Background

Hepato- and nephrotoxicity of fluoride have been demonstrated in animals, but few studies have examined potential effects in humans. This population-based study examines the relationship between chronic low-level fluoride exposure and kidney and liver function among United States (U.S.) adolescents. This study aimed to evaluate whether greater fluoride exposure is associated with altered kidney and liver parameters among U.S. youth.

Methods

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2013–2016). We analyzed data from 1983 and 1742 adolescents who had plasma and water fluoride measures respectively and did not have kidney disease. Fluoride was measured in plasma and household tap water. Kidney parameters included estimated glomerular filtration rate (calculated by the original Schwartz formula), serum uric acid, and the urinary albumin to creatinine ratio. Liver parameters were assessed in serum and included alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, blood urea nitrogen, gamma-glutamyl transferase, and albumin. Survey-weighted linear regression examined relationships between fluoride exposure and kidney and liver parameters after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons.

Results

The average age of adolescents was 15.4 years. Median water and plasma fluoride concentrations were 0.48 mg/L and 0.33 μmol/L respectively. A 1 μmol/L increase in plasma fluoride was associated with a 10.36 mL/min/1.73 m² lower estimated glomerular filtration rate (95% CI: −17.50, −3.22; p = 0.05), a 0.29 mg/dL higher serum uric acid concentration (95% CI: 0.09, 0.50; p = 0.05), and a 1.29 mg/dL lower blood urea nitrogen concentration (95%CI: −1.87, −0.70; p < 0.001). A 1 mg/L increase in water fluoride was associated with a 0.93 mg/dL lower blood urea nitrogen concentration (95% CI: −1.44, −0.42; p = 0.007).

Conclusions

Fluoride exposure may contribute to complex changes in kidney and liver related parameters among U.S. adolescents. As the study is cross-sectional, reverse causality cannot be ruled out; therefore, altered kidney and/or liver function may impact bodily fluoride absorption and metabolic processes.

中文翻译：

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美国青少年的氟化物暴露与肾功能和肝功能：NHANES，2013-2016 年

背景

氟化物的肝毒性和肾毒性已在动物身上得到证实，但很少有研究探讨对人类的潜在影响。这项基于人群的研究探讨了美国青少年长期低水平氟化物暴露与肾功能和肝功能之间的关系。这项研究旨在评估美国青少年中更多的氟化物暴露是否与肾脏和肝脏参数的改变有关。

方法

这项横断面研究利用了国家健康和营养检查调查（2013-2016）的数据。我们分析了 1983 名和 1742 名青少年的数据，他们分别进行了血浆和水氟化物测量，但没有患有肾脏疾病。测量血浆和家用自来水中的氟化物。肾脏参数包括估计肾小球滤过率（通过原始施瓦茨公式计算）、血清尿酸和尿白蛋白与肌酐的比率。评估血清中的肝脏参数，包括丙氨酸转氨酶、天冬氨酸转氨酶、碱性磷酸酶、血尿素氮、γ-谷氨酰转移酶和白蛋白。调查加权线性回归检查了协变量调整后氟化物暴露与肾脏和肝脏参数之间的关系。Holm-Bonferroni 校正考虑了多重比较。

结果

青少年的平均年龄为15.4岁。水和血浆氟化物浓度中位数分别为 0.48 mg/L 和 0.33 μmol/L。血浆氟化物增加 1 μmol/L 与估计肾小球滤过率降低10.36 mL/min/1.73 m ²相关（95% CI：-17.50，-3.22； p  = 0.05），血清尿酸升高 0.29 mg/dL尿素氮浓度降低（95% CI：0.09，0.50；p  = 0.05），血尿素氮浓度降低 1.29 mg/dL（95% CI：-1.87，-0.70；p  < 0.001）。水中氟化物每增加 1 mg/L，血液尿素氮浓度就会降低 0.93 mg/dL（95% CI：-1.44，-0.42；p  = 0.007）。

结论

氟化物暴露可能导致美国青少年肾脏和肝脏相关参数发生复杂的变化。由于该研究是横断面研究，因此不能排除反向因果关系；因此，肾脏和/或肝脏功能的改变可能会影响体内氟化物的吸收和代谢过程。