atrial-natriuretic-factor and Weight-Loss

Natriuretic peptides (NPs) are released from the heart in response to pressure and volume overload. B-type natriuretic peptide (BNP) and N-terminal-proBNP have become important diagnostic tools for assessing patients who present acutely with dyspnea. The NP level reflects a compilation of systolic and diastolic function as well as right ventricular and valvular function. Studies suggest that using NPs in the emergency department can reduce the consumption of hospital resources and can lower costs by either eliminating the need for other, more expensive tests or by establishing an alternative diagnosis that does not require hospital stay. Caveats such as body mass index and renal function must be taken into account when analyzing NP levels. Natriuretic peptide levels have important prognostic value in multiple clinical settings, including in patients with stable coronary artery disease and with acute coronary syndromes. In patients with decompensated heart failure due to volume overload, a treatment-induced drop in wedge pressure is often accompanied by a rapid drop in NP levels. Knowing a patient's NP levels might thus assist with hemodynamic assessment and subsequent treatment titration. Monitoring NP levels in the outpatient setting might also improve patient care and outcomes.

Topics: Atrial Natriuretic Factor; Cardiovascular Diseases; Death, Sudden, Cardiac; Heart Diseases; Heart Failure; Hemodynamics; Humans; Kidney Failure, Chronic; Monitoring, Physiologic; Natriuretic Peptide, Brain; Natriuretic Peptide, C-Type; Obesity; Peptide Fragments; Prognosis; Pulmonary Edema; Pulmonary Embolism; Pulmonary Wedge Pressure; Renal Dialysis; Stroke; Weight Loss

Reports that sodium glucose cotransporter 2 inhibitors decrease cardiovascular death and events in patients with diabetes have attracted attention in the cardiology field. We conducted a study of canagliflozin in patients with chronic heart failure and type II diabetes.. Thirty-five Japanese patients with chronic heart failure and type II diabetes were treated with canagliflozin for 12 months. The primary endpoints were the changes of subcutaneous, visceral, and total fat areas at 12 months determined by computed tomography. Secondary endpoints included markers of glycemic control, renal function, and oxidative stress, as well as lipid parameters, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), flow-mediated dilation (FMD), and echocardiographic left ventricular function.. All fat areas (subcutaneous, visceral, and total) showed a significant decrease at 12 months. ANP and BNP also decreased significantly, along with improvement of renal function, oxidized LDL, and E/e', FMD increased significantly after canagliflozin treatment.. Canagliflozin demonstrated cardiac and renal protective effects as well as improving oxidative stress, diastolic function, and endothelial function. This drug was effective in patients who had heart failure with preserved ejection fraction and could become first-line therapy for such patients with diabetes. Trial registration UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000021239.

Topics: Adiposity; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Biomarkers; Blood Glucose; Canagliflozin; Chronic Disease; Diabetes Mellitus, Type 2; Female; Heart; Heart Failure; Humans; Japan; Kidney; Male; Middle Aged; Natriuretic Peptide, Brain; Prospective Studies; Sodium-Glucose Transporter 2 Inhibitors; Time Factors; Treatment Outcome; Weight Loss

