April 20, 2009 -- Women who have the chronic skin condition psoriasis appear
to be at higher risk of getting diabetes and high blood pressure, a new study
"We knew there was some association between psoriasis and diabetes and high
blood pressure," says Abrar Qureshi, MD, MPH, assistant professor of
dermatology at Harvard Medical School and a dermatologist at Brigham and
Women's Hospital, Boston. "The question was, which came first."
In the study, he tells WebMD, "We were able to show women with psoriasis had
a higher risk of developing diabetes and hypertension."
The study is published in the April issue of the Archives of
Qureshi and colleagues studied 78,061 women who participated in the Nurses'
Health Study II, a long-running study that first collected data in 1989 from
more than 116,000 women (all registered nurses) and followed up with
questionnaires about their health every two years.
All were free of diabetes and high blood pressure at the study's start. In
2005, the women reported whether they had ever gotten a diagnosis of psoriasis
from a doctor. After excluding the women who already had diabetes or
hypertension, the researchers focused on 78,061 women, including 1,813 with a
diagnosis of psoriasis.
Psoriasis affects up to 3% of the population, according to the researchers.
Five types occur, according to the American Academy of Dermatology, with
different symptoms and signs. The most common is plaque psoriasis, marked by
itchy patches of red, raised skin covered by a silvery-white scale that shows
up most often on the elbows, knees, scalp, and lower back.
Psoriasis and the Link With Hypertension and Diabetes
The researchers followed the women who had a diagnosis of psoriasis for 14
years to determine if those were more likely to develop diabetes and high blood
The results: the women who had psoriasis were 63% more likely to get
diabetes and 17% more likely to get high blood pressure.
This was true even after accounting for such factors that could boost the
risks of the other conditions, such as obesity and smoking status.
"We were surprised to see the numbers so high, especially for diabetes,"
Why the link? Qureshi says it may be underlying inflammation, thought to
play a role in all three diseases. His team will try to duplicate the study in
men to see if the link holds.
Though previous studies have also found a link between the three diseases,
Qureshi says they were studies that looked only at one point in time, while his
study has a long follow-up period and many participants.
It's not known whether anti-inflammatory treatments can reduce the risk of
getting the other diseases, he says. The research does suggest that psoriasis
should be viewed as not just a skin disease, but as a systemic disorder, he
Qureshi's study was partially funded by the National Cancer Institute. He
has served as a consultant and speaker for the drug companies Abbott, Amgen,