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2.
NPJ Vaccines ; 8(1): 98, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37433788

RESUMO

As part of a multicenter study evaluating homologous and heterologous COVID-19 booster vaccines, we assessed the magnitude, breadth, and short-term durability of binding and pseudovirus-neutralizing antibody (PsVNA) responses following a single booster dose of NVX-CoV2373 in adults primed with either Ad26.COV2.S, mRNA-1273, or BNT162b2 vaccines. NVX-CoV2373 as a heterologous booster was immunogenic and associated with no safety concerns through Day 91. Fold-rises in PsVNA titers from baseline (Day 1) to Day 29 were highest for prototypic D614G variant and lowest for more recent Omicron sub-lineages BQ.1.1 and XBB.1. Peak humoral responses against all SARS-CoV-2 variants were lower in those primed with Ad26.COV2.S than with mRNA vaccines. Prior SARS CoV-2 infection was associated with substantially higher baseline PsVNA titers, which remained elevated relative to previously uninfected participants through Day 91. These data support the use of heterologous protein-based booster vaccines as an acceptable alternative to mRNA or adenoviral-based COVID-19 booster vaccines. This trial was conducted under ClinicalTrials.gov: NCT04889209.

4.
Clin Infect Dis ; 77(4): 560-564, 2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37036397

RESUMO

In a randomized clinical trial, we compare early neutralizing antibody responses after boosting with bivalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines based on either BA.1 or BA.4/BA.5 Omicron spike protein combined with wild-type spike. Responses against SARS-CoV-2 variants exhibited the greatest reduction in titers against currently circulating Omicron subvariants for both bivalent vaccines.


Assuntos
COVID-19 , Humanos , COVID-19/prevenção & controle , SARS-CoV-2/genética , Anticorpos Neutralizantes , Vacinas Combinadas , Anticorpos Antivirais
5.
EClinicalMedicine ; 55: 101718, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36386035

RESUMO

Background: Recognising the importance of clinical outcomes assessments (COAs), the Response Assessment in Neuro-Oncology-Patient Reported Outcome (RANO-PRO) Working Group recommended inclusion of core symptoms and functions in clinical care or research for malignant glioma patients. This study evaluated the association of the recommended symptoms (pain, perceived cognition, seizures, aphasia, symptomatic adverse events) and functions (weakness, walking, work, usual activities) with disease progression in these patients. Methods: In this retrospective cohort study, patients with malignant glioma were included from the US National Cancer Institute Neuro-Oncology Branch Natural History Study (NOB-NHS) which follows primary central nervous system tumour patients aged 18 years and older throughout their disease trajectory. The M.D. Anderson Symptom Inventory-Brain Tumor (MDASI-BT), EQ-5D-3L, Karnofsky Performance Status (KPS), and Neurologic Function scores (NFS) were evaluated in relation to disease progression by chi-square tests, independent- and paired-samples t-tests, adjusted for multiple comparisons at first assessment and over time to a second assessment. Radiographic disease progression was determined on the interpretation of the imaging study by a radiologist and neuro-oncologist using standard criteria as part of clinical trial participation or routine standard of care. The priority constructs were evaluated to provide initial evidence of their relevance, relationship to disease status over time, and sensitivity to change in a diverse group of patients with malignant glioma. Findings: Seven hundred and sixty-five patients had enrolled into the NOB-NHS between September 1, 2016 and January 31, 2020. Three hundred and thirty-six patients had a diagnosis of a malignant glioma (anaplastic astrocytoma, anaplastic oligodendroglioma, glioblastoma, and gliosarcoma) and were included in the current study. The sample was 64% male (n = 215), 36% female (n = 121), median age of 52 years (IQR = 18.75), 82% White (n = 276), and 65% had tumour recurrence (n = 219). One hundred and fifty-four (46%) had radiographic disease progression. Difficulty remembering, fatigue, and weakness were worse in the group whose imaging was interpreted as radiographic disease progression versus stable disease, as well as the functions of walking, work, activity, and self-care (1.1 < difference < 1.8). Patients with disease progression were four times more likely to have a poor KPS (≤80) and worse NFS. Among patients with disease progression at a second assessment (n = 112), all symptoms, except seizures, worsened between first assessment and disease progression and up to 22% of patients (n = 25) reported worsening mobility, self-care, and usual activity; 46% (n = 51) and 35% (n = 30) had worsened KPS and NFS, respectively. On average, 4 symptoms or functions (SD = 3) were reported as moderate-to-severe and 30% (n = 33) and 23% (n = 26) had a change to moderate-to-severe fatigue and walking, respectively, at time of disease progression. Over 7% of patients with worsening (n = 7 of 100) reported every symptom and function as having changed the most severely including seizures with fatigue and activity reported as the top symptom and function, respectively. Interpretation: The identified core symptoms and functions worsened at the time of progression, supporting the relevance and sensitivity of the priority constructs identified by the RANO-PRO Working Group for clinical care and clinical trials for malignant glioma patients. Funding: The Natural History Study is supported by Intramural Project 1ZIABC011786-03.