In weight loss trials, a considerable inter-individual variability in reduction of fat mass and changes of insulin resistance is observed, even under standardized study conditions. The underlying mechanisms are not well understood. Given the metabolic properties of the atrial natriuretic peptide (ANP) system, we hypothesized that ANP signaling might be involved in this phenomenon by changes of ANP secretion or receptor balance. Therefore, we investigated the impact of systemic, adipose and myocellular ANP system on metabolic and anthropometric improvements during weight loss.. We comprehensively investigated 143 subjects (31 male, 112 female) before and after a 3 month-standardized weight loss program. The time course of BMI, fat mass, insulin sensitivity, circulating mid-regional proANP (MR-proANP) levels as well as adipose and myocellular natriuretic receptor A (NPR-A) and C (NPR-C) mRNA expression were investigated.. BMI decreased by -12.6±3.7%. This was accompanied by a remarkable decrease of adipose NPR-C expression (1005.0±488.4 vs. 556.7±465.6; p<0.001) as well as a tendency towards increased adipose NPR-A expression (4644.7±946.8 vs. 4877.6±869.8; p=0.051). Weight loss induced changes in NPR-C (ΔNPR-C) was linked to relative reduction of total fat mass (ΔFM) (r=0.281; p<0.05), reduction of BMI (r=0.277; p<0.01), and increase of free fatty acids (ΔFFA) (r=-0.258; p<0.05). Basal NPR-C expression and weight loss induced ΔNPR-C independently explained 22.7% of ΔFM. In addition, ΔMR-proANP was independently associated with improvement of insulin sensitivity (standardized ß=0.246, p<0.01).. ANP receptor expression predicted the degree of weight loss induced fat mass reduction. Our comprehensive human data support that peripheral ANP signalling is involved in control of adipose tissue plasticity and function during weight loss. (Funded by the Deutsche Forschungsgemeinschaft (KFO281/2), the Berlin Institute of Health (BIH) and the German Centre for Cardiovascular Research (DZHK/BMBF); ClinicalTrials.gov number: NCT00850629).

Topics: Adipose Tissue; Adiposity; Adult; Atrial Natriuretic Factor; Blood Glucose; Body Mass Index; Caloric Restriction; Counseling; Exercise Therapy; Female; Humans; Insulin; Insulin Resistance; Lipids; Male; Middle Aged; Obesity; Overweight; Receptors, Atrial Natriuretic Factor; Weight Loss; Weight Reduction Programs

To examine 24-h blood pressure (24BP), systemic haemodynamics and the effect of sodium intake on 24BP in obese patients before and after gastric bypass surgery [laparoscopic Roux-en-Y gastric bypass (LRYGB)], and to determine whether weight loss from LRYGB might be related to an increase in plasma concentrations of atrial natriuretic peptide.. Twelve hypertensive and 12 normotensive morbidly obese patients underwent LRYGB: 24BP, systemic haemodynamics and mid-regional pro-atrial natriuretic peptide (MRproANP) were assessed before, 6 weeks and 12 months after surgery. The effect of high versus low sodium intake on 24BP was evaluated before and 12 months after LRYGB.. Six weeks after LRYGB, the average weight loss was 20 kg, with a further 21 kg weight loss 1 year after surgery. In hypertensive patients, 24BP was significantly reduced at 6 weeks, but not 1 year after LRYGB. However, antihypertensive medications were successively reduced from baseline to 1 year after surgery. In normotensive patients, there was no change in 24BP 6 weeks after LRYGB, but a tendency towards a reduction 1 year after the operation. Plasma concentrations of MRproANP were subnormal prior to surgery in hypertensive patients and increased by 77% 1 year after the operation. In normotensive patients, preoperative concentrations were normal and increased only by 6%. High sodium intake induced plasma volume expansion, increased stroke volume and cardiac output, but no significant change in 24BP - neither before nor after LRYGB.. LRYGB resulted in a significant 24BP reduction and a substantial increase in MRproANP plasma concentrations in hypertensive, obese patients 6 weeks after surgery, suggesting a causal link between obesity-hypertension and altered release/degradation of cardiac natriuretic peptides.

Topics: Adult; Atrial Natriuretic Factor; Blood Pressure; Female; Gastric Bypass; Humans; Hypertension; Laparoscopy; Male; Middle Aged; Obesity, Morbid; Time Factors; Weight Loss

