Assuntos
Insuficiência Cardíaca/diagnóstico por imagem , Hipoalbuminemia/diagnóstico por imagem , Linfopenia/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/diagnóstico por imagem , Feminino , Seguimentos , Insuficiência Cardíaca/complicações , Humanos , Hipoalbuminemia/complicações , Linfopenia/complicações , Masculino , Pessoa de Meia-Idade , Enteropatias Perdedoras de Proteínas/complicações , Enteropatias Perdedoras de Proteínas/diagnóstico por imagem , Cintilografia
7.
J Am Coll Nutr ; 29(6): 563-74, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21677120

RESUMO

Neurohormonal activation involving the hypothalamic-pituitary-adrenal axis and adrenergic nervous and renin-angiotensin-aldosterone systems is integral to stressor state-mediated homeostatic responses. The levels of effector hormones, depending upon the degree of stress, orchestrate the concordant appearance of hypokalemia, ionized hypocalcemia and hypomagnesemia, hypozincemia, and hyposelenemia. Seemingly contradictory to homeostatic responses wherein the constancy of extracellular fluid would be preserved, upregulation of cognate-binding proteins promotes coordinated translocation of cations to injured tissues, where they participate in wound healing. Associated catecholamine-mediated intracellular cation shifts regulate the equilibrium between pro-oxidants and antioxidant defenses, a critical determinant of cell survival. These acute and chronic stressor-induced iterations in extracellular and intracellular cations are collectively referred to as the cation crossroads. Intracellular cation shifts, particularly excessive accumulation of Ca2+, converge on mitochondria to induce oxidative stress and raise the opening potential of their inner membrane permeability transition pores (mPTPs). The ensuing loss of cationic homeostasis and adenosine triphosphate (ATP) production, together with osmotic swelling, leads to organellar degeneration and cellular necrosis. The overall impact of iterations in extracellular and intracellular cations and their influence on cardiac redox state, cardiomyocyte survival, and myocardial structure and function are addressed herein.


Assuntos
Cátions/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Adenosina Trifosfatases/metabolismo , Antioxidantes/metabolismo , Catecolaminas/metabolismo , Homeostase , Humanos , Hipocalcemia/sangue , Hipocalcemia/metabolismo , Hipopotassemia/sangue , Hipopotassemia/metabolismo , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Deficiência de Magnésio/sangue , Mitocôndrias/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Necrose/metabolismo , Neurotransmissores/metabolismo , Estresse Oxidativo , Hormônio Paratireóideo/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sistema Renina-Angiotensina/fisiologia , Selênio/sangue , Selênio/deficiência , Estresse Fisiológico , Regulação para Cima , Zinco/sangue , Zinco/deficiência
8.
Am J Med Sci ; 338(4): 255-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19707112

RESUMO

BACKGROUND: In nondiabetic patients hospitalized with multiorgan failure, neurohormonal activation can lead to stress-induced hyperglycemia (>140 mg/dL), as could Mg(2+) and Zn(2+) deficiencies. However, it is currently uncertain whether nondiabetic African Americans (AA) hospitalized with either chronic, decompensated biventricular failure (DecompHF) having hepatic and splanchnic congestion, ionized hypomagnesemia and hypozincemia, or acute left heart failure (LHF) would exhibit hyperglycemia at admission. METHODS: We retrospectively examined admission serum glucose in 77 AA patients without a history of diabetes, who were hospitalized with heart failure. This examination included 41 patients admitted during a 4-month period with chronic DecompHF and whose clinical presentation included findings of expanded intra- and extravascular volumes, together with echocardiographic evidence of marked tricuspid regurgitation and distended inferior vena cava, without respiratory variation. These patients were compared with 14 nondiabetic patients hospitalized during the same time period with acute LHF. We also studied admission serum glucose in 22 patients who were admitted with DecompHF having documented hypomagnesemia and hypozincemia. RESULTS: Admission serum glucose (mean +/- standard error of mean) in patients with chronic DecompHF was 105.41 +/- 4.08 mg/dL and was modestly elevated (140-160 mg/dL) in 3 patients. In those with acute LHF, glucose was 94.86 +/- 3.96 mg/dL and did not exceed 140 mg/dL in any patient. Glucose (103.2 +/- 4.3 mg/dL) was not elevated in patients having chronic DecompHF and reduced ionized Mg(2+) and serum Zn(2+) (0.44 +/- 0.01 mmol/L and 69.6 +/- 3.2 mug/dL, respectively). CONCLUSIONS: Hyperglycemia at admission was infrequent in nondiabetic AA patients hospitalized with either acute LHF or chronic DecompHF, which may have also included hypomagnesemia and hypozincemia. This calls into question the need for intensive insulin therapy in these patients.


