Higher BMI ups risk of developing psoriasis

Body mass index (BMI) appears to contribute to the development of psoriasis, according to a study, which notes a graded association between BMI and risk of psoriasis.

“Psoriasis has been linked to obesity, although data on the incidence of psoriasis according to BMI are limited,” the investigators said.

This retrospective cohort analysis was conducted to compare the incidence of psoriasis among patients stratified by BMI category: normal or underweight, overweight, obese class 1, and obese class 2/3. Participants were composed of a demographically heterogeneous sample of more than 1.5 million patients in the US between 1 January 2008 and 9 September 2019.

The crude incidence of psoriasis per 10,000 person-years was 9.5 (95 percent confidence interval [CI], 9.1‒10.0) among normal or underweight patients, 11.9 (95 percent CI, 11.4‒12.4) among overweight patients, 14.2 (95 percent CI, 13.6‒14.9) among obese class 1 patients, and 17.4 (95 percent CI, 16.6‒18.2) among obese class 2/3 patients.

The risk of developing psoriasis was markedly higher among participants who were overweight (adjusted hazard ratio [aHR], 1.19, 95 percent CI, 1.12‒1.27; p<0.001), obese class 1 (aHR, 1.43, 95 percent CI, 1.34‒1.53; p<0.001), and obese class 2/3 (aHR, 1.83, 95 percent CI, 1.71‒1.95; p<0.001) than those with a BMI <25.0 kg/m².

This study had certain limitations, one of which was that the investigators could not measure the influence of obesity on psoriasis severity.