6.
Neurooncol Pract ; 9(6): 526-535, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36388423

RESUMO

Background: Sleep disturbance (SD) is common in patients with cancer and has been associated with worse clinical outcomes. This cross-sectional study explored the prevalence of SD in a primary brain tumor (PBT) population, identified associated demographic and clinical characteristics, and investigated co-occurrence of SD with other symptoms and mood disturbance. Methods: Demographic, clinical characteristics, MD Anderson Symptom Inventory-Brain Tumor, and Patient Reported Outcome Measurement Information System Depression and Anxiety Short-Forms were collected from PBT patients at study entry. Descriptive statistics, Chi-square tests, and independent t-tests were used to report results. Results: The sample included 424 patients (58% male, 81% Caucasian) with a mean age of 49 years (range 18-81) and 58% with high-grade gliomas. Moderate-severe SD was reported in 19% of patients and was associated with younger age, poor Karnofsky Performance Status, tumor progression on MRI, and active corticosteroid use. Those with moderate-severe SD had higher overall symptom burden and reported more moderate-severe symptoms. These individuals also reported higher severity in affective and mood disturbance domains, with 3 to 4 times higher prevalence of depressive and anxiety symptoms, respectively. The most frequently co-occurring symptoms with SD were, drowsiness, and distress, though other symptoms typically associated with tumor progression also frequently co-occurred. Conclusions: PBT patients with moderate-severe SD are more symptomatic, have worse mood disturbance, and have several co-occurring symptoms. Targeting interventions for sleep could potentially alleviate other co-occurring symptoms, which may improve life quality for PBT patients. Future longitudinal work examining objective and detailed subjective sleep reports, as well as underlying genetic risk factors, will be important.

7.
Cell Rep Med ; 3(7): 100679, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35798000

RESUMO

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibits reduced susceptibility to vaccine-induced neutralizing antibodies, requiring a boost to generate protective immunity. We assess the magnitude and short-term durability of neutralizing antibodies after homologous and heterologous boosting with mRNA and Ad26.COV2.S vaccines. All prime-boost combinations substantially increase the neutralization titers to Omicron, although the boosted titers decline rapidly within 2 months from the peak response compared with boosted titers against the prototypic D614G variant. Boosted Omicron neutralization titers are substantially higher for homologous mRNA vaccine boosting, and for heterologous mRNA and Ad26.COV2.S vaccine boosting, compared with homologous Ad26.COV2.S boosting. Homologous mRNA vaccine boosting generates nearly equivalent neutralizing activity against Omicron sublineages BA.1, BA.2, and BA.3 but modestly reduced neutralizing activity against BA.2.12.1 and BA.4/BA.5 compared with BA.1. These results have implications for boosting requirements to protect against Omicron and future variants of SARS-CoV-2. This trial was conducted under ClincalTrials.gov: NCT04889209.


Assuntos
COVID-19 , Vacinas Virais , Ad26COVS1 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Humanos , RNA Mensageiro , SARS-CoV-2/genética , Vacinas Sintéticas , Vacinas de mRNA
8.
N Engl J Med ; 386(11): 1046-1057, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35081293