The action of atrial natriuretic peptide (ANP) on natriuresis, diuresis and vasodilatation, insulin resistance, liver, kidney, and adipose tissue may contribute to the healthy metabolic and cardiovascular development. Even though the circulating level of ANP is reduced in patients with obesity, its response to weight loss remains poorly explored in pediatric populations.. To evaluate the effects of ANP variations in response to interdisciplinary weight loss intervention on metabolic syndrome (MetS) and cardiometabolic risks in adolescents with obesity.. 73 adolescents with obesity attended a 20-week clinical interdisciplinary weight loss therapy including clinical, nutritional, psychological and exercise training approach. Body composition, biochemical analyses and blood pressure were evaluated. MetS was classified according to the International Diabetes Federation (IDF) (2007). After the treatment, volunteers were divided according to Increasing (n=31) or Decreasing (n=19) ANP plasma levels.. Both groups present significant reduction of body weight, Body Mass Index (BMI), waist, neck and hip circumferences (WC, NC and HC, respectively) and increasing fat-free mass (FFM). Interestingly, a significant reduction in body fat, TG/HDL-c ratio and MetS prevalence (from 23% to 6%) was observed in the Increased ANP group only.. This study suggests that an increase in ANP serum levels after weight loss therapy could be associated with improvements in cardiometabolic risks and the reduced prevalence of MetS in adolescents with obesity.. A ação do peptídeo natriurético atrial (ANP) na natriurese, diurese e vasodilatação, resistência à insulina, fígado, rim e tecido adiposo pode contribuir para o desenvolvimento metabólico e cardiovascular saudável. Embora o nível circulante de ANP seja reduzido em pacientes com obesidade, sua resposta à perda de peso ainda é pouco explorada em populações pediátricas.. Avaliar os efeitos das variações do ANP em resposta à intervenção interdisciplinar para perda de peso na Síndrome Metabólica (SMet) e nos riscos cardiometabólicos em adolescentes com obesidade.. 73 adolescentes com obesidade participaram de uma terapia interdisciplinar para perda de peso de 20 semanas, incluindo uma abordagem clínica, nutricional, psicológica e de exercícios físicos. A composição corporal, análises bioquímicas e pressão sanguínea foram avaliadas. A SMet foi classificada de acordo com a Federação Internacional de Diabetes (IDF) (2007). Após o tratamento, os voluntários foram divididos de acordo com os níveis de plasma do ANP aumento (n=31) ou ANP redução (n=19).. Ambos os grupos apresentaram redução significativa de peso corporal, índice de massa corporal (IMC) e circunferências de cintura, pescoço e quadril (CC, CP e CQ, respectivamente), e aumento da massa livre de gordura (MLG). É interessante observar que houve uma redução significativa na gordura corporal, na razão de TG/HDL-c e na prevalência de SMet (de 23% para 6%) somente no grupo com ANP aumento.. Este estudo sugere que o aumento nos níveis séricos de ANP após a terapia para perda de peso pode estar associado a melhorias nos riscos cardiometabólicos e na prevalência reduzida de SMet em adolescentes com obesidade.

Topics: Adolescent; Atrial Natriuretic Factor; Body Composition; Body Mass Index; Cardiovascular Diseases; Child; Humans; Metabolic Syndrome; Pediatric Obesity; Weight Loss

Relative atrial natriuretic peptide (ANP) deficiency has been implicated in the pathogenesis of obesity-associated cardiovascular and metabolic disease. We tested the hypothesis that more than 5% body weight reduction through 6 months hypocaloric dieting alters ANP release at rest and more so during exercise in overweight or obese patients.. Venous mid-regional pro-ANP concentration was assessed at rest and after incremental exhaustive exercise testing before and after weight reduction. We also measured natriuretic peptide receptor A and C mRNA expression in subcutaneous adipose tissue to gauge both ANP responsiveness and clearance mechanisms.. The average weight reduction of 9.1 ± 3.8  kg was associated with reductions in visceral and subcutaneous abdominal fat mass, liver fat content, insulin resistance, and ambulatory blood pressure. However, mid-regional pro-ANP plasma concentrations were unchanged with weight loss (51 ± 24 vs. 53 ± 24  pmol/l). Exercise elicited similar acute mid-regional pro-ANP increases before and after weight loss. Adipose tissue natriuretic peptide receptor type A mRNA expression remained unchanged, whereas natriuretic peptide receptor type C mRNA decreased with weight loss.. We conclude that physical exercise acutely increases ANP release in obese patients, whereas modest diet-induced weight loss primarily affects ANP clearance mechanisms. Interventions combining weight loss and regular physical exercise may be particularly efficacious in reversing obesity-associated relative natriuretic peptide deficiency.

