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1.
J Clin Monit Comput ; 34(3): 541-551, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31175500

RESUMO

The utility of capnography to detect early respiratory compromise in surgical patients after anesthesia is unclear due to limited prospective data. The purpose of this trial was to determine the frequency and duration of capnography-detected respiratory adverse events in the post-anesthesia care unit (PACU). In this prospective observational trial, 250 consenting patients undergoing elective surgery with general anesthesia were monitored by standard monitoring together with blinded capnography and pulse oximetry monitoring. The capnography notification settings were adjusted to match nursing (Level II) and physician (Level I) alarm thresholds. 163 (95%) patients had a Level II notification and 135 (78%) had a Level I notification during standard monitoring. The most common events detected by the capnography monitor included hypocapnia, apnea, tachypnea, bradypnea and hypoxemia, with silent notification duration for these events ranging from 17 ± 13 to 189 ± 127 s. During standard monitoring, 15 respiratory adverse events were reported, with 8 events occurring when valid blinded/silenced capnography and pulse oximetry data was collected simultaneously. Capnography and the Integrated Pulmonary Index™ algorithm (IPI) detected respiratory adverse events earlier than standard monitoring in 75% and 88% of cases, respectively, with an average early warning time of 8 ± 11 min. Three patients' blinded capnography was unblinded to facilitate clinical care. Respiratory adverse events are frequent in the PACU, and the addition of capnography and IPI to current standard monitoring provides potentially clinically relevant information on respiratory status, including early warning of some respiratory adverse events.Trial registration ClinialTrials.gov Identifier NCT02707003 (https://clinicaltrials.gov/ct2/show/NCT02707003).

4.
BMJ Open ; 7(6): e013402, 2017 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-28667196

RESUMO

OBJECTIVE: To evaluate the effect of capnography monitoring on sedation-related adverse events during procedural sedation and analgesia (PSA) administered for ambulatory surgery relative to visual assessment and pulse oximetry alone. DESIGN AND SETTING: Systematic literature review and random effects meta-analysis of randomised controlled trials (RCTs) reporting sedation-related adverse event incidence when adding capnography to visual assessment and pulse oximetry in patients undergoing PSA during ambulatory surgery in the hospital setting. Searches for eligible studies published between 1 January 1995 and 31 December 2016 (inclusive) were conducted in PubMed, the Cochrane Library and EMBASE without any language constraints. Searches were conducted in January 2017, screening and data extraction were conducted by two independent reviewers, and study quality was assessed using a modified Jadad scale. INTERVENTIONS: Capnography monitoring relative to visual assessment and pulse oximetry alone. PRIMARY AND SECONDARY OUTCOME MEASURES: Predefined endpoints of interest were desaturation/hypoxaemia (the primary endpoint), apnoea, aspiration, bradycardia, hypotension, premature procedure termination, respiratory failure, use of assisted/bag-mask ventilation and death during PSA. RESULTS: The literature search identified 1006 unique articles, of which 13 were ultimately included in the meta-analysis. Addition of capnography to visual assessment and pulse oximetry was associated with a significant reduction in mild (risk ratio (RR) 0.77, 95% CI 0.67 to 0.89) and severe (RR 0.59, 95% CI 0.43 to 0.81) desaturation, as well as in the use of assisted ventilation (OR 0.47, 95% CI 0.23 to 0.95). No significant differences in other endpoints were identified. CONCLUSIONS: Meta-analysis of 13 RCTs published between 2006 and 2016 showed a reduction in respiratory compromise (from respiratory insufficiency to failure) during PSA with the inclusion of capnography monitoring. In particular, use of capnography was associated with less mild and severe oxygen desaturation, which may have helped to avoid the need for assisted ventilation.


