Urinary phthalates and body mass index in preschool children: The MIREC Child Development Plus study
- DOI
- Language of the publication
- English
- Date
- 2021-01-11
- Type
- Article
- Author(s)
- Ashley-Martin, Jillian
- Dodds, Linda
- Arbuckle, Tye E.
- Lanphear, Bruce P.
- Muckle, Gina
- Foster, Warren G.
- Ayotte, Pierre
- Zidek, Angelika
- Asztalos, Elizabeth
- Bouchard, Maryse F.
- Kuhle, Stefan
- Publisher
- Elsevier
Abstract
Childhood exposure to phthalates, a class of chemicals with known reproductive and developmental effects, has been hypothesized to increase the risk of obesity, but this association is not well understood in preschool children. We examined the association between urinary concentrations of phthalate metabolites and concurrently measured body mass index (BMI) and skinfolds among children between the ages of two and five years. We collected anthropometric measures and biomonitoring data on approximately 200 children enrolled in the Maternal-Infant Research on Environmental Chemicals Child Development Plus study. We measured 22 phthalate metabolites in children's urine and used the 19 metabolites detected in at least 40% of samples. Our primary outcome was BMI z-scores calculated using the World Health Organization growth standards. Skinfold z-scores were secondary outcomes. We used multivariable linear regression to evaluate the association between tertiles of phthalate concentrations and each anthropometric measure. We also used weighted quantile sum regression to identify priority exposures of concern. Our analytic sample included 189 singleton-born children with complete anthropometric data. Children with concentrations of the parent compound di-n-butyl phthalate (∑DnBP) in the third tertile had 0.475 (95% CI: 0.068, 0.883) higher BMI z-scores than those in the lower tertile. ∑DnBP was identified as a priority exposure in the weighted quantile sum regression BMI model. In this population of Canadian preschool aged children, we identified DnBP as a potential chemical of concern in regard to childhood obesity. Future research with serial phthalate measurements and anthropometric measurements in young children will help confirm these findings.
Plain language summary
"Health Canada helps to protect the health of Canadians by assessing and managing the risks associated with exposure to environmental chemicals. Phthalates are a group of chemicals used in plastics to soften and increase flexibility. Some research has suggested that childhood exposure to phthalates may increase the risk of obesity. The objective of this study was to examine the association between phthalates and markers of obesity among young children in the MIREC study. When the child was between 2 and 5 years of age, a urine sample was collected and analysed for phthalates. At the same time, the child’s height, weight and skin-fold thickness was measured. Body mass index (BMI) was calculated as kg/m2 where kg is the child’s weight in kilograms and m2 is their height in metres squared. Skin-fold thickness of the triceps (back side middle upper arm) and subscapular (under the lowest point of the shoulder blade) were measured. Data were available for 189 singleton children. This study found that children with higher concentrations of di-n-butyl phthalate had higher BMI. Over 90% of the children had detectable concentrations of this phthalate in their urine. In this population of Canadian preschool aged children, this phthalate may be associated with childhood obesity. However, this study has a number of limitations which lessen its ability to study causes of obesity. Future studies should collect multiple urine samples over time to estimate phthalate exposure and measure child growth as the child ages."
Subject
- Health,
- Health and safety