COVID-19, the deadly new disease caused by the new coronavirus, has “substantially higher” chances of progressing among smokers, according to researchers at UC San Francisco.
A meta-analysis, which looked at 11,590 COVID-19 patients in 19 independent studies, showed smokers to be at nearly twice the risk of non-smokers for the virus to worsen once a patient becomes infected.
“Smoking is associated with substantially higher risk of COVID-19 progression,” Dr. Stanton A. Glantz, the director of the UCSF Center for Tobacco Control Research and Education, said in a news release. “This finding suggests that California’s ongoing strong tobacco control measures that have lowered smoking may, together with the state’s other strong public health interventions, be contributing to California’s efforts to thwart the effect of COVID-19.”
Nearly one in three of smokers studied had their symptoms progress vs. fewer than one in five of non-smokers. Of the 11,590 patients with COVID-19, 731 were classified as smokers. Of those, 231, or 29.8%, had their conditions worsen, compared to 17.6% of non-smokers.
Although the number of COVID-19 patients classified as smokers is below that of the overall population, researchers attribute this to an underassessment, rather than one theory making the rounds that smoking provides a “protective effect” on the lungs. Previous research has shown smokers to have a higher risk of infection and mortality from MERS, another viral respiratory illness caused by a coronavirus.
Because the studies only looked at those who had already tested positive, researchers weren’t able to conclude if smoking is a risk factor for contracting the disease. Variables in the questions between studies mean the findings don’t differentiate between current and former smokers, nor does it account for e-cigarette or marijuana use.
Only one state has a lower percentage of its adults who smoke than California, according to 2017 analysis from the Centers for Disease Control and Prevention. First was Utah at 8.9%, then California at 11.3%.Both states have comparatively low fatality rates from COVID-19, at 1.0 per 100,000 residents and 3.3 per 100,000, respectively, but the states hit hardest by the virus fall right behind them on the CDC list. New York, New Jersey, Connecticut and Massachusetts all have smoking rates below 15%, but also the highest per-capita death rates from the virus in the nation.
