Melamine increases the apparent protein content of foods because of its high nitrogen content. This was probably the reason behind the recent contamination of infant formula milks with melamine in China. Researchers in Beijing have reported their findings in 589 children screened for urinary tract stones after possible exposure to melamine-contaminated formula milk.
Of 589 children aged up to 36 months examined, 421 had received contaminated formula. On ultrasonography, 50 children had definite urinary tract stones. Eight of these had not been given the melamine-containing formula. One hundred and twelve had suspected stones and 427 no stones. Children with stones, suspected stones and no stones were equally likely to have haematuria (6%) or pyuria (3%). Glomerular function was abnormal in 10% of children with stones. Children given a high-melamine formula had a sevenfold increase in risk of stones. Prematurity was also associated with increased risk of stones. Further data are provided from Hong Kong and Taiwan in letters to the editor.
Melamine-contaminated formula increased the risk of renal tract stones.
Guan N, et al. Melamine-contaminated powdered formula and urolithiasis in young children. NEJM 2009;360:1067–1074; Langman CB. Melamine, powdered milk, and nephrolithiasis in Chinese infants. Ibid: 1139–1141 (editorial); Ho SSY, et al. Ultrasonographic evaluation of melamine-exposed children in Hong Kong. Ibid: 1156–1157 (letter); Wang I-J, et al. Melamine and nephrolithiasis in children in Taiwan. Ibid: 1157–1158 (letter).