The obesity factor: Researchers study psoriasis, co-morbidities

Key Points

Montreal, Canada - Increasingly, researchers are looking at the relationship between psoriasis and co-morbidities such as obesity, with implications for counselling and treatment, a leading Canadian dermatologist says.

"There is an increasing interest in co-morbidities in psoriasis, particularly abdominal obesity," says Richard Langley, M.D., a dermatologist and director of research in the division of dermatology, department of medicine, Dalhousie University in Halifax, Nova Scotia.

"It is thought that abdominal obesity may lead to the release of certain pro-inflammatory mediators, which have been postulated to result in atherosclerosis," Dr. Langley says. "Psoriasis itself has been questioned as having an independent effect (on abdominal obesity) according to recent studies."

"It is important that we look at this young population and we think about these risk factors on two fronts," Dr. Langley tells Dermatology Times.

"If we know the patient is at risk for becoming obese and developing co-morbidities, it would help if we counsel those patients. Secondly, we can raise a hypothesis of whether we impact these patients early with anti-inflammatory therapies. Etanercept and methotrexate have been shown to be effective in reducing C-reactive protein in rheumatoid patients. It may be a reason to treat these patients early," he says.

Previous study

Dr. Langley and investigators conducted a phase 3 randomized, controlled trial published in the New England Journal of Medicine that examined the effect of etanercept on children with moderate-to-severe plaque psoriasis. It found that pediatric patients with plaque psoriasis had elevated levels of C-reactive protein, a marker for inflammation and cardiovascular morbidities.

Given that psoriasis is a chronic disease, it's critical that clinicians find a treatment in the pediatric population that is sustainable, safe and effective, according to Dr. Langley. "In some cases, we have to decide how we will manage severe cases if they don't respond to topical treatments," he says.

"Choosing phototherapy can be onerous for the patients because they have to fit it into their schedules and miss school. If the phototherapy is not an option, then we may need to move onto systemic agents," he adds.

But the issue with systemic agents in pediatric patients, Dr. Langley says, involves concern over side effects with long-term management.

"These are chronic diseases that require long-term treatment if they have severe disease," he explains.

Children and teens that were included in the study had a score on the Psoriasis Severity Index Scale (PASI) of at least 12, with scores ranging from zero to 72. They were aged four to 17. Higher scores indicate greater disease severity. Participants were also judged using a static physician's global assessment of at least three, with zero indicating clear and five indicating severe psoriasis. They also had psoriasis that involved at least 10 percent of the body surface area and had a history of the disease for at least six months.

The 48-week study looked at the impact of administering the TNF receptor compared to placebo in 211 patients with psoriasis age 4 to 17. A total of 106 patients were initially randomized to receive etanercept; 105 were randomized to receive placebo.

After 12 weeks of the study, etanercept was delivered in an open-label fashion to study subjects for 24 weeks. At 36 weeks, just over two thirds (68 percent) of patients who received etanercept from the outset achieved PASI 75, and 65 percent of patients who received placebo reached PASI 75.

At the 36-week period, 12 weeks of withdrawal-re-treatment followed in weeks 37 to 48, evaluating the impact of withdrawal of the medication and further re-treatment.

During that period, investigators observed a loss of response in 29 of 69 patients (42 percent) who were receiving placebo at the second randomization.

Side effects were not dissimilar from those seen in other biologic studies, Dr. Langley says, describing etanercept as effective and well-tolerated in the pediatric population.

Disclosure: Dr. Langely reports no relevant financial disclosures.