Background: Phthalates are an endocrine-disrupting chemical which leech from plastics, and is associated with metabolic syndrome. Associations change based on demographic profile such as age and sex. Exposure can be reduced by modifying diet and personal care product consumption. More research is needed to determine which sex-age subgroups are most at-risk for metabolic syndrome from phthalates.

Objectives: We examined associations between phthalates and metabolic syndrome among specific sex-age groups, men and women aged 20-39, 40-59, and 60-years and over.

Methods: Adult (≥ 20-years) participants (n=5218) in NHANES 2001-2016 were analyzed. Five urinary phthalate metabolites (MBzP, MEP, MiBP, MnBP, MCPP) and DEHP metabolites (ΣDEHP) were measured by the CDC. Metabolite concentrations were evaluated at population-specific quartiles, with Q1 as referent quartile. Presence of metabolic syndrome was defined by the Adult Treatment Panel III’s criteria. Survey weights were readjusted to correct for differential selection probabilities in NHANES. Adjusted odds ratios (aOR) and 95% confidence intervals were calculated using multiple logistic regression models, which adjusted for confounders. Data management and statistical analysis were performed with SAS v9.4 and SUDAAN v11.03.

Results: Geometric means of the six phthalate metabolites did not significantly vary by metabolic syndrome. After adjustments, in MBzP 40-59-year-old women had significantly higher odds of metabolic syndrome for Q2 (aOR=1.92; 95%CI: 1.14–3.23), Q3 (3.44;1.99–5.95), and Q4 (3.62;1.89–6.96). In ∑DEHP, 40-59-year-old men had higher odds at Q2 (1.75;1.02–3.01), Q3 (1.47;0.85–2.54),and Q4 (2.68;1.51–4.77).

Conclusion: Higher concentrations of MBzP and ΣDEHP was associated with increased odds of metabolic syndrome in 40-59-year-old women and men, respectively.