Smoking Worsens Ankylosing Spondylitis Damage

Research on the effects of cigarette smoking in people with ankylosing spondylitis (AS) continues to show that lighting up is linked to faster-moving spinal damage, a hallmark of this type of inflammatory arthritis. AS is part of group of autoimmune diseases called axial spondyloarthritis that primarily affect the spine and sacroiliac joints (where the spine and pelvis meet).

People with AS who smoke also report more mood problems and poorer quality of life, according to new data from a large British registry of people with the condition who have been followed for more than six years.

“Our study is one of many showing that smokers with axial spondyloarthritis — including AS — report more severe disease and poorer health than non-smokers, but we are the first to show just how many different aspects of poor health are associated with smoking,” says rheumatologist Sizheng (Steven) Zhao, MD, lead author of the study published in 2018 in Rheumatology .

Dr. Zhao, a clinical research assistant in the Department of Musculoskeletal Biology at the University of Liverpool in the UK, and his colleagues found that smokers with AS reported more anxiety and depression and worse sleep, fatigue and quality of life. They also noted that smokers were more often diagnosed with psoriasis, an autoimmune disease that’s linked to AS.

Gender Differences

Dr. Zhao’s study found that both men and women with AS who smoked had worse disease than those who had never smoked or had quit. But the negative effects in disease activity, markers of inflammation, and quality of life were larger in men who were still smoking than in women who smoked. And men got more benefits from quitting.

“The effect of quitting was more pronounced among men. We don’t know for sure why this is,” Dr. Zhao says. “Men and women may report their symptoms differently; also, men tender to be heavier smokers than women. This study did not report a ‘dose effect’ of smoking, but other studies, have shown that greater intensity of smoking is associated with worse outcomes in AS.”

Other research in AS, including a 2018 Arthritis Care & Research study, has reported that smoking in men — but not in women — is linked to more rapidly progressing disease. That study also linked the habit in men to development of bony growths called syndesmophytes that lead to spinal fusion, which causes a loss of flexibility and chronic pain.

Scientist aren’t sure how smoking contributes to poorer outcomes in AS. Many think inflammation caused by smoke inhalation plays a role in speeding up disease-related damage.

“Since smokers are also more likely to have other lifestyle and health factors that are bad for their AS, it is difficult to untangle the effects of smoking from these other factors,” says Dr. Zhao, who stresses that people with the condition who smoke should quit.

Quitting Slows Down Damage

Any history of smoking is linked to worse disease and function in AS compared with people who have never smoked, according to a study of more than 900 people with the disease published in 2017 in Arthritis Care & Research .

Quitting does improve the clinical picture, however. The study found that people with AS who stopped smoking had lower levels of disease activity and better function and quality of life than current smokers. Study investigators estimated that the benefits of stopping smoking were roughly equivalent to 30% and 16%, respectively, of the effects patients might get with intensive physical therapy and treatment with biologic medications.

“Smoking is bad for health in general. It increases risk of heart disease, cancer and rheumatoid arthritis ,” Dr. Zhao says. “Almost all patients with rheumatic diseases, including AS, have a higher risk of cardiovascular diseases . Since smoking greatly increases cardiovascular risk, cessation should be universally recommended and promoted, along with other healthy lifestyle changes such as diet and exercise.”