Urinary trace elements in association with premature ovarian insufficiency and reproductive hormones in a Chinese population

Homeostasis disturbance of trace elements has been linked to adverse reproductive consequences, including premature ovarian insufficiency (POI) in women, but limited evidence has been reported so far. This case-control study evaluated the associations between 5 common urinary trace elements [copper (Cu), manganese (Mn), Iron (Fe), Selenium (Se), and zinc (Zn)] and the odds for POI. Urinary concentrations of these 5 metals and serum levels of POI-related reproductive hormones of 169 cases and 209 healthy controls were measured. The urinary levels of Cu and Se in women with POI were significantly higher than those in the controls. The positive associations were observed between Cu levels and the odds of POI [for the medium tertile: odds ratio (OR) = 3.79, 95% CI: 1.98-7.27, p < 0.001; for the highest tertile: OR = 3.85, 95% CI: 2.00-7.41, p < 0.001]. The highest tertile of urinary Se levels was associated with increasing POI risk (for the highest tertile: OR = 2.54, 95% CI: 1.38-4.70, compared with the lowest tertile, p for trend = 0.001). In POI patients, urinary concentrations of Zn and Fe were negatively associated with serum levels of follicle-stimulating hormone (FSH). Our findings suggested that higher exposure levels of Cu and Se might lead to an increased risk of POI.