Aim: Nephropathy associated with aristolochic acid (AA) has been documented by human and animal studies. Ancient Chinese herbology claimed to reduce toxicity in their mixtures. It was the objective of this study to determine the risk of chronic kidney disease (CKD) associated with AA-related Chinese herbal products (CHP) or mixtures of herbs in a national cohort.
Methods: A retrospective follow-up study was conducted, using a systematic random sample (200 000 people) in the National Health Insurance reimbursement database during 1997-2002. The incidence rates of CKD and end-stage renal disease (ESRD) were calculated for the whole sample and those that had used CHP suspected to contain AA. Cox regression models were constructed to control potential confounders, including age, sex, hypertension, diabetes mellitus, and use of non-steroidal anti-inflammatory drugs and acetaminophen.
Results: A total of 199 843 persons were included in the final analysis, 102 464 (51.3%) men and 97 379 (48.7%) women, with an average incidence rate of 1964/10(6) person-years for CKD and 279/10(6) person-years for ESRD. After controlling other risk factors, the hazard ratios for development of CKD seemed to increase for patients that had consumed more than 30 g Mu-Tong, and more than 60 g Fangchi.
Conclusion: Prescription of more than 30 g Mu-Tong or more than 60 g Fangchi CHP was associated with an increased risk of developing CKD. In addition to prohibiting the use of Guan-Mu-Tong and Guang-Fangchi, patients who have used these CHP should continue to be followed up.