LOS ANGELES — Two studies on psoriasis presented at the annual meeting of the Society for Investigative Dermatology show an association between the disease and increased mortality, as well as an increased risk for hypertension, heart disease, and diabetes.
In the first study, severe psoriasis was an independent predictor of death and increased patients' mortality risk by 50%, compared with normal control patients' risk, in a cohort study of more than 713,000 patients.
No increased risk for death was seen in patients with mild psoriasis, however, compared with controls, Shanu Kohli Kurd said at the meeting. Ms. Kurd and her associates derived the 50% greater mortality risk for severe psoriasis after adjusting for the effects of age and gender.
Patients with severe psoriasis should receive comprehensive health assessments to try to reduce their risk of death, suggested Ms. Kurd, a clinical research fellow in dermatology at the University of Pennsylvania, Philadelphia, and her associates. Multiple comorbidities that have been associated with psoriasis may increase mortality, but even after adjusting for the effects of major comorbidities, the risk of death was 40% higher in patients with severe psoriasis, compared with controls.
Severe psoriasis was defined as disease requiring systemic therapy; mild psoriasis did not require such therapy. Data drawn from the General Practice Research Database, compiled in the United Kingdom from 1987 to 2002, accounted for 3,951 patients with severe psoriasis, 133,568 patients with mild psoriasis, and up to 5 control patients for each psoriasis patient, seen in the same practices in the same time periods.
The overall incidence of death was 12 patients per 1,000 patient-years in each of three other groups: the mild psoriasis group, the 560,358 controls for the mild psoriasis group, and the 15,075 controls for the severe psoriasis group. In patients with severe psoriasis, however, overall incidence of death was 21 patients per 1,000 patient-years, Ms. Kurd reported.
The relative risk of death was greatest for younger patients with severe psoriasis, and was not affected by gender. At age 35 years, patients with severe psoriasis were 2.5 times more likely to die, compared with control patients. By age 95 years, severe psoriasis incurred only a 10% increased relative risk of death. The increased relative risk of death persisted in analyses that excluded patients with concomitant psoriatic arthritis or rheumatologic disease.
The median age of death for patients with severe psoriasis was 74 years in males and 75 years in females, compared with 77 years in males and 81 years in females in the control group.
The study was funded in part by Centocor Inc., which markets infliximab.
The second study found increased rates of hypertension, heart disease, and diabetes in patients with psoriasis, compared with the general population, according to Dr. Wayne P. Gulliver.
Dr. Gulliver and his associate at a medical research organization in St. John's, Nfld., analyzed data from the province of Newfoundland and Labrador, where the population has a high prevalence of psoriasis linked to two genetic markers for psoriasis (HLA-Cw6 and tumor necrosis factor-α238).
Surveys of 100 patients with mild to moderate psoriasis and 100 patients with severe psoriasis—all older than age 50 years—found hypertension in 25% of the mild to moderate group and 21% of the severe psoriasis group, compared with 14% of the general population aged 30–64 years.
Heart disease had been diagnosed in 14% of the mild to moderate group, 10% of the severe psoriasis group, and 4% of the general population. Diabetes was present in 10% of the mild to moderate group, 12% of the severe psoriasis group, and 4% of the general population.
Records on 169 separate patients with psoriasis who had died showed that they lived 10 years fewer, on average, compared with the average life span in Canada. Cardiovascular or genitourinary disease was more likely to be the immediate cause of death in the psoriasis group, compared with death statistics in Newfoundland and Labrador.
In the psoriasis deaths, 44% were caused by cardiovascular disease, compared with 36% in the general population. Genitourinary disease was the cause of 3% of deaths in the psoriasis group and none in the general population.
The study's findings should “lead to early diagnosis and improved outcomes for the patients,” Dr. Gulliver suggested.
The study was funded in part by Merck Serono S.A., which markets efalizumab in Europe.