Bodyweight variability and the risk of psoriasis: a nationwide population-based cohort study

Background Bodyweight variability has been suggested to exacerbate chronic inflammation and increase the risk of adverse cardiovascular events. Little is known whether high variability in bodyweight affects the development of psoriasis. Objective To investigate the association between weight variability and the risk of psoriasis. Methods Using a representative cohort enrolled in the national health examination programme conducted by the Korean National Health Insurance Service, 8 016 907 people who were free of psoriasis and who underwent at least three health examinations between 2010 and 2015 were followed until the end of 2017. We classified participants numerically according to the variability indices and defined high variability (Q4) as the highest quartile of variability. Cox proportional hazard regression models were used to evaluate the risk of psoriasis according to the quartile groups of bodyweight variability. Results In total, 187 128 (2.33%) participants developed psoriasis during a median follow-up of 3.4 years. There was an association between baseline body mass index and the risk of psoriasis. In the multivariable model adjusting for confounding variables, an incrementally increased risk of psoriasis was observed for higher quartiles compared with the lowest quartile group (Q1). The hazard ratio (HR) and 95% confidence intervals comparing the highest (Q4) and lowest quartiles (Q1) of bodyweight variability were 1.06 (1.05-1.07) for psoriasis. Conclusion High bodyweight variability was significantly associated with an increased risk of psoriasis. These findings imply that clinicians should encourage patients to maintain proper bodyweight to help prevent psoriasis.