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The original version of this article, published on 10 January 2020, contained a mistake. An author's name was misspelled.
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Exercise is recommended for people with osteoporosis, but the effect for people who have suffered vertebral fracture is uncertain. This study shows that a multicomponent exercise-program based on recommendations for people with osteoporosis improved muscle strength, balance, and fear of falling in older women with osteoporosis and vertebral fracture. INTRODUCTION: Guidelines for exercise strongly recommend that older adults with osteoporosis or osteoporotic vertebral fracture should engage in a multicomponent exercise programme that includes resistance training in combination with balance training. Prior research is scarce and shows inconsistent findings. This study examines whether current exercise guidelines for osteoporosis, when applied to individuals with vertebral fractures, can improve health outcomes. METHODS: This single blinded randomized controlled trial included 149 older women diagnosed with osteoporosis and vertebral fracture, 65+ years. The intervention group performed a 12-week multicomponent exercise programme, the control group received usual care. Primary outcome was habitual walking speed, secondary outcomes were physical fitness (Senior Fitness Test, Functional Reach and Four Square Step Test), health-related quality of life and fear of falling. Descriptive data was reported as mean (standard deviation) and count (percent). Data were analyzed following intention to treat principle and per protocol. Between-group differences were assessed using linear regression models (ANCOVA analysis). RESULTS: No statistically significant difference between the groups were found on the primary outcome, walking speed (mean difference 0.04 m/s, 95% CI - 0.01-0.09, p = 0.132). Statistically significant between-group differences in favour of intervention were found on FSST (dynamic balance) (mean difference - 0.80 s, 95% CI - 1.57 to - 0.02, p = 0.044), arm curl (mean difference 1.55, 95% CI 0.49-2.61, p = 0.005) and 30-s STS (mean difference 1.85, 95% CI 1.04-2.67, p < 0.001), as well as fear of falling (mean difference - 1.45, 95% CI - 2.64 to - 0.26, p = 0.018). No statistically significant differences between the groups were found on health-related quality of life. CONCLUSION: Twelve weeks of a supervised multicomponent resistance and balance exercise programme improves muscle strength and balance and reduces fear of falling, in women with osteoporosis and a history of vertebral fractures. TRIAL REGISTRATION: ClincialTrials.gov Identifier: NCT02781974. Registered 25.05.16. Retrospectively registered.
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Acidentes por Quedas/prevenção & controle , Terapia por Exercício , Osteoporose/terapia , Aptidão Física , Qualidade de Vida , Fraturas da Coluna Vertebral/terapia , Idoso , Medo , Feminino , Humanos , Equilíbrio PosturalRESUMO
BACKGROUND: The significance of basal renal nitric oxide (NO) availability in the regulation of renal perfusion and sodium excretion in human congestive heart failure (CHF) has not been described previously. METHODS AND RESULTS: We studied the effects of acute systemic NO synthesis inhibition with N(G)-monomethyl-L-arginine (L-NMMA) in 12 patients with CHF and 10 healthy control subjects (CON) in a randomized placebo-controlled study. Effect parameters were renal plasma flow (RPF), renal vascular resistance (RVR), glomerular filtration rate (GFR), urine sodium excretion and plasma levels of vasoactive hormones. L-NMMA was associated with a significant decrease in RPF (CON-LNMMA: -13 ± 3% [P = .014]; CHF-LNMMA: -17 ± 7% [P = .017]) and a profound increase in RVR in both CHF and CON (CON-LNMMA: +26 ± 6% [P = .009]; CHF-LNMMA: +37 ± 70% [P = .005]). Significant decreases in sodium excretion were found in both CHF-LNMMA and CON-LNMMA. Relative changes from baseline were not statistically different between CHF-LNMMA and CON-LNMMA. After L-NMMA, RPF values correlated inversely with plasma aldosterone in CHF-LNMMA (P = .01). L-NMMA induced an increase in A-type natriuretic peptide (ANP) only in CHF-LNMMA (+18 ± 8%; P = .035), which correlated significantly with basal ANP levels (P = .034). CONCLUSIONS: There was no difference in the renal response to L-NMMA in CHF vs CON, suggesting that the impact of NO on renal perfusion and sodium excretion is maintained in stable CHF. We suggest that NO influences the release of ANP during high levels of atrial stretch in CHF.