Topics: Adipose Tissue; Adult; Atrial Natriuretic Factor; Blood Pressure Monitoring, Ambulatory; Diet, Reducing; Exercise; Female; Humans; Insulin Resistance; Male; Middle Aged; Obesity; Receptors, Atrial Natriuretic Factor; Rest; Weight Loss; Weight Reduction Programs

To investigate the effects of delivery route and maternal anesthesia type and the roles of vasoactive hormones on early postnatal weight loss in term newborns.. Ninety-four term infants delivered vaginally (group 1, n=31), cesarean section (C/S) with general anesthesia (GA) (group 2, n=29), and C/S with epidural anesthesia (EA) (group 3, n=34) were included in this study. All infants were weighed at birth and on the second day of life and intravenous (IV) fluid infused to the mothers for the last 6 h prior to delivery was recorded. Serum electrolytes, osmolality, N-terminal proANP (NT-proANP), brain natriuretic peptide (BNP), aldosterone and plasma antidiuretic hormone (ADH) concentrations were measured at cord blood and on the second day of life.. Our research showed that postnatal weight loss of infants was higher in C/S than vaginal deliveries (5.7% vs. 1.3%) (p < 0.0001) and in EA group than GA group (6.8% vs. 4.3%) (p < 0.0001). Postnatal weight losses were correlated with IV fluid volume infused to the mothers for the last 6 h prior to delivery (R = 0.814, p = 0.000) and with serum NT-proANP (R = 0.418, p = 0.000), BNP (R = 0.454, p = 0.000), and ADH (R = 0.509, p = 0.000) but not with aldosterone concentrations (p > 0.05).. Large amounts of IV fluid given to the mothers who were applied EA prior to the delivery affect their offsprings' postnatal weight loss via certain vasoactive hormones.

Topics: Anesthesia, Obstetrical; Anesthetics; Atrial Natriuretic Factor; Birth Weight; Child Development; Delivery, Obstetric; Female; Humans; Infant, Newborn; Male; Natriuretic Peptide, Brain; Peptide Hormones; Pregnancy; Term Birth; Weight Loss

Loss of fat mass is a key feature of cancer cachexia and has been attributed to increased adipocyte lipolysis. The mechanism behind this alteration is unknown and was presently investigated. We studied mature s.c. fat cells and differentiated preadipocytes from 26 cancer patients with and without cachexia. Hormone-induced lipolysis and expression of lipolysis-regulating genes were determined together with body composition and in vivo lipolytic activity (fasting plasma glycerol or fatty acids related to body fat). Body fat was reduced by 40% and in vivo lipolytic activity was 2-fold increased in cachexia (P = 0.001). In mature adipocytes, the lipolytic effects of catecholamines and natriuretic peptide were 2- to 3-fold increased in cachexia (P < 0.001). This was completely counteracted by inhibiting the rate-limiting lipolysis enzyme hormone-sensitive lipase (HSL). In cachexia, the expression levels of HSL mRNA and protein were increased by 50% and 100%, respectively (P = 0.005-0.03), which strongly correlated with in vitro lipolytic stimulation (r = 0.7-0.9). The antilipolytic effect of insulin in mature fat cells and the stimulated lipolytic effect in differentiated preadipocytes were unaltered in cachexia. Patients who lost weight due to other factors than cancer cachexia had no change in adipocyte lipolysis. In conclusion, adipocyte lipolysis is increased in cancer cachexia not due to nonepigenic factors or to weight loss per se, but most probably because of enhanced expression and function of adipocyte HSL. The selective inhibition of this enzyme may prevent fat loss in cancer patients.

