Navegando por Palavras-chave "gas exchange"
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- ItemSomente MetadadadosAerobic exercise capacity in normal adolescents and those with type 1 diabetes mellitus(Blackwell Publishing, 2005-09-01) Komatsu, Willian R.; Gabbay, Monica Andrade Lima [UNIFESP]; Lazaretti-Castro, Marise [UNIFESP]; Saraiva, Gabriela L.; Chacra, Antonio Roberto; Barros Neto, Turibio Leite [UNIFESP]; Dib, Sergio A.; Universidade Federal de São Paulo (UNIFESP)Objective: To compare the aerobic exercise capacity between normal adolescents and those with type I diabetes mellitus (T1DM).Methods: An experimental group with 72 individuals diagnosed with T1DM aged 9-20, time from diagnosis 4.9 +/- 3.6 yr, without clinical cardiopulmonary disease or anemia and a control group (C) with 46 healthy individuals aged 10-18, matched by age, weight, height, body mass index, and lean and fat mass (kg), underwent an incremental aerobic exercising test on a motorized treadmill, where gas exchange variables - peak pulmonary ventilation (VE), peak oxygen consumption (VO2), and carbon dioxide production (CO2) - as well as their heart rate (HR) and time to exhaustion were recorded.Results: Body mass composition had no significant difference between experimental and control groups, and male and female subjects had similar exercising performances. the mean of hemoglobin A1c in the control group was 5.2 +/- 0.9% and in the diabetic group 8.1 +/- 2.2%; p = 0.000. the patients with T1DM showed lower levels of aerobic capacity than the control group. Their respective values for each variable were as follows: (i) maximal VO2 (T1DM: 41.57 +/- 7.68 vs. C: 51.12 +/- 9.94 mL/kg/min; p < 0.001) and (ii) maximal VE (T1DM: 76.39 +/- 19.93 vs. C: 96.90 +/- 25.72 mL/kg/min; p < 0.001). Patients with T1DM also had an earlier time to exhaustion (T1DM: 8.75 +/- 1.60 vs. 10.82 +/- 1.44 min).Conclusions: Adolescent patients with T1DM showed a reduced aerobic exercising capacity when compared to healthy peers matched to anthropometric conditions. This potential condition should be taken into consideration by the time of evaluation of the aerobic performance of these patients with glycemic control level.
- ItemSomente MetadadadosClinical, radiographic and functional predictors of pulmonary gas exchange impairment at moderate exercise in patients with sarcoidosis(Karger, 2004-01-01) Barros, WGP; Neder, J. A.; Pereira, CAC; Nery, L. E.; Universidade Federal de São Paulo (UNIFESP)Background: Pulmonary gas exchange impairment (GEI) is a common consequence of intrathoracic sarcoidosis presenting with important therapeutic and prognostic implications. Objective: To determine the role of clinical, radiographic and functional variables in predicting GEI during moderate exercise at the estimated lactate threshold (theta(L)) in patients with sarcoidosis. Methods: Fifty-four outpatients (29 females) with biopsy-proven sarcoidosis had clinical evaluation (baseline dyspnea index), lung function tests and an incremental cardiopulmonary exercise test with theta(L) estimation. On a separate day, patients underwent a constant work rate test at theta(L) with assessment of arterial blood gas tensions. Results: There was no evidence of GEI [DeltaP (A - a) O-2/VO2 >20 mm Hg.l.min(-1)] in patients with radiographic stages 0-1 (n = 13). in the remaining 41 patients, GEI was associated with more extensive radiographic involvement and reduced diffusing capacity of the lung for carbon monoxide (DLCO), forced expiratory volume in 1 s, total lung capacity and forced vital capacity (% predicted; p < 0.05); baseline dyspnea index and resting arterial blood gas tensions, in contrast, were not significantly related to GEI. DLCO correlated best with GEI. the negative predictive value of DLCO >70% predicted (absent-to-mild impairment) was 91.3% (sensitivity = 81.8%) and the positive predictive value of DLCO less than or equal to50% predicted (severe impairment) was 83.3% (specificity = 96.6%, likelihood ratio = 13.35). There was no improvement in diagnostic accuracy when other physiological tests were added to DLCO. These results were consistent with those found in a multiple logistic regression analysis with GEI as the dependent variable (p < 0.01). Conclusions: Conventional chest radiography and DLCO measurements suffice to estimate the individual risk of GEI at moderate exercise in patients with sarcoidosis. Copyright (C) 2004 S. Karger AG, Basel.
- ItemSomente MetadadadosA simplified strategy for the estimation of the exercise ventilatory thresholds(Lippincott Williams & Wilkins, 2006-05-01) Neder, Jose Alberto [UNIFESP]; Stein, R.; Universidade Federal de São Paulo (UNIFESP); Univ Fed Rio Grande SulPurpose: To analyze the limits of agreement between exercise ventilatory threshold values (VT1 and VT2) estimated from a combination of pulmonary gas exchange and ventilatory variables (cardiopulmonary exercise testing) and those derived from an alternative approach based oil the ventilatory response only (VE. ventilometry). Methods: Forty-two nontrained subjects (24 males, aged 18-48, peak VO2 = 33.1 +/- 8.6 mL(.)min(-1.)kg(-1)) performed a maximum incremental cardiopulmonary exercise testing on all electromagnetically braked cycle ergometer. the participants breathed through a Pilot tube (Cardio(2) System (TM), MGC) and a fixed-resistance ventilometer (Micromed, Brazil), which were connected in series. HR values at the estimated VT (VTHR1 and VTHR2) were obtained by the conventional method (ventilatory equivalents. end-expiratory pressures for O-2 and CO2 and the V-slope procedure) and an experimental approach (VE vs time, VE/time vs time. and breathing frequency vs time). Results: There were no significant between-method differences on VTHR1, VTHR2, VTVE1, VTVE2, and peak VE (P > 0.05). After certification of data normality, a Bland-Altman analysis revealed that the mean bias 95% confidence interval of the between-method differences were lower for VTHR2 than VTHR1 (2 +/- 9 and 0 +/- 17 bpm, respectively). VTHR2 according to ventilometry differed more than 10 bpm from the standard procedure in 3 out of 42 subjects (9%). Between-method differences were independent of the level of fitness, as estimated from peak VO2 (P > 0.05). Conclusions: A simplified approach, based oil the ventilatory response as a function of time, call provide acceptable estimates of the exercise ventilatory thresholds-especially VT2-during ramp-incremental cycle ergometry. This new strategy might prove to be useful for exercise training prescription in nontrained adults.