Assuntos
Capnografia/estatística & dados numéricos , Sedação Consciente/efeitos adversos , Sedação Profunda/efeitos adversos , Segurança do Paciente , Bradicardia/etiologia , Humanos , Monitorização Fisiológica , Oximetria , Ensaios Clínicos Controlados Aleatórios como Assunto , Respiração Artificial/estatística & dados numéricos , Insuficiência Respiratória/etiologia
5.
Anesth Analg ; 124(4): 1153-1159, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28099286

RESUMO

BACKGROUND: Intermittent measurement of respiratory rate via observation is routine in many patient care settings. This approach has several inherent limitations that diminish the clinical utility of these measurements because it is intermittent, susceptible to human error, and requires clinical resources. As an alternative, a software application that derives continuous respiratory rate measurement from a standard pulse oximeter has been developed. We sought to determine the performance characteristics of this new technology by comparison with clinician-reviewed capnography waveforms in both healthy subjects and hospitalized patients in a low-acuity care setting. METHODS: Two independent observational studies were conducted to validate the performance of the Medtronic Nellcor Respiration Rate Software application. One study enrolled 26 healthy volunteer subjects in a clinical laboratory, and a second multicenter study enrolled 53 hospitalized patients. During a 30-minute study period taking place while participants were breathing spontaneously, pulse oximeter and nasal/oral capnography waveforms were collected. Pulse oximeter waveforms were processed to determine respiratory rate via the Medtronic Nellcor Respiration Rate Software. Capnography waveforms reviewed by a clinician were used to determine the reference respiratory rate. RESULTS: A total of 23,243 paired observations between the pulse oximeter-derived respiratory rate and the capnography reference method were collected and examined. The mean reference-based respiratory rate was 15.3 ± 4.3 breaths per minute with a range of 4 to 34 breaths per minute. The Pearson correlation coefficient between the Medtronic Nellcor Respiration Rate Software values and the capnography reference respiratory rate is reported as a linear correlation, R, as 0.92 ± 0.02 (P < .001), whereas Lin's concordance correlation coefficient indicates an overall agreement of 0.85 ± 0.04 (95% confidence interval [CI] +0.76; +0.93) (healthy volunteers: 0.94 ± 0.02 [95% CI +0.91; +0.97]; hospitalized patients: 0.80 ± 0.06 [95% CI +0.68; +0.92]). The mean bias of the Medtronic Nellcor Respiration Rate Software was 0.18 breaths per minute with a precision (SD) of 1.65 breaths per minute (healthy volunteers: 0.37 ± 0.78 [95% limits of agreement: -1.16; +1.90] breaths per minute; hospitalized patients: 0.07 ± 1.99 [95% limits of agreement: -3.84; +3.97] breaths per minute). The root mean square deviation was 1.35 breaths per minute (healthy volunteers: 0.81; hospitalized patients: 1.60). CONCLUSIONS: These data demonstrate the performance of the Medtronic Nellcor Respiration Rate Software in healthy subjects and patients hospitalized in a low-acuity care setting when compared with clinician-reviewed capnography. The observed performance of this technology suggests that it may be a useful adjunct to continuous pulse oximetry monitoring by providing continuous respiratory rate measurements. The potential patient safety benefit of using combined continuous pulse oximetry and respiratory rate monitoring warrants assessment.


Assuntos
Capnografia/normas , Hospitalização/tendências , Oximetria/normas , Taxa Respiratória/fisiologia , Adulto , Capnografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oximetria/métodos , Fotopletismografia/métodos , Fotopletismografia/normas , Reprodutibilidade dos Testes
7.
J Clin Monit Comput ; 29(1): 113-20, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24796734

RESUMO

Respiratory rate is recognized as a clinically important parameter for monitoring respiratory status on the general care floor (GCF). Currently, intermittent manual assessment of respiratory rate is the standard of care on the GCF. This technique has several clinically-relevant shortcomings, including the following: (1) it is not a continuous measurement, (2) it is prone to observer error, and (3) it is inefficient for the clinical staff. We report here on an algorithm designed to meet clinical needs by providing respiratory rate through a standard pulse oximeter. Finger photoplethysmograms were collected from a cohort of 63 GCF patients monitored during free breathing over a 25-min period. These were processed using a novel in-house algorithm based on continuous wavelet-transform technology within an infrastructure incorporating confidence-based averaging and logical decision-making processes. The computed oximeter respiratory rates (RRoxi) were compared to an end-tidal CO2 reference rate (RRETCO2). RRETCO2 ranged from a lowest recorded value of 4.7 breaths per minute (brpm) to a highest value of 32.0 brpm. The mean respiratory rate was 16.3 brpm with standard deviation of 4.7 brpm. Excellent agreement was found between RRoxi and RRETCO2, with a mean difference of -0.48 brpm and standard deviation of 1.77 brpm. These data demonstrate that our novel respiratory rate algorithm is a potentially viable method of monitoring respiratory rate in GCF patients. This technology provides the means to facilitate continuous monitoring of respiratory rate, coupled with arterial oxygen saturation and pulse rate, using a single non-invasive sensor in low acuity settings.