Topics: Adipocytes; Atrial Natriuretic Factor; Cachexia; Female; Gastrointestinal Neoplasms; Gene Expression; Humans; Insulin; Lipolysis; Male; Norepinephrine; RNA, Messenger; Sterol Esterase; Weight Loss

The combination of long-term hypercapnia and hypoxia decreases pulmonary vascular remodeling and attenuation of right ventricular (RV) hypertrophy. However, there is limited information in the literature regarding the first stages of acclimatization to hypercapnia/hypoxia. The purpose of this study was to investigate the effect of four-day hypoxia (10% O2) and hypoxia/hypercapnia (10% O2 + 4.4% CO2) on the protein composition of rat myocardium. Expression of the cardiac collagen types and activities of matrix metalloproteinases (MMPs) and of their tissue inhibitor TIMP-1 were followed. The four-day hypoxia changed protein composition of the right ventricle only in the hypercapnic condition; remodeling was observed in the extracellular matrix (ECM) compartments. While the concentrations of pepsin-soluble collagenous proteins in the RV were elevated, the concentrations of pepsin-insoluble proteins were decreased. Furthermore, the four-day hypoxia/hypercapnia increased the synthesis of cardiac collagen due to newly synthesized forms; the amount of cross-linked particles was not affected. This type of hypoxia increased cardiac collagen type III mRNA, while cardiac collagen type I mRNA was decreased. MMP-2 activity was detected on the zymographic gel through appearance of two bands; no differences were observed in either group. mRNA levels for MMP-2 in the RV were significantly lower in both the hypoxic and hypoxic/hypercapnic animals. mRNA levels for TIMP-1 were reduced in the RV of both the hypoxic and hypoxic/hypercapnic animals. Hypoxia with hypercapnia increased the level of mRNA (6.5 times) for the atrial natriuretic peptide (ANP) predominantly in the RV. The role of this peptide in remodeling of cardiac ECM is discussed.

Topics: Animals; Atrial Natriuretic Factor; Collagen Type I; Collagen Type III; Extracellular Matrix Proteins; Gene Expression Profiling; Hypercapnia; Hypoxia; Male; Matrix Metalloproteinases; Myocardium; Peptide Mapping; Rats; Rats, Wistar; Time Factors; Tissue Inhibitor of Metalloproteinase-1; Ventricular Remodeling; Weight Loss

Urodilatin (URO) is a member of the natriuretic family, cleaved by the kidney, which acts as a paracrine hormone in the regulation of natriuresis and diuresis. In newborn infants the excretion of urodilatin and its biological effects have not been explored.. We measured urinary URO excretion, by direct RIA (radioimmunoassay), as well as its correlation to neonatal body weight loss, and sodium homeostasis in 30 full-term newborn infants on the 4th day of life.. The URO excretion, estimated as URO:creatinine ratio, was significantly correlated to sodium excretion.. These data show that in full-term newborn infants the mechanisms that control synthesis, excretion and signal transduction of URO are developed and that URO contributes to natriuresis regulation.

Topics: Apgar Score; Atrial Natriuretic Factor; Body Weight; Creatinine; Homeostasis; Humans; Infant, Newborn; Natriuresis; Peptide Fragments; Sodium; Weight Loss

For several years, the severe side effects associated with the use of high doses of the aldosterone antagonist, spironolactone, limited its clinical use. Studies have recently shown efficacy and minimal side effects of low-dose spironolactone combined with standard therapy in the treatment of heart failure and hypertensive patients. The authors evaluated the effects of low-dose spironolactone alone or in combination with angiotensin-converting enzyme (ACE) inhibitors on the progression of left ventricular dysfunction and remodeling in a congenic rat model of hypertrophic cardiomyopathy. The congenic SS-16/Mcwi rats developed severe cardiac hypertrophy despite being normotensive even on high-salt diet. SS-16/Mcwi and SS/Mcwi rats were fed a low-salt (0.4% NaCl) diet and were treated with vehicle (CON), spironolactone (20 mg/kg/d subcutaneously), captopril (100 mg/kg/d drinking water), or both spironolactone and captopril for 4 weeks. Blood pressure, plasma peptides, cardiac fibrosis, and echocardiography measurements were evaluated. Spironolactone at a low dose had no effect on blood pressure, cardiac hypertrophy, and fibrosis in either strain. However, in combination with captopril, spironolactone decreased the cardiac hypertrophy more than captopril treatment alone. In the SS-16/Mcwi rats, the combined therapy significantly preserved the cardiac index when compared with control. These data indicate that the addition of low-dose spironolactone to captopril treatment was more effective in preventing the progression of heart hypertrophy and ventricular dysfunction in the SS-16/Mcwi than captopril alone. This study suggests that combined spironolactone and captopril therapy may be useful in the treatment of hypertrophic cardiomyopathy.

