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Bariatric surgery may ease psoriasis symptoms, or it may not

Psoriasis and psoriatic arthritis symptoms curbed by bariatric surgery

Our Review Summary

Tablet with the diagnosis Psoriasis on the displayThis is a chart review study which shows that losing excess weight by undergoing bariatric surgery could lessen the pain and inflammation experienced by psoriasis sufferers. While the treatment sounds hopeful, important information about the other (overall) benefits of bariatric surgery, its risks, alternatives and costs, including costs of treating complications, were all missing from this news release.

This news release comes from a poster presented at a national meeting, which has not yet undergone peer review. Many key elements were not well described or sufficiently highlighted.  The fact that this research comes from observational data (chart review) is important since we cannot infer causation from this type of research, and it is possible that some other factor stemming from the surgery besides the weight loss (for example, changes in diet or absorption of key nutrients) was responsible for the remission in psoriasis symptoms, rather than the weight loss itself.


Why This Matters

Psoriasis affects millions of Americans, and many people with moderate to severe psoriasis develop psoriatic arthritis in their lifetimes. If obesity contributes to the development of this painful condition, then weight loss methods such as bariatric surgery may reduce those symptoms. Psoriasis sufferers may have few options to treat what is a lifetime of inflammation and pain, so if safe and effective methods to reduce those symptoms are available, many people could benefit. However, it needs to be pointed out that bariatric surgery is indicated only for morbid obesity, and it is not clear whether other weight loss therapies would result in the same benefit.


Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

The release contained no cost information related to bariatric surgery and its potential complications. Bariatric surgery has become commonplace but it is costly and carries risk. The release should have also mentioned the theoretical costs related to better symptom control for psoriasis sufferers who have undergone bariatric surgery. These could include a possible reduction in costs of anti-inflammatory drugs or other therapies.

Does the news release adequately quantify the benefits of the treatment/test/product/procedure?


Although it is hard for a reader to picture what a severity score of 5.6 for psoriasis would actually look like, the news release at least gives us the range of possible scores (0-10) and the absolute reduction in scores for disease severity. It would have been helpful to know if such a reduction would allow a psoriasis patient to stop using one of their medications or need fewer interventions. We assume that these are the averages of the scores of the 86 patients who underwent surgery (the “significant reductions in their “disease severity scores dropping from 5.6 to 4.4, and scores falling from 6.4 to 4.5 for those with psoriatic arthritis.”)

The study monitored patients on average for more than six years, “with an average excess weight loss of 46.2 percent body weight.”  It would have been helpful to also include the average pre-surgery starting weight of the volunteers.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

Sadly, no harms related to bariatric surgery were mentioned, nor were the likelihood of complications due to the surgery and the rate of reversals that are often necessary.

Psoriasis is an important problem but clearly bariatric surgery would not be a first-line treatment for the condition. The trade-offs in terms of risks of complications and required lifestyle changes after bariatric surgery are critical considerations for a patient hoping to reduce their psoriasis symptoms.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The release relates that this is an analysis of existing data and how many subjects were included in the analysis, as well as the rating scale.

However, the release never cautions readers that this was an observational study subject to a variety of limitations, and the language used in the release strongly suggests a cause-and-effect relationship between bariatric surgery and symptom reductions. Examples:

  • “…the findings suggest that losing excess weight may improve symptoms in people who have these lifelong conditions.”
  • “The researchers say excess weight loss may reduce the body-wide inflammation and pain triggered by extreme excesses of fat tissue.”
  • “Our new study shows that those who shed excess weight could see significant symptomatic relief.”

It would have been more appropriate to state that surgery and weight loss were associated with symptom improvement, rather than that they “improve” or “reduce” symptoms.

We’d also liked to have been provided with information on how the patients (outside the 55 percent of patients with psoriasis and 62 percent of patients with psoriatic arthritis who reported improvements in their disease) fared in relation to the bariatric surgery.

Does the news release commit disease-mongering?


No evidence of disease mongering here. The story cites accurate numbers for psoriasis in the United States.

As a caution, we’d like to add that anytime bariatric surgery is mentioned as a treatment option, it should be stressed that it is a procedure of last resort, only offered to those who are severely obese, have additional health problems such as cardiovascular disease, and for whom other, safer weight-loss options have not worked.

Does the news release identify funding sources & disclose conflicts of interest?


The news release discloses that the patient histories that were reviewed came from bariatric surgery patients of NYU Langone, the institution that issued the news release. It states, “For the study, Reddy and colleagues reviewed the medical charts of 9,073 weight-loss surgery patients who were treated between 2002 and 2013 at NYU Langone’s Weight Management Program.”

Does the news release compare the new approach with existing alternatives?

Not Satisfactory

It would have been nice to know how other patients losing weight in the conventional sense compared to these patients. Alternatives to bariatric surgery exist and should have been mentioned. Two alternatives to bariatric surgery for reduction of psoriasis symptoms —  conventional weight loss and other treatments for psoriasis (topical agents, medications, and UV treatment) — that would reduce symptoms at least as much as surgery should have been discussed here. Presumably patients who lost weight through non-surgical means would have also benefited from having their psoriasis symptoms reduced.

Does the news release establish the availability of the treatment/test/product/procedure?


Bariatric surgery is widely available and most people with internet access (or any access to medical care) can figure that out fairly quickly in their area.

Does the news release establish the true novelty of the approach?

Not Satisfactory

One could easily come away from this release thinking that these researchers are the first to report psoriasis symptom reduction in those undergoing bariatric surgery (with resultant weight loss). However, such findings have been reported before, and the release does not acknowledge this.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?


The language is generally appropriate, and hasn’t exaggerated the effects of the bariatric surgery.

Total Score: 5 of 10 Satisfactory


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