Moderate to severe psoriasis may be associated with increased risk for chronic kidney disease

Moderate to severe psoriasis (more than 3% of body surface area affected) is associated with an increased risk of chronic kidney disease (CKD), independent of traditional risk factors such as diabetes and heart disease, a study found.

Researchers used a primary care electronic medical records database in the United Kingdom to identify 143,883 adults with psoriasis and match them to a control group of 689,702 patients without psoriasis, seen between 2003 and 2010.

Mild psoriasis was defined as disease affecting 2% or less of body surface area. Moderate disease was defined as 3% to 10% of body surface area affected. Severe to extensive disease was defined as more than 10% of body surface area affected or as receipt of phototherapy or oral or injectable biologic medications.

Study results appeared online Oct. 15 at BMJ.

Patients with psoriasis, particularly those with severe disease, were at greater risk of developing moderate to advanced (stage 3 to 5) CKD compared with control patients. For all patients with psoriasis, the hazard ratio (HR) was 1.05 (95% CI, 1.02 to 1.07); for mild disease, the HR was 0.99 (95% CI, 0.97 to 1.02); and for severe disease, the HR was 1.93 (95% CI, 1.79 to 2.08). Those with severe psoriasis were more than 4 times as likely to develop end-stage renal disease requiring dialysis (adjusted HR, 4.15; 95% CI, 1.70 to 10.11).

The researchers conducted a subgroup analysis of 8,731 psoriasis patients with measurements of affected body surface area and matched them to 87,310 patients without psoriasis. There was a greater risk of CKD in patients with moderate and severe disease in a dose-response effect. After adjustment for age, sex, cardiovascular disease, diabetes, hypertension, hyperlipidemia, body mass index, use of nonsteroidal anti-inflammatory drugs and duration of observation, the odds ratios of CKD were 0.89 (95% CI, 0.72 to 1.10) for mild disease, 1.36 (95% CI, 1.06 to 1.74) for moderate disease and 1.58 (95% CI, 1.07 to 2.34) for severe disease. The adjusted prevalence odds ratio of CKD was 0.90 (95% CI, 0.64 to 1.28) in patients with psoriasis of less than 2 years' duration and 1.24 (95% CI, 1.01 to 1.53) in patients with 10 or more years' duration.

The authors recommend closer monitoring for kidney problems in patients with moderate or severe disease. “Closer monitoring for renal insufficiency, such as routine screening urinalysis for microalbuminuria and serum creatinine and blood urea nitrogen testing, should be considered for patients with psoriasis affecting 3% or more of the body surface area. Increased screening efforts will allow for earlier detection and intervention to reduce the substantial morbidity and mortality associated with chronic kidney disease,” they wrote. “Additionally, the risk versus benefit of potentially nephrotoxic drugs in patients with moderate to severe psoriasis should be carefully considered.”