Bariatric Surgery Lowers Psoriasis Risk in Obese Patients

A new study suggests that bariatric surgery (vertical gastroplasty, gastric banding, or gastric bypass) is associated with a lower risk of developing psoriasis, compared to usual care.

Researchers at Sahlgrenska Academy (SA; Göteborg, Sweden) and the National Institute for Health and Welfare (Helsinki, Finland) conducted a study to assess the effect of bariatric surgery on the incidence of psoriasis and psoriatic arthritis (PsA) in participants of the Swedish Obese Subjects (SOS) study, of whom 1,991 underwent bariatric surgery, and 2,018 served as controls; none had psoriasis or PsA at baseline. Psoriasis and PsA diagnoses were retrieved from the Swedish National Patient Register and personal questionnaires.

The results showed that during follow-up of up to 26 years, a total of 174 patients developed psoriasis, including 46 who developed PsA. Bariatric surgery was associated with a lower incidence of psoriasis compared with usual care; no significant difference was detected among the three surgical procedures. In addition, both smoking and a longer duration of obesity were independently associated with a higher risk for psoriasis. No significant difference in the risk of developing PsA was detected when comparing the surgery and the control groups. The study was published on November 27, 2017, in Obesity.

“Obesity is a risk factor for both psoriasis and PsA. A high body mass index also has a negative impact on the response to treatment in patients with psoriasis or PsA,” concluded lead author Cristina Maglio, MD, of the SA. “It has been hypothesized that gastric bypass induces remission of psoriasis because of an anti-inflammatory effect mediated by a rapid increase in glucagon-like peptide-1 levels after surgery. Another possible explanation is that the role of obesity in modulating the risk of PsA is not as strong as for psoriasis.”

Psoriasis is a chronic skin condition with intermittent relapses characterized patches, papules, and plaques, which usually itch. Plaque psoriasis is the most common form, and typically manifests as red and white scaly patches on the top layer of the skin. Psoriasis is linked to many other health problems such as inflammatory bowel disease (IBD), depression, obesity, hypertension, ischemic heart disease, and stroke. Up to one-third of subjects with psoriasis are affected by psoriatic arthritis (PsA), which is characterized by chronic joint and soft tissue inflammation.

Related Links:
Sahlgrenska Academy
National Institute for Health and Welfare