Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: We have shown that disease activity has an effect on radiographic progression over the long-term and that gender and symptom duration are effect modifiers. Smoking has been shown to predict radiographic progression. We sought to investigate whether smoking influenced this longitudinal relationship between disease activity and radiographic damage.
Methods: Patients from the Outcome in AS International Study (OASIS) were followed-up for 12 years, with biannual clinical and radiographic assessments. Two readers independently scored the x-rays according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and scores were averaged. Disease activity was assessed by the ASDAS-CRP. The relationship between ASDAS and radiographic damage was investigated using generalized estimating equations, with auto-regressive (i.e. adjusted for the 2-year previous mSASSS) models with a 2-year time-lag. Interactions were tested with baseline smoking status and if significant, analyses were repeated in strata.
Results: A total of 127 patients were included (71% males, mean (SD) age 41(12) years, mean symptom duration 18(11) years and 82% HLA-B27 positive). Smoking status modified the relationship between disease activity and radiographic damage significantly (p<0.001), and this effect extended to other strata: males (p=0.002) and patients with shorter symptom duration (<18y) (p=0.009); Overall, an increase in one ASDAS-unit led to an increase in 0.72 mSASSS-units per 2 years. In smokers, this value reached 1.94 mSASSS-units and in male smokers 2.15 mSASSS-units (Table). Comparing the magnitude of the effect of ASDAS on mSASSS in smokers vs non-smokers, smokers had a 5.5 fold amplified effect, whereas male smokers had a 13.4 fold amplified effect compared to female non-smokers. Smokers with short symptom duration had a 8.1-fold amplified effect compared to non-smokers with long symptom duration (Figure).
Conclusion: Smoking amplifies the effect of disease activity on radiographic damage (5-fold). This effect is further amplified in male smokers (13.4-fold) in comparison with female non-smokers.
Table – Longitudinal relationship between ASDAS and radiographic damage in different strata
|
Stratification for |
Effect analyzed
|
Multivariable regression models (auto-regressive and time-lagged) µ (95%CI)* |
|
Smoking status |
– ASDAS in non-smokers (n = 78) |
0.35 (0.04; 0.65) |
|
– ASDAS in smokers (n = 49) |
1.94 (1.00; 2.87) |
|
|
Smoking status & gender |
– ASDAS in women, non-smokers (n = 29) |
0.16 (-0.13; 0.44) |
|
– ASDAS in women, smokers (n = 9) |
0.47 (-0.12; 1.06) |
|
|
– ASDAS in men, non-smokers (n = 49) |
0.44 (0.02; 0.86) |
|
|
– ASDAS in men, smokers (n = 40) |
2.15 (1.01; 3.30) |
|
|
Smoking status & symptom duration |
– ASDAS in symptom duration <18y, non-smokers (n = 39) |
0.52 (0.24; 0.80) |
|
– ASDAS in symptom duration <18y, smokers (n = 31) |
2.11 (0.86; 3.36) |
|
|
– ASDAS in symptom duration >=18y, non-smokers (n = 35)
|
0.26 (-0.18; 0.70) |
|
|
– ASDAS in symptom duration >=18y, smokers (n = 13)
|
0.88 (0.15; 1.62) |
* Results refer to different multivariable models. De µ indicates the progression in mSASSS per unit increase in ASDAS
Disclosure:
S. Ramiro,
None;
A. M. van Tubergen,
None;
R. Landewé,
None;
C. Stolwijk,
None;
M. Dougados,
None;
F. Van den Bosch,
None;
D. van der Heijde,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/disease-activity-in-male-smokers-has-a-10-fold-amplified-effect-on-radiographic-damage-in-comparison-with-female-non-smokers-in-ankylosing-spondylitis/