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Taxa de Filtração Glomerular/fisiologia , Insuficiência Cardíaca/sangue , Rim/irrigação sanguínea , Rim/metabolismo , Óxido Nítrico/sangue , Resistência Vascular/fisiologia , Idoso , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Velocidade do Fluxo Sanguíneo/fisiologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/urina , Humanos , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/urina , Resistência Vascular/efeitos dos fármacos , ômega-N-Metilarginina/farmacologia , ômega-N-Metilarginina/uso terapêuticoRESUMO
BACKGROUND: The governance structures associated with health data are evolving in response to advances in digital technologies that enable new ways of capturing, using, and sharing different types of data. Increasingly, health data moves between different contexts such as from healthcare to research, or to commerce and marketing. Crossing these contextual boundaries has the potential to violate societal expectations about the appropriate use of health data and diminish public trust. Understanding citizens' views on the acceptability of and preferences for data use in different contexts is essential for developing information governance policies in these new contexts. METHODS: Focus group design presenting data sharing scenarios in England, Iceland, and Sweden. RESULTS: Seventy-one participants were recruited. Participants supported the need for data to help understand the observable world, improve medical research, the quality of public services, and to benefit society. However, participants consistently identified the lack of information, transparency and control as barriers to trusting organisations to use data in a way that they considered appropriate. There was considerable support for fair and transparent data sharing practices where all parties benefitted. CONCLUSION: Data governance policy should involve all stakeholders' perspectives on an ongoing basis, to inform and implement changes to health data sharing practices that accord with stakeholder views. The Findings showed that (1) data should be used for ethical purposes even when there was commercial interest; (2) data subjects and/or public institutions that provide and share data should also receive benefits from the sharing of data; (3) third parties use of data requires greater transparency and accountability than currently exists, (4) there should be greater information provided to empower data subjects.
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Disseminação de Informação , Confiança , Inglaterra , Grupos Focais , Humanos , Islândia , Disseminação de Informação/ética , SuéciaRESUMO
OBJECTIVE: To compare hip fracture risk in soft and hard protected falls with the risk in unprotected falls and to compare the incidence of hip fractures in nursing homes providing soft and hard hip protectors. METHODS: An observational study conducted within the framework of a cluster randomized trial in 18 nursing homes. Nursing homes were randomized to offer either soft or hard hip protectors. Individual participants were followed for falls for 18 months. RESULTS: Of 1236 participating residents, 607 suffered 2926 falls; 590 of the 2926 falls were categorized as soft protected, 852 as hard protected, and 1388 as unprotected falls. Sixty-six verified hip fractures occurred: eight in soft protected falls, 11 in hard protected falls, and 45 in unprotected falls. The hip fracture risk in soft and hard protected falls was almost 60% lower than in unprotected falls (OR (soft) 0.36, 95% CI 0.17 to 0.77; OR (hard) 0.41, 95% CI 0.19 to 0.89). The incidence of hip fracture was 4.6 and 6.2 per 100 person-years in nursing homes providing soft and hard hip protectors, respectively (p = 0.212). CONCLUSION: Both types of hip protector have the potential, when worn correctly, to reduce the risk of a hip fracture in falls by nearly 60%. Both can be recommended to nursing-home residents as a means of preventing hip fractures.
