the world health organization ( who ) reports that chronic obstructive pulmonary disease ( copd ) was responsible for more than three million fatalities in 2011 , accounting for 5.8% of all deaths.1,2 although 30% of adults 35 years of age with tobacco / occupational exposure and at least one respiratory symptom exhibited airway obstruction on spirometry , this test is often delayed until later stages of the disease because early symptoms of copd are not frequently recognized.35 however , it has already been demonstrated that airflow obstruction may be observed on spirometry in copd patients in the initial stages of the disease , even in the absence of respiratory symptoms.5 it is known that arterial hypertension occurs in more than 50% of copd patients diagnosed at a primary health care level.6 however , the prevalence of copd among subjects with arterial hypertension , a disease often diagnosed and followed by primary health care providers , is unknown . the purpose of the present study was to determine the prevalence of copd among adults with tobacco / occupational exposure and arterial hypertension with and without respiratory symptoms in three primary health care facilities in goiania , brazil . cross - sectional study . adults aged 40 years with tobacco / occupational exposure and systemic arterial hypertension diagnosed according to the brazilian society of cardiology criteria and who were undergoing treatment at a primary health care facility were eligible for the study.7 signed informed consent was necessary for enrollment . exclusion criteria were reported to be asthma , presence of reversibility of the airway obstruction demonstrated on spirometry test ; pneumothorax ; angina ; recent ( within 3 months ) myocardial infarction or pulmonary embolism or hemoptysis or brain , eye , ear , thoracic , or abdominal surgery ; presence of known thoracic , abdominal , or cerebral aneurysms ; severe hypertension ( mean arterial pressure > 130 mmhg ) at the time of spirometry ; acute illness or symptoms that might interfere with test performance ( nausea , vomiting , coughing , or acute diarrhea ) ; and patients with mental confusion or dementia.8 subjects were also excluded if they had incomplete interviews or could not complete the spirometric test . brazil s health care system is organized into primary , secondary , and tertiary levels . each fhp facility is responsible for a community of about 1,000 families , and has a family health team of one doctor , one nurse , one auxiliary nurse , and four to six community health agents . community health agents visit 150 families every month on average , and the fhp provides promotive , preventive , curative , and rehabilitative services . this study was conducted at ciams ( center for integrated health care health ) novo horizonte , uabsf ( primary care unit of the family health program ) caravelas , and uabsf santa rita facilities in the same geographic area of goiania , a city in brazil s midwest region . after signing the informed consent , participants completed a pretested , standardized respiratory questionnaire including the following : demographics ; smoking habits ; exposure to biomass smoke ; education ; occupational exposure to chemicals and particulate matter ; respiratory symptoms ; use of medications ; previous spirometry testing ; previous medical diagnosis of tuberculosis , asthma , chronic bronchitis , emphysema , or copd ; self - reported exacerbation and hospitalization due to copd and comorbid conditions ( heart disease , stroke , diabetes , and asthma ) . anthropometrics , blood pressure , spirometry , and oxygen saturation measurements were performed in all enrolled subjects . spirometry was performed using the portable , battery - operated ultrasound easy one spirometer ( ndd medical technologies , zurich , switzerland ) . spirometry was performed at baseline and 15 minutes after the administration of 400 g of salbutamol , according to the criteria of the american thoracic society and european respiratory society for acceptability and reproducibility.9 positive bronchodilator responsiveness was defined using the following criteria : forced vital capacity ( fvc ) and/or forced expiratory volume in 1 second ( fev1 ) 12% plus 200 ml improvement.10 the presence of copd was based on the postbronchodilator fev1/fvc < 0.70 , a fixed value proposed by the global initiative for obstructive lung disease ( gold ) criteria , among subjects 40 years old or more with tobacco / occupational exposure and no asthma diagnosis.11 reversibility of the airway obstruction diagnosis was defined as the presence of positive bronchodilator responsiveness as defined by the american thoracic society.12 a significant biomass exposure was defined as a subject with more than 80 hours / year with a minimum exposure of 10 years.13 a subject was included in the group with respiratory symptoms in the presence of any of the following symptoms : dyspnea , cough , wheezing , or sputum production , and was included in the group without respiratory symptoms if all were absent . the results were analyzed using stata version 13.0 ( stata - corp , college station , tx , usa ) . chi - square or fisher s exact test ( when applicable ) was used for dichotomous variables . pairwise correlation analysis was performed between pulmonary function parameters and the blood