Weight loss could improve psoriasis outcomes
MedWire News: US researchers report that weight loss could play a potential role in the treatment of psoriasis after they observed a dramatic improvement in the condition of two patients who underwent gastric bypass surgery.
They believe the link between obesity and psoriasis could be explained by the state of chronic inflammation seen in obese individuals, which includes elevation of T helper 1 (TH-1) cytokines, such as tumor necrosis factor (TNF)α.
"Reducing the inflammation from excess adipose tissue could have a therapeutic benefit in psoriatic lesions by way of reducing levels of TNF-α or leptin," report Eric Hossler and colleagues from the Geisinger Medical Center in Danville, Pennsylvania, USA.
They report two cases of Roux-en Y gastric bypass surgery in two obese female patients with severe plaque psoriasis. The first had plaques affecting up to 75% of her body, and the second had plaques affecting more than 50% of her body.
The first patient had a pre-surgery body mass index (BMI) of 52 kg/m2, and reached a nadir BMI of 34 kg/m2 after surgery. The second patient weighed 97 kg before surgery, which dropped to 66 kg at 6 months after surgery afterwards.
In both cases, the patients reported an improvement in their psoriasis after surgery, with the second patients' body surface area involvement reducing to just 9%.
The first patient was followed up for more than 6 years after surgery, during which time she experienced no rebound of psoriasis, which covered just 5% of her body surface area at last follow-up, report Hossler et al.
The team explains that the adipose tissue of obese individuals can secrete 2.5 times more TNF-α - which plays a major role in the chronic inflammation found in psoriasis plaques - messenger RNA than adipose tissue from healthy individuals.
A further possible explanation could involve leptin levels, which are higher in obese patients (and directly correlate with the percentage of body fat) and have been previously been shown to be higher in patients with psoriasis than in their healthy peers.
"Leptin affects T lymphocytes and cytokine secretion and causes a shift toward a TH-1 phenotype (eg, that found in psoriasis) while suppressing TH-2," write Hossler and co-investigators in the Journal of the American Academy of Dermatology.
On the basis of their findings, the research team believes future studies will support weight loss as a potential therapy for psoriasis patients, and could "play a role in adjunctive therapy with more traditional medical therapies for psoriasis."
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By Sarah Guy