Assuntos
Monitorização Fisiológica/métodos , Oximetria/métodos , Taxa Respiratória , Idoso , Algoritmos , Feminino , Hemoglobinas/química , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/química , Fotopletismografia/métodos , Valores de Referência , Reprodutibilidade dos Testes , Respiração , Processamento de Sinais Assistido por Computador , Análise de Ondaletas
8.
Redox Rep ; 20(1): 42-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25180827

RESUMO

Our purpose was to characterize changes in paraoxonase 1 (PON1) activity and concentration after single aerobic exercise sessions conducted before and after 6 weeks of niacin therapy in men with metabolic syndrome (MetS). Twelve men with MetS expended 500 kcal by walking at 65% of VO2max before and after a 6-week regimen of niacin. Niacin doses were titrated by 500 mg/week from 500 to 1500 mg/day and maintained at 1500 mg/day for the last 4 weeks. Fasting blood samples were collected before and 24 hours after each exercise session and analyzed for PON1 activity, PON1 concentration, myeloperoxidase (MPO), apolipoprotein A1, oxidized low-density lipoprotein (oLDL), lipoprotein particle sizes and concentrations. PON1 activity, PON1 concentration, MPO, and oLDL were unaltered following the independent effects of exercise and niacin (P > 0.05 for all). High-density lipoprotein particle size decreased by 3% (P = 0.040) and concentrations of small very low-density lipoprotein increased (P = 0.016) following exercise. PON1 activity increased 6.1% (P = 0.037) and PON1 concentrations increased 11.3% (P = 0.015) with the combination of exercise and niacin. Exercise and niacin works synergistically to increase PON1 activity and concentration with little or no changes in lipoproteins or markers of lipid oxidation.


Assuntos
Arildialquilfosfatase/sangue , Terapia por Exercício , Síndrome Metabólica/sangue , Niacina/uso terapêutico , Adulto , Apolipoproteína A-I/sangue , Exercício Físico , Humanos , Lipídeos/química , Lipoproteínas HDL/sangue , Masculino , Síndrome Metabólica/enzimologia , Pessoa de Meia-Idade , Obesidade/complicações , Oxigênio/química , Peroxidase/sangue , Vasodilatadores/química
9.
Acad Emerg Med ; 20(8): 753-60, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24033617

RESUMO

OBJECTIVES: Studies focusing on minor head injury in intoxicated patients report disparate prevalences of intracranial injury. It is unclear if the typical factors associated with intracranial injury in published clinical decision rules for computerized tomography (CT) acquisition are helpful in differentiating patients with and without intracranial injuries, as intoxication may obscure particular features of intracranial injury such as headache and mimic other signs of head injury such as altered mental status. This study aimed to estimate the prevalence of intracranial injury following minor head injury (Glasgow Coma Scale [GCS] score ≥14) in intoxicated patients and to assess the performance of established clinical decision rules in this population. METHODS: This was a prospective cohort study of consecutive intoxicated adults presenting to the emergency department (ED) following minor head injury. Historical and physical examination features included those from the Canadian CT Head Rule, National Emergency X-Radiography Utilization Study (NEXUS), and New Orleans Criteria. All patients underwent head CT. RESULTS: A total of 283 patients were enrolled, with a median age of 40 years (interquartile range [IQR] = 28 to 48 years) and median alcohol concentration of 195 mmol/L (IQR = 154 to 256 mmol/L). A total of 238 of 283 (84%) were male, and 225 (80%) had GCS scores of 15. Clinically important injuries (injuries requiring admission to the hospital or neurosurgical follow-up) were identified in 23 patients (8%; 95% confidence interval [CI] = 5% to 12%); one required neurosurgical intervention (0.4%, 95% CI = 0% to 2%). Loss of consciousness and headache were associated with clinically important intracranial injury on CT. The Canadian CT Head Rule had a sensitivity of 70% (95% CI = 47% to 87%) and NEXUS criteria had a sensitivity of 83% (95% CI = 61% to 95%) for clinically important injury in intoxicated patients. CONCLUSIONS: In this study, the prevalence of clinically important injury in intoxicated patients with minor head injury was significant. While the presence of the common features associated with intracranial injury in nonintoxicated patients should raise clinical suspicion for intracranial injury in intoxicated patients, the Canadian CT Head Rule and NEXUS criteria do not have adequate sensitivity to be applied in intoxicated patients with minor head injury.


