Relationships among Exposure to Environmental Pollutants, Endogenous Hormones, and Kidney Disease Risk

Chronic kidney disease (CKD) is a significant public health problem. Environmental factors may impact the development and progression of CKD; however, neither the factors related to progression nor the mechanisms of action have been well elucidated. Our aim was to examine the associations among measured levels of endogenous hormones, persistent organic pollutants (POPs), and parameters of kidney function using cross-sectional and longitudinal data from the National Health and Nutrition Examination Survey (NHANES) and the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Two of our analyses evaluated the cross-sectional and prospective associations of endogenous levels of pituitary, sex-steroid, and thyroid hormones with measures of kidney health within a cohort of Hispanic and Latino adults. We showed that circulating levels of thyroid stimulating hormone (TSH) were inversely associated with estimated glomerular filtration rate (eGFR) and positively associated with incident albuminuria. Among post-menopausal females, luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations were inversely associated with eGFR cross-sectionally and LH was inversely associated with odds of incident albuminuria. Among males, LH was inversely associated with eGFR and positively associated with urinary albumin to creatinine ratio (UACR) and odds of albuminuria at baseline, but longitudinal associations were not significant. Among males, free testosterone was inversely associated with UACR cross-sectionally, and total testosterone was inversely associated eGFR longitudinally. We then evaluated the cross-sectional and prospective associations of POPs with measures of kidney health using the HCHS/SOL data. Polychlorinated biphenyl (PCB) concentrations were associated with small increases in UACR over time. Concentrations of 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (DDE) were associated with lower levels of UACR over time. When we used cross-sectional data from the NHANES, we found that PCB concentrations were positively associated with eGFR and UACR among males, and concentrations of heptachlor epoxide were associated with increased odds of low eGFR among both sexes. Future investigation of these data will include interaction and mediation analyses. Our results require further validation and reproduction in additional cohorts but suggest that POPs and endogenous hormones are involved in the pathology of CKD.