Researchers writing in the New England Journal of Medicine have demonstrated a strong link between heart function and mild chronic obstructive pulmonary disease (COPD). According to their research, COPD diminishes the heart’s ability to pump effectively even when the disease has mild or no symptoms.

The new study’s results suggest that the harmful effects COPD can have on the heart occur much earlier than previously believed: in mild cases and even before symptoms appear.

The researchers measured heart and lung structure and function in 2,816 generally healthy adults (average age of 61) using breathing tests and imaging studies of the chest. Study participants were part of the MESA Lung Study, an extension of the Multi-Ethnic Study of Atherosclerosis (MESA), a large, National Heart Lung and Blood Institute-supported study focused on finding early signs of heart, lung, and blood diseases before symptoms appear.

MRI and CT scans uncovered mild abnormalities in heart and lung function in many participants. The link between lung and heart function was strongest in current smokers, who are at risk for both diseases, and especially in those with emphysema. The findings also appeared, to a lesser extent, in people with mild COPD who had never smoked.

"These results raise the intriguing possibility that treating lung disease may, in the future, improve heart function," said lead author Graham Barr, MD, Dr. PH, principal investigator of the MESA Lung Study. "Further research is needed to prove whether treating mild COPD will help the heart work better."

The results of this study may be widely applicable to the general US population because the MESA study population is ethnically mixed and covers a broad age range of apparently healthy people, according to the study authors.