Assuntos
Intoxicação Alcoólica/complicações , Lesões Encefálicas/epidemiologia , Traumatismos Craniocerebrais/complicações , Adulto , Lesões Encefálicas/diagnóstico por imagem , Estudos de Coortes , Colorado , Traumatismos Craniocerebrais/diagnóstico por imagem , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
10.
J Clin Monit Comput ; 26(1): 45-51, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22231359

RESUMO

OBJECTIVE: The presence of respiratory information within the pulse oximeter signal (PPG) is a well-documented phenomenon. However, extracting this information for the purpose of continuously monitoring respiratory rate requires: (1) the recognition of the multi-faceted manifestations of respiratory modulation components within the PPG and the complex interactions among them; (2) the implementation of appropriate advanced signal processing techniques to take full advantage of this information; and (3) the post-processing infrastructure to deliver a clinically useful reported respiratory rate to the end user. A holistic algorithmic approach to the problem is therefore required. We have developed the RR(OXI) algorithm based on this principle and its performance on healthy subject trial data is described herein. METHODS: Finger PPGs were collected from a cohort of 139 healthy adult volunteers monitored during free breathing over an 8-min period. These were subsequently processed using a novel in-house algorithm based on continuous wavelet transform technology within an infrastructure incorporating weighted averaging and logical decision making processes. The computed oximeter respiratory rates (RR(oxi)) were then compared to an end-tidal CO2 reference rate RR(ETCO2). RESULTS: RR(ETCO2) ranged from a lowest recorded value of 2.97 breaths per min (br/min) to a highest value of 28.02 br/min. The mean rate was 14.49 br/min with standard deviation of 4.36 br/min. Excellent agreement was found between RR(oxi) and RR(ETCO2), with a mean difference of -0.23 br/min and standard deviation of 1.14 br/min. The two measures are tightly spread around the line of agreement with a strong correlation observable between them (R2 = 0.93). CONCLUSIONS: These data indicate that RR(oxi) represents a viable technology for the measurement of respiratory rate of healthy individuals.


Assuntos
Algoritmos , Oximetria , Taxa Respiratória , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Valores de Referência , Processamento de Sinais Assistido por Computador , Análise de Ondaletas , Adulto Jovem
11.
Obesity (Silver Spring) ; 19(9): 1742-6, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21738236

RESUMO

It has been suggested that body fat distribution may be an important determinant of the impact of adiposity on endothelial function. We tested the hypothesis that overweight/obese adults with abdominal adiposity exhibit worse endothelial vasodilator and fibrinolytic function than overweight/obese adults without abdominal adiposity. Sixty adult men were studied: 20 normal weight (BMI: 22.3 ± 0.7 kg/m2; waist circumference (WC): 84.9 ± 2.0 cm); 20 overweight/obese with WC <102 cm (29.2 ± 0.3 kg/m2; 98.1 ± 0.7 cm); and 20 overweight/obese with WC ≥102 cm (30.0 ± 0.4 kg/m2; 106.7 ± 1.0 cm). Forearm blood flow (FBF) responses to intra-arterial acetylcholine and sodium nitroprusside (SNP) were measured. Additionally, net endothelial release of tissue-type plasminogen activator (t-PA) was determined in response to bradykinin (BK) and SNP. Overweight/obese men demonstrated lower (~30%; P < 0.01) FBF responses to acetylcholine compared with normal weight controls. However, there were no differences in FBF responses to acetylcholine between overweight/obese men with (4.1 ± 0.3-10.8 ± 1.3 ml/100 ml tissue/min) and without (4.5 ± 0.3-11.6 ± 0.8 ml/100 ml tissue/min) abdominal adiposity. Similarly, endothelial t-PA release to BK was lower (~40%; P < 0.05) in the overweight/obese men compared with normal weight controls; however, t-PA release was not different between the overweight/obese men with (-0.7 ± 0.4-40.4 ± 6.2 ng/100 ml tissue/min) and without (-0.3 ± 0.6-48 ± 7.5 ng/100 ml tissue/min) abdominal adiposity. These results indicate that abdominal obesity is not associated with greater impairment in endothelial vasodilation and fibrinolytic capacity in overweight/obese men. Excess adiposity, regardless of anatomical distribution pattern, is associated with impaired endothelial function.


