Can Weight Loss Help Reduce Psoriatic Arthritis Symptoms?
Interview with Elaine Husni, MD, MPH
Obesity has a distinct connection with psoriatic arthritis (PsA), as obese patients are more susceptible to developing this chronic condition.1
For those obese patients already diagnosed with PsA, the accumulation of excess abdominal fat appears to negatively impact their response to biologic agents. Indeed, researchers have found that obese patients have a noticeably lower probability of achieving minimal disease activity compared to those at a normal weight.2,3
This raises questions about how the metabolic effects of excess adipose tissue can influence the body’s inflammatory processes and perhaps play a significant, synergistic role in the pathologies of inflammatory disorders, like plaque psoriasis (PsO) and PsA.
Adipose tissue was long believed to be a simple storage site of fat. Now, it appears adipose tissue is a significant driver of metabolic activity. Excess adipose tissue proliferates pro-inflammatory molecules, called adipokines, which include adiponectin, leptin, plasminogen activator inhibitor-1 (PAI-1), interleukin (IL)-6, and tumor necrosis factor (TNF)-α.
Given that adipose tissue is a metabolically-active source of this inflammatory setting, obesity is considered a low-grade chronic systemic inflammatory disease, a legitimate additive cardio-metabolic risk factor for patients with PsA.4-7
So if obesity does worsen outcomes for PsA patients, could weight loss be the key to improving PsA outcomes?
Does Weight Loss and Bariatric Surgery Help PsA?
The answer appears to be yes, especially for obese patients with severe cases of PsO and PsA. A new study presented at the American College of Rheumatology (ACR) annual meeting, held in November, 2015, in San Francisco, California, reported significant symptom improvements in patients after they had received bariatric surgery. This finding suggests that emergency weight loss (EWL) could have a major positive impact for obese PsA patient outcomes, noted the researchers.8
In the retrospective study, the researchers searched through a database of over 9,000 cases of bariatric surgeries performed at a single clinic from 2002 to 2013. They found 86 patients who had been diagnosed with PsO and/or PsA and compiled information about their disease history, treatments, and symptoms before and after the surgery.
The majority of psoriasis patients (55%) and PsA patients (62%) reported a substantial subjective improvement of their symptoms 1 year following the bariatric surgery. Using a disease severity scale (0-10), post-surgery decreases were significant for PsO and PsA patients (5.6 vs 4.4 and 6.4 vs 4.5, respectively). Patients with severe cases of PsO and PsA showed post-surgical improvements even more pronounced (7.7 vs 5.7, and 8.2 vs 4.8, P<0.01, respectively).
There may even be a positive relationship between the degree of EWL and subsequent symptom improvement, noted the researchers. In secondary analyses, patients with severe PsO and PsA were older at diagnosis (37 vs 26 years, P=0.02) with much higher disease ratings at the time of their surgery (8.9 vs 7.4, P<0.01). A year after the surgery, however, the PsO and PsA symptoms trended towards significant improvements when patients achieved higher EWL (59.5% vs 43.5% and 55.4% vs 43.8%, respectively).
Dieting Alone Shows Benefit
“I think there still needs to be more studies to really define this true surgical effect,” said Elaine Husni, MD, MPH, of the Cleveland Clinic Foundation in Ohio. “I think at this point the study just shows a very interesting association of massive weight loss and improvement of symptoms.”
Large, prospective trials to further understand surgical EWL in the context of PsO and PsA management is a hopeful avenue to explore, given the fact these findings seem to corroborate with other investigations conducted over the last few years, she noted.
Body weight changes have been shown to have a major impact on clinical response to therapy, and this weight loss does not necessarily have to come from an invasive, bariatric procedure.
Caloric restriction dieting, particularly rich in mono- and polyunsaturated fatty acids, dietary fiber, and antioxidants has been shown to reduce circulating inflammatory markers, notably C-reactive protein (CRP) and TNF-α.9 A low-caloric Mediterranean-style diet reduces important metabolic markers, like cholesterol and triglycerides.9
Regardless of the type of diet, generally successful weight loss (≥5% from baseline values) has been associated with a higher rate of achieving minimal disease activity (OMERACT criteria)10 in obese PsA patients starting treatment with TNF-α blockers and fewer rheumatological markers (ie, ESR, CRP, VAS, global VAS and HAQ).11
Prompting lifestyle changes in PsA patients can be difficult to do, though. “I think we all agree that lifestyle changes should be part of our practice, whether it should be the primary care provider, pain specialist, rheumatologist or the cardiologist, I think is probably up for debate,” noted Dr. Husni.