title: [A cohort study of longer-term impact of melamine contaminated formula on infant health].
abstract: OBJECTIVE
  To prospectively evaluate the health status of infants with exposure to melamine-contaminated milk formula prior to September 2008.
  
  
  METHODS
  The cohort study was conducted in an area close to the manufacturer of Sanlu dairy products. There were three groups (n = 47 each). In September 2008, the exposure group I included infants with exposure to melamine and a diagnosis of renal abnormalities, the exposure group IIhad exposure to melamine but there was no diagnosis of renal abnormalities and the non-exposure group had no exposure to melamine. The exposure II and non-exposure groups were matched with those of exposure group I by birthplaces, gender and date of birth ( ± 3 months). Kidney function tests (urea nitrogen, serum creatinine, uric acid, serum albumin, β2-microglobulin and cystatin C), liver function tests (alanine aminotransferase and aspartate aminotransferase), growth and development assessment and urinary system ultrasonography were implemented between November 2011 and June 2012. The analysis of covariance (least significant difference method) was performed to compare the differences of relevant variables among three groups.
  
  
  RESULTS
  The urinary system ultrasonography showed that all abnormalities disappeared in exposure group I and all infants of another two groups had normal ultrasonography. There were statistically significant differences in serum uric acid and albumin of kidney function in exposure group I, exposure group II and non-exposure group ((344 ± 75) and (338 ± 98) and (282 ± 69) µmol/L , (47 ± 5) and (47 ± 6) and (43 ± 5) g/L, all P < 0.05) among three groups. However the differences in the remaining markers of kidney function, markers of liver function and Z scores of weight-for-age and height-for age were all statistically insignificant (all P > 0.05). Further pair-wise comparisons showed that the levels of serum uric acid and albumin in exposure group I were higher than those in non-exposure group (P = 0.001 and 0.010). And the levels of serum uric acid and albumin in exposure group II were also higher than those in non-exposure group (P = 0.003 and 0.005).
  
  
  CONCLUSIONS
  All affected infants have recovered from kidney abnormalities. Early infant exposure to melamine-contaminated milk formula appears to have no obvious impact on liver function and growth. But its potential impact on kidney function should be further assessed.
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Pei-xin
authors.initials: PX
authors.lastname: Wang
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Hong-tian
authors.initials: HT
authors.lastname: Li
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Lin-lin
authors.initials: LL
authors.lastname: Wang
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Yu-bo
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Institute of Reproductive & Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China. Email: liujm@pku.edu.cn.
authors.forename: Jian-meng
authors.initials: JM
authors.lastname: Liu
mesh_terms: D000418:Albumins / Q000032:analysis; D016022:Case-Control Studies; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005506:Food Contamination; D006801:Humans; D007223:Infant; D041943:Infant Formula; D007668:Kidney / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007677:Kidney Function Tests; D008099:Liver / Q000503:physiopathology; D008111:Liver Function Tests; D008297:Male; D011446:Prospective Studies; D014227:Triazines / Q000633:toxicity*; D014463:Ultrasonography; D014527:Uric Acid / Q000097:blood
chemical_list: D000418:Albumins; D014227:Triazines; D014527:Uric Acid; C011907:melamine