Clinical characteristics preceding development of COPD

<bold>Background:</bold> Clinical characteristics prior to development of COPD are largely unknown but may provide tools for preventive measures. <bold>Aim:</bold> To evaluate clinical characteristics preceding development of airway obstruction. <bold>Methods:</bold> After re-examination of four population-based cohorts in 2002-04, n=993 cases with FEV1/VC<0.70 and n=993 controls without airway obstruction were included in the OLIN COPD study. Previous clinical examinations during the 1980s and 90s provide retrospective data. Those with FEV1/VC<0.70 already at their first examination were excluded whereafter 496 future cases and 809 controls remained, all with FEV1/VC>0.70. Mean person-years between first examination and recruitment to the OLIN COPD study was 10.8 (SD 3.7) years. <bold>Results:</bold> At first examination, the mean BMI (28.7 and 28.8) and sex distribution (54.6 and 51.0% men) were similar, while mean age was lower (53.6y and 56.1y, p<0.001) and ever smoking more common (74 and 53%, p<0.001) in future cases than controls. The burden of respiratory symptoms was greater among future cases vs. controls; longstanding cough (38 vs. 24%), productive cough (45 vs. 22%), chronic productive cough (16 vs. 6%), wheeze (63 vs. 32%) and dyspnoea (mMRC≥2) (19 vs. 9%), all p<0.001. Further, both physician-diagnosed asthma and ischemic heart disease were more common among future cases than controls (18 vs. 7%, p<0.001 and 13 vs. 8%, p=0.010). <bold>Conclusion:</bold> A higher burden of respiratory symptoms, smoking, physician-diagnosed asthma and ischemic heart disease, but not BMI, associated with development of airway obstruction within a decade. Identification of risk profiles for the development of COPD provide screening tools for preventive measures and early diagnosis.