Associations of urinary polycyclic aromatic hydrocarbons with age at natural menopause in U.S. women aged 35-65, NHANES 2003-2012.

Polycyclic aromatic hydrocarbons (PAHs) mediated ovarian toxicity has been demonstrated in animal experiments. However, this issue has not been assessed in humans. Based on the National Health and Nutrition Examination Survey (NHANES) 2003-2012, data analysis was restricted to 1221 general U.S. women aged 35-65 years with complete data of interest. Levels of nine PAH metabolites in spot urine specimens were measured by isotope dilution gas chromatography/tandem mass spectrometry (GC-MS/MS). Self-reported information on the menopause status and age at menopause were obtained during interview. Cox proportional hazards regression was employed to assess the associations between PAH levels and natural menopause. Compared with women in the first quartile, subjects in the highest quartile of 1-Hydroxynapthalene [hazard ratio (HR) = 1.46, 95% confidence interval (CI) = 1.06 to 2.011, 2-Hydroxynapthalene (HR = 1.51, 95% CI = 1.12 to 2.05) and 3-Hydroxyfluorene (HR = 1.51, 95% CI = 1.06 to 2.16), or in the second quartile of 9-Hydroxyfluorene (HR = 1.53, 95% CI = 1.05 to 2.22), had elevated risks of earlier onset of natural menopause. Our findings suggested positive associations between urinary PAH levels and earlier age at natural menopause in the general U.S. women. Prospective studies are warranted to confirm the causality in the future. (C) 2018 Elsevier Ltd. All rights reserved.