The effect of inspired oxygen fraction on peak oxygen uptake during arm exercise

Item does not contain fulltextIt has been shown that peak oxygen uptake (O(2)peak) during leg exercise is enhanced by an increased inspiratory oxygen fraction ( FiO(2)), indicating that oxygen supply is the limiting factor. Whether oxygen supply is a limiting factor in arm exercise performance is unknown. The purpose of this study, therefore, was to examine the effect of different levels of FiO(2 )on O(2)peak during arm exercise in healthy individuals. Nine men successfully performed three incremental arm-cranking exercise tests with FiO(2)15%, FiO(2)21% and FiO(2)50% applied in counterbalanced order. A significant FiO(2 )dependency was observed for O(2)peak ( p=0.02) and power output ( p=0.03) and post hoc tests revealed a significant difference in O(2)peak between 15 and 50% FiO(2 )( p=0.02), but not between 15 and 21% FiO(2), and 21 and 50% FiO(2). The results of this study show that O(2)peak is enhanced with increasing FiO(2), and suggest that O(2)peak during arm exercise is limited by oxygen supply rather than by the metabolic machinery within the muscle itself

Early intervention with inhaled corticosteroids in subjects with rapid decline in lung function and signs of bronchial hyperresponsiveness: results from the DIMCA programme.

Contains fulltext : 51862.pdf (publisher's version ) (Open Access)BACKGROUND: Asthma is generally accepted as an inflammatory disease that needs steroid treatment. However, when to start with inhaled steroids remains unclear. A study was undertaken to determine when inhaled corticosteroids should be introduced as the first treatment step. OBJECTIVE: To investigate the effectiveness of early introduction of inhaled steroids on decline in lung function in steroid-naive subjects with a rapid decline in lung function in general practice. SUBJECTS: Patients with signs/symptoms suspect of asthma (i.e., persistent and/or recurrent respiratory symptoms) and a decline in forced expiratory volume in 1 s (FEV(1)) during 1-year monitoring of 0.080 l or more and reversible obstruction (> or =10% predicted) or bronchial hyperresponsiveness (PC(20)< or =8 mg/ml) were studied. They had been identified in a population screening aiming to detect subjects at risk for chronic obstructive pulmonary disease (COPD) or asthma. DESIGN: A placebo-controlled, randomized, double-blind study. METHODS: 75 subjects out of a random population of 1155 were found eligible, and 45 were willingly to participate. Subjects were randomly treated with placebo or fluticasone propionate 250 microg b.i.d., and FEV(1) and PC(20) were monitored over a 2-year period. OUTCOME VARIABLES: The primary outcome measure was decline in FEV(1); the secondary outcome measure was bronchial hyperresponsiveness (PC(20)). RESULTS: 22 subjects were randomly allocated to the active group with inhaled corticosteroids and 23 to placebo. Change of FEV(1) in the active treated group was +43 ml in post-bronchodilator FEV(1) (p =0.341) and +62 ml/year (p =0.237) in pre-bronchodilator FEV(1) after 1 year, and -22 ml (p =0.304) for post-bronchodilator FEV(1) and -9.4 ml (p =0.691) for pre-bronchodilator FEV(1) after 2 years, compared to placebo. The effect on PC(20) was almost one dose-step (p =0.627) after 1 year and one dose-step (p =0.989) after 2 years. CONCLUSION: In this study, the early introduction of inhaled corticosteroids in newly diagnosed asthmatic subjects with rapid decline in lung function did not prove to be either clinically relevant or statistically significant in reversing the decline in FEV(1). For PC(20), no significant changes were detected

Baroreflex and chemoreflex function after bilateral carotid body tumor resection

Objective To investigate whether bilateral carotid body tumor resection invariably and chronically affects arterial baroreflex or peripheral chemoreflex function. Methods We studied eight consecutive patients (two men and six women; ages 48.1 +/- 11.8 years), a median time of 3.4 years (range 1.3-20.6 years) after bilateral carotid body tumor resection, and 12 healthy control individuals (eight men and four women; ages 53.7 +/- 10.1 years). Baroreflex sensitivity (phenylephrine), blood pressure and its variability (24 h Spacelabs and 5 h Portapres recordings), responses to standard cardiovascular reflex tests and the ventilatory responses to normocapnic and hypercapnic hypoxia were assessed. Results Baroreflex sensitivity was lower in patients (6.4 +/- 7.2 ms/mmHg) than in controls (14.7 +/- 6.6 ms/mmHg; P +/- 0.011). Mean office blood pressure and heart rate were normal in patients (1123.3 +/- 11.9/79.0 +/- 7.3 mmHg and 67.5 +/- 9.4 beats/min, respectively) and controls (117.8 +/- 10.6/74.0 +/- 6.8 mmHg and 61.1 +/- 9.2 beats/min, respectively). Blood pressure variability was increased during ambulatory measurements. Three patients exhibited orthostatic hypotension. The Valsalva ratio, an index of baroreflex-mediated cardiovagal innervation, was lower in patients (1.4 +/- 0.2) than in controls (1.8 +/- 0.5; P +/- 0.008). The normocapnic ventilatory response to hypoxia was absent in all patients, whereas a small residual response to hypoxia was observed under hypercapnic conditions in two patients. Conclusions Bilateral carotid body tumor resection results in heterogeneous expression of arterial baroreflex dysfunction, whereas the normocapnic hypoxic drive is invariably abolished as a result of peripheral chemoreflex failure. (C) 2003 Lippincott Williams Wilkin

Anabolic steroids in part reverse glucocorticoid-induced alterations in rat diaphragm

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An Integral assessment framework of health status in chronic obstructive pulmonary disease (COPD).

Contains fulltext : 69722.pdf (publisher's version ) (Closed access)BACKGROUND: To date, many health status instruments exist, but the validity of these instruments is questionable. This is caused by the fact that health status is poorly defined. Purpose: To develop a validated framework that improves conceptual insight into health status and its domains. METHODS: Based on theoretical and clinical considerations, we defined the domains of health status into concrete sub-domains by formulating conceptual models. Guided by these conceptual models, for each sub-domain, existing instruments were selected. We validated the conceptual models in the data of 168 COPD patients. Using factor analysis, underlying concepts in the data were identified. RESULTS: The resulting framework included physiological functioning, complaints, functional impairment, and quality of life. These main domains were shown to be subdivided into 15 sub-domains. CONCLUSIONS: The present study shows that health status consists of conceptually distinct sub-domains. Integral assessment of health status thus entails measuring all sub-domains. Existing instruments measure only few sub-domains. Integral assessment of health status thus requires the combination of different instruments. The present framework of health status can help in composing such a battery of instruments. Patient profiles obtained by the framework are essential in individualizing treatment