Evaluation of Exposure to Bisphenol A, Bisphenol F, and Phthalates in Patients with Phenylketonuria and Its Differences According to Dietary Status.

Background: Phenylketonuria (PKU) is the most common amino acid metabolism disorder. Patients with blood phenylalanine (Phe) levels of ≥6 mg/dL require treatment, and the most definitive treatment is the Phe-restricted diet. Bisphenols and phthalates are widely used endocrine-disrupting chemicals (EDCs) found in personal care products, baby bottles, and food packaging.

Methods: In this study, we evaluated the possible routes of exposure to these EDCs in patients diagnosed with PKU (n = 105, 2-6 years of age) and determined the relationship between the plasma levels of bisphenol A (BPA), bisphenol F (BPF), di-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), mono-(2ethylhexyl) phthalate (MEHP), and dietary regimens. Participant characteristics and exposure routes were evaluated according to their dietary treatment status.

Results: Thirty-four of these patients were on a Phe-restricted diet, while the remaining 71 had no dietary restrictions. DBP and DEHP levels were higher in those using plastic tablecloths (p = 0.049 and p = 0.04, respectively). In addition, plasma DBP levels were higher in those who used bottled water (p = 0.01). Being under 4 years of age, using plastic food containers, and using plastic shower curtains were characteristics associated with higher MEHP levels (p = 0.027, p = 0.019, and p = 0.014, respectively). After adjustment for baseline characteristics (Model 1), the odds of having a plasma BPA level in the upper tertile were 3.34 times higher in the free-diet group (95% CI = 1.09-10.25). When we additionally adjusted for plastic exposure (Model 2), the odds ratio was found to be 18.64 (95% CI = 2.09-166.42) for BPA. In the free-diet group, the probability of having plasma DEHP levels in the upper tertile was increased by a relative risk of 3.01 (p = 0.039, 95% CI = 1.06-8.60).

Conclusion: Our results indicate that exposure to bisphenols and phthalates varies with dietary treatment. The difference in sources of exposure to EDCs between the diet and non-diet groups indicates that diet plays an important role in EDC exposure.