The thought that we have barely scratched the surface of what we need to know about COVID-19 to stay safe is enough to keep any of us up at night.

Fear of all of the unknowns is keeping us all guessing: what if I’ve already had it and didn’t know it? If I have it, will I be one of the lucky ones with mild symptoms? Do I have any underlying conditions that make me more susceptible to severe disease? What determines who lives and who dies?

We may not have all of the answers, but we now have the first attempt at an answer to the questions: What if I have chronic obstructive pulmonary disease (COPD)? And, what if I am a smoker?

COVID-19 is the disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is currently causing a global pandemic. Given the localization of the infection in the respiratory system, there is a lot of interest in understanding whether smokers or those suffering from  COPD have more severe symptoms or increased mortality due to COVID-19.

COPD is a chronic, progressive disease that obstructs breathing. Over time, patients with COPD display inflammation or thickening of the airway, develop damage to the air sacs of the lungs that facilitate gas exchange, or overproduce the mucus of the airway. These changes disrupt the normal functioning of the airway and over time, make it difficult to breathe.

In 2017, COPD was the fourth leading cause of death in the United States, with approximately 16 million people in the country living with the condition. Smoking is the leading cause of COPD, and therefore, many cases of COPD can be prevented by smoking cessation. 

Smoking cigarette
Smoking is the leading cause of COPD, a chronic disease that obstructs breathing.

A new study published in PLOS ONE found that, compared with ex-smokers, current smokers were 1.45 times more likely to have more severe COVID-19 symptoms. The study found that COVID-19 patients who had COPD were also more likely to have more severe symptoms. 

The researchers performed a meta-analysis (an analysis that uses data from multiple studies) of 15 studies that reported COVID-19 epidemiological and clinical characteristics, as well as COPD as a simultaneously occurring disease. These 15 studies (all but 1 from the USA were from China) included 2473 patients with a confirmed COVID-19 diagnosis, 184 of whom (7.4%) had died. Severe COVID-19 symptoms and complications were defined in this study as admittance to an intensive care unit, requirement for oxygenation or mechanical ventilation, or death.

Overall, 35 of the patients included in the study had COPD; in these patients, COVID-19 was considered severe in 22 (63%) cases and non-severe in 13 (37%). In the 2 studies that reported mortality rates, there was a slightly higher mortality rate in COVID-19 patients with COPD (60%) than those without COPD (55%).

Of the 221 current or ex-smokers included, 22.3% of current smokers and 46% of ex-smokers reported severe COVID-19 complications. 

Smokers were 1.45 times more likely to have more severe COVID-19 symptoms.

So what does all this mean?

Although the population was small, the results of this study found that smokers and patients with COPD may have more severe COVID-19 symptoms and may be at greater risk of death. The prevalence of COPD among the 2473 patients included in the study (2.3%) was lower than the global (9–10%) or Chinese (13.6%) prevalence, which may mean that the effect of COPD on COVID-19 severity was underestimated.

Since COVID-19 is a relatively new disease, population-based studies are only beginning to be published. Since this disease is ravaging global healthcare systems and disrupting society in general, there may also be a significant amount of yet unreported data that will emerge. Additionally, the studies that have been published may not have been similarly performed and are therefore difficult to compare to one another, complicating the ability of researchers to provide a clear answer.

The results of this study provide the first look at the risk for severe COVID-19 symptoms and increased mortality for this patient population, and suggest that smoking cessation programs and other preventative measures may help reduce the risk posed by COVID-19 for these patients.

For more on how to quit smoking, check out a previous blog post here.