HealthDay News — Smoking is tied to an increased risk for psoriasis, but may not be a cause of psoriasis, according to a study published online Feb. 22 in Frontiers in Immunology.
Charlotte Näslund-Koch, from Copenhagen University Hospital-Herlev and Gentofte in Denmark, and colleagues used data from 105,912 individuals participating in the Copenhagen General Population Study to assess whether smoking (measured both observationally and by the presence of the genetic variant CHRNA3 rs1051730, which is strongly associated with high lifelong cumulative smoking) is independently associated with psoriasis.
The researchers found that the risk for developing moderate-to-severe psoriasis was higher in smokers versus never smokers (hazard ratios [95 percent confidence intervals], 1.64 [1.35 to 2.00] and 2.23 [1.82 to 2.73] in ever smokers with ≤20 pack-years and in ever smokers with >20 pack-years, respectively). The odds of developing moderate-to-severe psoriasis trended higher for the CHRNA3 rs10511730 T-allele in ever smokers (odds ratio, 1.05; 95 percent confidence interval, 0.95 to 1.16).
“These results suggest that smoking is an independent, but not a causal risk factor for psoriasis,” the authors write. “However, even though we do not find a causal association between smoking and moderate-to-severe psoriasis, smoking restriction and cessation remain important to minimize risk of smoking-related comorbidities.”
Several authors disclosed financial ties to the pharmaceutical industry.