Associated risk factors for chronic kidney disease of unknown etiologies in 241 patients

Background: Apart from the well-known etiologies, there are still a high proportion of patients with chronic kidney disease of unknown etiology (CKDu), which has rarely been reported on. In this study, we explored the potential associated risk factors for CKDu and identified those that occur in childhood. Methods: 700 patients with CKD we were selected randomly from 4 hospitals in Chengdu and 241 were screened for CKDu. The following clinical information was analyzed: demographic data, life style, personal and family history, nephrotoxic drugs, exposure to poison, allergies, and recurrent respiratory infections in childhood. Results: Among 700 CKD patients, 34.43% (241/700) were CKDu. Of the 241 patients, there were 67.63% (163/241) with at least 1 associated risk factor and 56.44% (92/163) with more than 1. Patients with a personal history of an associated risk factor represented the largest proportion (31.95%, 77/241), while 28.63% (69/241) of the CKDu patients had risk factors appearing in childhood. Logistic regression analysis supported the results. Conclusions: The study demonstrated that most so-called CKDu patients do have an identifiable etiology, and that several associated risk factors contribute to it. Of all the risk factors, age >60 years, nephrotoxic drugs, exposure to poison, and alcohol consumption were the independent significant factors for CKDu. Furthermore, many risk factors that caused kidney injury started in childhood.