Is smoking an independent and causal risk factor for psoriasis? Researchers analyzed data from the Copenhagen General Population Study, which included information on lifestyle factors, biochemistry, and genotype data of more than 100,000 individuals. In the observational analyses, the researchers found that the risk of developing moderate to severe psoriasis was higher in individuals who were never smokers, particularly those with higher levels of smoking (measured in pack-years). Researchers concluded that while smoking was independently associated with a higher risk of moderate to severe psoriasis in the observational analyses, the genetic analyses did not support a causal relationship between smoking and psoriasis.
Reference: Näslund-Koch C, Vedel-Krogh S, Bojesen SE, et al. Smoking is an independent but not a causal risk factor for moderate to severe psoriasis: A Mendelian randomization study of 105,912 individuals. Front Immunol. 2023 Feb 22;14:1119144. doi: 10.3389/fimmu.2023.1119144. PMID: 36911745; PMCID: PMC9992829.
