Kidney Disease More Likely with Moderate to Severe Psoriasis
An analysis of the medical records of 143,883 psoriasis patients in the United Kingdom found that people with severe psoriasis were twice as likely to acquire chronic kidney disease as those whose psoriasis was mild or who had no psoriasis at all.
The analysis is reported in the BMJ.
When a person's kidneys progressively become less effective at filtering blood, whatever the cause, physicians will diagnose them with chronic kidney disease (CKD). In the United States, diabetes is the most common cause and accounts for 44 percent of new cases. The incidence overall is about 0.5 percent per year among people age 20 to 64, and about 10 times that for people older.
End-stage renal disease, also known as kidney failure, requires that patients receive dialysis or a transplant, or else they will die. Often the loss of function can be slowed or even reversed, however, when it is diagnosed early. Fortunately, from a public health perspective, tests of kidney function are part of a routine urine analysis and blood work. You should discuss with your primary care physician if you should have a test, according Dr. Joel Gelfand, an associate professor of dermatology and epidemiology at the University of Pennsylvania, and principal author of the report.
The association of psoriasis with kidney disease expands the list of bodily systems that psoriasis appears capable of affecting beyond the skin and (as in psoriatic arthritis) the joints. An "explosion" of studies, as Gelfand describes them, have revealed among people with psoriasis elevated risks for heart attack and diabetes (the pancreas). Now with the kidney disease association, the urinary system appears vulnerable as well. As recently as seven years ago, Gelfand said, “nobody appreciated comorbidity at all," adding that the importance of major medical problems associated with psoriasis was not well recognized.
He attributes the change to larger and better patient databases and the use of modern methods of analysis, as well as a better understanding of the genetics and immune defects in psoriasis.
As a test, the authors reperformed their calculations, alternately excluding subjects who were taking cyclosporine and/or methotrexate, those taking azathioprine and those who used non-steroidal anti-inflammatory drugs such as ibuprofen. These drugs, although all at least somewhat toxic toward the kidneys, were not responsible for kidney disease occurring more frequently among people with psoriasis. Cyclosporine and methotrexate may have contributed somewhat to the increased frequency observed, but the results were unclear.
The report suggests further research needs to be conducted to investigate the effect that different psoriasis treatments have on the risk of CKD, as well as to examine what type of kidney malfunction might be particularly associated with psoriasis.
Patients with more than 3 percent of their body surface affected by psoriasis were the group that showed an elevated CKD risk. Those with less than that showed no additional risk.
October 22, 2013