Disease activity also appears to have a higher impact on X-ray damage in earlier phases of AS: Smokers who had had the disease for less than 18 years had 3.4 times more X-ray damage compared to smokers who had had the disease for more than 18 years (and 8 times more damage compared to non-smokers who had had the disease for more than 18 years).

The researchers say these findings indicate that young, male patients with AS could develop less spinal damage and have better long-term outcomes if they stop smoking.

Can Smoking Trigger Autoimmunity in RA?

Eric M. Ruderman, MD, a professor of medicine in the division of rheumatology at Northwestern University Feinberg School of Medicine, in Chicago, says while considerable research has shown that smoking worsens the progression of rheumatoid arthritis, this is one of the first studies showing the same is true with ankylosing spondylitis.

“If you want to try and prevent people from having progression and damage on X-rays, you need to control disease activity,” says Dr. Ruderman. “Smoking has a huge effect. Independent of everything else, if you smoke you will have more progression on X-rays over time, which could affect your function.”

This study only shows a correlation between smoking and X-ray damage but it doesn’t explain the mechanism involved. Dr. Ruderman says it would be nice if future research looked at the effect of smoking cessation over time.

But he says even before that data is available, patients know enough about the harmful effects of smoking right now. “It’s one more reason there may be a benefit to stop smoking,” he says. “At least you potentially won’t do more damage.”