Assuntos
Gordura Abdominal/patologia , Adiposidade , Endotélio Vascular/fisiopatologia , Obesidade/patologia , Obesidade/fisiopatologia , Sobrepeso/patologia , Sobrepeso/fisiopatologia , Biomarcadores/sangue , Índice de Massa Corporal , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Fibrinólise , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade Abdominal/sangue , Obesidade Abdominal/patologia , Obesidade Abdominal/fisiopatologia , Sobrepeso/sangue , Inibidor 1 de Ativador de Plasminogênio/sangue , Fluxo Sanguíneo Regional/efeitos dos fármacos , Ativador de Plasminogênio Tecidual/sangue , Vasodilatação/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Vasodilatadores/farmacologia , Circunferência da Cintura
13.
J Appl Physiol (1985) ; 109(6): 1756-61, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20864561

RESUMO

CD31(+) T cells, or so-called "angiogenic T cells," have been shown to demonstrate vasculoprotective and neovasculogenic qualities. The influence of age on CD31(+) T-cell number and function is unclear. We tested the hypothesis that circulating CD31(+) T-cell number and migratory capacity are reduced, apoptotic susceptibility is heightened, and telomere length is shortened with advancing age in adult humans. Thirty-six healthy, sedentary men were studied: 12 young (25 ± 1 yr), 12 middle aged (46 ± 1 yr), and 12 older (64 ± 2 yr). CD31(+) T cells were isolated from peripheral blood samples by magnetic-activated cell sorting. The number of circulating CD31(+) T cells (fluorescence-activated cell sorting analysis) was lower (P < 0.01) in older (24% of CD3(+) cells) compared with middle-aged (38% of CD3(+) cells) and young (40% of CD3(+) cells) men. Migration (Boyden chamber) to both VEGF and stromal cell-derived factor-1α was markedly blunted (P < 0.05) in cells harvested from middle-aged [306.1 ± 45 and 305.6 ± 46 arbitrary units (AU), respectively] and older (231 ± 65 and 235 ± 62 AU, respectively) compared with young (525 ± 60 and 570 ± 62 AU, respectively) men. CD31(+) T cells from middle-aged and older men demonstrated greater apoptotic susceptibility, as staurosporine-stimulated intracellular caspase-3 activation was ∼ 40% higher (P < 0.05) than young. There was a progressive age-related decline in CD31(+) T-cell telomere length (young: 10,706 ± 220 bp; middle-aged: 10,179 ± 251 bp; and older: 9,324 ± 192 bp). Numerical and functional impairments in this unique T-cell subpopulation may contribute to diminished angiogenic potential and greater cardiovascular risk with advancing age.


Assuntos
Envelhecimento/imunologia , Apoptose , Doenças Cardiovasculares/imunologia , Quimiotaxia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Telômero/metabolismo , Adulto , Fatores Etários , Idoso , Envelhecimento/genética , Envelhecimento/metabolismo , Envelhecimento/patologia , Apoptose/genética , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Caspase 3/metabolismo , Separação Celular/métodos , Quimiocina CXCL12/metabolismo , Citocromos c/metabolismo , Citometria de Fluxo , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Subpopulações de Linfócitos T/patologia , Linfócitos T/patologia , Telomerase/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto Jovem
14.
Can J Physiol Pharmacol ; 88(8): 777-81, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20725134

