ASPO Abstracts
Exposure to phthalates and its association with body mass index
Category: Molecular Epidemiology & Environment, Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2018
Abstract Body:
Phthalates, endocrine-disrupting chemicals used as plasticizers in consumer products, are hypothesized to increase obesity and, as a result, risk of obesity-related cancers. However, findings are not consistent across studies. Identifying whether exposure to phthalates impact obesity is critical for understanding the pathways by which phthalates may affect cancer risk. We performed a cross-sectional analysis of 1,257 women aged 50-79 years selected from the Women’s Health Initiative. Urinary levels of thirteen phthalate metabolites (PMs) were measured using high performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Trained study personnel measured participants’ weight and height at in-person clinic visits. Body mass index (BMI; weight (kg)/height squared (m2)) was categorized as: under/normal weight (<24.9 kg/m2), overweight (25.0—29.9 kg/m2), and obese (30.0 kg/m2). Multinominal logistic regression analysis was used to estimate associations between each PM, categorized in quartiles, and BMI, with adjustment for urinary creatinine, age, race/ethnicity, alcohol use, physical activity, smoking status, healthy eating index, dietary energy intake, hormone replacement therapy, income and education level. Compared to women in the 1st quartile (Q1) of the PM’s distribution, those in the 4th quartile (Q4) were more likely to be overweight and obese: e.g., mono-carboxyoctyl phthalate (MCOP; p<0.001; OR 2.8, 95%CI 1.7-4.5 and OR 2.7, 95%CI 1.5-4.7, respectively), mono-2-ethyl-5-hidroxyhexyl phthalate (MEHHP; p<0.05; OR 2.0, 95%CI 1.2-3.4 and OR 2.8, 95%CI 1.6-5.0, respectively), monoisobutyl phthalate (MiBP; p<0.05; OR 2.0, 95%CI 1.2-3.3 and OR 2.1, 95%CI 1.2-3.7, respectively). Mono-hydroxybutyl phthalate (MHBP) was significantly inversely associated with obesity (OR 0.6, 95%CI 0.3-0.9 for Q4 vs Q1). We observed positive associations between several PMs and obesity in this cross-sectional study, which suggests that environmental exposure to PMs may be relevant to the ongoing obesity epidemic. However, we also observed an inverse association with MHBP, underscoring the need to examine each PM independently. Future prospective studies are necessary to deepen our understanding of how phthalates relate to obesity and obesity-related cancers.
Keywords: Phthalate metabolites overweight obesity endocrine-disruptors obesity-related cancer