Chronic Obstructive PulmonaryDisease : Early detection and prevention in primary care

• Background and aims. Early detection of Chronic Obstructive Pulmonary Disease (COPD) and secondary prevention by means of smoking cessation are the only available methods of stopping the progression of the disease. The overall aim was to examine the possibilities of early detection and prevention of COPD in General Practice. The specific aims were to evaluate a method of detecting COPD at its early stages, to investigate the rate of emphysema in smokers with normal lung function and smokers defined as preclinical COPD, to investigate the effects of performed spirometries and brief smoking cessation advice on smoking habits and to test if concentrations of certain biomarkers in blood, saliva and exhaled breath condensate (EBC) could identify subjects with COPD or non-COPD subjects supposed to be at risk of developing COPD.Methods. The first study evaluated an invitational method, which offered voluntary screening spirometry to a targeted population of smokers 40-55 years old. In the second follow-up study, all smokers with COPD and half of the smokers with normal lung function (NLF) were annually invited for spirometry and brief smoking cessation advice for a duration of 3 years, with half of the smokers with NLF being tested only last year. In the third study, 54 smokers with NLF were examined with High Resolution Computed Tomography (HRCT), with blood samples also being collected from each subject. In study four, 19 subjects categorised as having COPD, 30 non-COPD subjects and 15 healthy non-smoking volunteers were studied by means of spirometry, DLCO, and analysis of biomarkers in EBC, saliva and serum.Results. A total of 512 smokers responded. The prevalence of COPD was 27.5% and was classified as mild in 85% of the sufferers, moderate in 13% and severe in 2%. At year 1, 10% of the smokers with COPD had been continuously abstinent from smoking, compared to 2% of smokers with NLF. The prolonged abstinence rate increased yearly, and at year 3 the smoking cessation rates in smokers with COPD was 25% compared to 7% in smokers with NLF. By visual analysis, HRCT showed signs of emphysema in 43% of the subjects. Emphysema was also associated with low BMI. Higher serum concentrations of lysozyme and lower DLCO were recorded in those with COPD compared to non-COPD subjects. With the exception of chlorine, none of the remaining biomarkers were detected in EBC.Conclusions. By invitational targeted screening, COPD can be easily detected in its mild stages by using spirometry. By becoming diagnosed with COPD, smokers seem to be more motivated to stop smoking, and COPD patients should repeatedly be offered spirometry and smoking cessation advice which may prevent the progression of the disease to a severe disabling form. HRCT may detect smoke related parenchymal lung damage (i.e. emphysema) in symptom-free smokers with normal spirometry. Serum lysozyme and DLCO appeared to be the strongest discriminator between COPD and non-COPD subjects. The use of EBC as a tool to measure exhaled inflammatory biomarkers involved in COPD is as yet uncertain.

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