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Alpha-melanocyte-stimulating hormone (alpha-MSH) is a part of the hormonal stress system with proven cardiovascular effects. Heart rate recovery (HRR) following exercise is strongly correlated to overall fitness and future adverse cardiovascular events. The current study examined the predictive value of alpha-MSH for HRR following exercise testing.Cardiopulmonary exercise testing (CPET) on a treadmill was used to measure HR and oxygen consumption (VÌO2) in 16 elite male wrestlers (W), 21 water polo player (WP) and 20 sedentary subjects (C) matched for age. Plasma levels of alpha-MSH were measured by radioimmunoassay technique in four phases of CPET: 1) 10 min pre-CPET at rest; 2) at the initation of CPET; 3) at peak CPET; and 4) at the third minute of recovery. The WP group had significantly higher HRR compared to than W and C groups, who did not have significantly different values. Significant difference in alpha-MSH measurements and patterns during CPET between groups was not observed (p > 0.05). When combining all three groups, we observed a significant correlation between VÌO2 recovery and alpha-MSH recovery/peak (r = -0.3, p = 0.022). HRR and ΔHRR/peak significantly correlated with alpha-MSH at all four measurment points (r = -0.4; p < 0.01 for all). On multiple regression analysis, which included anthropometric and hormonal measures, the best independent predictor of HRR and ΔHRR/peak was alpha-MSH during recovery (B = -1.0, -0.5; SE = 0.3, 0.1; CI = -1.5 to -0.4, -0.7 to -0.2; p = 0.001 respectively). In conclusion, alpha-MSH measured during exercise recovery holds predictive value for HRR and ΔHRR/peak, suggesting a contributing role to integrative regulation of overall cardiopulmonary performance. CONDENSED ABSTRACT: Present study examined the predictive value of alpha-melanocyte stimulating hormone (alpha-MSH) for heart rate recovery (HRR) in elite male wrestlers, water polo players and sedentary subjects matched for age. Alpha-MSH measured during exercise recovery holds predictive value for HRR and ΔHRR/peak, suggesting a contributing role to integrative regulation of overall cardiopulmonary performance.
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CONTEXT: Adrenal lesions are frequent among patients with sporadic neuroendocrine tumors (spNETs) or multiple endocrine neoplasia type 1 (MEN1). Armadillo repeat-containing 5 (ARMC5)-inactivating variants cause adrenal tumors and possibly other neoplasms. OBJECTIVE: The objective of this work is to investigate a large cohort spNETs or MEN1 patients for changes in the ARMC5 gene. PATIENTS AND METHODS: A total of 111 patients, 94 with spNET and 17 with MEN1, were screened for ARMC5 germline alterations. Thirty-six tumors (18 spNETs and 18 MEN1 related) were collected from 20 patients. Blood and tumor DNA samples were genotyped using Sanger sequencing and microsatellite markers for chromosomes. ARMC5 and MEN1 expression were assessed by immunohistochemistry. RESULTS: In 76 of 111 (68.4%) patients, we identified 16 different ARMC5 germline variants, 2 predicted as damaging. There were no differences in the prevalence of ARMC5 variants depending on the presence of MEN1-related adrenal lesions. Loss of heterozygosity (LOH) at chromosome 16p and ARMC5 germline variants were present together in 23 or 34 (67.6%) tumors; in 7 of 23 (30.4%) their presence led to biallelic inactivation of the ARMC5 gene. The latter was more prevalent in MEN1-related tumors than in spNETs (88.9% vs 38.9%; P = .005). LOH at the chromosome 16p (ARMC5) and 11q (MEN1) loci coexisted in 16/18 MEN1-related tumors, which also expressed lower ARMC5 (P = .02) and MEN1 (P = .01) proteins compared to peritumorous tissues. CONCLUSION: Germline ARMC5 variants are common among spNET and MEN1 patients. ARMC5 haploinsufficiency or biallelic inactivation in spNETs and MEN1-related tumors suggests that ARMC5 may have a role in modifying the phenotype of patients with spNETs and/or MEN1 beyond its known role in macronodular adrenocortical hyperplasia.
