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Melamine-tainted milk product-associated urinary stones in children
Zheng Wang1, Hong Luo, Wenwei Tu
1West China Second University Hospital, Sichuan University, Chengdu, China.
Insights
Melamine-tainted milk products (MTMP) caused urinary stones in young children. Higher melamine levels and lower family income were risk factors for severe MTMP-associated kidney stones.
Area of Science:
- Pediatric Nephrology
- Toxicology
- Public Health
Background:
- A 2008 outbreak in China linked urinary stones to melamine-tainted milk products (MTMP).
- This study investigated clinical features and risk factors in affected children.
Purpose of the Study:
- To identify clinical characteristics of children with MTMP-associated urinary stones.
- To determine risk factors contributing to the development and severity of these stones.
Main Methods:
- Renal ultrasound screening of 7328 children presenting with suspected urinary stones.
- Analysis of clinical data, family history, feeding patterns, and stone composition.
Main Results:
- Urinary stones were found in 2.58% of children (189/7328), with 51 admitted.
- Younger age (1-3 years) and high melamine content (>5500 mg/kg) in MTMP were significant risk factors.
- Lower family income correlated with increased risk of inpatient care.
Conclusions:
- MTMP-associated urinary stones disproportionately affect young children.
- Severity of stones is linked to socioeconomic factors, with poorer families experiencing more severe outcomes.
Background:
An outbreak of urinary stones related to consumption of melamine-tainted milk products (MTMP) occurred in China in 2008. The aim of the present study was to evaluate such children to identify their clinical features and risk factors.
Methods:
Renal ultrasound was performed for 7328 children who presented to a Sichuan teaching hospital between 13 September and 15 October 2008 due to concern of such stones. Clinical data, family information, feeding history and urinary stones were analyzed.
Results:
Of the 7328 children, 189 (2.58%) had ultrasound findings of urinary stones, and 51 were admitted. Age (mean ± SD) was 27.4 ± 25.5 months, and 101 were male and 88, female. The odds ratio (OR) for urinary stones for infants and young children (1-3 years) as compared to older children (>3 years), was 2.42 (95% confidence interval [CI], 1.64-3.56; P < 0.0001) and 1.95 (95%CI, 1.31-2.89; P < 0.0011), respectively. Independent risk factors associated with urinary stones included consumption of MTMP with melamine at > 5500 mg/kg (OR, 13.3; 95%CI, 6.8-26.1, P < 0.0001) as compared to that with melamine at < 200 mg/kg, and younger father (P = 0.0006). On logistic regression, the only risk factor associated with inpatient care was lower family income per person (OR, 4.4; 95%CI, 1.2-15.9, P = 0.02). Repeat ultrasound for 51 children at mean follow up of 15.3 ± 8.9 days found that 33 passed out all stones, which was associated with a larger number of smaller stones (P = 0.003). Urinary stones contained melamine and uric acid, but no cyanuric acid.
Conclusions:
MTMP-associated urinary stones were more frequent in young children and more severe in children from poorer families.
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