Assuntos
Negro ou Afro-Americano , Glicemia/análise , Insuficiência Cardíaca/sangue , Diabetes Mellitus , Feminino , Insuficiência Cardíaca/etnologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
Am J Med Sci ; 335(4): 292-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18414068

RESUMO

BACKGROUND: Factors contributing to heart failure (HF) in African Americans (AA) are under investigation. Reduced 25(OH)D confers increased cardiovascular risk, including HF. METHODS: We monitored serum 25(OH)D, 1,25(OH)2D3, parathyroid hormone (PTH), and creatinine clearance in 102 AA residing in Memphis: 58 hospitalized with decompensated HF of >or=4 weeks in 34 (21 men; 53.3 +/- 1.8 years) or of 1 to 2 weeks in 24 (17 men; 49.6 +/- 2.4 years) and associated with a dilated cardiomyopathy and reduced ejection fraction (<35%); 19 outpatients with compensated HF (14 men; 52.6 +/- 2.7 years) with comparable ejection fraction; 16 outpatients (9 men; 55.4 +/- 2.9 years) with heart disease, but without HF; and 9 healthy volunteers (3 men; 35.8 +/- 3.5 years). RESULTS: Serum 25(OH)D 65 pg/mL was found in all AA with decompensated HF of >or=4 weeks (132.4 +/- 12.0 pg/mL) and 67% with 1 to 2 weeks duration (82.3 +/- 7.9 pg/mL), but only 11% with compensated HF (45.8 +/- 6.1 pg/mL), 12% without HF (29.6 +/- 5.4 pg/mL), and none of the volunteers (31.1 +/- 3.9 pg/mL). Creatinine clearance did not differ between patient groups. CONCLUSIONS: Hypovitaminosis D is prevalent amongst AA residing in Memphis, with or without HF. Elevations in serum PTH in keeping with secondary hyperparathyroidism are only found in AA with decompensated HF, where hypovitaminosis D and other factors are contributory.


Assuntos
Negro ou Afro-Americano , Insuficiência Cardíaca/etiologia , Deficiência de Vitamina D/etnologia , Adulto , Idoso , Calcitriol/sangue , Creatinina/metabolismo , Feminino , Insuficiência Cardíaca/etnologia , Insuficiência Cardíaca/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Vitamina D/análogos & derivados , Vitamina D/sangue
10.
Vasc Health Risk Manag ; 3(5): 743-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18078025

RESUMO

Not all patients with heart failure, defined as a reduced ejection fraction, will have an activation of the RAAS, salt and water retention, or the congestive heart failure (CHF) syndrome. Beyond this cardiorenal perspective, CHF is accompanied by a systemic illness that includes oxidative stress, a proinflammatory phenotype, and a wasting of soft tissues and bone. A dyshomeostasis of calcium, magnesium, zinc, selenium, and vitamin D contribute to the appearance of oxidative stress and to compromised endogenous defenses that combat it. A propensity for hypovitaminosis D, given that melanin is a natural sunscreen, and for secondary hyperparathyroidism in African-Americans make them more susceptible to these systemic manifestations of CHF-a situation which is further threatened by the calcium and magnesium wasting that accompanies the secondary aldosteronism of CHF and the use of loop diuretics.


