High cardiorespiratory fitness offsets effect of low socioeconomic status on COPD risk

Low socioeconomic status is linked to increased risk of chronic obstructive pulmonary disorder (COPD) among middle-aged men, but high cardiorespiratory fitness can even out this risk increase, a study has shown.

The study involved a prospective cohort of 2,312 Finnish men aged 42–61 years at baseline. Socioeconomic status was self-reported, while cardiorespiratory fitness was measured using respiratory gas exchange analysers. Researchers categorized both exposures as low and high based on median cutoffs.

Over a median follow-up of 26.0 years, 120 men developed COPD. Multivariable Cox proportional hazards regression showed that men with low vs high socioeconomic status were at significantly higher risk of COPD. Likewise, men with high vs low cardiorespiratory fitness had a much higher COPD risk.

Compared with the group with high socioeconomic status and low cardiorespiratory fitness, the group with low socioeconomic status and low cardiorespiratory fitness had a more than twofold higher risk of COPD (hazard ratio [HR], 2.36, 95 percent confidence interval [CI], 1.44–3.87).

On the other hand, there was no risk increase observed in the group of men with low socioeconomic status and high cardiorespiratory fitness relative to the group with high socioeconomic status and low cardiorespiratory fitness (HR, 1.46, 95 percent CI, 0.82–2.60).