Abstract：
OBJECTIVE: The systemic illnesses associated with chronic lead exposure are partially explained by the interaction between lead and calcium metabolism. Lead exposure is posited to alter calcium levels either by altering calcium homeostasis markers or altering bone remodeling. The present study investigated the interaction between blood lead levels and calcium homeostasis markers and bone remodeling markers among lead-smelting plant workers.
METHODS: Adult male workers employed at the lead-smelting plant were clinically investigated as part of their regular occupational health assessment program. Additionally, control participants without occupational lead exposure, employed in administrative and white-collar jobs were invited to participate in the study. Sociodemographic and occupational details were collected by pre-standardized semi-structured questionnaires from all consenting participants, followed by clinical examination and blood collection. Blood lead levels were estimated using microwave-assisted acid digestion and the inductively coupled plasma mass spectrometry technique. Serum calcium and total protein and alkaline phosphatase levels were estimated as per standard biochemical techniques. 25-hydroxy vitamin-D3, calcitriol, and osteocalcin were estimated using the enzyme-linked immunosorbent assay. In addition to comparative analysis for comparing the two groups, independent linear regression models were explored to investigate the associations between serum calcium and blood lead and osteocalcin levels.
RESULTS: A total of 189 lead-exposed men employed at the lead-smelting plant and 25 male control participants consented to participate. The two groups were similar in age, diet, and body mass index. Occupationally exposed individuals exhibited significantly lower serum calcium and higher bone remodeling markers (osteocalcin and alkaline phosphatase) as compared to controls. However, the serum 25-hydroxy vitamin-D3 and calcitriol levels were not significantly different between the two groups. Lastly, the serum lead and osteocalcin were weakly but significantly associated with serum calcium levels after controlling for variations in total protein, diet, 25-hydroxy vitamin-D3, calcitriol, and alkaline phosphatase in the study participants.
CONCLUSIONS: Current observations reinforce the adverse role of lead exposure on calcium metabolism. Although lead exposure is posited to affect calcium metabolism by multiple pathways, current study observations favor the bone remodeling pathway. The observations recommend periodic screening for calcium and bone health among lead-exposed adults.
METHODS: Adult male workers employed at the lead-smelting plant were clinically investigated as part of their regular occupational health assessment program. Additionally, control participants without occupational lead exposure, employed in administrative and white-collar jobs were invited to participate in the study. Sociodemographic and occupational details were collected by pre-standardized semi-structured questionnaires from all consenting participants, followed by clinical examination and blood collection. Blood lead levels were estimated using microwave-assisted acid digestion and the inductively coupled plasma mass spectrometry technique. Serum calcium and total protein and alkaline phosphatase levels were estimated as per standard biochemical techniques. 25-hydroxy vitamin-D3, calcitriol, and osteocalcin were estimated using the enzyme-linked immunosorbent assay. In addition to comparative analysis for comparing the two groups, independent linear regression models were explored to investigate the associations between serum calcium and blood lead and osteocalcin levels.
RESULTS: A total of 189 lead-exposed men employed at the lead-smelting plant and 25 male control participants consented to participate. The two groups were similar in age, diet, and body mass index. Occupationally exposed individuals exhibited significantly lower serum calcium and higher bone remodeling markers (osteocalcin and alkaline phosphatase) as compared to controls. However, the serum 25-hydroxy vitamin-D3 and calcitriol levels were not significantly different between the two groups. Lastly, the serum lead and osteocalcin were weakly but significantly associated with serum calcium levels after controlling for variations in total protein, diet, 25-hydroxy vitamin-D3, calcitriol, and alkaline phosphatase in the study participants.
CONCLUSIONS: Current observations reinforce the adverse role of lead exposure on calcium metabolism. Although lead exposure is posited to affect calcium metabolism by multiple pathways, current study observations favor the bone remodeling pathway. The observations recommend periodic screening for calcium and bone health among lead-exposed adults.
摘要：
目的：与慢性铅暴露相关的全身性疾病部分解释为铅和钙代谢之间的相互作用。铅暴露可以通过改变钙稳态标志物或改变骨重塑来改变钙水平。本研究调查了铅冶炼厂工人中血铅水平与钙稳态标志物和骨重塑标志物之间的相互作用。
方法：作为常规职业健康评估计划的一部分，对铅冶炼厂雇用的成年男性工人进行了临床调查。此外,没有职业性铅暴露的控制参与者，从事行政和白领工作的人被邀请参加这项研究。社会人口统计学和职业细节通过预先标准化的半结构化问卷从所有同意的参与者收集，然后进行临床检查和采血。使用微波辅助酸消化和电感耦合等离子体质谱技术估算血铅水平。根据标准生化技术估计血清钙和总蛋白和碱性磷酸酶水平。25-羟基维生素D3，骨化三醇，和骨钙蛋白使用酶联免疫吸附测定法进行估算。除了比较分析比较两组，采用独立的线性回归模型研究血清钙与血铅和骨钙蛋白水平之间的关系.
结果：共有189名接触铅的男性受雇于铅冶炼厂，25名男性对照参与者同意参加。两组年龄相似,饮食，和体重指数。与对照组相比，职业暴露的个体表现出明显较低的血清钙和较高的骨重塑标志物（骨钙蛋白和碱性磷酸酶）。然而,两组血清25-羟维生素D3和骨化三醇水平无显著差异.最后,在控制总蛋白变化后，血清铅和骨钙蛋白与血清钙水平弱但显著相关，饮食，25-羟基维生素D3，骨化三醇，和研究参与者的碱性磷酸酶。
结论：目前的观察结果加强了铅暴露对钙代谢的不利作用。尽管铅暴露可能通过多种途径影响钙代谢，目前的研究观察有利于骨重建途径。观察结果建议定期筛查暴露于铅的成年人的钙和骨骼健康。
方法：作为常规职业健康评估计划的一部分，对铅冶炼厂雇用的成年男性工人进行了临床调查。此外,没有职业性铅暴露的控制参与者，从事行政和白领工作的人被邀请参加这项研究。社会人口统计学和职业细节通过预先标准化的半结构化问卷从所有同意的参与者收集，然后进行临床检查和采血。使用微波辅助酸消化和电感耦合等离子体质谱技术估算血铅水平。根据标准生化技术估计血清钙和总蛋白和碱性磷酸酶水平。25-羟基维生素D3，骨化三醇，和骨钙蛋白使用酶联免疫吸附测定法进行估算。除了比较分析比较两组，采用独立的线性回归模型研究血清钙与血铅和骨钙蛋白水平之间的关系.
结果：共有189名接触铅的男性受雇于铅冶炼厂，25名男性对照参与者同意参加。两组年龄相似,饮食，和体重指数。与对照组相比，职业暴露的个体表现出明显较低的血清钙和较高的骨重塑标志物（骨钙蛋白和碱性磷酸酶）。然而,两组血清25-羟维生素D3和骨化三醇水平无显著差异.最后,在控制总蛋白变化后，血清铅和骨钙蛋白与血清钙水平弱但显著相关，饮食，25-羟基维生素D3，骨化三醇，和研究参与者的碱性磷酸酶。
结论：目前的观察结果加强了铅暴露对钙代谢的不利作用。尽管铅暴露可能通过多种途径影响钙代谢，目前的研究观察有利于骨重建途径。观察结果建议定期筛查暴露于铅的成年人的钙和骨骼健康。