pressure values , and the bonferroni method was used for adjusting significance levels . this study was conducted according to good clinical practices , and was approved by the ethics committee of the hospital of the federal university of gois under number 195/2011 . adults aged 40 years with tobacco / occupational exposure and systemic arterial hypertension diagnosed according to the brazilian society of cardiology criteria and who were undergoing treatment at a primary health care facility were eligible for the study.7 signed informed consent was necessary for enrollment . exclusion criteria were reported to be asthma , presence of reversibility of the airway obstruction demonstrated on spirometry test ; pneumothorax ; angina ; recent ( within 3 months ) myocardial infarction or pulmonary embolism or hemoptysis or brain , eye , ear , thoracic , or abdominal surgery ; presence of known thoracic , abdominal , or cerebral aneurysms ; severe hypertension ( mean arterial pressure > 130 mmhg ) at the time of spirometry ; acute illness or symptoms that might interfere with test performance ( nausea , vomiting , coughing , or acute diarrhea ) ; and patients with mental confusion or dementia.8 subjects were also excluded if they had incomplete interviews or could not complete the spirometric test . brazil s health care system is organized into primary , secondary , and tertiary levels . each fhp facility is responsible for a community of about 1,000 families , and has a family health team of one doctor , one nurse , one auxiliary nurse , and four to six community health agents . community health agents visit 150 families every month on average , and the fhp provides promotive , preventive , curative , and rehabilitative services . this study was conducted at ciams ( center for integrated health care health ) novo horizonte , uabsf ( primary care unit of the family health program ) caravelas , and uabsf santa rita facilities in the same geographic area of goiania , a city in brazil s midwest region . after signing the informed consent , participants completed a pretested , standardized respiratory questionnaire including the following : demographics ; smoking habits ; exposure to biomass smoke ; education ; occupational exposure to chemicals and particulate matter ; respiratory symptoms ; use of medications ; previous spirometry testing ; previous medical diagnosis of tuberculosis , asthma , chronic bronchitis , emphysema , or copd ; self - reported exacerbation and hospitalization due to copd and comorbid conditions ( heart disease , stroke , diabetes , and asthma ) . anthropometrics , blood pressure , spirometry , and oxygen saturation measurements were performed in all enrolled subjects . spirometry was performed using the portable , battery - operated ultrasound easy one spirometer ( ndd medical technologies , zurich , switzerland ) . spirometry was performed at baseline and 15 minutes after the administration of 400 g of salbutamol , according to the criteria of the american thoracic society and european respiratory society for acceptability and reproducibility.9 positive bronchodilator responsiveness was defined using the following criteria : forced vital capacity ( fvc ) and/or forced expiratory volume in 1 second ( fev1 ) 12% plus 200 ml improvement.10 the presence of copd was based on the postbronchodilator fev1/fvc < 0.70 , a fixed value proposed by the global initiative for obstructive lung disease ( gold ) criteria , among subjects 40 years old or more with tobacco / occupational exposure and no asthma diagnosis.11 reversibility of the airway obstruction diagnosis was defined as the presence of positive bronchodilator responsiveness as defined by the american thoracic society.12 a significant biomass exposure was defined as a subject with more than 80 hours / year with a minimum exposure of 10 years.13 a subject was included in the group with respiratory symptoms in the presence of any of the following symptoms : dyspnea , cough , wheezing , or sputum production , and was included in the group without respiratory symptoms if all were absent . the results were analyzed using stata version 13.0 ( stata - corp , college station , tx , usa ) . chi - square or fisher s exact test ( when applicable ) was used for dichotomous variables . pairwise correlation analysis was performed between pulmonary function parameters and the blood pressure values , and the bonferroni method was used for adjusting significance levels . this study was conducted according to good clinical practices , and was approved by the ethics committee of the hospital of the federal university of gois under number 195/2011 . over a 17-month period , 1,325 patients were admitted to all three primary health care facilities , of which 570 ( 40% ) reported treatment for arterial hypertension in one of three facilities ( figure 1 ) . among these 570 subjects , 316 ( 55% ) met the inclusion criteria and were invited to participate in the study . two hundred and five were nonsmokers without significant biomass exposure , 10 were < 40 years of age , 17 patients refused to sign the consent form , and 22 patients could not perform spirometry ; thus , 316 subjects were enrolled in the study . two hundred and thirty - three patients ( 73.7% ) with arterial hypertension reported at least one respiratory symptom , while 83 ( 26.3% ) reported