MAUI, HAWAII – Serious weight loss brings big improvement in psoriatic arthritis in obese patients, at least short term, according to a Swedish, single-arm, prospective, proof-of-concept study.
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Dr. Eric M. Ruderman
A dose-response effect was evident: the greater the lost poundage, the bigger the improvement across multiple dimensions of psoriatic arthritis.
The short-term efficacy was eye-catching, especially in view of the well-recognized increased prevalence of obesity in psoriatic arthritis patients. But the jury is still out as to the long-term impact of this nonpharmacologic therapy, Eric M. Ruderman, MD, said at the 2019 Rheumatology Winter Clinical Symposium.
He has spoken with the Swedish investigators and was happy to learn they’re continuing to follow study participants long term.
“That’s going to be the key, right? Because if you do this for 12 weeks, like every other fad crash diet, and then you let the weight go right back on again, you haven’t really accomplished anything. I think the key will be what happens at a year,” according to Dr. Ruderman, professor of medicine and associate chief for clinical affairs in the division of rheumatology at Northwestern University, Chicago.
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Dr. Arthur Kavanaugh
The study included 46 obese psoriatic arthritis patients who signed on for a structured, medically supervised very-low-energy diet lasting 12-16 weeks, depending upon their baseline obesity level. The commercially available liquid diet (Cambridge Weight Plan Limited) is a type of therapy widely prescribed by Swedish physicians, clocking in at a mere 640 kcal/day.
“I don’t know about you, but I ate that at breakfast this morning,” quipped symposium director Arthur Kavanaugh, MD, professor of medicine at the University of California, San Diego.
Following completion of the strict very-low-energy diet, patients were gradually reintroduced to a less-draconian, solid-food, energy-restricted diet, to be followed through the 12-month mark. The full 12-month protocol was supervised by staff in the obesity unit at Sahlgrenska University Hospital in Gothenburg, Sweden. The 12-month results will be presented at the annual European Congress of Rheumatology in Madrid.
Of the 46 starters, 41 made it to the 6-month follow-up assessment. At that point they’d lost a median of 18.2 kg, or 18.6% of their baseline body weight. Their body mass index had dropped from an average of 35.2 to 29.8 kg/m2. And their psoriatic arthritis had improved significantly. For example, their median Disease Activity Score using 28 joint counts based upon C-reactive protein (DAS28-CRP) decreased from 2.9 at baseline to 2.4 at 6 months, with ACR 20, -50, and -70 responses of 51.2%, 34.1%, and 7.3% while disease-directed medications were held constant (Arthritis Res Ther. 2019 Jan 11;21[1]:17. doi: 10.1186/s13075-019-1810-5).
The investigators reported the very-low-energy diet phase was generally well tolerated. A total of 34 of the 41 patients deemed it “easier or much easier” than expected, prompting Dr. Ruderman to comment: “Because they thought it was going to be awful.”
Dr. Ruderman and Dr. Kavanaugh reported serving as consultants to numerous pharmaceutical companies.