RESUMO

BACKGROUND: Although the three vaccines against coronavirus disease 2019 (Covid-19) that have received emergency use authorization in the United States are highly effective, breakthrough infections are occurring. Data are needed on the serial use of homologous boosters (same as the primary vaccine) and heterologous boosters (different from the primary vaccine) in fully vaccinated recipients. METHODS: In this phase 1-2, open-label clinical trial conducted at 10 sites in the United States, adults who had completed a Covid-19 vaccine regimen at least 12 weeks earlier and had no reported history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection received a booster injection with one of three vaccines: mRNA-1273 (Moderna) at a dose of 100 µg, Ad26.COV2.S (Johnson & Johnson-Janssen) at a dose of 5×1010 virus particles, or BNT162b2 (Pfizer-BioNTech) at a dose of 30 µg. The primary end points were safety, reactogenicity, and humoral immunogenicity on trial days 15 and 29. RESULTS: Of the 458 participants who were enrolled in the trial, 154 received mRNA-1273, 150 received Ad26.COV2.S, and 153 received BNT162b2 as booster vaccines; 1 participant did not receive the assigned vaccine. Reactogenicity was similar to that reported for the primary series. More than half the recipients reported having injection-site pain, malaise, headache, or myalgia. For all combinations, antibody neutralizing titers against a SARS-CoV-2 D614G pseudovirus increased by a factor of 4 to 73, and binding titers increased by a factor of 5 to 55. Homologous boosters increased neutralizing antibody titers by a factor of 4 to 20, whereas heterologous boosters increased titers by a factor of 6 to 73. Spike-specific T-cell responses increased in all but the homologous Ad26.COV2.S-boosted subgroup. CD8+ T-cell levels were more durable in the Ad26.COV2.S-primed recipients, and heterologous boosting with the Ad26.COV2.S vaccine substantially increased spike-specific CD8+ T cells in the mRNA vaccine recipients. CONCLUSIONS: Homologous and heterologous booster vaccines had an acceptable safety profile and were immunogenic in adults who had completed a primary Covid-19 vaccine regimen at least 12 weeks earlier. (Funded by the National Institute of Allergy and Infectious Diseases; DMID 21-0012 ClinicalTrials.gov number, NCT04889209.).


Assuntos
Vacina de mRNA-1273 contra 2019-nCoV/imunologia , Ad26COVS1/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacina BNT162/imunologia , Vacinas contra COVID-19/imunologia , Imunogenicidade da Vacina , Adulto , Idoso , Idoso de 80 Anos ou mais , Vacinas contra COVID-19/efeitos adversos , Feminino , Humanos , Imunização Secundária/efeitos adversos , Injeções Intramusculares/efeitos adversos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia
9.
medRxiv ; 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34671773

RESUMO

Background: While Coronavirus disease 2019 (Covid-19) vaccines are highly effective, breakthrough infections are occurring. Booster vaccinations have recently received emergency use authorization (EUA) for certain populations but are restricted to homologous mRNA vaccines. We evaluated homologous and heterologous booster vaccination in persons who had received an EUA Covid-19 vaccine regimen. Methods: In this phase 1/2 open-label clinical trial conducted at ten U.S. sites, adults who received one of three EUA Covid-19 vaccines at least 12 weeks prior to enrollment and had no reported history of SARS-CoV-2 infection received a booster injection with one of three vaccines (Moderna mRNA-1273 100-µg, Janssen Ad26.COV2.S 5×1010 virus particles, or Pfizer-BioNTech BNT162b2 30-µg; nine combinations). The primary outcomes were safety, reactogenicity, and humoral immunogenicity on study days 15 and 29. Results: 458 individuals were enrolled: 154 received mRNA-1273, 150 received Ad26.CoV2.S, and 153 received BNT162b2 booster vaccines. Reactogenicity was similar to that reported for the primary series. Injection site pain, malaise, headache, and myalgia occurred in more than half the participants. Booster vaccines increased the neutralizing activity against a D614G pseudovirus (4.2-76-fold) and binding antibody titers (4.6-56-fold) for all combinations; homologous boost increased neutralizing antibody titers 4.2-20-fold whereas heterologous boost increased titers 6.2-76-fold. Day 15 neutralizing and binding antibody titers varied by 28.7-fold and 20.9-fold, respectively, across the nine prime-boost combinations. Conclusion: Homologous and heterologous booster vaccinations were well-tolerated and immunogenic in adults who completed a primary Covid-19 vaccine regimen at least 12 weeks earlier.

