Psoriasis, a chronic inflammatory skin disease, affects between 1 percent and 3 percent of the population, according to background information in the article. Recent studies indicate that psoriasis is associated with an increased risk of other illnesses and death. "Systemic inflammation in psoriasis and an increased prevalence of unhealthy lifestyle factors have been independently associated with obesity, insulin resistance and an unfavorable cardiovascular risk profile," the authors write.

Abrar A. Qureshi, M.D., M.P.H., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues studied 78,061 women involved in the Nurses' Health Study II, a group of female nurses age 27 to 44 years in 1991. Participants—all of whom were free of diabetes and hypertension at the beginning of the study—responded to a survey which included a question about lifetime history of psoriasis in 2005 and were assessed for the development of diabetes or hypertension during the 14-year follow-up.

Of the women, 1,813 (2.3 percent) reported a diagnosis of psoriasis. A total of 1,560 (2 percent) developed diabetes and 15,724 (20 percent) developed hypertension. Women with psoriasis were 63 percent more likely to develop diabetes and 17 percent more likely to develop hypertension than women without psoriasis. These associations remained strong even after the researchers considered age, body mass index and smoking status.

Inflammation could be a biologically plausible explanation for the association between psoriasis and hypertension as well as that between psoriasis and diabetes, the authors note. Inflammation is a risk factor for high blood pressure and may also contribute to insulin resistance, a pre-diabetic stage where the body does not respond to the glucose-regulating hormone insulin. Alternatively, systemic steroid therapy or other treatments for psoriasis may promote development of diabetes or hypertension.

"These data illustrate the importance of considering psoriasis a systemic disorder rather than simply a skin disease," the authors conclude. "Further research is needed to better understand the mechanisms underlying these associations and to find out whether psoriasis therapy can reduce the risk for diabetes and hypertension."

This work was partly supported by grants from the National Cancer Institute.

Editorial: Research Uncovers Effects of Diabetes Throughout the Body

The article is one of seven in this issue that relates to diabetes and its effects on the skin, write William H. Eaglstein, M.D., of Stiefel Laboratories Inc., and Jeffrey P. Callen, M.D., of University of Louisville, Ky., and associate editor of Archives of Dermatology, in an accompanying editorial.

The issue is being published in conjunction with a JAMA theme issue on diabetes. The March issues of Archives of Ophthalmology and Archives of Neurology, along with the April issues of Archives of Pediatrics & Adolescent Medicine and Archives of Surgery, also feature research on diabetes, obesity and their related co-morbidities.

"Although a link between diabetes mellitus and psoriasis was suggested as early as 1908, the article by Qureshi et al reporting on a study of 78,061 U.S. female nurses is the first to prospectively document the link between psoriasis and both diabetes mellitus and hypertension," Drs. Eaglstein and Callen write.

Note: If no author is given, the source is cited instead.

• Psoriasis
• Diabetes
• Hypertension
• Skin Care
• Diseases and Conditions
• Hormone Disorders

• Diabetes mellitus type 2
• Psoriasis
• Dandruff
• Hypertension
• Candidiasis
• Rash