Assuntos
Proteínas do Domínio Armadillo/genética , Neoplasia Endócrina Múltipla Tipo 1/genética , Tumores Neuroendócrinos/genética , Adenoma/epidemiologia , Adenoma/genética , Adolescente , Neoplasias das Glândulas Suprarrenais/epidemiologia , Neoplasias das Glândulas Suprarrenais/genética , Adulto , Idoso , Criança , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Mutação em Linhagem Germinativa , Humanos , Perda de Heterozigosidade , Masculino , Pessoa de Meia-Idade , Neoplasia Endócrina Múltipla Tipo 1/epidemiologia , Tumores Neuroendócrinos/epidemiologia , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/genética , Paraganglioma/epidemiologia , Paraganglioma/genética , Neoplasias das Paratireoides/epidemiologia , Neoplasias das Paratireoides/genética , Neoplasias Hipofisárias/epidemiologia , Neoplasias Hipofisárias/genética , Análise de Sequência de DNA , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/genética , Adulto JovemRESUMO
BACKGROUND: Sporadic clear-cell renal cell carcinoma (ccRCC) is associated with mutations in the VHL gene, upregulated mammalian target of rapamycin (mTOR) activity and glycolytic metabolism. Here, we analyze the effect of VHL mutational status on the expression level of mTOR, eIF4E-BP1, AMPK, REDD1, and PDK3 proteins. METHODS: Total proteins were isolated from 21 tumorous samples with biallelic inactivation, 10 with monoallelic inactivation and 6 tumors with a wild-type VHL (wtVHL) gene obtained from patients who underwent total nephrectomy. The expressions of target proteins were assessed using Western blot. RESULTS: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. Tumors with monoallelic inactivation of VHL underexpressed REDD1 in comparison to wtVHL tumors (P = 0.042), tumors with biallelic VHL inactivation (P < 0.005) and control tissue (P = 0.004). Additionally, REDD1 expression was higher in tumors with VHL biallelic inactivation than in control tissue (P = 0.008). Only in wt tumor samples PDK3 was overexpressed in comparison to tumors with biallelic inactivation of VHL gene (P = 0.012) and controls (P = 0.016). In wtVHL ccRCC, multivariate linear regression analysis revealed that 97.4% of variability in PDK3 expression can be explained by variations in AMPK amount. CONCLUSION: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. We have shown for the first time VHL dependent expression of PDK3 and we provide additional evidence that VHL mutational status affects REDD1 expression in sporadic ccRCC.
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Alterations in von Hippel-Lindau gene (VHL) do not determine deregulation of hypoxia-inducible factors (HIFs) in clear-cell renal carcinoma (ccRCC). Their effects on tuberous sclerosis proteins (TSC1/2) and heat shock protein 90 (Hsp90) expressions in sporadic ccRCC are unknown. Therefore, we analyze the impact of VHL alterations and HIF-α production on the expression of TSC proteins and Hsp90 in these tumors. Alterations in VHL gene region exhibited 37/47 (78.7%) tumors. Monoallelic inactivation (intragenic mutation or LOH) was found in 10 (21.3%) and biallelic inactivation (intragenic mutation plus LOH) in 27 (57.4%) ccRCCs. Tumorous expression of HIF-α mRNAs, HIF-α, Hsp90 and TSC2 were VHL independent; TSC2 was underexpressed in all tumors by immunostaining (P<0.001). Immunoblotting revealed that TSC1 production was lower in tumors with monoallelic VHL inactivation than in control (P=0.01) and tissues with biallelic VHL inactivation (P=0.019), while tumors lacking HIF-1α (16/47) concurrently overexpressed HIF-2α and underexpressed TSC1 in comparison to controls (P=0.01 for both) and HIF-1α positive tumors (P=0.015 and P=0.050). Significant portion of variability (56.4%) in tumor diameter was explained by oscillations in nuclear grade, and TSC1 and HIF-2α expression in VHL altered tumors. In conclusion, while TSC2 is broadly downregulated in sporadic ccRCC, TSC1 expression is reduced in two subsets of these tumors, those with monoallelic VHL gene inactivation and those with concurrent low HIF-1α and high HIF-2α expression. Hence, the involvement of nuclear grade, TSC1 and HIF-2α in the progression of VHL altered tumors, implies the interplay between pVHL and TSC1.
