The Potential Biomarker of Di(2-ethylhexyl) Phthalate Exposure during Catheterization.

BACKGROUND: Di(2-ethylhexyl) phthalate (DEHP) may produce toxicity, posing a risk to human health. Medical devices composed of DEHP are frequently used in catheterization, but few studies have investigated DEHP exposure during catheterization. The aim of this prospective series was to characterize the exposure pattern of DEHP during catheterization.

METHODS: We enrolled 16 patients with congenital heart disease undergoing catheterization. Collection of urine was done to measure DEHP metabolites on hospitalization, before catheterization, after catheterization, and at discharge. The following DEHP metabolites were measured: mono-(2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and the ratio of MEHP to overall metabolites (MEHP%) was determined. DEHP exposure from polyvinyl chloride (PVC)-containing catheter and infusion systems were recorded in detail. Differences in DEHP levels before and after catheterization were analyzed.

RESULTS: Urinary levels of MEHP, MEHHP, and MEOHP significantly decreased from before catheterization to after catheterization (all p < 0.01), but did not change significantly from initial hospitalization to before catheterization. Urinary MEHP% significantly decreased from initial hospitalization to before catheterization (p < 0.001), then increased after catheterization (p < 0.001), and decreased gradually at discharge (p = 0.03). Urinary MEHP% after catheterization and at discharge was significantly positively related to the duration of using PVC-containing catheter systems. There was a significant positive correlation between urinary MEHP% and the duration of using PVC-containing infusion system before catheterization, and a borderline significant correlation at both post-catheterization time slots.

CONCLUSIONS: Our results demonstrated that urinary MEHP% may be a potential biomarker of DEHP contamination from the use of PVC-containing catheters or infusion systems.