Assuntos
Negro ou Afro-Americano , Insuficiência Cardíaca/etnologia , Insuficiência Cardíaca/metabolismo , Estado Nutricional/etnologia , Negro ou Afro-Americano/etnologia , Aldosterona/metabolismo , Humanos , Estresse Oxidativo
11.
Cardiovasc Hematol Agents Med Chem ; 5(4): 295-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17979692

RESUMO

The clinical syndrome congestive heart failure (CHF) has its origins rooted in a salt-avid state mediated largely by effector hormones of the renin-angiotensin-aldosterone system (RAAS). In addition, a systemic illness accompanies chronic RAAS activation. Its features include: the presence of oxidative stress in diverse tissues coupled with a reduction in activity of endogenous oxidoreductases, such as Cu/Zn-superoxide dismutase and Se-glutathione peroxidase; a proinflammatory phenotype with activated immune cells and increased circulating levels of proinflammatory cytokines; and a catabolic state with loss of soft tissues and bone that eventuates in a wasting syndrome termed cardiac cachexia. Pathogenic mechanisms and pathophysiologic expressions of this illness are under active investigation. In this context and less well appreciated is the importance of a dyshomeostasis of various minerals, including Ca2+, Mg2+, Zn, and Se, and their impact on the systemic and progressive nature of CHF. A convergence of multiple factors, some hormonal (e.g., aldosteronism, secondary hyperparathyroidism, hypovitaminosis D), others pharmacologic (e.g., loop diuretics, angiotensin-converting enzyme inhibitors), predispose to the heightened excretion of these minerals in urine and feces while parathyroid hormone promotes intracellular Ca2+ overloading in diverse tissues. The importance of these macro- and micronutrients to the appearance of oxidative stress, compromised antioxidant defenses, an immunostimulatory state and tissue wasting needs to be critically addressed. So, too, must the potential for nutriceuticals, complementary to today's pharmaceuticals, to assist in the overall management of CHF.


Assuntos
Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Hiperaldosteronismo/fisiopatologia , Aldosterona/fisiologia , Cálcio/metabolismo , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Magnésio/metabolismo , Hormônio Paratireóideo/metabolismo , Sistema Renina-Angiotensina , Selênio/metabolismo , Vitamina D/metabolismo , Zinco/metabolismo
12.
Am J Med Sci ; 334(2): 145-8, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17700209

RESUMO

Exercise-related syncope is frequently an ominous symptom associated with advanced cardiovascular disease. Asystole during or after exercise is a rare occurrence in persons with structural heart disease and is an even rarer cause of syncope in healthy persons. Herein we report on a healthy 40-year-old man who was hospitalized after a syncopal episode that followed playing basketball. He recalled several near-syncopal episodes after strenuous exercise over the past 6 months, during which time he used marijuana. A loss of sinoatrial activity and appearance of ventricular asystole occurred immediately after monitored exercise to suggest parasympathetic dominance, which could be related to long-term cannabinoid use.


Assuntos
Exercício Físico/fisiologia , Parada Cardíaca/etiologia , Fumar Maconha/efeitos adversos , Síncope Vasovagal/etiologia , Adulto , Humanos , Masculino
13.
Am J Med Sci ; 333(6): 390-3, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17570995

RESUMO

A subset of patients with mitral valve disease has a marked rise in pulmonary vascular resistance (PVR) that is disproportionate to elevations in pulmonary venous pressure. Termed a "hyperactive" pulmonary vasculature, the elevation in PVR falls promptly and dramatically in response to mitral valve replacement. We report a 55-year-old man with progressive, exertional dyspnea of several months' duration who had signs of congestive heart failure (CHF) with moderate mitral valvular regurgitation and aortic stenosis by echocardiographic interrogation. These lesions in combination, together with his CHF and disproportionate elevation in pulmonary artery systolic pressure (90 mm Hg) and PVR (527 dyne x s x cm(-5)), raised the prospect of valvular replacement. There followed a normalization of PVR and marked improvement in his symptoms and signs of CHF in response to pharmacologic management with an ACE inhibitor, loop diuretic, and aldosterone receptor antagonist to negate any further consideration of surgery.