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Carcinoma de Células Renais/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Renais/genética , Mutação , Proteínas Supressoras de Tumor/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Proteína 1 do Complexo Esclerose Tuberosa , Proteína 2 do Complexo Esclerose Tuberosa , Proteínas Supressoras de Tumor/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismoRESUMO
The usage of alcohol is widespread, but the effects of acute alcohol ingestion on exercise performance and the stress hormone axis are not fully elucidated.We studied 10 healthy white men, nonhabitual drinkers, by Doppler echocardiography at rest, spirometry, and maximal cardiopulmonary exercise test (CPET) in two visits (2-4 days in between), one after administration of 1.5âg/kg ethanol (whisky) diluted at 15% in water, and the other after administration of an equivalent volume of water. Plasma levels of NT-pro-BNP, cortisol, and adrenocorticotropic hormone (ACTH) were also measured 10âmin before the test, at maximal effort and at the third minute of recovery. Ethanol concentration was measured from resting blood samples by gas chromatography and it increased from 0.00â±â0.00 to 1.25â±â0.54 (Pâ<â0.001). Basal echocardiographic and spirometric parameters were normal and remained so after acute alcohol intake, whereas ACTH, cortisol, and NT-pro-BNP nonsignificantly increased in all phases of the test. CPET data suggested a trend toward a slight reduction of exercise performance (peak VO2â=â3008â±â638 vs. 2900â±â543âml/min, ns; peak workloadâ=â269â±â53 vs. 249â±â40âW, ns; test duration 13.7â±â2.2 vs. 13.3â±â1.7âmin, ns; VE/VCO2 22.1â±â1.4 vs. 23.3â±â2.9, ns). Ventilatory equivalent for carbon dioxide at rest was higher after alcohol intake (28â±â2.5 vs. 30.4â±â3.2, Pâ=â0.039) and maximal respiratory exchange ratio was lower after alcohol intake (1.17â±â0.02 vs. 1.14â±â0.04, Pâ=â0.04). In conclusion, we showed that acute alcohol intake in healthy white men is associated with a nonsignificant exercise performance reduction and stress hormone stimulation, with an unchanged exercise metabolism.
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Consumo de Bebidas Alcoólicas/sangue , Tolerância ao Exercício/fisiologia , Consumo de Oxigênio/fisiologia , Hormônio Adrenocorticotrópico/sangue , Adulto , Dióxido de Carbono/sangue , Ecocardiografia Doppler , Teste de Esforço , Voluntários Saudáveis , Humanos , Hidrocortisona/sangue , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Projetos Piloto , EspirometriaRESUMO
The aim of this study was to evaluate the predictive value of adrenocorticotropic hormone (ACTH), cortisol and ACTH receptor polymorphism (ACTHRP) for left ventricular (LV) remodeling. Thirty-six elite male athletes, as chronic stress adaptation models, and twenty sedentary age and sex-mached subjects emabarked on standard and tissue Doppler echocardiography to assess cardiac parameters at rest. They performed maximal cardiopulmonary test, which was used as an acute stress model. ACTH and cortisol were measured at rest (10min before test), at beginning, at maximal effort, at 3rd min of recovery, using radioimmunometric and radioimmunoassey techniques, respectively. Promoter region of ACTHR gene (18p11.2) was analysed from blood samples using reverse polymerization reaction with the analysis of restriction fragment length polimorphisam by SacI restriction enzyme. Normal genotype was CTC/CTC, heterozygot for ACTHRP CTC/CCC and homozygot CCC/CCC. In all participants, ACTH and cortisol increased during acute stress, whereas in recovery ACTH increased and cortisol remained unchanged. 49/56 examiners manifested CTC/CTC, 7/56 CTC/CCC and 0/56 CCC/CCC. There was no difference in ACTHRP frequency between groups (χ(1)(2)=0.178, p=0.67). LV mass (LVM) and LV end-diastolic volume (LVVd) were higher in athletes than in controls (p<0.01) and lower in CTC/CTC than in CTC/CCC genotype (219.43±46.59(SD)g vs. 276.34±48.86(SD)g, p=0.004; 141.24±24.46(SD)ml vs. 175.29±37.07(SD)ml, p=0.002; respectively). In all participants, predictors of LVM and LVVd were ACTH at rest (B=-1.00,-0.44; ß=-0.30,-0.31; p=0.026,0.012, respectively) and ACTHRP (B=56.63,34; ß=0.37,0.40; p=0.003,0.001, respectively). These results demonstrate that ACTH and ACTHRP strongly predict cardiac morphology suggesting possible regulatory role of stress system activity and sensitivity in cardiac remodeling.