no respiratory symptoms . forty - one patients ( 17.6% ) with arterial hypertension and a respiratory symptom , and 10 patients ( 12% ) with arterial hypertension and no respiratory symptoms were diagnosed with copd ( p=0.24 ) . however , the prevalence of copd cases with no previous diagnosis was greater among patients with no respiratory symptoms than among those with respiratory symptoms ( 100% ; 56.1% ) ( p=0.01 ) . there were no additional differences related to other variables such as age , smoking history , and others as shown in table 1 . this study shows that there was no difference in the prevalence of copd among patients with arterial hypertension and tobacco / occupational exposure ; they either had respiratory symptoms or not . more than half of the patients with respiratory symptoms were unaware of their diagnosis , whereas all the patients without symptoms did not know they had copd . in fact , systemic arterial hypertension has been described as a major comorbidity associated with copd , as demonstrated by a population - based case - control study conducted in switzerland with 340,948 copd hospitalizations . the authors found that among 82 comorbidities studied , arterial hypertension was the comorbidity with the highest prevalence among copd patients ( 24% ) versus 16% in patients without copd ( 95% confidence interval 1.70 [ 1.61.7 ] , p<0.001).14 similar results were observed in the knhanes v cohort ( korean national health and nutrition examination survey ) : among 15 comorbidities , only arterial hypertension and history of pulmonary tuberculosis were independently associated with copd after adjustment for confounders.15 furthermore , a japanese study demonstrated that 25% of patients with cardiovascular disease have copd and were not previously diagnosed . these findings emphasize the need for active case finding strategies among higher - risk groups in order to diagnose copd in the earlier stages of the disease.16 our findings suggest that regardless of the presence of respiratory symptoms , people aged 40 or above with tobacco / occupational exposure and arterial hypertension may benefit from a spirometry to screen a potential case of copd . the diagnosis of copd is based on the association between risk factor , airway obstruction in spirometry , and the presence of symptoms among subjects aged older than 40 years ( gold).17 our sample included individuals without symptoms . however , it should be pointed out that there are no data to prove or refute the efficacy of screening copd cases among asymptomatic subjects using the spirometry test ( gold).17 considering that all individuals who reported asthma and those who had reversibility of the spirometry test were excluded from our study , we believe that the positive predictive value of the airway obstruction as demonstrated by the spirometry in this particular sample ( subjects with the most common copd comorbidity sharing copd risk factors ) , even without respiratory symptoms , is probably very high for copd diagnosis . furthermore , respiratory symptoms can not be detected in the earliest stages of copd.18 it is therefore necessary to perform studies assessing the value of the spirometry test for screening and diagnosis ( among subjects without and with respiratory symptoms , respectively ) of copd among high - risk populations in different epidemiologic scenarios in order to confirm these current findings.18 our findings suggest that regardless of the presence of respiratory symptoms , individuals aged 40 years with tobacco / occupational exposure and arterial hypertension may benefit from spirometric evaluation for diagnosis and screening of copd cases in the earliest stages of the disease .
backgroundthe diagnosis of chronic obstructive pulmonary disease ( copd ) is often delayed until later stages of the disease . 
 the purpose of the present study was to determine the prevalence of copd among adults on treatment for systemic arterial hypertension independently of the presence of respiratory symptoms.methodsthis cross - sectional study included adults aged 40 years with tobacco / occupational exposure and systemic arterial hypertension diagnosed at three primary health care facilities in goiania , brazil . 
 patients were evaluated using a standardized respiratory questionnaire and spirometry . 
 copd prevalence was measured considering the value of forced vital capacity and/or forced expiratory volume in 1 second < 0.70.resultsof a total of 570 subjects , 316 ( 55% ) met inclusion criteria and were invited to participate . 
 two hundred and thirty - three ( 73.7% ) patients with arterial hypertension reported at least one respiratory symptom , while 83 ( 26.3% ) reported no respiratory symptoms ; 41 ( 17.6% ) patients with arterial hypertension and at least one respiratory symptom , and 10 ( 12% ) patients with arterial hypertension but no respiratory symptoms were diagnosed with copd ( p=0.24 ) . 
 the prevalence of copd in people with no previous copd diagnosis was greater among those with no respiratory symptoms ( 100% ) than among those with respiratory symptoms ( 56.1% ) ( p=0.01).conclusionour findings suggest that regardless of the presence of respiratory symptoms , individuals aged 40 years with tobacco / occupational exposure and arterial hypertension may benefit from spirometric evaluation .