April 20 (HealthDay News) -- A new study lends more credence to a long-suspected connection between psoriasis, diabetes and hypertension.

Researchers reporting in the April issue of the Archives of Dermatology suspect the link may have to do with the chronic inflammation that is associated with all three conditions.

"We were able to prospectively evaluate the risk of diabetes and hypertension in U.S. women who had psoriasis," said study author Dr. Abrar A. Qureshi, an assistant professor of dermatology at Brigham and Women's Hospital and Harvard Medical School in Boston.

"The big question a lot of people have been asking is whether there are common threads in autoimmune diseases, and whether those who develop one autoimmune or inflammatory condition are at risk of developing others," Qureshi explained.

Previous research had indicated that psoriasis is associated with a higher risk of other illnesses and even death.

Meanwhile, the vast majority of individuals with diabetes go on to develop high blood pressure, while a smaller proportion of people with high blood pressure develop diabetes.

The authors used data on 78,061 women aged 27 to 44 who participated in the Nurses' Health Study. None of the women, who were followed for 14 years, had diabetes at the start of the study.

Women with psoriasis turned out to have a 63 percent increased risk of developing diabetes and a 17 percent increased risk of developing high blood pressure, compared to women without psoriasis.

Inflammation is a risk factor for elevated blood pressure and may help foster insulin resistance, which is a precursor to diabetes. Chronic inflammation could explain the association, the authors stated. So could the use of steroids to treat psoriasis although, they pointed out, this course of treatment is not common in the United States.

Importantly, the connection between psoriasis and the other two conditions was independent of body-mass index, ruling out the possibility that obesity or metabolic syndrome might explain the phenomenon.

Now the question is what to do with the findings.

"It does open up the question of whether patients evaluated [for psoriasis] in a doctor's office or dermatologist's office should be screened for diabetes, although it's probably too early to jump to that conclusion," Qureshi said. "We can't carte blanche start screening for diabetes, but it's worth considering screening for diabetes even in patients who are not obese."

And screening for insulin resistance may be something else to consider, added Dr. Spyros Mezitis, an endocrinologist with Lenox Hill Hospital in New York City.

"We need more research to see if patients you're seeing with psoriasis should be treated for insulin resistance or at least screened for it," he said.

SOURCES: Abrar A. Qureshi, M.D., co-director, Center for Skin and Related Musculoskeletal Diseases, Brigham and Women's Hospital, and assistant professor, department of dermatology, Harvard Medical School, Boston; Spyros Mezitis, M.D., endocrinologist, Lenox Hill Hospital, New York City; April 2009, Archives of Dermatology