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Hormônio Adrenocorticotrópico/genética , Hidrocortisona/genética , Receptores da Corticotropina/genética , Remodelação Ventricular/genética , Hormônio Adrenocorticotrópico/sangue , Adulto , Atletas , Ecocardiografia Doppler , Feminino , Coração/fisiopatologia , Humanos , Hidrocortisona/sangue , Masculino , Polimorfismo Genético , Regiões Promotoras Genéticas , Receptores da Corticotropina/sangue , Fatores de Risco , Remodelação Ventricular/fisiologiaRESUMO
Brain natriuretic peptide (NT-pro-BNP) was implicated in the regulation of hypothalamic-pituitary-adrenocortical (HPA) responses to psychological stressors. However, HPA axis activation in different physical stress models and its interface with NT-pro-BNP in the prediction of cardiopulmonary performance is unclear. Cardiopulmonary test on a treadmill was used to assess cardiopulmonary parameters in 16 elite male wrestlers (W), 21 water polo player (WP) and 20 sedentary age-matched subjects (C). Plasma levels of NT-pro-BNP, cortisol and adrenocorticotropic hormone (ACTH) were measured using immunoassay sandwich technique, radioimmunoassay and radioimmunometric techniques, respectively, 10min before test (1), at beginning (2), at maximal effort (3), at 3rdmin of recovery (4). In all groups, NT-pro-BNP decreased between 1 and 2; increased from 2 to 3; and remained unchanged until 4. ACTH increased from 1 to 4, whereas cortisol increased from 1 to 3 and stayed elevated at 4. In all groups together, ΔNT-pro-BNP2/1 predicted peak oxygen consumption (B=37.40, r=0.38, p=0.007); cortisol at 3 predicted heart rate increase between 2 and 3 (r=-0.38,B=-0.06, p=0.005); cortisol at 2 predicted peak carbon-dioxide output (B=2.27, r=0.35, p<0.001); ΔACTH3/2 predicted peak ventilatory equivalent for carbon-dioxide (B=0.03, r=0.33, p=0.003). The relation of cortisol at 1 with NT-pro-BNP at 1 and 3 was demonstrated using logistic function in all the participants together (for 1/cortisol at 1 B=63.40, 58.52; r=0.41, 0.34; p=0.003, 0.013, respectively). ΔNT-pro-BNP2/1 linearly correlated with ΔACTH4/3 in WP and W (r=-0.45, -0.48; p=0.04, 0.04, respectively). These results demonstrate for the first time that HPA axis and NT-pro-BNP interface in physical stress probably contribute to integrative regulation of cardiopulmonary performance.
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Sistema Hipotálamo-Hipofisário/fisiologia , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Resistência Física/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Hormônio Adrenocorticotrópico/sangue , Adulto , Atletas , Dióxido de Carbono/sangue , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Hidrocortisona/sangue , Masculino , Consumo de Oxigênio/fisiologia , Estresse FisiológicoRESUMO
Brain natriuretic peptide (NT-pro-BNP) is used as marker of cardiac and pulmonary diseases. However, the predictive value of circulating NT-pro-BNP for cardiac and pulmonary performance is unclear in physiological conditions. Standard echocardiography, tissue Doppler and forced spirometry at rest were used to assess cardiac parameters and forced vital capacity (FVC) in two groups of athletes (16 elite male wrestlers (W), 21 water polo player (WP)), as different stress adaptation models, and 20 sedentary subjects (C) matched for age. Cardiopulmonary test on treadmill (CPET), as acute stress model, was used to measure peak oxygen consumption (peak VO2), maximal heart rate (HRmax) and peak oxygen pulse (peak VO2/HR). NT-pro-BNP was measured by immunoassey sandwich technique 10min before the test - at rest, at the beginning of the test, at maximal effort, at third minute of recovery. FVC was higher in athletes and the highest in W (WP 5.60±0.29 l; W 6.57±1.00 l; C 5.41±0.29 l; p<0.01). Peak VO2 and peak VO2/HR were higher in athletes and the highest in WP. HRmax was not different among groups. In all groups, NT-pro-BNP decreased from rest to the beginning phase, increased in maximal effort and stayed unchanged in recovery. NT-pro-BNP was higher in C than W in all phases; WP had similar values as W and C. On multiple regression analysis, in all three groups together, ΔNT-pro-BNP from rest to the beginning phase independently predicted both peak VO2 and peak VO2/HR (r=0.38, 0.35; B=37.40, 0.19; p=0.007, 0.000, respectively). NT-pro-BNP at rest predicted HRmax (r=-0.32, B=-0.22, p=0.02). Maximal NT-pro-BNP predicted FVC (r=-0.22, B=-0.07, p=0.02). These results show noticeable predictive value of NT-pro-BNP for both cardiac and pulmonary performance in physiological conditions suggesting that NT-pro-BNP could be a common regulatory factor coordinating adaptation of heart and lungs to stress condition.
