Search

Background: Several COPD phenotypes have been described; the COPD-asthma overlap is one of the most recognized. The aim of this study was to evaluate the prevalence of three subgroups (asthma, COPD, and COPD-asthma overlap) in the Latin American Project for the Investigation of Obstructive Lung Disease (PLATINO) study population, to describe their main characteristics, and to determine the association of the COPD-asthma overlap group with exacerbations, hospitalizations, limitations due to physical health, and perception of general health status (GHS)., Methods: The PLATINO study is a multicenter population-based survey carried out in five Latin American cities. Outcomes were self-reported exacerbations (defined by deterioration of breathing symptoms that affected usual daily activities or caused missed work), hospitalizations due to exacerbations, physical health limitations, and patients' perception of their GHS obtained by questionnaire. Subjects were classified in three specific groups: COPD--a postbronchodilator (post-BD) FEV₁/FVC ratio of < 0.70; asthma--presence of wheezing in the last year and a minimum post-BD increase in FEV₁ or FVC of 12% and 200 mL; and overlap COPD-asthma--the combination of the two., Results: Out of 5,044 subjects, 767 were classified as having COPD (12%), asthma (1.7%), and COPD-asthma overlap (1.8%). Subjects with COPD-asthma overlap had more respiratory symptoms, had worse lung function, used more respiratory medication, had more hospitalization and exacerbations, and had worse GHS. After adjusting for confounders, the COPD-asthma overlap was associated with higher risks for exacerbations (prevalence ratio [PR], 2.11; 95% CI, 1.08-4.12), hospitalizations (PR, 4.11; 95% CI, 1.45-11.67), and worse GHS (PR, 1.47; 95% CI, 1.18-1.85) compared with those with COPD., Conclusions: The coexisting COPD-asthma phenotype is possibly associated with increased disease severity.

Background: COPD is a highly prevalent disease but underdiagnosed, undertreated and possibly under-recognized by patients. Limited information exists regarding patients' perception of COPD severity. We compared patients' general health status perception, degree of breathlessness and physical activity limitation with the severity of their respiratory condition measured by airway obstruction, in a population-based sample., Methods: We used postbronchodilator FEV(1)/FVC<0.70 to define COPD. Patients' perception of their general health status was derived from the question "in general you would say that your health is: excellent, very good, good, fair or poor?", Results: Spirometry was performed in 5314 subjects: an FEV(1)/FVC ratio below 0.70 was found in 759 subjects. In persons with COPD, general health status decreased with increasing GOLD stages. Over one-half of subjects with stage 2 and one third of those with stages 3 and 4 reported their health status as good to excellent. There was also a disparity between airway obstruction severity and breathlessness intensity. Although the more severe COPD stages were frequently associated with significant compromise of work and everyday activities, patients often tended to provide an optimistic self evaluation of their health status., Conclusions: The discrepancy observed between general health status, dyspnea severity, physical activity limitation and airway obstruction most likely reflect patients' underperception of disease severity, emphasizing the need for improving case-finding measures and multi-component evaluation of COPD subjects.

Background: Recurrent exacerbations are common in COPD patients. Limited information exists regarding exacerbation frequency in COPD patients from epidemiologic studies. We examined the frequency of self-reported exacerbations and the factors influencing exacerbation frequency among COPD patients in a population-based study conducted in Latin America., Methods: We used a post-bronchodilator FEV(1)/FVC ratio of < 0.70 to define COPD. Exacerbation was self-reported and defined by symptoms (deterioration of breathing symptoms that affected usual daily activities or caused missed work)., Results: Spirometry was performed in 5,314 subjects. There were 759 subjects with airflow limitation; of these, 18.2% reported ever having had an exacerbation, 7.9% reported having an exacerbation, and 6.2% reported having an exacerbation requiring at least a doctor visit within the past year. The proportion of individuals with an exacerbation significantly increased by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, from 4.2% in stage 1 to 28.9% in stages 3 and 4. The self-reported exacerbation rate was 0.58 exacerbations per year. The rate of exacerbations requiring at least a doctor visit and length of stay in hospital due to exacerbations also increased as COPD severity progressed. The factors associated with having an exacerbation in the past year were dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and disease severity of GOLD stages 3 and 4., Conclusions: The proportion of individuals with airflow limitation and self-reported exacerbation increases as the disease severity progresses. Dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and more severe obstruction were significantly associated with having an exacerbation in the past year.

Background: The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD., Methods: COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2))., Results: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI., Conclusions: BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.