10.
Neurooncol Pract ; 8(4): 460-474, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34277024

RESUMO

BACKGROUND: Primary central nervous system (CNS) tumors are often associated with high symptom burden and a poor prognosis from the time of diagnosis. The purpose of this study is to describe patient-reported outcomes (PRO) data from long-term survivors (LTS; ≥5-year survival post-diagnosis). METHODS: Clinical/treatment/molecular characteristics and PROs (symptom burden/interference (MDASI-BT/SP), perceived cognition (Neuro-QoL), anxiety/depression (PROMIS), and general health status (EQ-5D-3L)) were collected on 248 adult LTS between 9/2016 and 8/2019. Descriptive statistics and regression analysis were used to report results. RESULTS: Participants had a median age of 47 years (19-82) and were primarily White (83%) males (51%) with high-grade tumors (59%) and few mutations. Forty-two percent of the 222 brain tumor LTS reported no moderate-to-severe symptoms, whereas 45% reported three or more; most common symptoms were fatigue (40%), difficulty remembering (29%), and drowsiness (28%). Among spine tumor LTS (n = 42), nearly half reported moderate-to-severe weakness, pain, fatigue, and numbness/tingling, with 72% experiencing activity-related interference. Severe anxiety, depression, and cognitive symptoms were reported in up to 23% of the sample. Brain tumor LTS at higher risk for severe symptoms were more likely to be young, unemployed, and have poor KPS (Karnofsky Performance Status), whereas high symptom-risk spinal cord tumor LTS had poor KPS and received any tumor treatment. CONCLUSIONS: Findings indicate LTS fall into distinct cohorts with no significant symptoms or very high symptom burden, regardless of tumor grade or mutational profile. These LTS data demonstrate the need for survivorship care programs and future studies to explore the symptom trajectory of all CNS tumor patients for prevention and early interventions.

11.
J Neurooncol ; 147(2): 397-404, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32096067

RESUMO

PURPOSE: Body image (BI) is an important issue for cancer patients, as patients with BI concerns are susceptible to depression, anxiety, difficulty coping, and poor quality of life (QoL). While this concern has been documented in patients with other malignancies, no data exists of this QoL issue in patients with primary brain tumors (PBT). METHODS: A cross-sectional survey of 100 PBT patients was conducted on an IRB approved prospective protocol using structured questionnaires. Participants completed the body image scale (BIS), Appearance Scheme Inventory Revised (ASI-R), MD Anderson Symptom Inventory Brain Tumor (MDASI-BT), and Patient-Reported Outcomes Measurement Information System (PROMIS) Depression, Anxiety, and Psychosocial Impact Positive measures. RESULTS: The prevalence of clinically significant body image dissatisfaction (BIS ≥ 10) was 28% (95% CI 19-37%), median BIS score was 5 (range 0-27). The median ASI-R composite score was 2.9 (range 1.5-4.7). BIS was significantly correlated with the ASI-R (r = 0.53, 95% CI 0.37 to 0.65). The mean PROMIS Depression score was 48.4 (SD = 8.9), PROMIS Anxiety score was 49.4 (SD = 9.9), and PROMIS Psychosocial Illness Impact Positive score was 48.9 (SD = 9.7). BIS was significantly correlated with age, and trended with BMI and sex. The PROMIS Psychosocial Illness Impact Positive and PROMIS Anxiety scores were the most strongly related to BIS. CONCLUSIONS: This study, the first to explore altered body image in PBT patients, revealed clinically significant body image dissatisfaction in nearly 1/3 of patients, similar to other malignancies. These findings underscore the potential contribution of disease and treatment-related body image concerns on psychosocial wellbeing in patients with PBT.


Assuntos
Ansiedade/epidemiologia , Imagem Corporal/psicologia , Neoplasias Encefálicas/psicologia , Depressão/epidemiologia , Qualidade de Vida , Adulto , Idoso , Ansiedade/psicologia , Neoplasias Encefálicas/patologia , Estudos Transversais , Depressão/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Prognóstico , Estudos Prospectivos , Estados Unidos/epidemiologia , Adulto Jovem
12.
Clin Cancer Res ; 17(21): 6831-9, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21908572

