Exposure to heavy metals and hormone levels in midlife women: The Study of Women's Health Across the Nation (SWAN)

• Published in: Environmental pollution (1987) 2023-01, Vol.317, p.120740-120740, Article 120740
• Main Authors: Wang, Xin, Ding, Ning, Harlow, Siobán D., Randolph, John F., Mukherjee, Bhramar, Gold, Ellen B., Park, Sung Kyun
• Format: Article
• Language: English
• Subjects: Arsenic; Bayes Theorem; Cadmium; Estradiol; Female; Follicle Stimulating Hormone; Gonadal Steroid Hormones; Heavy metals; Humans; Lead; Mercury; Metals, Heavy; Prospective Studies; Sex hormones; Testosterone; Women's Health
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.120740

Exposure to heavy metals may alter the circulating levels of sex hormones. However, epidemiologic studies on heavy metals and sex hormones have been limited, and results have been inconsistent. We assessed the associations of heavy metals assayed in urine, including arsenic, cadmium, lead, and mercury, with repeated measures of serum estradiol (E2), follicle-stimulating hormone (FSH), testosterone, and sex hormone-binding globulin (SHBG) levels in the Study of Women's Health Across the Nation Multi-Pollutant Study. The sample included 1355 White, Black, Chinese, and Japanese women, aged 45–56 years at baseline (1999–2000), whose serum hormone levels were repeatedly measured through 2017. Urinary metal concentrations were measured at baseline. Linear mixed effect models were used to calculate percent changes in serum hormone levels per doubling of urinary metal concentrations, adjusting for demographics, socioeconomic status, lifestyle, health-related factors, and urinary creatinine. After multivariable adjustment, a doubling of urinary metal concentration was associated with lower E2 levels by 2.2% (95% CI: 4.0%, −0.3%) for mercury and 3.6% (95% CI: 5.7%, −1.6%) for lead; higher FSH levels by 3.4% (95% CI: 0.9%, 5.9%) for lead; and higher SHBG levels by 3.6% (95% CI: 1.3%, 5.9%) for cadmium. The overall joint effect using the Bayesian kernel machine regression showed that metal mixtures were inversely associated with E2 and positively associated with FSH levels. No association was found between metals and testosterone levels. Results from this prospective cohort study demonstrate that environmental heavy metal exposures, including cadmium, mercury, and lead, may disturb circulating levels of E2, FSH, and SHBG in midlife women. [Display omitted] •Heavy metal exposures disrupted sex hormone levels in midlife women.•Lead was associated with lower E2 and higher FSH levels.•Mercury was associated with lower E2 levels.•Cadmium was associated with higher SHBG levels.