Background: Although tobacco smoke is the main cause of COPD, relatively little attention has been paid to its potential damage to skeletal muscle. This article addresses the effect of smoking on skeletal muscle., Methods: The vastus lateralis muscle was studied in 14 non-COPD smokers (FEV(1)/FVC, 78 +/- 5%) and 20 healthy control subjects (FEV(1)/FVC, 80 +/- 3%). Muscular structure, enzyme activity, constitutive and inducible nitric oxide (NO) synthases (endothelial NO oxide synthase [eNOS], neuronal NO synthase [nNOS] and inducible NO synthase [iNOS]), nitrites, nitrates, nitrotyrosine, and the presence of macrophages were analyzed., Results: In smokers, type I muscle fibers cross-sectional area was decreased, and a similar trend was found in type IIa fibers. Lactate dehydrogenase levels and the percentage of fibers with low oxidative and high glycolytic capacity were increased in smokers. nNOS (96.9 +/- 11.7 vs 125.4 +/- 31.9 ng/mg protein; p < 0.01) and eNOS (38.9 +/- 11.0 vs 45.2 +/- 7.7 ng/mg protein [+/- SD]; p < 0.05) were lower in smokers, while fiber type distribution, capillarity measures, beta-hydroxy-acyl-CoA-dehydrogenase levels, iNOS, nitrite, nitrate, and nitrotyrosine levels, and macrophage number in the muscle tissue were similar to the nonsmoker subjects., Conclusions: Smokers presented some alterations of skeletal muscle such as oxidative fiber atrophy, increased glycolytic capacity, and reduced expression of the constitutive NO synthases (eNOS and nNOS). The findings support some muscular structural and metabolic damage but not the presence of local inflammation in the smokers. In addition, they suggest a possible effect of tobacco smoke impairing the normal process of NO generation.

Background: COPD is a major worldwide problem with a rising prevalence. Despite its importance, there is a lack of information regarding underdiagnosis and misdiagnosis of COPD in different countries. As part of the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar study, we examined the relationship between prior diagnostic label and airway obstruction in the metropolitan areas of five Latin American cities (São Paulo, Santiago, Mexico City, Montevideo, and Caracas)., Methods: A two-stage sampling strategy was used in each of the five areas to obtain probability samples of adults aged >or= 40 years. Participants completed a questionnaire that included questions on prior diagnoses, and prebronchodilator and postbronchodilator spirometry. A study diagnosis of COPD was based on airway obstruction, defined as a postbronchodilator FEV(1)/FVC < 0.70., Results: Valid spirometry and prior diagnosis information was obtained for 5,303 participants; 758 subjects had a study diagnosis of COPD, of which 672 cases (88.7%) had not been previously diagnosed. The prevalence of undiagnosed COPD was 12.7%, ranging from 6.9% in Mexico City to 18.2% in Montevideo. Among 237 subjects with a prior COPD diagnosis, only 86 subjects (36.3%) had postbronchodilator FEV(1)/FVC < 0.7, while 151 subjects (63.7%) had normal spirometric values. In the same group of 237 subjects, only 34% reported ever undergoing spirometry prior to our study., Conclusions: Inaccurate diagnostic labeling of COPD represents an important health problem in Latin America. One possible explanation is the low rate of spirometry for COPD diagnosis.

Study Objective: The present study evaluated the relationship between health status (HS) and peripheral muscle histochemical characteristics in chronic obstructive pulmonary disease (COPD), and identified selected independent respiratory and extrapulmonary variables that predicted the HS of these patients., Design: Cross-sectional study., Setting: Outpatient respiratory clinic of a university hospital., Patients and Methods: We studied 29 patients (63+/-10 yrs) with a forced expiratory volume in 1s (FEV1) of 39+/-12%. All patients underwent vastus lateralis muscle biopsies for histochemical analysis. They also had spirometry, arterial blood gas analysis, body mass index (BMI), dyspnea determined with the MMRC scale and responded to the St. George's Respiratory Questionnaire (SGRQ) for HS assessment., Results: SGRQ total score correlated with fiber type distribution. A stepwise multiple regression identified three independent predictors of SGRQ total score: type I fiber proportion, BMI, and FEV1; r = 0.78 and r2 = 0.61., Conclusions: These results indicate that impaired HS in COPD is related to the peripheral muscle changes characterized by less type I fibers proportion. The findings argue in favor of an important contribution of the systemic consequences on the HS in COPD independently from the airflow limitation severity, and help to explain the observation of the poor correlation between the degree of airflow limitation and SGRQ total score.