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Acidentes por Quedas/estatística & dados numéricos , Fraturas do Quadril/prevenção & controle , Equipamentos de Proteção , Idoso , Idoso de 80 Anos ou mais , Métodos Epidemiológicos , Feminino , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Humanos , Masculino , Noruega/epidemiologia , Casas de Saúde/estatística & dados numéricosRESUMO
The introduction of the anti-CD20 antibody rituximab in combination with chemotherapy (R-chemo) has improved the prognosis of patients with follicular lymphoma (FL). During the last decade, the addition of a maintenance treatment with rituximab (MR) after R-chemo has been tested with the hope of further improving the outcome of these patients. Using 2 independent population-based cohorts, we investigated the effect of up-front MR on time related end points as well as the risk of histological transformation (HT). FL patients were included if they: (1) completed first-line induction treatment with R-chemo, (2) were alive after induction treatment and eligible for MR, and (3) had no evidence of HT at this time point. The training cohort consisted of 733 Danish patients of whom 364 were consolidated with MR; 369 were not. Patients receiving MR more often had advanced clinical stage (90% vs 78%), high Follicular Lymphoma International Prognostic Index (FLIPI) score (64% vs 55%), and bone marrow infiltration (49% vs 40%). Those consolidated with MR had an improved 5-year overall survival (OS; 89% vs 81%; P = .001) and progression-free survival (PFS; 72% vs 60%; P < .001). In the training cohort, MR was associated with a reduction of HT risk (P = .049). Analyses of an independent validation cohort of 190 Finnish patients confirmed the favorable impact of MR on 5-year OS (89% vs 81%; P = .046) and PFS (70% vs 57%; P = .005) but did not find a reduced risk of HT. The present population-based data suggest that the outcome of patients with FL has improved after consolidation of R-chemo with MR.
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Linfoma Folicular/tratamento farmacológico , Quimioterapia de Manutenção/métodos , Rituximab/uso terapêutico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Estudos de Coortes , Quimioterapia de Consolidação/métodos , Feminino , Humanos , Linfoma Folicular/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Países Escandinavos e Nórdicos , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemAssuntos
Metilação de DNA , DNA de Neoplasias/metabolismo , Regulação Leucêmica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/metabolismo , Linfoma de Célula do Manto/metabolismo , Proteínas de Neoplasias/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Receptores Imunológicos/biossíntese , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma de Célula do Manto/patologia , Masculino , Proteínas RoundaboutRESUMO
UNLABELLED: A comparison between soft- and hard-shelled hip protectors in nursing homes shows no clinical relevant difference in acceptance and probability of continued use. However, significantly more users of the soft hip protector used the protector 24 hours a day. INTRODUCTION AND HYPOTHESIS: Uptake and adherence with the use of hip protectors are poor due to discomfort and impracticality. The aim of the study was to compare uptake and adherence between soft- and hard-shelled hip protectors. We hypothesized a higher uptake and adherence with soft hip protectors than with hard ones. METHODS: This cluster randomized study was performed for 18 months in 18 Norwegian nursing homes. Each nursing home was randomly allocated either soft or hard hip protectors. A total of 1,236 participants were enrolled in the study of which 314 and 290 started to use soft and hard hip protectors, respectively. RESULTS: The uptake among participants in nursing homes provided soft hip protectors was not significantly different from the uptake in nursing homes provided hard protectors. The probability of continued use was a little higher among users of soft hip protector. There were significantly more 24-hour users among those people using the soft protector. CONCLUSION: Our results indicate that changing the design might not solve the compliance issue, but may be a step in the right direction, especially for those people who are in need of 24-hour use.
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Fraturas do Quadril/prevenção & controle , Instituição de Longa Permanência para Idosos , Casas de Saúde , Cooperação do Paciente/estatística & dados numéricos , Equipamentos de Proteção/estatística & dados numéricos , Acidentes por Quedas , Idoso de 80 Anos ou mais , Análise por Conglomerados , Feminino , Humanos , Masculino , NoruegaRESUMO
During the years 1956-69, 74 cases of invasive cervical carcinoma treated by simple hysterectomy were referred to the Norwegian Radium Hospital. The 5 year survival for those with free operative borders was 77.1% as compared with 30.7% for those cases in which the tumour was transected during operation. Before operation for a supposed benign condition, cancer should always be ruled out. If simple hysterectomy is performed and cervical cancer found in the specimen, immediate postoperative megavoltage radiotherapy affords the best chance of cure.
