Many studies have shown that lipids play important roles in bone metabolism. However, the association between high-density lipoprotein cholesterol (HDL-C) and bone mineral density (BMD) is unclear. Therefore, this study aimed to investigate the linear or nonlinear relation between HDL-C levels and BMD and addressed whether the HDL-C levels had the potential values for predicting the risk of osteoporosis or osteopenia. Two researchers independently extracted all information from the National Health and Nutrition Examination Survey (NHANES) database. Participants over 20 years of age with available HDL-C and BMD data were enrolled in the final analysis. The linear relationship between HDL-C levels and BMD was assessed using multivariate linear regression models. Moreover, the nonlinear relationship was also characterized by fitted smoothing curves and generalized additive models. In addition, the odds ratio (OR) for osteopenia and osteoporosis was evaluated with multiple logistic regression models. The weighted multivariable linear regression models demonstrated that HDL-C levels displayed an inverse association with BMD, especially among females and subjects aged 30 to 39 or 50 to 59. Moreover, the nonlinear relationship characterized by smooth curve fittings and generalized additive models suggested that (i) HDL-C levels displayed an inverted U-shaped relationship with BMD among women 30 to 39 or over 60 years of age; (ii) HDL-C levels exhibited a U-shaped association with BMD among women 20 to 29 or 50 to 59 years of age. In addition, females with high HDL levels (62-139 mg/dL) had an increased risk of osteopenia or osteoporosis. This study demonstrated that HDL-C levels exhibit an inverse correlation with BMD. Especially in females, clinicians need to be alert to patients with high HDL-C levels, which may indicate an increased risk of osteoporosis or osteopenia. For these patients, close monitoring of BMD and early intervention may be necessary.

中文翻译：

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高密度脂蛋白胆固醇与骨矿物质密度呈负相关，具有潜在的骨丢失预测价值

许多研究表明，脂质在骨代谢中起重要作用。然而，高密度脂蛋白胆固醇 (HDL-C) 与骨矿物质密度 (BMD) 之间的关联尚不清楚。因此，本研究旨在研究 HDL-C 水平与 BMD 之间的线性或非线性关系，并探讨 HDL-C 水平是否具有预测骨质疏松症或骨质减少风险的潜在价值。两名研究人员独立地从国家健康和营养调查 (NHANES) 数据库中提取了所有信息。20 岁以上且拥有 HDL-C 和 BMD 数据的参与者被纳入最终分析。使用多元线性回归模型评估 HDL-C 水平和 BMD 之间的线性关系。而且，非线性关系的特征还在于拟合的平滑曲线和广义加法模型。此外，使用多重逻辑回归模型评估骨质减少和骨质疏松症的优势比 (OR)。加权多元线性回归模型表明，HDL-C 水平与 BMD 呈负相关，尤其是在女性和 30 至 39 岁或 50 至 59 岁的受试者中。此外，以平滑曲线拟合和广义加性模型为特征的非线性关系表明（ i) 30 至 39 岁或 60 岁以上女性的 HDL-C 水平与 BMD 呈倒 U 型关系；(ii) 在 20 至 29 岁或 50 至 59 岁的女性中，HDL-C 水平与 BMD 呈 U 型关联。此外，高 HDL 水平 (62-139 mg/dL) 的女性患骨质减少或骨质疏松症的风险增加。该研究表明，HDL-C 水平与 BMD 呈负相关。特别是在女性中，临床医生需要警惕高 HDL-C 水平的患者，这可能表明骨质疏松症或骨质减少的风险增加。对于这些患者，可能需要密切监测 BMD 和早期干预。