Risk factors for acute kidney injury (AKI) in infants with melamine-associated urolithiasis and follow-up: A multi-center retrospective analysis

An epidemic of urinary tract stones was noted among infants in China, 2008. This event was believed to be associated with consumption melamine-contaminated powdered formula. The patients with symptoms and clinical manifests had already been analyzed in our previous studies. In this study, our aim is to investigate the risk factors of melamine-associated acute kidney injury (AKI) and the potential relationship toward children growth in our five years follow-up. A total of 619 infants with melamine-associated urolithiasis were admitted into 20 different hospitals in the Gansu province, China. All clinical data were divided into AKI and control groups according to the occurrence of AKI. Univariate and multivariate analyses were performed with a logistic regression model to assess the independent risk factors of AKI. Logistic regression analysis revealed that the odds ratio (OR) of AKI was 19.62 in the group of infants who consumed Sanlu® milk powdered infant milk formula. A higher prevalence of AKI was observed in infants age of 6-11 months (OR: 9.59, p < 0.01) and 12-17 months (OR: 5.06, p < 0.01). Multivariate analysis also indicated that any one symptoms of upper respiratory tract infection (URTI), diarrhea, dehydration and fever (OR: 4.29, p < 0.01) were independent risk factors of AKI. Therefore, this study demonstrated that high melamine infant formula (Sanlu® milk powdered infant formula), age (6-17 months) and symptoms of URTI, diarrhea, dehydration or fever were risk factors of AKI in infants with melamine-associated urolithiasis.