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Histerectomia Vaginal , Histerectomia , Neoplasias do Colo do Útero/cirurgia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Complicações Pós-Operatórias , Prognóstico , Estudos Retrospectivos , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/radioterapiaRESUMO
The effects of 15 days of detraining and 15 days of retraining were studied in 6 well-trained runners. Detraining resulted in significant decreases in the mean activities of succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) of 24% and 13% respectively, but no significant increases in these enzymes activities occured with retraining. Maximal oxygen uptake (VO2 max) decreased by 4% with detraining (p less than 0.05), and increased by a similar amount with retraining. Performance time in an intense submaximal run decreased by 25% (p less than 0.05) with inactivity, but still averaged 9% below the initial level after retraining. Maximal heart rate and peak heart rate during the performance run were higher after detraining by 4 and 9 beats per min, respectively (p less than 0.05). With retraining, these heart rate values were decreased by 7 and 9 beats per min (p less than 0.05). Blood lactate concentrations after the VO2 max and performance run were approximately 20% lower after detraining and retraining (p less than 0.05). Muscle fibre areas for three subjects tended to be larger in biopsy samples taken after detraining and retraining. These data suggest that even short periods of detraining result in significant changes in indices of physiological capacity and function in subjects near their upper limit of adaptation, and that a longer period of retraining is necessary for muscle to re-adapt to its original trained state.
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Músculos/metabolismo , Adaptação Fisiológica , Adulto , Metabolismo Energético , Hemodinâmica , Humanos , L-Lactato Desidrogenase/metabolismo , Lactatos/metabolismo , Masculino , Músculos/irrigação sanguínea , Músculos/enzimologia , Consumo de Oxigênio , Educação Física e Treinamento , Respiração , Succinato Desidrogenase/metabolismoRESUMO
The purpose of this study was to quantify the influence of training habits on the changes in plasma atrial natriuretic peptide (ANP), plasma brain natriuretic peptide (BNP) and urine aquaporin-2 (u-AQP2) during exercise by studying trained and untrained healthy subjects. Eleven trained subjects (7 males, 4 females) and 10 untrained subjects (8 males, 2 females) performed a maximal aerobic exercise test. ANP and BNP were determined every 3 min and at maximum exercise by radioimmunoassay (RIA), and u-AQP2 was determined before and after the exercise test by RIA. The absolute increase in ANP during exercise was higher in the trained subjects (trained subjects: 5.6 pmol/L; untrained subjects: 2.4 pmol/L, p < 0.05) and was positively correlated to ANP at rest (p < 0.03). The maximum absolute increase in BNP during exercise was the same in the two groups (trained subjects: 0.5 pmol/L; untrained subjects: 0.6 pmol/L, NS) and tended to correlate positively with resting BNP in the trained subjects (p = 0.07). Exercise did not change u-AQP2 excretion in either trained subjects (rest: 372 ng/mmol creatinine; exercise: 314 ng/mmol creatinine, NS) or untrained subjects (rest: 263 ng/mmol creatinine; exercise: 338 ng/mmol creatinine, NS). The absolute increase in ANP during exercise was higher in trained subjects than in untrained subjects and was positively correlated to ANP at rest. This might reflect the normal cardiovascular adaptation to exercise. The increase in BNP during exercise was unrelated to training habits. Training habits did not affect the u-AQP2 excretion during exercise.
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Aquaporinas/urina , Fator Natriurético Atrial/sangue , Exercício Físico/fisiologia , Peptídeo Natriurético Encefálico/sangue , Aptidão Física , Adulto , Aquaporina 2 , Aquaporina 6 , Teste de Esforço , Feminino , Humanos , Masculino , RadioimunoensaioRESUMO
The effects of physical training on elderly, fragile patients with rheumatoid arthritis (RA) who are on low-dose steroids were investigated. The controlled study included 24 patients who had been treated with low-dose steroids for 2 years. Each patient was assigned either to a treatment group receiving training or to an untrained control group. The training took place over a 3-month period and was based on a protocol using progressive interval training consisting of bicycle exercises, heel lifts, and step-climbing. The exercises were performed twice weekly for 45 minutes. Comparison of the two groups showed that disease activity did not increase in the trained group and that fewer, but not significantly fewer, swollen joints were observed in this group (p = 0.06). No significant changes were noticed in erythrocyte sedimentation rate, tender joints, or morning stiffness. The work capacity of the trained patients were doubled and the numbers of repetitions increased 76%. Individually adapted exercise programs can therefore be recommended for elderly rheumatoid arthritis patients on steroid treatment.
