Association of diethylhexyl phthalate with obesityrelated markers and body mass change from birth to 3 months of age

Background Several studies have suggested potential links of phthalates to obesity in children and adults. Limited evidence, however, has been available for the relations between diethylhexyl phthalate (DEHP) and obesity-related markers or body mass change in early life. Methods 128 healthy pregnant women were recruited and, after delivery, their newborns' first urine and umbilical cord blood samples were collected. We measured urinary levels of two DEHP metabolites, mono- (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono- (2-ethyl-5-oxohexyl) phthalate (MEOHP). We also measured the levels of leptin, total cholesterol and triglyceride (TG) in cord serum, and used them along with weight, length, head circumference and ponderal index (PI, 100 g/cm³) at birth, as obesity-related markers, and estimated the relations between DEHP metabolites and obesity-related markers using generalised linear models. For the evaluation of body mass increase by early life DEHP exposure, body mass index (BMI) z-score change during 3 months after birth by DEHP metabolites in the first urine samples of the newborns were evaluated using logistic regression. Results DEHP exposure was associated with decrease of PI and increase of TG (PI, β=-0.11, p=0.070 and TG, β=0.14, p=0.027), especially for boys (PI, β= -0.13, p=0.021; and TG, β=0.19, p=0.025). Moreover, DEHP exposure was positively associated with body mass increase during 3 months after birth (change of BMI z-scores, OR=4.35, p=0.025). Conclusions Our findings suggest that DEHP exposure may affect body mass change in early life through changes of obesity-related markers.