A new study shows that patients who inhale both cigarette smoke and wood smoke have their risk for developing worsening COPD by a fourfold amount.
The study was first released in the online version of American Journal of Respiratory and Critical Care Medicine and reported on again at m medicalnewstoday.com, "Wood Smoke Exposure Multiplies Damage From Smoking increases Risk of COPD."
Inhaled smoke can be first or second hand, and wood smoke can be used for home heating or cooking or can be inhaled in the ambient air from other homes or businesses in the area. Either way, science already shows that the chemicals of cigarette smoke can damage the lungs and cause COPD.
Yet science now shows that inhaling wood smoke is "likely to (cause) epigenetic changes in the DNA that further increase their risk of COPD and related pulmonary problems," the medicalnewstoday.com article notes.
Dr. Yohannes Tesfaigzi and his colleagues studied sputum samples of over 1800 COPD patients and used their smoking and demographic information to come to their conclusion. They studied the eight genes known to be associate with lung cancer.
The medline article notes "They found that wood smoke exposure was significantly and independently associated with an increased risk of respiratory disease, especially among current smokers, non-Hispanic whites and men. Furthermore, wood smoke exposure was associated with specific COPD outcomes in people who had aberrantly methylated p16 or GATA4 genes, and both factors together increased the risk more than the additive of the two risk factors together. They also found that people with more than two of the eight genes analyzed showing methylation were also significantly more likely to have a lower than predicted FEV1 than those with fewer than two methylated genes."
This study is significant because not only does it prove there is a genetic link to developing COPD, it likewise provides evidence to COPD patients that if they smoke they should avoid heating their homes with wood. Likewise, it's evidence physicians and COPD experts can use to convince their patients to not heat their homes with wood, especially if the patient is a smoker.
Other studies also showed that inhaling cigarette smoke and wood smoke together increased the risk for worsening COPD as compared to inhaling just cigarette smoke or inhaling just wood smoke.
"We observed increased inflammatory response in mice that were exposed to both cigarette smoke and low concentrations of wood smoke compared to those exposed to cigarette smoke only. We would like to use this animal model to determine the mechanisms underlying this exacerbation," said Dr. Tesfaigzi.