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Corticosteroides/uso terapêutico , Artrite Reumatoide/reabilitação , Exercício Físico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the enzyme cyclooxygenase and thereby block the prostaglandin (PG) synthesis in the kidneys. In animals, PG interferes with the formation of aquaporin 2 in the distal renal tubules. The purpose was to measure the effect of ibuprofen on urinary excretion of aquaporin-2 (u-AQP2), urinary output, urinary osmolality (u-osm) and plasma concentration of vasopressin (AVP) in a dose-response study using placebo and ibuprofen 600mg and 1200mg. In 12 healthy subjects, urine was collected in 6 periods between 07.00 h and 13.00 h, and blood samples were drawn at 60-min intervals. The study medication was given 10 h and 1 h before the study. U-AQP2 and AVP were determined by radioimmunoassays. U-AQP2 decreased 33% in the placebo group and increased 47% in the ibuprofen groups. There was a highly significant difference between the placebo group, on the one hand, and the ibuprofen groups, on the other. There was a small but significant increase in AVP in the placebo group and the 600 mg ibuprofen group, but not in the 1200 mg ibuprofen group. Urinary output was at maximum after 2 h, with a 394%, 1020% and 714% increase for placebo, 600 mg ibuprofen and 1200 mg ibuprofen, respectively. U-osm decreased during the experiment in all three groups. Inhibition of renal prostaglandin synthesis by ibuprofen affects the distal part of the nephron by increasing u-AQP2. This increase was not related to changes in AVP, urinary output or urinary osmolality. We suggest that the increased excretion of AQP2 can be explained by an increase in the ratio of AQP2 that is shed into the urine because the endocytic retrieval of AQP2 from the apical membrane is impaired. This could not be revealed by changes in the osmoregulatory system by the low doses of ibuprofen used in the present study.
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Anti-Inflamatórios não Esteroides/administração & dosagem , Aquaporinas/urina , Ibuprofeno/administração & dosagem , Administração Oral , Adulto , Aldosterona/sangue , Angiotensina II/sangue , Aquaporina 2 , Aquaporina 6 , Arginina Vasopressina/sangue , Pressão Sanguínea , Estudos Cross-Over , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Néfrons/efeitos dos fármacos , Néfrons/metabolismo , Concentração Osmolar , Valores de Referência , Renina/sangue , Sódio/urina , Urina , Água/metabolismoRESUMO
BACKGROUND: Patients with liver cirrhosis and chronic heart failure (CHF) have a reduced capacity to excrete water. Studies in healthy humans have shown that an acute water load reduces the excretion of aquaporin-2 in urine (u-AQP-2). We wanted to test the hypothesis that an acute water load reduces u-AQP-2 less in patients with liver cirrhosis or CHF than in healthy humans. METHODS: Fourteen healthy subjects, 14 patients with liver cirrhosis, and 14 patients with CHF were given an oral water load of 20 mL/kg. Urine was collected every 30 minutes for 4 hours for analysis of u-AQP-2. Blood samples were drawn at the beginning and at the end of the study for analysis of arginine vasopressin (AVP). u-AQP-2 was determined by radioimmunoassay. RESULTS: During the study period, urinary output was 22.8% higher than water intake in the healthy controls and increased 14-fold from baseline, but in patients with liver cirrhosis and CHF urinary output was 14% and 24% less than the intake, while urinary output increased 7- and 19-fold from baseline, respectively. u-AQP2 decreased significantly more in patients with CHF (39%) than in healthy controls (17%) but it was unchanged in those with liver cirrhosis. AVP decreased 46% in patients with CHF, but was unchanged in healthy controls and those with liver cirrhosis. A 24-hour urinary excretion of AQP-2 was significantly elevated in patients with CHF (median, 25.7 nmol/mol creatinine) compared to healthy controls (15.7 nmol/mol creatinine) and those with liver cirrhosis (17 nmol/mol creatinine). CONCLUSION: The excretion of AQP-2 in urine is abnormal both in liver cirrhosis in which we find less suppression of u-AQP2 by an acute water load and in CHF in which we find a high baseline level and an exaggerated suppression of u-AQP2 by an acute water load.