Topics: Administration, Oral; Aldosterone; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Congenic; Atrial Natriuretic Factor; Blood Pressure; Captopril; Cardiomyopathy, Hypertrophic; Disease Models, Animal; Diuretics; Dose-Response Relationship, Drug; Drug Therapy, Combination; Echocardiography; Injections, Subcutaneous; Myocardium; Organ Size; Random Allocation; Rats; Rats, Inbred Strains; Spironolactone; Ventricular Function, Left; Weight Loss

Many previous studies have shown that aquaporin-2 (AQP2), the vasopressin-regulated water channel, is excreted in the urine and that the excretion increases in response to vasopressin. Moreover, recently a close correlation between AQP2 excretion in urine and kidney AQP2 expression has been demonstrated, showing that urinary excretion of AQP2 is a reliable indicator for AQP-2 function. As head-out water immersion causes an expansion in the central vascular volume equal to that induced by 2 liters of saline, without modifying plasma composition, we used immersion in water to evaluate if the response to acute expansion of the central vascular volume could involve vasporessin (AVP) and AQP2. In healthy subjects, concentrations of plasma atrial natriuretic factor (ANF) and AVP, and urinary AQP2 were measured during a 2-hour immersion period. In all subjects, immersion caused a prompt and marked increase in immunoreactive ANF (23.0 +/- 2.12 pg/ml at second hour vs. 2.17 +/- 0.42 pg/ml at baseline) and in urinary excretion of AQP2 (23.9 +/- 2. 69 pmol/mg creatinine at second hour vs. 4.42 +/- 0.14 pmol/mg creatinine at baseline), while a significant decrease was found in plasma AVP. Recovery was associated with a prompt return to pre-study levels. These findings demonstrate that heat-out water immersion stimulates urinary excretion of AQP2 in absence of an increase in plasma AVP.

Topics: Adult; Aquaporin 2; Aquaporin 6; Aquaporins; Atrial Natriuretic Factor; Blood Pressure; Diuresis; Female; Humans; Male; Reference Values; Vasopressins; Water; Water-Electrolyte Balance; Weight Loss

Following birth there is a contraction in the extracellular compartment, marked clinically by natriuresis, diuresis and weight loss. It is uncertain how these postnatal phenomena, which suggest an interrelationship with cardiopulmonary adaptation, are brought about. The aim of this study was to evaluate the temporal relationship between alterations in circulating atrial natriuretic peptide (ANP), respiratory status, sodium excretion and extracellular fluid volume (ECFV) in preterm babies, in the first days after birth. Eighteen male infants below 34 weeks gestational age were studied longitudinally, measuring urine output, sodium balance, arterial-alveolar oxygen ratio and circulating ANP. Daily changes in ECFV were assessed by endogenous chloride balance, following baseline measurement of bromide space. There was a clear period of improvement in respiratory function in 15 babies and in these there was a highly significant elevation in circulating ANP, either immediately prior to, or during, the period of improvement. In three infants there was no definable period of respiratory improvement. In four babies, two of whom had very mild respiratory distress, there was an immediate decline in ECFV after birth, in contrast to the remaining 14 infants, in whom there was an initial increase. This study demonstrates that there is a temporal relationship between improvement in respiratory function and an acute elevation in circulating ANP. Babies with respiratory distress syndrome are at risk of initial expansion of the extracellular compartment after birth. This is likely to increase morbidity. These observations are of relevance with regard to the clinical management of newborns with respiratory distress syndrome.