RESUMO

PURPOSE: To determine the maximum tolerated dose (MTD), toxicities, and pharmacokinetic/pharmacodynamic profile of the Hsp90 inhibitor PF-04929113 (SNX-5422) in patients with advanced solid tumors and lymphomas. METHODS: This was a single-institution, phase I, dose-escalation study of PF-04929113 administered twice weekly. Endpoints included determination of dose-limiting toxicities (DLT), MTD, the safety profile of PF-04929113, pharmacodynamic assessment of PF-04929113 on Hsp70 induction, pharmacokinetic analysis of PF-04928473 (SNX-2112) and its prodrug PF-04929113, and assessment of response. RESULTS: Thirty-three patients with advanced malignancies were treated. Dose escalation was continued up to 177 mg/m(2) administered orally twice a week. One DLT (nonseptic arthritis) was noted. No grade 4 drug-related adverse events were seen; grade 3 adverse events included diarrhea (9%), nonseptic arthritis (3%), aspartate aminotransferase elevation (3%), and thrombocytopenia (3%). No objective responses were seen in 32 evaluable patients. Fifteen patients (47%) had stable disease; 17 patients (53%) had progressive disease. Pharmacokinetic data revealed rapid absorption, hepatic, and extrahepatic clearance, extensive tissue binding, and almost linear pharmacokinetics of the active drug PF-04928473. Pharmacodynamic studies confirmed inhibition of Hsp90 and a linear correlation between pharmacokinetic parameters and Hsp70 induction. CONCLUSIONS: PF-04929113 administered orally twice a week is well tolerated and inhibits its intended target Hsp90. No objective responses were seen, but long-lasting stabilizations were obtained. Although no clinically significant drug-related ocular toxicity was seen in this study, the development of PF-04929113 has been discontinued because of ocular toxicity seen in animal models and in a separate phase I study.


Assuntos
Benzamidas/administração & dosagem , Benzamidas/efeitos adversos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Indazóis/administração & dosagem , Indazóis/efeitos adversos , Linfoma/tratamento farmacológico , Neoplasias/tratamento farmacológico , Adulto , Idoso , Benzamidas/farmacocinética , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Glicina , Proteínas de Choque Térmico HSP90/sangue , Humanos , Indazóis/farmacocinética , Linfoma/sangue , Linfoma/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/metabolismo
13.
Anticancer Res ; 31(3): 961-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21498721

RESUMO

BACKGROUND: The synthetic retinoid fenretinide (N-(4-hydroxyphenyl)retinamide, 4-HPR) has shown promising anticancer activity in preclinical studies, but its limited oral bioavailability has hindered clinical assessment. A novel lipid matrix, Lym-X-Sorb (LXS), was evaluated to improve fenretinide bioavailability and attain higher plasma concentrations. PATIENTS AND METHODS: Adults with refractory malignancies were administered fenretinide/LXS oral powder in 2 divided doses over 24 h for 7 consecutive days every 21 days in a standard phase I dose-escalation study with pharmacokinetic analysis. RESULTS: The principal toxicities observed were diarrhea, reversible night blindness, and allergic reaction. The maximum tolerated dose regimens were 1,000 mg/m(2)/day divided into 2 daily doses for 7 days, every 21 days, and 800 mg/m(2)/day divided into 3 daily doses for 7 consecutive days, every 21 days. CONCLUSION: Better fenretinide formulations are needed to improve adult patient acceptability and compliance and to achieve the consistent systemic exposures associated with activity in preclinical models.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Fenretinida/administração & dosagem , Fenretinida/uso terapêutico , Lipídeos/química , Linfoma/tratamento farmacológico , Administração Oral , Adulto , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Fenretinida/efeitos adversos , Fenretinida/farmacocinética , Humanos , Linfoma/sangue , Masculino , Pessoa de Meia-Idade , Pós
15.
Am J Clin Nutr ; 88(6): 1685-96, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19064532