RESUMO

Short sleep duration is associated with increased cardiovascular disease (CVD) morbidity. Endothelial vasomotor dysfunction represents a potential mechanism contributing to the increased CVD risk associated with habitual short sleep duration. Endothelin (ET)-1 is a potent vasoconstrictor peptide that is associated with endothelial vasomotor dysfunction and increased CVD risk. Currently, there is no information regarding the influence of short sleep duration on ET-1 vasoconstrictor activity in adults. We tested the hypothesis that ET-1-mediated vasoconstrictor activity is greater in adults who sleep less than 7 h/night (short sleep duration) compared with those who sleep 7-9 h/night (normal sleep duration). Forearm blood flow (FBF) responses to intra-arterial infusion of BQ-123 (100 nmol/min for 60 min), a selective ETA receptor antagonist, were determined in 80 adults: 50 with normal sleep duration (32 males and 18 females; age: 56.6 +/- 1.2 years; sleep: 7.6 +/- 0.1 h/night) and 30 with short sleep duration (17 males and 13 females; age: 56.5 +/- 1.2 years; sleep: 6.1 +/- 0.1 h/night). In response to BQ-123, adults reporting short sleep duration had a greater increase in resting FBF compared with adults reporting normal sleep duration (approximately 20% vs. approximately 8%; P < 0.05). There was an inverse relation between mean nightly sleep duration and the FBF response to BQ-123 at 60 min (r = -0.29, P < 0.05). These findings indicate that habitual short sleep duration is associated with greater ET-1-mediated vasoconstrictor tone. Increased ET-1 vasoconstrictor activity may contribute to the elevated CVD risk associated with chronic reductions in sleep duration.


Assuntos
Endotelina-1/metabolismo , Privação do Sono/fisiopatologia , Vasoconstrição/fisiologia , Anti-Hipertensivos/farmacologia , Antagonistas dos Receptores de Endotelina , Endotelina-1/antagonistas & inibidores , Feminino , Antebraço/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos Cíclicos/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Vasoconstrição/efeitos dos fármacos
15.
Bone ; 47(3): 542-5, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20685405

RESUMO

Low bone mineral density is highly prevalent in postmenopausal women. Osteopenia in postmenopausal women is a predictor of adverse cardiovascular events. A potential mechanism contributing to the increased cardiovascular risk in postmenopausal women with osteopenia is endothelial vasomotor dysfunction. Endothelin (ET)-1 is a potent vasoconstrictor peptide that is associated with endothelial vasomotor dysfunction and increased cardiovascular risk. Currently, there is no information on osteopenia and ET-1 vasoconstrictor activity in postmenopausal women. We tested the hypothesis that ET-1 mediated vasoconstrictor activity is greater in postmenopausal women with osteopenia compared with those without. Forearm blood flow responses to intra-arterial infusion of BQ-123 (100 nmol/min for 60 min), a selective ET(A) receptor antagonist, were determined in postmenopausal women: 10 with osteopenia (age: 56+/-1 yr, lumbar spine T-score between -1.5 and -2.5) and 12 without osteopenia (age: 60+/-2 yr, T-score>-1.5). In women with osteopenia, forearm blood flow increased approximately 25% (P<0.05) in response to BQ-123. However, in the women without osteopenia, resting forearm blood flow was not significantly changed. In conclusion, these results suggest that osteopenia is associated with greater ET-1-mediated vasoconstrictor tone. Increased ET-1 vasoconstrictor activity may contribute to the elevated cardiovascular risk in postmenopausal women with osteopenia.


Assuntos
Doenças Ósseas Metabólicas/fisiopatologia , Endotelina-1/metabolismo , Pós-Menopausa , Vasoconstrição/fisiologia , Anti-Hipertensivos/farmacologia , Densidade Óssea , Antagonistas dos Receptores de Endotelina , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Pessoa de Meia-Idade , Tono Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Peptídeos Cíclicos/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/metabolismo
16.
Obesity (Silver Spring) ; 18(8): 1667-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20057377

RESUMO

Lifestyle modification in the form of weight reduction by caloric restriction alone or in combination with regular aerobic exercise significantly improves endothelium-dependent vasodilation in overweight and obese adults. We determined whether regular aerobic exercise, independent of weight loss, improves endothelium-dependent vasodilation in overweight and obese adults. Twenty overweight and obese adults (age 53 +/- 1 years; BMI: 30.2 +/- 0.8 kg/m(2)) were studied before and after a 3-month aerobic exercise training intervention. Forearm blood flow (FBF) responses were determined (via plethysmography) in response to intra-arterial infusion of acetylcholine and sodium nitroprusside. There were no changes in body mass or composition with the intervention. FBF responses to acetylcholine were approximately 35% higher (P < 0.01) after (4.1 +/- 0.9 to 14.7 +/- 4.3 ml/100 ml tissue/min) compared with before (4.2 +/- 0.8 to 11.0 +/- 3 ml/100 ml tissue/min) exercise training. FBF responses to sodium nitroprusside were unchanged. These results indicate that regular aerobic exercise improves endothelium-dependent vasodilation in overweight and obese adults, independent of changes in body mass or composition.