Topics: Atrial Natriuretic Factor; Diuresis; Extracellular Space; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Longitudinal Studies; Male; Natriuresis; Respiration; Weight Loss

The N-terminus of the atrial natriuretic factor (ANF) prohormone (ie, proANF 1-98) contains two vasodilatory peptides consisting of amino acids (aa): aa 1-30 (ie, proANF 1-30) and aa 31-67 (ie, proANF 31-67) of the 126 aa prohormone. The relationship of this N-terminus to the renin-aldosterone axis and blood pressure reduction was investigated in 18 obese subjects (5 hypertensive and 13 normotensive) placed on a 12-week, low sodium (40 mmol), weight reducing diet. The N-terminus of the ANF prohormone and proANF 31-67, which circulates as a distinct entity after being proteolytically cleaved from the N-terminus, were significantly (p less than 0.001) higher (767 +/- 1.01 and 816 +/- 135 fmol/ml) in the obese hypertensive group compared with the obese normotensive group (377 +/- 24 and 356 +/- 17 fmol/ml, respectively) prior to beginning the weight reduction program. There was a dramatic fall in the N-terminus and in proANF 31-67 after 1 week of weight reduction in both obese groups, which correlated with the decrease in mean arterial pressure during the first week and throughout the 12 weeks of weight reduction (r = .54, p less than 0.001 and r = .59, p less than 0.001, respectively). ProANF 1-98 had a significant (p less than 0.01) inverse correlation with plasma renin in both obese groups. ProANF 31-67, likewise, had an inverse correlation with plasma renin in the hypertensive (p less than 0.002), as well as the normotensive (p less than 0.03) subjects. ProANF 31-67 did not significantly correlate with aldosterone in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Aldosterone; Atrial Natriuretic Factor; Blood Pressure; Diet, Reducing; Female; Humans; Hypertension; Male; Middle Aged; Obesity; Peptide Fragments; Protein Precursors; Time Factors; Weight Loss

Topics: Atrial Natriuretic Factor; Humans; Hypertension; Obesity; Weight Loss

Plasma atrial natriuretic peptide (ANP) and aldosterone concentrations, and plasma renin activity (PRA) were measured by radioimmunoassay concurrently in 20 healthy full term infants, in cord blood, at 24 hours after birth and on the 4th day of life. ANP and aldosterone increased significantly at 24 hours and was persistently elevated on the 4th day of life. PRA remained unchanged during the first four days of life. In cord blood, ANP concentrations were correlated with aldosterone concentrations (r = 0.49, p less than 0.05) and hematocrit (r = 0.58, p less than 0.02). At the 24 hours of life, plasma ANP concentrations were correlated with weight loss observed on the 4th day of life (r = -0.70, p less than 0.005), while the percentage changes in plasma aldosterone concentrations were correlated with percentage changes in systolic blood pressure (BP) (r = 0.49, p less than 0.05). These findings suggest that during the early newborn period ANP and aldosterone act as an integrated system which has a role in regulation blood pressure and intravascular volume homeostasis.

Topics: Age Factors; Aldosterone; Atrial Natriuretic Factor; Birth Weight; Blood Pressure; Evaluation Studies as Topic; Fetal Blood; Hematocrit; Humans; Infant, Newborn; Radioimmunoassay; Renin; Renin-Angiotensin System; Water-Electrolyte Balance; Weight Loss