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Pulmão/metabolismo , Peptídeo Natriurético Encefálico/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Capacidade Vital , Humanos , Masculino , Valor Preditivo dos Testes , Adulto JovemRESUMO
Glucocorticoid (GC) sensitivity depends on glucocorticoid receptor (GR) and heat shock proteins (Hsps). We investigated whether common GR genes (ER22/23EK, N363S, Bcl I, and 9ß) and adrenocorticotropin receptor promoter polymorphisms influence susceptibility for unilateral adrenal incidentaloma (AI), plus GR and Hsp expression in tumorous (n = 19), peritumorous (n = 13) and normal adrenocortical (n = 11) tissues. Patients (n = 112), population-matched controls (n = 100) and tumor tissues (n = 32) were genotyped for these polymorphisms. Postdexamethasone serum cortisol was higher in patients (p < 0.001). GR gene variants, larger allele of Bcl I (odds ratio [OR] 2.9; 95% confidence interval [CI] 1.7-5.1; p < 0.001] and minor allele of 9ß (OR 3.0; 95% CI 1.6-5.7; p < 0.001) were independent predictors of AI. In patients, the first allele is linked with larger tumors (p = 0.002) and the latter with higher postdexamethasone cortisol levels (p = 0.025). Both allele carriers had lesser waist circumference (p = 0.02), similar adrenocorticotropin and higher basal (p = 0.024) and postdexamethasone cortisol concentrations (p < 0.001). Tumorous and constitutional genotypes were similar. GR-D is the major receptor isoform in normal adrenal cortex by Western blotting. Loss of other receptor isoforms, decrease in immunostaining for GR (p < 0.0001), underexpression of chaperones (p ≤ 0.01) and the presence of inducible Hsp70 were found in adenomas. In conclusion, GR gene variants, C allele of Bcl I and minor allele of 9ß, are associated with AIs. Their concurrent presence in patients reduces GC sensitivity. Normal adrenal cortex preferentially expresses GR-D. In adenomas, the lack of other GR isoforms and underexpression of heat shock proteins perhaps permanently impair GC signaling, which could promote dysregulated cortisol production and tumor growth. The innate GC sensitivity probably modifies these effects.