Assuntos
Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitroprussiato/farmacologia , Pletismografia , Vasodilatação/efeitos dos fármacos , Perda de Peso
17.
Int J Sport Nutr Exerc Metab ; 19(1): 47-60, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19403953

RESUMO

PURPOSE: This study investigated the effects of short-term dietary changes on metabolism and duathlon performance. METHODS: Eleven men underwent a high-fat (HF; >65% fat from energy) or a high-carbohydrate (CHO; HC) diet (>60% CHO from energy). Energy intake was individualized, and commercially available foods were prepared and packaged for each participant 48 hr before they completed a laboratory-based duathlon (5-km run, 30 km cycling, and 10-km run). Blood samples were obtained before, immediately after, and 1 and 2 hr after the duathlon for determination of glucose, insulin, and glucagon. Oxygen consumption, ratings of perceived exertion (RPE), and respiratory-exchange ratio were assessed, and fat and CHO oxidation were estimated before, during, and after the duathlon. RESULTS: Dietary records indicated a significant difference in fat content ingested before the duathlons (p < .05). Time to complete the duathlon did not differ between the HC- and the HF-diet trials. CHO-oxidation rate was higher during the HC-diet trial than during the HF-diet trial (p = .006). Fat-oxidation rates were higher in the HF-diet trial than in the HC-diet trial (p = .001). No differences in RPE were found between dietary trials. Blood glucose concentration was higher immediately after the duathlon in the HC-diet trial than in the HF-diet trial and remained higher 1 and 2 hr after the duathlon (p < .05). CONCLUSION: Duathlon performance was not altered by short-term changes in dietary fat or CHO composition despite higher blood glucose concentrations under the HC condition.


Assuntos
Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Metabolismo Energético/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Resistência Física/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Área Sob a Curva , Glicemia/metabolismo , Estudos Cross-Over , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Glucagon/metabolismo , Humanos , Insulina/sangue , Masculino , Consumo de Oxigênio/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
18.
J Sports Sci Med ; 8(2): 252-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-24149534

RESUMO

The aim of the study was to investigate the association between the initial metabolic state and exercise-induced endotoxaemia on the appearance of gastrointestinal symptoms (GIS) during exercise. Eleven males (36.6 ± 4.9 yrs, 1.7 ± 0.1 m, 74.5 ± 7.7 kg, DEXA body fat % 17.2 ± 6.6, VO2max 57.4 ± 7.4 ml·kg(-1)·min(-1)) underwent two isoenergetic diets designed to change their initial metabolic status by either depleting or maintaining their hepatic and muscular glycogen content. These diets and accompanying exercise sessions were performed by each participant in the days before completing a laboratory-based duathlon (5-km run, 30-km cycling, 10-km run). Blood samples were obtained before, immediately and 1- and 2-h following the duathlon for determination of insulin (IN), glucagon (GL), endotoxin, aspartic aminotransferase (AST), and alanine aminotransferase (ALT) markers. GIS were assessed by survey before and after exercise. Diet content produced a different energy status as determined by macronutrient content and the IN/GL ratio (p < 0.05), and mild exercise-induced endotoxaemia was observed in both experimental duathlons. Regardless of the diet, the AST/ALT ratio following exercise and in the recovery phase indicated hepatocyte and liver parenchyma structural damage. In spite of GIS, no significant correlations between endotoxin levels and GIS were found. In conclusion, increased markers of endotoxaemia observed with the high-intensity exercise were unrelated to hepatic function and/or GIS before and after exercise. Key pointsGastrointestinal symptoms before, during, and after a competition are reported by approximately 20%-50% of the athletes participating in endurance events such as marathon, cycling and triathlon.Energy status, exercise-induced endotoxaemia and liver structural damage might be related to gastrointestinal symptoms.In this study, gastrointestinal symptoms observed before and after endurance exercise were unrelated to endotoxin levels or hepatic structural damage.

