Table 2_Association between dietary inflammatory index and all-cause mortality in patients with osteoporosis: data from NHANES.docx

BackgroundOsteoporosis is a common bone metabolic disease that poses a serious risk of fracture and death. The dietary inflammatory index (DII) is a tool for assessing the impact of diet on the inflammatory response in the body. This study aims to investigate the association of DII with the all-cause mortality of those patients.
MethodsThe study population was screened from the National Health and Nutrition Examination Survey (NHANES), after applying the exclusion criteria of age <18 years or missing information on DII, femoral bone marrow density (BMD), age, sex, ethnicity, and other variables. The DII was calculated according to the questionnaire interview of 24-h dietary data. Data analysis methods included the t-test, chi-squared test, weighted Cox regression, Kaplan–Meier (KM) survival analysis, XGBoost analysis, Pearson’s analysis, and interaction analysis.
ResultsA total of 361 patients were included in the study, comprising 264 women and 97 men. The Cox regression analysis results indicated that DII, glycohemoglobin, BMI, weight, age, race, and diabetes were independent factors for all-cause mortality (all p < 0.05). In addition, patients with higher DII levels had a higher risk of all-cause mortality than those with lower DII (p < 0.05). The KM survival curves indicated that patients with lower DII levels had a longer survival time (p < 0.05). The variable importance ranking, including DII and other variables, was as follows: age, weight, BMI, glycohemoglobin, DII, ethnicity, and diabetes. Pearson’s correlation analysis further indicated that DII was not significantly correlated with any of them.
ConclusionLower DII is independently associated with longer survival time in patients with osteoporosis.

研究背景
骨质疏松症（Osteoporosis）是一种常见的骨代谢疾病，可带来严重的骨折与死亡风险。饮食炎症指数（Dietary Inflammatory Index, DII）是用于评估饮食对机体炎症反应影响的工具。本研究旨在探讨DII与该类患者全因死亡率的关联。

研究方法
研究人群从美国国家健康与营养调查（National Health and Nutrition Examination Survey, NHANES）中筛选，排除年龄<18岁，或存在DII、股骨骨髓密度（Bone Marrow Density, BMD）、年龄、性别、种族及其他变量信息缺失的受试者。DII通过24小时膳食回顾访谈数据计算得到。本研究采用的数据分析方法包括t检验、卡方检验、加权Cox回归、Kaplan-Meier（KM）生存分析、XGBoost分析、Pearson相关分析及交互作用分析。

研究结果
本研究共纳入361例患者，其中女性264例，男性97例。Cox回归分析结果显示，DII、糖化血红蛋白、BMI、体重、年龄、种族及糖尿病均为全因死亡率的独立影响因素（所有p<0.05）。此外，DII水平较高的患者全因死亡风险显著高于DII水平较低者（p<0.05）。KM生存曲线分析显示，DII水平较低的患者生存时间更长（p<0.05）。包含DII在内的变量重要性排序如下：年龄、体重、BMI、糖化血红蛋白、DII、种族及糖尿病。Pearson相关分析进一步表明，DII与其余变量均无显著相关性。

研究结论
骨质疏松症患者中，较低的DII水平与更长的生存时间呈独立相关。