Summary
Chronic obstructive pulmonary disease (COPD) is characterized by chronic lung inflammation. The relationship between cardiorespiratory fitness (CRF) and COPD has not been well characterized. The study aimed to evaluate the independent and joint associations of inflammation (high-sensitivity C-reactive protein) and CRF with COPD risk in a cohort of white men.
Among 2274 Finnish men aged 42-61 year at baseline, serum hsCRP level was measured using an immunometric assay and CRF was assessed using a respiratory gas exchange analyzer. The level of hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and CRF as low and high. The measurements of hsCRP and CRF repeated 11 yr after baseline. The COPD risk decreased linearly with increasing CRF. Compared with men with normal hsCRP-low CRF, high hsCRP-low CRF was associated with an increased COPD risk. Both hsCRP and CRF are associated with COPD risk in middle-aged men.
In a middle-aged Finnish male population, both hsCRP (high-sensitivity C-reactive protein) and CRF (cardiorespiratory fitness) are each independently associated with the risk of COPD. The relationship between CRF and COPD risk is consistent with a graded dose-response relationship at CRF levels ranging from 31-43 mL/kg/min. However, high levels of CRF attenuate the increased risk of COPD related to high hsCRP levels.

Relevance
Although COPD has no cure, it is preventable and treatable; hence, modulation of risk factors could be essential in preventing COPD or delaying its progression.