基于结构方程模型“潜变量”生成过程研究中老年人群体格指标与骨密度的相关性

Correlation between the physical indicators and bone mineral density in middle-aged and elderly people based on the process of generating"latent variables"in structural equation modeling

目的探索50岁及以上中老年人的身高、体质量、大腿长度、腰围和臀围五个体格指标与骨密度的相关性,对制定干预措施提供参考。方法选取2017—2020年美国国家健康和营养调查数据库中50岁及以上体格指标与骨密度数据完整的2072名调查人群作为研究对象。首先,将身高、体质量、大腿长度、腰围和臀围5个相关的体格指标利用结构方程模型“潜变量”生成过程进行降维处理;其次,将降维后生成的新变量Body_index、性别、种族作为自变量,分析其与全脊柱骨密度的相关性。结果新变量Body_index与自变量身高、体质量、大腿长度、腰围和臀围进行多重线性拟合(R2为0.998),损失的信息<2.0%。多重线性回归分析发现,可以认为新变量Body_index与全脊柱骨密度存在线性相关关系(P<0.001),尚不能认为性别、种族与全脊柱骨密度存在线性关系(P>0.05)。结论身材矮小、偏瘦为中老年人骨密度较低的危险因素,提示高危人群为防止骨质疏松、骨折,应适当增加体重,合理膳食。

Objective To explore the correlation between five physical indicators,namely height,weight,thigh length,waist circumference,hip circumference,and bone mineral density in middle-aged and older adults aged 50 years and older,and to provide a reference for developing interventions.Methods A population of 2072 surveyed individuals aged 50 and older with complete data on physical indicators and bone density form 2017—2020 National Health and Nutrition Examination Survey database was selected as the study population.First,five related physical indicators,namely height,weight,thigh length,waist circumference,and hip circumference,were downscaled using structural equation modeling(SEM)"latent variable"generation process.Second,Body_index,gender,and ethnicity,generated after the downscaling process,were used as the independent variables to analyze the correlation between them and total spinal bone mineral density(BMD).Results The new variable Body_index was fitted to the independent variables height,weight,thigh length,waist circumference,and hip circumference in a multiple linear fit(R2 of 0.998)with less than 2.0%loss of information.Multiple linear regression analysis revealed that the new variable Body_index could be considered to have a linear correlation with total spinal BMD(P<0.001)and that gender and race could not yet be considered to have a linear relationship with total spinal BMD(P>0.05).Conclusion Short stature and thinness are risk factors for low BMD in middle-aged and elderly people,suggesting that high-risk groups should increase their body weight appropriately and eat a reasonable diet to prevent osteoporosis and fractures.