19.
Med Sci Sports Exerc ; 40(12): 2105-11, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18981938

RESUMO

INTRODUCTION: It is currently unclear as to how exercise prescription variables influence attenuations of postprandial lipemia (PPL) in men with the metabolic syndrome (MetS) after exercise. Therefore, the purposes of this investigation were to compare the effects of low- and moderate-intensity exercise and accumulated versus continuous exercise on PPL in males with MetS. METHODS: Fourteen males with MetS (waist circumference (WC) = 110.2 +/- 10.9 cm; triglycerides (TG) = 217 +/- 84 mg dL(-1); fasting blood glucose = 105 +/- 7 mg dL(-1); high-density lipoprotein cholesterol (HDL-C) = 44 +/- 7 mg dL(-1); systolic blood pressure (SBP) = 120 +/- 12 mm Hg; diastolic blood pressure (DBP) = 76 +/- 10 mm Hg) completed a control condition consisting of a high-fat meal and blood sampling at 2 h intervals for 6 h. Next, participants completed the following exercise conditions: 1) continuous moderate-intensity (MOD-1), 2) continuous low-intensity (LOW-1), and 3) two accumulated moderate-intensity sessions (MOD-2). The test meal and blood sampling were repeated 12-14 h after exercise. Area under the curve (AUC) scores and temporal postprandial responses were analyzed using repeated-measures ANOVA for TG and insulin. RESULTS: The TG AUC decreased by 27% after LOW-1. TG concentrations were also reduced by 22% and 21% at 4 h postmeal after LOW-1 and MOD-1, yet TG parameters were no different from the control condition after MOD-2 (P < 0.05 for all). CONCLUSION: These findings indicate that 500 kcal of continuous aerobic exercise before a meal attenuates PPL in men with MetS. This outcome can be achieved through low- or moderate-intensity exercise performed in a single session. Accumulating moderate-intensity exercise does not appear to effectively modulate PPL in men with MetS.


Assuntos
HDL-Colesterol/sangue , Exercício Físico , Síndrome Metabólica/metabolismo , Período Pós-Prandial , Triglicerídeos/sangue , Adulto , Área Sob a Curva , Pressão Sanguínea , Registros de Dieta , Gorduras na Dieta/administração & dosagem , Humanos , Insulina/sangue , Masculino , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade
20.
J Am Coll Health ; 57(1): 39-44, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18682344

RESUMO

UNLABELLED: Pedometer-determined physical activity (PA) is inversely related to body composition in middle-aged adults; however, researchers have not established such a relationship in college students. OBJECTIVE AND PARTICIPANTS: In this study, the authors attempted to characterize PA and examine its relationship with body composition in undergraduate college students (N = 88). METHODS: The authors measured the BC of 44 women (M age = 21 +/- 1 year, M body mass index [BMI] = 23.9 +/- 4 kg/m2) and 44 men (M age = 22 +/- 1 year, BMI = 26.9 +/- 0.9 kg/m2); participants also wore a pedometer for 7 days and completed a PA questionnaire. RESULTS: Men averaged significantly more steps/day (10,027 +/- 3,535) than did women (8,610 +/- 2,252). For women only, the authors observed significant correlations between steps/day and body composition variables. Men reported engaging in vigorous PA significantly more often than did women. CONCLUSIONS: These findings indicate that men engage in PA more often but that PA is related to body composition only in women. In addition, there is better agreement between pedometer-measured and self-reported PA in college-aged men than women.


Assuntos
Composição Corporal/fisiologia , Índice de Massa Corporal , Exercício Físico/fisiologia , Atividade Motora/fisiologia , Estudantes/estatística & dados numéricos , Caminhada/fisiologia , Adulto , Antropometria , Feminino , Humanos , Masculino , Serviços de Saúde Escolar , Autorrevelação , Fatores Sexuais , Sudeste dos Estados Unidos , Estudantes/psicologia , Inquéritos e Questionários , Universidades , Relação Cintura-Quadril
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