Despite well documents for manganese-induced neurological deficits, limited researches are available for effects of manganese (Mn) exposure on the bone. Here we aimed to explore the associations between long-term occupational Mn exposure and bone quality among retired workers. We conducted a cross-sectional study of 304 exposed subjects ( n , male = 161 and female = 143) and 277 control retired workers ( n , male = 65 and female = 212) recruited from a ferromanganese refinery. Self-reported occupation types were used as exposure classification confirmed by expert consultation. Bone quality was measured by quantitative ultrasound (QUS). In sex-stratified analyses throughout, stiffness index (SI) and T-score levels of the participants in the highest exposed group [tertile 3 of Mn cumulative exposure index (Mn-CEI)] were significantly lower as compared with the control group among female workers (SI, mean, 61.60 vs. 68.17; T-score, mean, −3.01 vs. −2.34, both  P  < 0.05). In addition, SI and T-score were found to be negatively associated with Mn-CEI only in the highest exposure group as compared with the female controls (both P  = 0.01). However, we did not find the significant difference for SI or T-score among the male subjects in exposure models and the male controls ( P  > 0.05). Our results suggest that female retired workers in the highest Mn-exposed model (tertile 3 of Mn-CEI) potentially experience a higher risk of developing osteoporosis compared with the female controls. Further investigations on possible mechanisms on bone quality alteration are needed in the future.

中文翻译：

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退休工人长期职业锰暴露与骨质量之间的关系

尽管有充分的文献证明锰引起的神经功能缺损，但有关锰（Mn）对骨骼的影响的研究仍很少。在这里，我们旨在探讨退休工人长期职业锰暴露与骨骼质量之间的关系。我们对304名暴露对象（ n ，男性= 161，女性= 143）和277名对照退休工人（ n ，男性= 65，女性= 212）是从一家锰铁精炼厂招募的。自我报告的职业类型用作专家咨询确认的暴露分类。通过定量超声（QUS）测量骨质量。在整个按性别进行的分层分析中，女性中暴露最高的人群[锰累积暴露指数的三分位数3（Mn-CEI）]的刚度指数（SI）和T得分水平明显低于对照组。工人（SI，平均值，61.60 vs. 68.17; T评分，平均值，-3.01 vs.-2.34，均  P  <0.05）。此外，与女性对照组相比，仅在最高暴露组中，SI和T分数与Mn-CEI负相关（均 P  = 0.01）。但是，我们在暴露模型和男性对照中未发现男性受试者的SI或T评分有显着差异（ P  > 0.05）。我们的结果表明，与女性对照组相比，处于最高Mn暴露模型（Mn-CEI的三分位数3）中的女性退休工人可能面临更高的患骨质疏松症的风险。将来需要进一步研究可能的骨质改变机制。