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Aquaporinas/urina , Ingestão de Líquidos/fisiologia , Insuficiência Cardíaca/urina , Cirrose Hepática/urina , Adulto , Aldosterona/sangue , Angiotensina II/sangue , Aquaporina 2 , Aquaporina 6 , Arginina Vasopressina/sangue , Fator Natriurético Atrial/sangue , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Concentração Osmolar , Renina/sangue , Urina , Equilíbrio Hidroeletrolítico/fisiologiaRESUMO
OBJECTIVE: Animal experiments have shown that lithium interferes with the formation of Aquaporin-2 in the distal renal tubuli. The effect of lithium on formation of renal water channels has not been studied in healthy humans. The aim of this study was to test the hypotheses that a single oral dose of lithium will reduce the formation of water channels both with and without stimulation with hypertonic saline infusion, and that this effect can be detected by measurement of urinary excretion of Aquaporin-2 (u-AQP2). METHODS: In healthy subjects, Study 1 (n = 11) and Study 2 (n = 12), urine was collected in 6 and 7 periods between 08.00 and 14.00, respectively, and blood samples were drawn at 30- to 60-min intervals. The study medication was given at 09.00; u-AQP2 was determined by radioimmunoassay. RESULTS: In Study 1 neither u-AQP2 nor urinary output were significantly changed by lithium. In Study 2, u-AQP2 was increased by hypertonic saline infusion in parallel with an increase in arginine vasopressin. At the end of the study, u-AQP2 was increased by 30% with placebo but only by 13% with the 600 mg lithium dose, and urinary output was significantly higher after 600 mg lithium than after placebo and 300 mg lithium. CONCLUSIONS: U-AQP2 was not significantly changed after a single oral dose of lithium. The antidiuretic response to hypertonic saline infusion was reduced when lithium was given. It is suggested that lithium increases urinary output by inhibiting trafficking of renal water channels in healthy humans.
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Antimaníacos/administração & dosagem , Aquaporinas/urina , Carbonato de Lítio/administração & dosagem , Solução Salina Hipertônica/administração & dosagem , Administração Oral , Adulto , Angiotensina II/sangue , Antimaníacos/sangue , Antimaníacos/urina , Aquaporina 2 , Aquaporina 6 , Arginina Vasopressina/sangue , Fator Natriurético Atrial/sangue , Pressão Sanguínea , Estudos Cross-Over , Feminino , Frequência Cardíaca , Humanos , Carbonato de Lítio/sangue , Carbonato de Lítio/urina , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Concentração Osmolar , Radioimunoensaio , Renina/sangue , Sódio/urina , UrinaRESUMO
Arginine vasopressin (AVP) mediates water transport in the renal collecting ducts by forming water channels of aquaporin-2 (AQP2) in the apical plasma membrane. AQP2 is excreted in human urine. We wanted to test the hypothesis that urinary excretion of AQP2 (u-AQP2) reflects the effect of AVP on the renal collecting ducts during water deprivation and hypertonic saline infusion in healthy subjects. Fifteen healthy subjects underwent a 24-h period of fluid restriction. Urine and blood samples were collected at timed intervals. Fifteen healthy subjects were given 7 ml/kg 3% hypertonic saline infusion for 30 min. Urine and blood samples were collected at timed intervals. During fluid restriction, the u-AQP2 rate increased from 3.9 (25th percentile: 3.1; 75th percentile: 5.2) to 7.6 (5.9-9.1; P < 0.001) ng/min, and the plasma AVP (p-AVP) level increased from 0.5 (0.4-0.6) to 3 (1.7-3.3) pmol/l. There was a positive correlation between the maximum change in u-AQP2 rate and the maximum change in p-AVP (r = 0.57, P < 0.03). During the infusion study, u-AQP2 rate was at maximum 90 min after the infusion [baseline: 4.5 ng/min (3.5-4.8); 90 min: 5 ng/min (4.5-6.0) P < 0.02]. p-AVP increased from 1.0 (0.9-1.1) to 1.5 (1.2-1.8; P < 0.002) pmol/l. There was a positive correlation between the maximum change in u-AQP2 rate and the maximum change in p-AVP (r = 0.83; P < 0.0001). It can be concluded that p-AVP and u-AQP2 are increased during thirst and hypertonic saline infusion and that u-AQP2 reflects the action of AVP on the collecting ducts.