Smoking increased radiographic damage in ankylosing spondylitis patients

SAN DIEGO — Patients with ankylosing spondylitis who smoked had a 5.5-fold effect of disease activity on radiographic damage, which more than doubled in male smokers compared with nonsmoking females, according to research presented at the American College of Rheumatology annual meeting.

“The impact of inflammation on radiographic damage is much higher in smokers than in nonsmokers,” researcher Sofia Ramiro, MD, of the Academic Medical Center, University of Amsterdam, Netherlands, said at a press conference.

Ramiro and colleagues followed 127 patients (mean age, 41 years; 71% men) with ankylosing spondylitis (mean symptom duration, 18 years) for 12 years, conducting biannual clinical and radiographic assessments. Two independent readers scored X-rays according to modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP) was used to measure inflammation. Estimating equations, with auto regressive models and a 2-year time lag, were used to study the relationship between ASDAS and radiographic damage. Baseline smoking status was tested with interactions.

The relationship between disease activity and radiographic damage was significantly modified by smoking status (P<.001) and extended to male patients (P=.002) and patients with shorter symptom duration (<18 years; P=.009).

“Overall, an increase in one ASDAS-unit led to an increase in 0.72 mSASSS-units per 2 years,” the researchers reported. The value reached 1.94 mSASSS-units in smokers (95% CI, 1-2.87) and 2.15 mSASSS-units (95% CI, 1.01-3.3) in male smokers.

Smokers had a 5.5-fold greater effect when comparing the impact of ADSAS on mSASSS in smokers vs. nonsmokers. The effect was increased 13.4-fold among male smokers compared with female nonsmokers (mc=0.16 mSASSS-units; 95% CI, –0.13 to 0.44), and there was an 8.1-fold amplified effect for smokers with short symptom duration (mc=2.11 mSASSS-units; 95% CI, 0.86-3.36) vs. nonsmokers with long symptom duration (mc=0.26 mSASSS-units; 95% CI, –0.18 to 0.7).

“Smoking cessation seems to be, especially among young males, an important take-home message that will probably lead to less radiographic damage and to better long-term outcomes,” Ramiro said.

“We all need to a better job with tobacco cessation guidance for our patients,” press conference moderator Christie Bartels, MD, MS, assistant professor, University of Wisconsin School of Medicine and Public Health, Department of Medicine, Division of Rheumatology, told Healio.com. “This is one more piece of evidence in a story that’s been unfolding that has shown us that patients with ankylosing spondylitis have higher disease activity, lower functional scores, and now we’re hearing an additional higher radiographic damage scores when they continue to smoke with the disease. This would be one more piece of evidence to tell your patient that it’s important for them to consider stopping smoking to improve their outcomes with ankylosing spondylitis.”

Disclosure: The researchers report no relevant financial disclosures.

For more information:

Ramiro S. #1510: Disease Activity in Male Smokers Has a >10-fold Amplified Effect on Radiographic Damage in Comparison with Female Nonsmokers in Ankylosing Spondylitis. Presented at: the 2013 American College of Rheumatology Annual Meeting; Oct. 26-30, San Diego.