Skin problems health centre

Psoriasis linked to hypertension and diabetes

April 20, 2009 -- Women who have the chronic skin condition psoriasis appear to be at higher risk of developing diabetes and high blood pressure, a new study shows.

"We knew there was some association between psoriasis and diabetes and high blood pressure", Dr Abrar Qureshi, assistant professor of dermatology at Harvard Medical School, says. "The question was, which came first. 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 Dermatology.

Qureshi, who is also a dermatologist at Boston's Brigham and Women's Hospital, and colleagues, studied 78,061 women who participated in the Nurses' Health Study II. This study of more than 116,000 female registered nurses living in America has been running since 1989, and questions women about their health every two years.

In 2005, 84,039 women reported whether they had ever been diagnosed with psoriasis. After excluding the women who already had diabetes or hypertension, the researchers focused on the 78,061 women, including 1,813 with a confirmed diagnosis of psoriasis.

In the UK, psoriasis affects around 2% of the population. There are five main types of the skin condition, in which skin cells reproduce too quickly. Each has different symptoms and signs but the most common type is plaque psoriasis which affects approximately 80% of those diagnosed with psoriasis. This is marked by itchy patches of red, raised skin covered by silvery-white scales. They most often appear 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 they were more likely to develop diabetes and high blood pressure.

The results: Women with psoriasis were 63% more likely to develop diabetes and 17% more likely to develop high blood pressure.

This was true even after accounting for such factors that could boost the risks of the other conditions, such as obesity, smoking status, alcohol intake, and level of physical activity.

"We were surprised to see the numbers so high, especially for diabetes", Qureshi says.

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 remains.

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 developing the other diseases, but the research does suggest that psoriasis should be viewed not just as a skin disease, but as a systemic disorder, he says.

Qureshi's study was partially funded by the American National Cancer Institute. He has served as a consultant and speaker for the drug companies Abbott, Amgen, and Genentech.