It’s no secret to any health professional, including rheumatologists, that smoking cigarettes or using other tobacco-based products is unhealthy. Yet how does smoking specifically affect rheumatic diseases, and what are some of the newest findings in this area? What role do e-cigarettes have in the smoking risk landscape? Those are the sorts of questions asked by researchers with an interest in this topic.
Zeroing in on RA, Lupus
“I think the main thing to realize is that when inhaled, smoking affects the body’s systems in many ways,” says Albert A. Rizzo, MD, FCCP, FACP, senior medical advisor for the American Lung Association. “Inflammation leads to lung diseases, and unfortunately, that same type of inflammation can occur in the rest of the body.”
The 2014 Surgeon General’s report on smoking links cigarette use to several rheumatological diseases, including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).1 It specifically implies a causal relationship between cigarette smoking and RA, but not SLE, and states that cigarette smoking can reduce the effectiveness of tumor necrosis factor-α inhibitors, which are often used to treat autoimmune disease.
The most likely cause for a connection between rheumatological diseases and smoking is a mix of a genetic predisposition and environemental factors—including tobacco use, Dr. Rizzo says.
One interesting correlation is the common presence of lung manifestations, such as nodules, scarring and fibrosis, among patients with RA and Sjögren’s syndrome. “Some of these diseases may manifest in the lungs earlier than the arthritic components,” Dr. Rizzo says. Whether this connection can be hastened by cigarette smoking is not always clear. Still, “to say the least, it’s a complex interaction,” he says.
Although smoking could potentially affect many types of rheumatological disease, the bulk of research seems to focus on RA and SLE.
“Most of the evidence shows increased inflammatory activities, radiographic changes, and severity of disease in lupus, rheumatoid arthritis and ankylosing spondylitis,” says Richard Lai, MD, FACP, FACR, Great Falls Clinic, Department of Rheumatology, and assistant professor of rheumatology, Idaho College of Osteopathic Medicine, Meridian, Idaho. “Smoking is also postulated as an independent risk factor to trigger the onset of rheumatoid arthritis,” he adds, citing 2014 research.2
“During the last decade or so, accumulating data has consistently demonstrated a strong association between cigarette smoking and rheumatoid arthritis risk, particularly for seropositive RA, with an interaction between smoking and underlying genetics,” says Medha Barbhaiya, MD, MPH, assistant attending rheumatologist and clinical researcher, Hospital for Special Surgery, and assistant professor, Weill Cornell Medical College, New York.
Research obtained from the Nurses’ Health Study found the association of smoking with RA risk appears to be highest among those who smoked greater than 10 pack-years.3 “The risk appeared elevated in past smokers until 20 years after cessation, after which it was similar to that of nonsmokers,” Dr. Barbhaiya says.
Regarding SLE, the Surgeon General’s report found inadequate evidence to infer the presence or absence of a causal relationship between cigarette smoking and SLE or the response to therapy once a patient has lupus.1 Previous data in patients with SLE have been conflicting, usually because of limited sample sizes, retrospective data and a lack of detailed risk-factor data, says Dr. Barbhaiya. However, some research has found a link between smoking and an increased risk of SLE development, particularly among current smokers, she adds.