Patients with psoriatic arthritis (PsA) who smoke are less likely to adhere to treatment regimens and have less symptom relief, according to findings published in the Annals of the Rheumatic Diseases.
To investigate the association between smoking and disease activity, treatment adherence and treatment responses, Pil Hojgaard of Gentofte Hospital in Copenhagen, Denmark, and colleagues followed patients with PsA who were initiating first therapy with the tumor necrosis factor-alpha (TNF-alpha) inhibitor drugs etanercept (Enbrel), infliximab (Remicade), or adalimumab (Humira).
A total of 1,388 patients with PsA from the Danish nationwide DANBIO registry were included in the study, of whom 1,148 (83%) had known smoking status (33% current, 41% never and 26% previous smokers). Median follow-up time was 1.22 years (interquartile range: 0.44–2.96).
The researchers found that patients with PsA who smoked had worse baseline patient-reported outcomes, shorter treatment adherence,and poorer response to TNF-alpha inhibitors compared with non-smokers. This was most pronounced in men and in patients treated with infliximab or etanercept.
After six months of treatment, only 24% of smokers improved by 20% (a measurement known as ACR20), compared with 33% of patients who never smoked, according to the study results.
Patient adherence to therapy was also lower for patients who smoked compared with patients who never smoked (median adherence time 1.56 years vs 2.43 years, respectively).