Symptom Severity Decreases in Patients with Psoriatic Arthritis who Undergo Weight-Loss Surgery

A retrospective analysis of patients who underwent weight-loss surgery suggests that significant weight loss significantly lessens the symptoms of psoriasis and psoriatic arthritis.

Researchers from NYU Langone Medical Center reviewed the medical records of 9,073 patients who underwent bariatric surgery at the facility’s weight management program between 2002 and 2013. They then gave surveys to and reviewed records from 21 patients who had been diagnosed with both psoriasis and psoriatic arthritis before they underwent surgery and another 65 who had been diagnosed with psoriasis alone.

A comparison of patient symptoms before and after their weight loss (which averaged 46.2% of baseline body weight) found that 55% of the patients with psoriasis alone reported improvements in their disease. The median disease severity score in the group — as measured on a 0 to 10 scale &mdash; fell from 5.6 to 4.4 (p<0.01). Among patients with both psoriasis and psoriatic arthritis, median disease score fell from 6.4 to 4.5 (p=0.01) and 62% of all patients reported improvements with their disease.

Those with severe disease at baseline fared even better over the course of the study, which had a median follow-up time of more than 6 years. Disease severity scores fell, on average, from 7.7 to 5.7 (p<0.01) among patients who had severe psoriasis at baseline and, on average, from 8.2 to 4.8 (p<0.01) among patients who began with severe psoriatic arthritis.

Secondary analysis suggested that this correlation between weight loss and symptom improvement may be causative: patients who lost more excess weight were more likely to report improvements in their disease and to enjoy greater reductions in disease burden. These improvements were generally durable enough to last throughout the follow-up period, but

“Although the natural history of psoriasis and psoriatic arthritis is typically chronic, a majority of patients experience improvement after bariatric surgery. Our results indicate an association between excess weight loss and symptomatic improvement in severe cases of psoriasis. Factors such as older age at diagnosis of psoriasis and severity of psoriasis may be used to identify patients with a greater likelihood of improvement,” wrote the investigators, who presented their findings at the 2015 ACR/ARHP Annual Meeting in San Francisco.

“Despite study limitations, we show for the first time an improvement in psoriatic arthritis after bariatric surgery and a possible association with surgical excess weight loss. Larger prospective studies are needed to further define the true effect of surgical weight loss on psoriasis and psoriatic arthritis.”

Numerous studies have found that obese patients with psoriasis and psoriatic arthritis “are more likely to experience certain adverse effects to medications and are less likely to respond favorably to systemic therapies,” wrote the authors of a 2010 research review that appeared in the Journal of the American Academy of Dermatology.

A least 1 other study, moreover, has found that weight loss tends to lessen disease burden. A 2013 paper published in JAMA Dermatology reported on 60 Danish patients who were randomized between normal diet and a 16-week diet that produced a mean weight loss of 15.4 kg. When researchers compared how the 16-week study had changed median scores from both groups on the Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI), they found that weight loss was associated with a nearly significant reduction on the former index (-2.0; 95% CI, 4.1 to −0.1; p&thinsp;=&thinsp;.06) and a significant reduction in the latter (−2.0; 95% CI, −3.6 to −0.3; p&thinsp;=&thinsp;.02).