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Neoplasias das Glândulas Suprarrenais/genética , Glucocorticoides/farmacologia , Chaperonas Moleculares/genética , Receptores de Glucocorticoides/genética , Córtex Suprarrenal/efeitos dos fármacos , Córtex Suprarrenal/metabolismo , Córtex Suprarrenal/patologia , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Estudos de Casos e Controles , Extratos Celulares , Feminino , Predisposição Genética para Doença , Haplótipos/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Receptores da Corticotropina/genética , Fatores de Risco , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
The role of cortisol in mediating basal metabolic rate (BMR) changes that accompany the adjustment of maternal body weight (BW) and body composition during pregnancy is unknown. We tested whether increase in BMR during pregnancy is explained by variations in cortisol secretion. Longitudinal changes in BW, fat mass (FM), fat-free mass (FFM), BMR, hormonal, and metabolic parameters in 31 parous Caucasian women at gestational weeks 12, 26, and 36 were examined. Individual differences (Delta) between the last and the first measurement occasions for each variable were calculated. By gestational week 36, BW and BMR increased while both FFM/FM and BMR/BW ratio decreased (P < 0.001 for all) suggesting higher proportion of FM accretion. Cortisol, leptin, and insulin-like growth factor-1 (IGF-1) concentration rose, whereas non-placental growth hormone (GH) and thyroid hormones declined (P < 0.001 for all). Insulin resistance changed; basal glucose (P < 0.001) and ghrelin (P < 0.014) declined, whereas insulin (P < 0.001), homeostatic model index (HOMA-IR) (P = 0.041), and free fatty acid (FFA) concentration (P = 0.007) increased. The elevation in BMR showed inverse correlations with DeltaBW (r = 0.37, P = 0.047) and Deltacortisol (r = -0.53, P = 0.004). Significant portion (51.6%) of the variation in BMR change was explained by increases of cortisol (27.1%), FFA (13.4%), and free triiodothyronine (11.1%). In conclusion, the changes in maternal cortisol concentration are in relationship with changes in BMR and BW, further suggesting that increased cortisol secretion during pregnancy could be linked with the maintenance of maternal BW and body composition.
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Metabolismo Basal/fisiologia , Hidrocortisona/metabolismo , Adulto , Glicemia/análise , Composição Corporal , Ácidos Graxos não Esterificados/sangue , Feminino , Idade Gestacional , Grelina/sangue , Hormônio do Crescimento/sangue , Humanos , Hidrocortisona/sangue , Resistência à Insulina , Fator de Crescimento Insulin-Like I/análise , Leptina/sangue , Gravidez , Hormônios Tireóideos/sangue , Aumento de PesoRESUMO
OBJECTIVE: There have been rare conflicting results reported concerning possible higher frequency of hearing loss in acromegalic patients. Our goal was to determine whether there is higher frequency of conductive hearing loss in acromegalics and what may cause it if there is any. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Thirty previously untreated patients with acromegaly were compared with 20 age- and sex-matched healthy control subjects. INTERVENTIONS: In all subjects: Otomicroscopy, tuning fork tests, audiometry tympanometry, cochleostapedial reflex, otoacoustic emissions. In acromegalics: endocrinologic assessment, MRI and if necessary, epipharyngoscopy. MAIN OUTCOME MEASURES: We searched for: 1) Signs of ossicle fixation: absence of stapedial reflex in the presence of normal tympanogram, conductive hearing loss, and absence of or grossly disturbed OAE; 2) Disturbances of middle ear ventilation: excessive negative pressure (tympanogram type C), or middle ear effusion (tympanogram type B). RESULTS: The only statistically significant difference between untreated acromegalics and healthy subjects was the presence of middle ear ventilation problem: 7/30 acromegalics (23%) in comparison to none out of 20 healthy controls (0%), p = 0.033. The acromegalics with middle ear ventilation problem were significantly older, had longer duration of the disease, and lower mean growth hormone (GH) levels in comparison with acromegalics without this problem (51.6 +/- 1.7 vs. 44.4 +/- 2.5 years, 11.6 +/- 2.4 vs. 7.7 +/- 0.4 years, 21.68 +/- 4.89 vs. 49.98 +/- 12.54 microg/L respectively). CONCLUSION: Patients with active acromegaly have more frequent middle ear ventilation problem than normal population, especially those with longer duration of the disease. Possible causes are discussed.