Assuntos
Pressão Sanguínea/fisiologia , Insuficiência da Valva Mitral/complicações , Artéria Pulmonar/metabolismo , Resistência Vascular/fisiologia , Dispneia/etiologia , Próteses Valvulares Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/cirurgia
14.
Clin Med Res ; 5(4): 238-43, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18367709

RESUMO

Congestive heart failure (CHF) is a clinical syndrome that features a failing heart together with signs and symptoms arising from renal retention of salt and water, mediated by attendant neurohormonal activation, and which prominently includes the renin-angiotensin-aldosterone system. More than this cardiorenal perspective, CHF is accompanied by a systemic illness whose features include an altered redox state in diverse tissues and blood, an immunostimulatory state with proinflammatory cytokines and activated lymphocytes and monocytes, and a wasting of tissues that includes muscle and bone. Based on experimental studies of aldosteronism and clinical findings in patients with CHF, there is an emerging body of evidence that secondary hyperparathyroidism is a covariant of CHF. The aldosteronism of CHF predisposes patients to secondary hyperparathyroidism because of a chronic increase in Ca(2+) and Mg(2+) losses in urine and feces, with a fall in their serum ionized levels and consequent secretion of parathyroid hormone. Secondary hyperparathyroidism accounts for bone resorption and contributes to a fall in bone strength that can lead to nontraumatic fractures. The long-term use of a loop diuretic with its attendant urinary wasting of Ca(2+) and Mg(2+) further predisposes patients to secondary hyperparathyroidism and attendant bone loss. Aberrations in minerals and micronutrient homeostasis that includes Ca(2+), Mg(2+), vitamin D, zinc and selenium appear to be an integral component of pathophysiologic expressions of CHF that contributes to its systemic and progressive nature. This broader perspective of CHF, which focuses on the importance of secondary hyperparathyroidism and minerals and micronutrients, raises the prospect that dietary supplements could prove remedial in combination with the current standard of care.


Assuntos
Insuficiência Cardíaca/sangue , Micronutrientes/sangue , Minerais/sangue , Humanos , Oxirredução , Sistema Renina-Angiotensina/fisiologia
15.
Transl Res ; 148(6): 301-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17162251

RESUMO

Heart failure is thought to be more common and of greater severity in African-Americans (AAs). Potential mechanisms remain uncertain. The importance of micronutrient deficiencies in the pathophysiologic expression of congestive heart failure (CHF) in AAs remains to be explored, including hypovitaminosis D, which can promote secondary hyperparathyroidism (SHPT), together with hypozincemia and hyposelenemia, the 2 most crucial trace minerals integral to diverse biologic functions. Serum parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), Zn, and Se were monitored in 30 AAs hospitalized during June through December 2005, with decompensated failure and reduced ejection fraction (EF) (<35%) of predominantly nonischemic origin treated with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB), furosemide, and spironolactone. Based on their symptomatic status before hospitalization, 15 patients were stratified as having protracted (>or=4 weeks) CHF, whereas 15 patients had short-term (1-2 weeks) CHF. These hospitalized patients were compared with 10 AA outpatients with stable, similarly treated compensated failure and comparable EF, and 9 AA normal volunteers without cardiovascular disease. Serum PTH was elevated in all patients with protracted CHF and in 60% of patients with short-term CHF, but not in compensated patients or normal volunteers. However, serum 25(OH)D was reduced in all patients with >or=4 weeks and 80% with either 1-2 weeks CHF or compensated failure compared with volunteers. Serum Zn was below normal in 11 of 15 patients with protracted CHF, in 8 of 15 patients with shorter duration CHF, and in 5 of 10 patients with compensated failure. Serum Se was reduced in all patients with >or=4 weeks, 60% with short-term CHF, and 90% of compensated patients. Concomitant to hypovitaminosis D, hypozincemia, and hyposelenemia, SHPT is a covariant of CHF in housebound AAs.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Insuficiência Cardíaca/fisiopatologia , Micronutrientes , Hormônio Paratireóideo/sangue , Selênio/sangue , Vitamina D/análogos & derivados , Zinco/sangue , Adulto , Idoso , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/etnologia , Humanos , Masculino , Pessoa de Meia-Idade , Selênio/deficiência , Vitamina D/sangue , Zinco/deficiência
16.
Heart Fail Rev ; 11(1): 45-55, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16819577