RESUMO

BACKGROUND: Essential hypertension is characterized by reciprocal relations between endothelial dysfunction and insulin resistance. Cocoa flavanols stimulate production of the vasodilator nitric oxide from vascular endothelium. OBJECTIVE: The objective was to test the hypothesis that consumption of cocoa may simultaneously lower blood pressure, improve endothelial dysfunction, and ameliorate insulin resistance in subjects with essential hypertension. DESIGN: We conducted a randomized, placebo-controlled, double-blind, crossover trial of a flavanol-rich cocoa drink (150 mL twice a day, approximately 900 mg flavanols/d) in individuals with essential hypertension (n = 20). Antihypertensive medications were discontinued before study enrollment. After a 7-d cocoa-free run-in period, cocoa or flavanol-poor placebo (approximately 28 mg flavanols/d) treatment for 2 wk was followed by a 1-wk washout and then crossover to the other treatment arm. Blood pressure was measured thrice weekly. At baseline and after each treatment period, we assessed insulin sensitivity (hyperinsulinemic-isoglycemic glucose clamp) and insulin-stimulated changes in brachial artery diameter and forearm skeletal muscle capillary recruitment (Doppler ultrasound with or without microbubble contrast). RESULTS: Cocoa treatment for 2 wk increased insulin-stimulated changes in brachial artery diameter when compared with placebo [median percentage increase from baseline (25th-75th percentile): 8.3 (4.2-11.3) compared with 5.9 (-0.3 to 9.6); P < 0.04]. Nevertheless, cocoa treatment did not significantly reduce blood pressure or improve insulin resistance and had no significant effects on skeletal muscle capillary recruitment, circulating plasma concentrations of adipocytokines, or endothelial adhesion molecules. CONCLUSIONS: Daily consumption of flavanol-rich cocoa for 2 wk is not sufficient to reduce blood pressure or improve insulin resistance in human subjects with essential hypertension. This trial was registered at clinicaltrials.gov as NCT00099476.


Assuntos
Cacau/química , Endotélio Vascular/efeitos dos fármacos , Flavonóis/farmacologia , Hipertensão/tratamento farmacológico , Resistência à Insulina , Insulina/metabolismo , Adulto , Idoso , Bebidas , Artéria Braquial , Cromatografia Líquida de Alta Pressão , Estudos Cross-Over , Método Duplo-Cego , Feminino , Flavonóis/sangue , Flavonóis/farmacocinética , Técnica Clamp de Glucose , Humanos , Hipertensão/sangue , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional , Resultado do Tratamento , Adulto Jovem
16.
Diabetes ; 55(11): 3142-50, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17065354

RESUMO

Glucosamine is a popular nutritional supplement used to treat osteoarthritis. Intravenous administration of glucosamine causes insulin resistance and endothelial dysfunction. However, rigorous clinical studies evaluating the safety of oral glucosamine with respect to metabolic and cardiovascular pathophysiology are lacking. Therefore, we conducted a randomized, placebo-controlled, double-blind, crossover trial of oral glucosamine at standard doses (500 mg p.o. t.i.d.) in lean (n = 20) and obese (n = 20) subjects. Glucosamine or placebo treatment for 6 weeks was followed by a 1-week washout and crossover to the other arm. At baseline, and after each treatment period, insulin sensitivity was assessed by hyperinsulinemic-isoglycemic glucose clamp (SI(Clamp)) and endothelial function evaluated by brachial artery blood flow (BAF; Doppler ultrasound) and forearm skeletal muscle microvascular recruitment (ultrasound with microbubble contrast) before and during steady-state hyperinsulinemia. Plasma glucosamine pharmacokinetics after oral dosing were determined in each subject using a high-performance liquid chromatography method. As expected, at baseline, obese subjects had insulin resistance and endothelial dysfunction when compared with lean subjects (SI(Clamp) [median {25th-75th percentile}] = 4.3 [2.9-5.3] vs. 7.3 [5.7-11.3], P < 0.0001; insulin-stimulated changes in BAF [% over basal] = 12 [-6 to 84] vs. 39 [2-108], P < 0.04). When compared with placebo, glucosamine did not cause insulin resistance or endothelial dysfunction in lean subjects or significantly worsen these findings in obese subjects. The half-life of plasma glucosamine after oral dosing was approximately 150 min, with no significant changes in steady-state glucosamine levels detectable after 6 weeks of therapy. We conclude that oral glucosamine at standard doses for 6 weeks does not cause or significantly worsen insulin resistance or endothelial dysfunction in lean or obese subjects.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Endotélio Vascular/fisiopatologia , Glucosamina/uso terapêutico , Resistência à Insulina/fisiologia , Obesidade/fisiopatologia , Magreza/fisiopatologia , Administração Oral , Adulto , Ácido Ascórbico/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 1/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Glucosamina/administração & dosagem , Glucosamina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Valores de Referência
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