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Acromegalia/complicações , Perda Auditiva Condutiva/etiologia , Testes de Impedância Acústica , Acromegalia/etiologia , Adenoma/complicações , Adulto , Idoso , Audiometria de Tons Puros , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Hormônio do Crescimento/análise , Humanos , Fator de Crescimento Insulin-Like I/análise , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Otite Média com Derrame/etiologia , Emissões Otoacústicas Espontâneas/fisiologia , Neoplasias Hipofisárias/complicações , Prevalência , Estudos ProspectivosRESUMO
CONTEXT: Plasma ghrelin concentration is diminished in gastrectomized patients. Acute ghrelin administration reduces insulin secretion, whereas insulin infusion has been shown to decrease ghrelin levels. Whether ghrelin has any effect on glucose utilization in humans is unknown. OBJECTIVE: Our objective was to reveal the effect of ghrelin on insulin-mediated glucose disposal in gastrectomized patients. STUDY AND SETTING: We conducted a double-blind, randomized, placebo-controlled, hospital-based study. PATIENTS: Seven men and three women who all had a previous total gastrectomy and truncal vagotomy entered and completed the study. INTERVENTION: Each individual received infusion of saline alone or saline with ghrelin (5.0 pmol/kg.min) during a 5-h hyperinsulinemic (80 mU/m(2).min) euglycemic clamp on 2 separate days. MAIN OUTCOME MEASURES: We assessed glucose disposal rate and concentrations of C-peptide, ghrelin, GH, IGF-I, IGF-binding protein (IGFBP)-3 and -1, cortisol, leptin, and adiponectin. RESULTS: Glucose disposal rate decreased during ghrelin infusion (control study 8.6 +/- 0.2 vs. 7.2 +/- 0.1 mg/kg.min P < 0.001). In experiments with saline infusion, levels of ghrelin (P < 0.001), C-peptide (P < 0.001), glucagon (P < 0.001), adiponectin (P = 0.005), cortisol (P = 0.012), IGF-I (P < 0.001), IGFBP-3 (P = 0.038), and IGFBP-1 (P = 0.001) fell in response to euglycemic hyperinsulinemia. GH concentration maintained at baseline, whereas leptin significantly rose (P < 0.001). In the ghrelin infusion study, the plateau level of ghrelin concentration (6963.6 +/- 212.9 pg/ml) was maintained from 90 min throughout the experiment. GH (P < 0.001) and cortisol (P = 0.04) concentrations rose, whereas C-peptide levels were more suppressed than in the control study (P < 0.001). Other hormones and IGFBPs changed similarly as in the study with saline infusion. CONCLUSION: It appears that ghrelin might be involved in the negative control of insulin secretion and glucose consumption in gastrectomized patients, at least after acute administration.
Assuntos
Glicemia/metabolismo , Gastrectomia , Insulina/metabolismo , Hormônios Peptídicos/administração & dosagem , Adiponectina/sangue , Adulto , Índice de Massa Corporal , Peptídeo C/sangue , Método Duplo-Cego , Ácidos Graxos não Esterificados/sangue , Feminino , Grelina , Glucagon/sangue , Técnica Clamp de Glucose , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Insulina/sangue , Secreção de Insulina , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Cinética , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Hormônios Peptídicos/sangue , Hormônios Peptídicos/fisiologia , PlacebosRESUMO
OBJECTIVE: Correction of GH and IGF-I levels are associated with improvements in insulin secretion, cardiac performance and body composition in patients with acromegaly, but whether these parallel post-treatment levels of GH-IGF-I axis activity is undefined. We investigate whether various biochemical outcomes after transsphenoidal pituitary surgery (TSS) in these patients are associated with clinically relevant differences in cardiac performance, insulin resistance and body composition. DESIGN: Cross-sectional study of consecutive patients with acromegaly admitted to the hospital between 2001 and 2002. PATIENTS AND METHODS: Forty-one patients after TSS for somatotroph pituitary adenoma and 23 patients with naive acromegaly serving as positive controls were enrolled in the study. Mean daily GH levels (mGH), IGF-I, leptin and lipid levels, glucose, insulin and GH concentrations during oral glucose tolerance test (oGTT) were measured in all study participants. Insulin resistance was measured by homeostatic model index (R(HOMA)). Body composition was assessed by dual-energy X-ray absorptiometry. Left ventricular mass index (LVM(i)) and cardiac index (C(i)) were determined by echocardiography. RESULTS: We found no difference in cardiac indices, insulin resistance, body composition