Plasma concentrations of atrial natriuretic peptide (ANP), arginine vasopressin (AVP), plasma renin activity (PRA) and aldosterone, were measured before and after 3 h of hemodialysis in 9 patients with end-stage renal disease on maintenance hemodialysis. Hormone concentrations were also determined in the same patients on a separate occasion after 1 h of ultrafiltration (UF). Plasma concentrations of ANP were significantly higher in the patients with ESRD than in a normal reference population and declined after both 1 h and 3 h of hemodialysis. Plasma concentrations of ANP failed to exhibit a significant decline after 1 h of UF. Plasma AVP concentrations were not significantly different after either hemodialysis or UF, while plasma aldosterone concentrations fell with hemodialysis. The decline in plasma aldosterone concentrations paralleled the decrease in dialysis-induced fall in serum potassium concentrations. There was no correlation between the blood pressures, heart rate, interdialytic weight gain and estimated fluid overload and any of the hormones measured except for the plasma renin activity (PRA) which correlated significantly with the systolic blood pressure. The data suggest that ANP may not be a major factor in blood pressure regulation in normotensive patients with ESRD and its elevation in patients with ESRD is most likely due to fluid overload and atrial distention as well as a possible reduction in its metabolic clearance in renal insufficiency. The fall in plasma ANP following hemodialysis is not due to its removal by dialysis but is most likely due to a reduction in ANP production caused by dialysis-induced correction of hypervolemia.

Topics: Adult; Arginine Vasopressin; Atrial Natriuretic Factor; Blood Pressure; Female; Heart Rate; Hemofiltration; Humans; Kidney Failure, Chronic; Male; Middle Aged; Radioimmunoassay; Renal Dialysis; Renin-Angiotensin System; Weight Loss

The effect of obesity and weight reduction upon circulating concentrations of atrial natriuretic peptide was assessed in an experimental model of the disease. Obese rats weighing in excess of 750 g were compared with formerly obese animals subjected to a 15-week period of caloric restriction resulting in a 40% reduction in body weight. Mean adipocyte size was significantly reduced with weight loss, as was estimated body fat. Mean arterial blood pressure remained normotensive for both groups, but a significant reduction in heart rate was associated with weight reduction. Circulating atrial natriuretic peptide was significantly elevated in the lean rats, which also exhibited decreased plasma renin activity and a negative sodium balance. Analysis of heart to body weight ratios implied that an obesity-associated, volume-induced cardiac hypertrophy remained even after the normalization of body fat. These results suggest that the diuresis and natriuresis accompanying weight reduction may be facilitated by atrial natriuretic peptide, which was elevated in part due to a persistent left ventricular hypertrophy following the transition from the obese to lean condition.

Topics: Adipose Tissue; Animals; Atrial Natriuretic Factor; Heart; Hemodynamics; Kidney; Obesity; Rats; Weight Loss

The relationship between atrial natriuretic factor (ANF), the renin-aldosterone axis, and blood pressure reduction with weight loss was investigated in 18 obese subjects (five hypertensive and 13 normotensive) placed on a 12-week, low-sodium (40 mmol), weight-reducing diet. ANF was significantly higher (P less than .02) in the obese hypertensive group compared with the obese normotensive group throughout the study. There was a dramatic fall in the circulating concentration of ANF after 1 week of weight reduction in both obese groups. Mean arterial pressure fell significantly in both groups, with the hypertensive group becoming normotensive during the first week of the diet. The marked changes in ANF and mean arterial pressure during the first week of the diet appeared related to reduced salt intake. Mean arterial pressure and ANF concentrations, however, continued to fall during the eighth to 12th week of weight reduction diet in the hypertensive patients when salt intake had been unchanged for several months. In both the hypertensive and normotensive subjects ANF paralleled blood pressure changes (r = .54, P less than .0001) throughout the 12-week study period. ANF was inversely correlated with plasma renin activity and aldosterone, with the most dramatic changes in their concentrations being during the first week of the diet. These results demonstrate that weight loss while ingesting a controlled low sodium diet is accompanied by changes in ANF that directly correlate with changes in blood pressure and inversely correlate with changes in the renin-aldosterone axis, which ANF is known to inhibit.

Topics: Adult; Aged; Aldosterone; Atrial Natriuretic Factor; Blood Pressure; Electrolytes; Female; Heart Rate; Humans; Hypertension; Male; Middle Aged; Obesity; Renin; Weight Loss