Associations of Phthalate Exposure with Adiposity and Metabolic Syndrome in US Adolescents and Adults, NHANES 2013-2018

Abstract

Abstract Background/Objective Phthalates are ubiquitous endocrine-disrupting chemicals and suspected obesogens. However, the associations with fat distribution and associated cardiometabolic complications remain unclear. Therefore, we examined the associations between phthalate exposure, body fat (total and distribution patterns), and metabolic syndrome (MetS) among US adolescents and adults. Methods We analyzed cross-sectional data from 829 adolescents and 3905 adults in the 2013-2018 National Health and Nutrition Examination Survey. Total percent body fat (%BF), visceral adipose tissue (VAT) mass, and android to gynoid (A/G) ratio were determined using dual-energy x-ray absorptiometry. Associations between molar sums of low molecular weight (∑LMW), high molecular weight (∑HMW), and di(2-ethylhexyl) phthalate (∑DEHP) metabolites, and adiposity indicators and MetS were analyzed with multivariable linear and logistic regressions. Models included sex interaction terms, were stratified by age group, and adjusted for relevant covariates. Results ∑HMW and ∑DEHP exposures were positively associated with %BF in males, and all phthalate groups were associated with greater VAT mass and A/G ratio in adolescent males. Five-fold increases in ∑HMW and ∑DEHP metabolites were associated with 21.7% (95% CI: 10.5-33.9) and 18.0% (95% CI: 7.72-29.2) greater VAT mass among adolescent males, respectively. Sex modified the relationship between ∑HMW exposure and A/G ratio among adolescents (interaction p-value = 0.0185). Phthalates were not associated with odds of MetS. When assessing individual MetS components, phthalates were associated with hyperglycemia in adult males. Conclusion Greater exposure to phthalates was associated with greater %BF in all males, and with fat distribution in adolescent males; however, phthalates were not linked to MetS.