RISK FACTORS FOR RENAL CALCULI IN PATIENTS WITH CROHN'S DISEASE

The incidence of nephrolithiasis has increased significantly, diet, obesity, and high animal protein intake having been reported to be risk factors. Nephrolithiasis has a great economic impact on society related to work absenteeism, recurrent attacks of renal colic, and urological interventions. Nephrolithiasis can also progress to renal failure. It is therefore important to identify the risk factors for nephrolithiasis. Inflammatory bowel diseases, which include Crohn's disease, represent a risk factor for the formation of renal calculi, due to the disease itself and to the use of drugs that can influence the metabolism of substances related to nephrolithiasis. In the past, Crohn's disease patients were often submitted to surgery, which is known to contribute to nephrolithiasis. New drugs have changed the clinical course of Crohn's disease, whose incidence has increased worldwide. Specialists should be on the alert not only for the complications of Crohn's disease but also for its extraintestinal manifestations, which can dramatically affect the quality of life of these patients and lead to renal failure. It is therefore important to screen this population for nephrolithiasis.

To determine the prevalence of nephrolithiasis in a population of patients with Crohn's disease; to determine whether drugs, previous surgery, location of the disease, and clinical activity are risk factors for nephrolithiasis; and to alert specialists to the importance of screening for nephrolithiasis (through simple methods) in order to prevent chronic kidney disease.

Were analyzed the electronic medical records of 93 Crohn's disease patients treated between 2009 and 2010 at the Inflammatory Bowel Disease Center of the Scope Clinic, located in the city of Campo Grande. All of the patients underwent ultrasound at the first medical appointment.

Of the 93 patients, 37 developed nephrolithiasis at some point during the study period. Risk factors for nephrolithiasis were disease location (P=0.023) and the use of ciprofloxacin (P=0.0001), corticosteroids (P=0.005), immunomodulators (P=0.001), or metronidazole (P=0.0005). Surgical status, age, and gender were not found to predispose to the formation of renal calculi.

This study demonstrates the importance of using imaging methods to screen Crohn's disease patients for nephrolithiasis, regardless of their surgical status.