Department of Urology, The Affiliated Second Hospital, Hengyang Medical school, University of South China, Hengyang, China.
Henan University, School of nursing and Health, Kaifeng, China.
Medicine (Baltimore). 2023 Oct 27;102(43):e35674. doi: 10.1097/MD.0000000000035674.
The association between coffee intake and bone mineral density (BMD) remains a subject of debate in epidemiological research. Furthermore, the potential relationship between BMD and urine caffeine or caffeine metabolites has not yet been explored. Therefore, the present study aimed to investigate the possible association between BMD and urine caffeine and its metabolites in U.S. adults. We employed multivariate linear and logistic regression models to analyze the relationship between urine caffeine and caffeine metabolites and lumbar BMD using data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014. Additionally, fitted smoothing curves and generalized additive models were used. After adjusting for several factors, we found no significant association between urine caffeine and its metabolites and BMD. However, subgroup analyses stratified by gender and ethnicity showed that the relationship between urine caffeine and its metabolites and lumbar BMD remained consistent. Our investigation revealed that the inflection points for the U-shaped relationship between urinary theophylline and paraxanthine and BMD were observed at levels of 0.006 mmol/L for theophylline and 0.052 mmol/L for paraxanthine. In this cross-sectional study, we found no significant correlation between urine caffeine and its metabolites and BMD. However, more research is required to confirm our findings, as well as to investigate the underlying mechanisms.
咖啡摄入量与骨密度（BMD）之间的关系在流行病学研究中仍然存在争议。此外，BMD 与尿咖啡因或咖啡因代谢物之间的潜在关系尚未得到探索。因此，本研究旨在调查美国成年人中 BMD 与尿咖啡因及其代谢物之间可能存在的关联。我们使用多变量线性和逻辑回归模型，利用 2009 年至 2014 年国家健康和营养检查调查（NHANES）的数据，分析了尿咖啡因及其代谢物与腰椎 BMD 之间的关系。此外，还使用了拟合平滑曲线和广义加性模型。在调整了几个因素后，我们没有发现尿咖啡因及其代谢物与 BMD 之间存在显著关联。然而，按性别和种族分层的亚组分析表明，尿咖啡因及其代谢物与腰椎 BMD 之间的关系仍然一致。我们的研究表明，在尿茶碱和对黄嘌呤之间 U 形关系的转折点处，茶碱的水平为 0.006mmol/L，对黄嘌呤的水平为 0.052mmol/L。在这项横断面研究中，我们没有发现尿咖啡因及其代谢物与 BMD 之间有显著相关性。然而，需要进一步的研究来证实我们的发现，并探讨潜在的机制。
