Metabolic syndrome is associated with an increased risk of psoriasis: A nationwide population-based study

Background Psoriasis is a chronic inflammatory skin disease characterized by an abnormal T-cell-mediated immune response, and is associated with metabolic syndrome (MetS) and components thereof. However, few prospective studies have investigated the associations between MetS and its components, on the one hand, and the risk of psoriasis, on the other. Therefore, we investigated the association between the presence of MetS and its components and the prospective risk of psoriasis development. Methods In total, 9,718,591 adults (2,595,878 in the MetS group and 7,122,713 in the comparison group) were evaluated using data from the Korean National Health Insurance Service (2009 to 2017). Results MetS was positively associated with an increased risk of psoriasis over an 8-year follow-up period after adjusting for age, sex, smoking status, alcohol consumption, physical activity, household income, and body mass index (hazard ratio 1.05, 95% confidence interval 1.04–1.06). The risk of psoriasis tended to increase as the number of MetS components increased, and this trend was significant in obese subjects (P for trend <0.001). Conclusion Psoriasis was significantly and positively associated with MetS and several components thereof; MetS severity and obesity affected these associations over 8 years of follow-up, suggesting that MetS is a risk factor for the development of psoriasis.