Increased adiposity and weight gain are strong risk factors for the development of psoriasis in women, according to a recently published study.
As such, weight loss may be a potential target for preventing and managing psoriasis, said Dr. Arathi R. Setty of Massachusetts General Hospital, Boston, and colleagues (Arch. Intern. Med. 2007;167:1670-5).
Earlier studies have noted an association between weight and psoriasis, but this is the first prospective study to be published, with 78,626 women participating as part of the Nurses' Health Study II, an ongoing longitudinal study of registered nurses from 15 U.S. states who were aged 25–42 years in 1989. They were followed for 1,085,658 person-years, during which time 892 women were newly diagnosed with psoriasis.
After adjusting for age, alcohol consumption, and smoking status, women who were in the highest category of body mass index (greater than 35 kg/m
Even women who were overweight, but not obese, had an increased risk of developing psoriasis. Women with a BMI of 25–30 had a 48% increased risk of developing psoriasis, compared with normal-weight women. The amount of weight a woman gained after the age of 18 was also associated with a higher risk of developing psoriasis, as was higher waist circumference, hip circumference, and waist-hip ratio.
Adiposity is associated with chronic, low-grade inflammation, and the investigators hypothesized that this may explain the increased risk of psoriasis in obese women. Adipose tissue overproduces certain inflammatory cytokines, some of which have been implicated in the pathophysiology of psoriasis. Weight loss decreases cytokines levels, which may translate to a reduced risk or reduced severity of psoriasis.