What Does Obesity Have To Do with Psoriasis?
The results of a new study conducted with twins indicate there is a common genetic factor shared by psoriasis and obesity. This finding was reported by a Danish team from the University of Copenhagen, Denmark, under direction of Ann Sophie Lonnberg, MD.
Psoriasis is a chronic inflammatory, autoimmune skin disease that can cause burning, itching or stinging. Typically it appears on the knees, scalp, and outside of the elbows, but it can develop in other sites as well.
As noted by the National Psoriasis Foundation, the disease “is associated with other serious health conditions, such as diabetes, heart disease and depression.” These relationships have been the subject of many studies, including the following ones, which focus on psoriasis, obesity, and diabetes.
New obesity and psoriasis study
Here are the findings the authors gathered by evaluating data from 33,588 twins:
- Of the 720 twin pairs in which one twin had psoriasis and the other one didn’t, the twin with the skin disease had a higher body mass index than the co-twin without psoriasis and they were more likely to be obese
- Prevalence of diabetes was the same in twins with psoriasis compared with co-twins without psoriasis
- Among 459 individuals who had diabetes, 7.6 percent (31) also had psoriasis compared with 4.1 percent (1,370) of individuals without diabetes
- The average body mass index of individuals who had psoriasis was 25 compared with 24.4 among those without psoriasis
- Overall, the researchers found a significant association between psoriasis and increasing body mass index and between psoriasis and type 2 diabetes
The authors concluded that “Results indicate a common genetic etiology [cause] of psoriasis and obesity.” However, “conducting future studies on specific genes and epigenetic factors that cause this association is relevant.”
Previous psoriasis and obesity studies
A team of Canadian investigators recently evaluated the association between obesity and psoriasis by examining data from nine studies and a total of 13, 823 psoriasis patients. Seven of the studies showed a statistically significant association between higher body mass index (obesity) and increased psoriasis severity. The authors recommended dermatologists note the body mass index of their psoriasis patients and offer them lifestyle counseling.
In a study conducted at Cincinnati Children’s Hospital, researchers pointed out that psoriasis often first appears during childhood and the growing evidence that psoriasis in adults is associated with obesity, type 2 diabetes, metabolic syndrome, hypertension, and cardiovascular disease. They pointed out that this association is “postulated to arise, at least in part, as a result of a systemic proinflammation state that is mediated by adipose [fat] tissue.”
Observational studies indicate that children and adolescents who have psoriasis may be at an increased risk of being overweight or obese along with having a greater chance for developing symptoms of metabolic syndrome. This association is of special concern because of the long-term health consequences for children and adolescents with psoriasis.
Fleming P et al. The relationship of obesity with the severity of psoriasis: a systematic review. Journal of Cutaneous Medicine and Surgery 2015 Sep-Oct; 19(5): 450-56
Gutmark-Little I, Shah KN. Obesity and the metabolic syndrome in pediatric psoriasis. Clinical Dermatology 2015 May-Jun; 33(3): 305-15
Lonnberg AS et al. Association of psoriasis with the risk for type 2 diabetes mellitus and obesity. JAMA Dermatology 2016 April 27 online
National Psoriasis Foundation
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