ESPE Abstracts

Background and aim: Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals found in everyday consumer products. These chemicals are considered endocrine disruptive. However, their effect on pubertal onset and development is still unclear. The aim of the current study was therefore to explore the relationship between PFAS exposure and pubertal development using novel objective pubertal phenotyping, e.g., ultrasound-determined testicular volume and ultrasound-based breast staging collected in the Bergen Growth Study 2 (BGS2).

Material and Methods: BGS2, conducted in 2016, was the first Norwegian pubertal reference study. Pubertal status was assessed with Tanner staging and ultrasound measurements in a cross-sectional sample of 301 boys and 200 girls (8-16 years). In addition, serum samples were analyzed for 19 different PFAS. Testicular volume-for-age z-scores were calculated for boys, and girls were classified as early (n= 32), average (n= 106), or late maturing (n= 62) based on ultrasound-measured breast development-for-age percentiles. To examine the associations between PFAS levels and age-adjusted degree of pubertal development, linear regression and logistic regression analysis were applied in boys and girls, respectively, and adjusted for age, height and educational level of parents.

Results: Perfluorooctanoic acid (PFOA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorohexanesulfonic acid (PFHxS) and perfluorooctanesulfonic acid (PFOS) were included in the analyzes as all had more than 90% of the samples above the limit of quantification. Boys with higher levels of PFNA (estimated beta coefficient (β), -0.14, 95% confidence interval [CI], -0.62 to 0.03) and PFOS (β, -0.17, 95%CI, -0.19 to -0.01) were more likely to be late maturing. In girls, higher levels of PFOA were associated with a reduced odds of being early compared to average and late maturing (OR: 0.13, 95%CI: 0.02, 0.89), and higher levels of PFNA was associated with an increased odds of being late compared to early and average maturing (OR: 3.14, 95%CI: 1.17, 8.43). No other associations were significant at a 0.05 level.

Conclusions: Higher levels of PFAS were associated with being late maturing in both sexes based on age-adjusted ultrasound puberty scores.