Evaluation of the global lung function initiative 2012 reference values for spirometry in a Swedish population sample

Background: The Global Lung Function Initiative 2012 (GLI) reference values are currently endorsed by several respiratory societies but evaluations of applicability for adults resident in European countries are lacking. The aim of this study was to evaluate if the GLI reference values are appropriate for an adult Caucasian Swedish population. Methods: During 2008-2013, clinical examinations including spirometry were performed on general population samples in northern Sweden, in which 501 healthy Caucasian non-smokers were identified. Predicted GLI reference values and Z-scores were calculated for each healthy non-smoking subject and the distributions and mean values for FEV1, FVC and the FEV1/FVC ratio were examined. The prevalence of airway obstruction among these healthy non-smokers was calculated based on the Lower Limit of normal (LLN) criterion (lower fifth percentile) for the FEV1/FVC ratio. Thus, by definition, a prevalence of 5% was expected. Results: The Z-scores for FEV1, FVC and FEV1/FVC were reasonably, although not perfectly, normally distributed, but not centred on zero. Both predicted FEV1 and, in particular, FVC were lower compared to the observed values in the sample. The deviations were greater among women compared to men. The prevalence of airway obstruction based on the LLN criterion for the FEV1/FVC ratio was 9.4% among women and 2.7% among men. Conclusions: The use of the GLI reference values may produce biased prevalence estimates of airway obstruction in Sweden, especially among women. These results demonstrate the importance of validating the GLI reference values in different countries.Peer reviewe

Anthropometric midarm measurements can detect systemic fat-free mass depletion in patients with chronic obstructive pulmonary disease

Our objective was to determine whether anthropometric measurements of the midarm (MA) could identify subjects with whole body fat-free mass (FFM) depletion. Fifty-five patients (31% females; age: 64.6 ± 9.3 years) with mild/very severe chronic obstructive pulmonary disease (COPD), 18 smokers without COPD (39% females; age: 49.0 ± 7.3 years) and 23 never smoked controls (57% females; age: 48.2 ± 9.6 years) were evaluated. Spirometry, muscle strength and MA circumference were measured. MA muscle area was estimated by anthropometry and MA cross-sectional area by computerized tomography (CT) scan. Bioelectrical impedance was used as the reference method for FFM. MA circumference and MA muscle area correlated with FFM and biceps and triceps strength. Receiver operating characteristic curve analysis showed that MA circumference and MA muscle area cut-off points presented sensitivity and specificity >82% to discriminate FFM-depleted subjects. CT scan measurements did not provide improved sensitivity or specificity. For all groups, there was no significant statistical difference between MA muscle area [35.2 (29.3-45.0) cm²] and MA cross-sectional area values [36.4 (28.5-43.3) cm²] and the linear correlation coefficient between tests was r = 0.77 (P < 0.001). However, Bland-Altman plots revealed wide 95% limits of agreement (-14.7 to 15.0 cm²) between anthropometric and CT scan measurements. Anthropometric MA measurements may provide useful information for identifying subjects with whole body FFM depletion. This is a low-cost technique and can be used in a wider patient population to identify those likely to benefit from a complete body composition evaluation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal do Amazonas Departamento de FisioterapiaUnisalesiano Centro Universitário Católico Salesiano Auxilium Departamento de FisioterapiaUniversidade Estadual Paulista Faculdade de Medicina de Botucatu Departamento de Clínica MédicaUniversidade Estadual Paulista Faculdade de Medicina de Botucatu Departamento de Doenças Tropicais e Diagnóstico por ImagemUniversidade Estadual Paulista Faculdade de Medicina de Botucatu Departamento de Clínica MédicaUniversidade Estadual Paulista Faculdade de Medicina de Botucatu Departamento de Doenças Tropicais e Diagnóstico por ImagemFAPESP: 04/00517-

Therapeutic ratio of hydrofluroalkane and chlorofluorocarbon formulations of fluticasone propionate

Objectives: To compare the therapeutic ratio of chlorofluorocarbon (CFC) and hydrofluoroalkane-134a (HFA) formulations of fluticasone propionate (FP). Methods: We performed a randomized, placebo-controlled, crossover study comparing 6 weeks of treatment with FP using 500 μg/d and 1,000 μg/d formulations of CFC and HFA. The primary end points were provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and overnight urinary cortisol/creatinine excretion. Results: Eighteen patients with mild-to-moderate asthma and geometric mean (SEM) PD20 of 82.3 μg (19.2 μg) completed the study. All treatments significantly improved PD20 values and morning peak expiratory flow vs placebo, while 1,000 μg/d was significantly better than 500 μg/d for the CFC formulation of FP (CFC-FP) but not the HFA formulation of FP (HFA-FP). Only 1,000 μg/d of CFC-FP caused significant suppression of overnight urinary cortisol/creatinine compared to placebo. There were no differences between formulations at either dose. Conclusions: The increased airway benefit with CFC-FP &gt; 500 μg/d was offset by greater systemic effects. Although HFA-FP had fewer systemic effects than CFC-FP at 1,000 μg/d, there was no benefit to increasing HFA-FP to &gt; 500 μg/d