RESUMO

An emerging body of evidence suggests secondary hyperparathyroidism (SHPT) may be an important covariant of congestive heart failure (CHF), especially in African-Americans (AA) where hypovitaminosis D is prevalent given that melanin, a natural sunscreen, mandates prolonged exposure of skin to sunlight and where a housebound lifestyle imposed by symptomatic CHF limits outdoor activities and hence sunlight exposure. In addition to the role of hypovitaminosis D in contributing to SHPT is the increased urinary and fecal losses of macronutrients Ca(2+) and Mg(2+) associated with the aldosteronism of CHF and their heightened urinary losses with furosemide treatment of CHF. Thus, a precarious Ca(2+) balance seen with reduced serum 25(OH)D is further compromised when AA develop CHF with circulating RAAS activation and are then treated with a loop diuretic. SHPT accounts for a paradoxical Ca(2+) overloading of diverse tissues and the induction of oxidative stress at these sites which spills over to the systemic circulation. In addition to SHPT, hypozincemia and hyposelenemia have been found in AA with compensated and decompensated heart failure and where an insufficiency of these micronutrients may have its origins in inadequate dietary intake, altered rates of absorption or excretion and/or tissue redistribution, and treatment with an ACE inhibitor or AT(1) receptor antagonist. Zn and Se deficiencies, which compromise the activity of several endogenous antioxidant defenses, could prove contributory to the severity of heart failure and its progressive nature. These findings call into question the need for nutriceutical treatment of heart failure and which is complementary to today's pharmaceuticals, especially in AA.


Assuntos
Negro ou Afro-Americano , Insuficiência Cardíaca/etnologia , Insuficiência Cardíaca/fisiopatologia , Micronutrientes/fisiologia , Animais , Cálcio/sangue , Cálcio/fisiologia , Citocinas/fisiologia , Insuficiência Cardíaca/sangue , Humanos , Hiperaldosteronismo/sangue , Hiperaldosteronismo/fisiopatologia , Imunidade Celular/fisiologia , Estado Nutricional , Estresse Oxidativo/fisiologia , Hormônio Paratireóideo/sangue , Selênio/sangue , Selênio/fisiologia , Vitamina D/sangue , Zinco/sangue , Zinco/fisiologia
17.
Congest Heart Fail ; 8(1): 37-48, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11821627

RESUMO

The role of the renin-angiotensin-aldosterone system (RAAS) is integral to salt and water retention, particularly by the kidneys. Over time, positive sodium balance leads first to intra- and then to extravascular volume expansion, with subsequent symptomatic heart failure. This report examines the role of the RAAS in regulating a less well recognized component essential to circulatory homeostasis--central blood volume. The regulation of central blood volume draws on integrative cardiorenal physiology and a key role played by the RAAS in its regulation. In presenting insights into the role of the RAAS in regulating central blood volume, this review also addresses other sodium-retaining states with a predisposition to edema formation, such as cirrhosis and nephrosis.


Assuntos
Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Circulação Sanguínea/fisiologia , Volume Sanguíneo/fisiologia , Homeostase/fisiologia , Humanos , Natriurese/fisiologia , Postura/fisiologia , Sistema Renina-Angiotensina/fisiologia
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