Article 5 adult 5 human 5 male 5 Humans 4 female 4 major clinical study 4 Female 3 Male 3 emphysema 3 middle aged 3 risk factor 3 Middle Aged 2 Pulmonary Disease, Chronic Obstructive 2 Risk Factors 2 Smoking 2 adverse event 2 chronic obstructive lung disease 2 cigarette smoking 2 clinical feature 2 complication 2 controlled study 2 disease exacerbation 2 lung cancer 2 pathophysiology 2 phenotype 2 retrospective study 2 smoking 2 Abdominal radiograph 1 Abdominal ultrasound 1