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.

Objective:To infer the prevalence and variables predictive of isolated nocturnal hypoxemia and obstructive sleep apnea (OSA) in patients with COPD and mild hypoxemia.Methods:This was a cross-sectional study involving clinically stable COPD outpatients with mild hypoxemia (oxygen saturation = 90-94%) at a clinical center specializing in respiratory diseases, located in the city of Goiânia, Brazil. The patients underwent clinical evaluation, spirometry, polysomnography, echocardiography, arterial blood gas analysis, six-minute walk test assessment, and chest X-ray.Results:The sample included 64 patients with COPD and mild hypoxemia; 39 (61%) were diagnosed with sleep-disordered breathing (OSA, in 14; and isolated nocturnal hypoxemia, in 25). Correlation analysis showed that PaO2 correlated moderately with mean sleep oxygen saturation (r = 0.45; p = 0.0002), mean rapid eye movement (REM) sleep oxygen saturation (r = 0.43; p = 0.001), and mean non-REM sleep oxygen saturation (r = 0.42; p = 0.001). A cut-off point of PaO2 ≤ 70 mmHg in the arterial blood gas analysis was significantly associated with sleep-disordered breathing (OR = 4.59; 95% CI: 1.54-13.67; p = 0.01). The model showed that, for identifying sleep-disordered breathing, the cut-off point had a specificity of 73.9% (95% CI: 51.6-89.8%), a sensitivity of 63.4% (95% CI: 46.9-77.9%), a positive predictive value of 81.3% (95% CI: 67.7-90.0%), and a negative predictive value of 53.1% (95% CI: 41.4-64.4%), with an area under the ROC curve of 0.69 (95% CI: 0.57-0.80), correctly classifying the observations in 67.2% of the cases. Conclusions:In our sample of patients with COPD and mild hypoxemia, the prevalence of sleep-disordered breathing was high (61%), suggesting that such patients would benefit from sleep studies.

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Resumo   Objetivo: Avaliar o desempenho de um CO-oxímetro para determinação do status do tabagismo em relação a um medidor de monóxido de carbono exalado em indivíduos atendidos na atenção básica. Métodos: Estudo transversal realizado em pacientes ambulatoriais atendidos nas unidades básicas de saúde de Anápolis-GO, submetidos à avaliação clínica, dosagem do monóxido de carbono exalado e medida do monóxido de carbono por CO-oximetria de pulso. Resultados: Foram incluídos 449 indivíduos, 106 tabagistas (23,6%), 89 ex-tabagistas (19,8%), 203 nunca fumantes (45,2%) e 51 fumantes passivos (11,4%). A CO-oximetria com ponto de corte de ≥4% mostrou uma especificidade de 77,3% (IC95% 72,5%-81,6%), uma sensibilidade de 52,8% (IC95% 42,9%-62,6%), valores preditivos positivo e negativo de 45,3% (IC95% 38,9%-51,9%), 82,1% (IC95% 78,8%-85%), respectivamente e a área sob a curva ROC de 0,73 (IC95% 0,67-0,78). A dosagem do monóxido de carbono exalado com ponto de corte de ≥5ppm mostrou uma especificidade de 96,2% (IC95% 93,6%-98%), sensibilidade de 79,2% (IC95% 70,3%-86,5%), valor preditivo positivo e negativo de 88,2% (IC95% 81,3%-92,8%), 92,9% (IC95% 89,9%-95%), respectivamente e a área sob a curva ROC de 0,91 (IC95% 0,87-0,95). COHb(%)≥4 demostrou OR:4,3; (IC 95% 2,7-7,1); p<0,0001. Conclusão: A CO-oximetria apresentou capacidade de identificação do tabagismo inferior à da dosagem do monóxido de carbono exalado, entretanto, quando COHb(%)≥4 há alta probabilidade de tabagismo.