and leptin levels between patients with complete biochemical remission and those with inadequately controlled disease (P > 0.05 for all) after TSS. Cured patients had lower values (mean +/- SD) of cardiac index (2.2 +/- 0.7 vs. 3.0 +/- 1.0 l/min/m(2); P = 0.04) compared with naive patients. A similar decrease in LVM(i) was observed in controlled (108.4 +/- 30.0 g/m(2); P = 0.015) and inadequately controlled disease (108.8 +/- 30.7 g/m(2); P = 0.03) in comparison with naive disease (160.3 +/- 80.6 g/m(2)). Insulin resistance and leptin changed in opposite ways. In controlled and inadequately controlled disease, R(HOMA) index was lower (2.2 +/- 1.4; P = 0.001 and 3.1 +/- 2.0; P = 0.05 vs. 5.1 +/- 3.1) while leptin concentration was higher (14.9 +/- 8.7 microg/l, P = 0.004 and 12.8 +/- 7.8 microg/l, P = 0.05 vs. 7.4 +/- 3.8 microg/l) than in naive disease. In all patients, leptin correlated negatively with cardiac index (r = -0.46; P = 0.001) and IGF-I levels (r = -0.45; P < 0.001). Independent predictors of biochemical remission, based on normal IGF-I levels only, were cardiac [P = 0.04, odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2-0.9] and R(HOMA) index (P = 0.009, OR 0.6; 95% CI 0.4-0.8). Similar results were obtained if the definition of cure included both normal IGF-I levels and the ability to achieve GH nadir < 1 microg/l during oGTT. Insulin resistance (P = 0.02, OR 0.6; 95% CI 0.4-0.9) and leptin level (P = 0.002, OR 1.3; 95% CI 1.1-1.6) were independent predictors of normalized mGH values. CONCLUSION: This study shows that cardiac indices, insulin resistance and body composition were not different between patients with complete biochemical remission and those with discordant GH and IGF-I levels. It appears that even incomplete disease control after TSS can result in improvement of these clinical markers.
Assuntos
Acromegalia/cirurgia , Absorciometria de Fóton , Acromegalia/sangue , Acromegalia/etiologia , Adenoma/sangue , Adenoma/complicações , Adenoma/cirurgia , Adulto , Idoso , Área Sob a Curva , Biomarcadores/sangue , Glicemia/análise , Composição Corporal , Ecocardiografia , Feminino , Hormônio do Crescimento/sangue , Humanos , Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Leptina/sangue , Lipídeos/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/sangue , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/cirurgia , Indução de Remissão , Falha de TratamentoRESUMO
PURPOSE: We sought to determine the prevalence and characteristics of heart failure in patients with newly diagnosed acromegaly. SUBJECTS AND METHODS: We assessed 102 consecutive patients who had acromegaly (44 men; age range, 22 to 71 years) for signs and symptoms of heart failure. We included a control group of 33 nonobese healthy subjects (13 men; age range, 26 to 70 years). Cardiac morphologic parameters, left ventricular mass index, ejection fraction, end-systolic wall stress, and cardiac index were measured by echocardiography. Endocrinological assessment was performed in all participants. RESULTS: Of the 102 patients, 10 (10%) had overt heart failure at the time of diagnosis of acromegaly, 9 of whom were men (P <0.01). Patients with acromegaly and heart failure had an increased mean (+/- SD) left ventricular end-diastolic diameter (76 +/- 11 mm) compared with those without heart failure (53 +/- 6 mm, P <0.001) and control subjects (49 +/- 5 mm, P <0.001). Patients with heart failure had higher left ventricular mass index (230 +/- 56 g/m2 vs. 118 +/- 40 g/m(2), P <0.001) and end-systolic wall stress (237 +/- 79 x 10(3) dyn/cm2 vs. 111 +/- 42 x 10(3) dyn/cm2, P <0.001), but lower ejection fraction (42% +/- 17% vs. 66% +/- 9%, P <0.001), in comparison with patients without heart failure. The mean cardiac index was significantly higher in patients with heart failure (4.3 +/- 1.8 L/min-m2) than in those without heart failure (3.5 +/- 0.8 L/min-m2, P = 0.04) or in control subjects (3.1 +/- 0.6 L/min-m2, P = 0.002). Two factors were independently associated with heart failure in acromegalic patients: cardiac index (odds ratio [OR] per SD of 1.0 L/min-m2 = 16; 95% confidence interval [CI]: 1.8 to 135) and ejection fraction (OR per SD of 12% = 0.7; 95% CI: 0.6 to 0.9). CONCLUSION: High output heart failure with a modest decline in ejection fraction is frequently detected at the time of diagnosis of acromegaly. Left ventricular hypertrophy in these patients is characterized by a dilated ventricle and an increased left ventricular mass that is primarily due to the enlarged chamber diameter.