Researchers have identified an apparent association between increased psoriasis severity and increased Body Mass Index (BMI) scores, suggesting that dermatologists should record the BMI of their psoriasis patients and offer them lifestyle counselling. That’ s according to a paper published in the Journal of Cutaneous Medicine and Surgery (Sept. 2015; 19(5):450–456).
The authors conducted a systematic literature review as part of a larger collaborative effort from a mixed team of dermatologists and rheumatologists, says study author Dr. Wayne Gulliver, chief medical officer and primary investigator at Newlab Life Sciences, and professor of medicine at Memorial University in St . John’ s, Newfoundland and Labrador. The team is investigating areas where their specialties have common interests, especially in psoriasis and psoriatic arthritis.
Common comorbidities observed
“We are noting that a number of our patients are having a number of common comorbidities—cardiovascular disease, diabetes, hyperlipodemia, obesity, metaboloic syndrome,” Dr. Gulliver says. “So, led by Dr. [Boulos] Haraoui , a rheumatologist from Montreal , and Dr. [Robert] Bissonnette, a dermatologist from Montreal, they gathered a group of like-minded rheumatologists and dermatologists to get together and discuss these issues.”
In this study, PubMed, EMBASE, and the Cochrane Database were searched for human subject studies with data on age, sex, BMI, what proportion of participants were obese, and psoriasis severity index score (PASI). Of 254 articles identified, nine were used, totalling 134,823 patients with psoriasis. Of the nine studies included, seven found a statistically significant association between increased psoriasis severity and higher BMI.
BMI has impact on comorbidities
“With this [paper], we know the relationship between psoriasis and obesity,” says Dr. Gulliver.“Obesity is a really important aspect because it impacts the comorbidities to patients.” Patients who are obese are more likely to have metabolic syndrome, hypertension, hyperlipidemia, and fatty liver, he says, all of which are known to be linked to morbidity and mortality issues.
Dr. Gulliver and the other authors of the paper caution that most of the included studies were cross-sectional or case-control, so that the temporality of the association is difficult to determine.
The correlation between BMI and psoriasis severity is not too surprising, Dr. Gulliver says. “We know as well that abdominal obesity, especially, is an inflammatory condition. It adds to the overall inflammatory burden of the patient, which again can result in greater challenges in terms of clearing the patient and improving the underlying psoriasis and probably psoriatic arthritis.”
Because of the association between obesity and psoriatic disease severity, and the inflammation-related comorbidities of psoriasis, working as a team with a psoriasis patient’s other doctors is the best way to ensure better outcomes, says Dr. Gulliver.
“As clinicians, it is important to identify this [association between BMI and psoriasis severity] and try to use therapeutic options that will not worsen these underlying issues linked to obesity, but to identify to the family doctor that increased BMI or obesity has an impact on the disease as well as the treatment, and on the overall patient life,” Dr. Gulliver says.
Make BMI part of clinical assessment
“We need to record [BMI], make it a part of the patient’s assessment and offer them lifestyle counselling either through ourselves, through the family doctor, or other specialties such asdieticians,” Dr. Gulliver says.
At the minimum, the topic should be brought up with the patient and inform them that their BMI is having an impact on both their disease and on their treatment.
“If we can positively impact these patient’s weight issues, bring it down, it may improve outcomes, may decrease co-morbidities, and may allow us to help get the patient’s disease burden under better control,” says Dr. Gulliver.
He cites a study that looked at the potential benefit of adding a weight loss regimen to low-dosecyclosporine therapy for moderate to severe chronic plaque psoriasis (The American Journal of Clinical Nutrition Nov. 2008; 88(5):1242–1247). That study showed “that if you treat patients with cyclosporine and routine care they do okay. But if you give them cyclosporine and a weight management program, they actually do better,” says Dr. Gulliver.
This article originally appeared in the April / May 2016 issue of The Chronicle of Skin & Allergy