Karavasiloglou Nena, Selinger Eliska, Gojda Jan, Rohrmann Sabine, Kühn Tilman
Division of Chronic Disease Epidemiology, Institute for Epidemiology, Biostatistics and Prevention, University of Zurich, Zurich, Switzerland.
Centre for Research on Diabetes, Metabolism and Nutrition of Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
J Nutr. 2020 May 1;150(5):1266-1271. doi: 10.1093/jn/nxaa018.
Persons following plant-based diets have lower bone mineral density (BMD) and higher fracture risk, possibly due to suboptimal nutrient supply. However, anthropometric measures were not considered as potential confounders in many previous studies, and body mass index (BMI) is positively associated with BMD but also generally lower among vegans and vegetarians.
Our objective was to investigate if BMD measurements differ between vegetarians and nonvegetarians from the adult general population when accounting for important determinants of BMD, especially BMI and waist circumference.
Using data from the NHANES (cycles 2007-2008 and 2009-2010), we evaluated the differences in BMD (femoral neck, total femoral, and total lumbar spine) between adult vegetarians and nonvegetarians. Linear regression models were used to determine the associations between BMD and diet. Statistical models were adjusted for important factors, i.e., age, sex, race/ethnicity, smoking status, alcohol consumption, serum vitamin D and calcium concentrations, waist circumference, and BMI.
In statistical models adjusted for age, sex, race/ethnicity, menopausal status, and education level, BMD values were significantly lower among vegetarians than among nonvegetarians (P < 0.001). These differences were attenuated upon adjustment for lifestyle factors, and became statistically nonsignificant upon adjustment for anthropometric variables (BMI and waist circumference) for femoral neck (0.77 compared with 0.79 g/cm2 among vegetarians versus nonvegetarians, P = 0.10) and total femoral BMD (0.88 compared with 0.90 g/cm2, P = 0.12). A small but statistically significant difference remained for total lumbar spine BMD (1.01 compared with 1.04 g/cm2, P = 0.005).
These findings suggest that lower BMD among adult vegetarians is in larger parts explained by lower BMI and waist circumference.
遵循植物性饮食的人群骨矿物质密度（BMD）较低且骨折风险较高，这可能是由于营养供应欠佳所致。然而，在许多既往研究中，人体测量指标未被视为潜在混杂因素，而且体重指数（BMI）与BMD呈正相关，但素食者和纯素食者的BMI通常也较低。
我们的目的是研究在考虑BMD的重要决定因素，尤其是BMI和腰围时，成年普通人群中素食者和非素食者的BMD测量值是否存在差异。
利用美国国家健康与营养检查调查（NHANES，2007 - 2008年周期和2009 - 2010年周期）的数据，我们评估了成年素食者和非素食者之间BMD（股骨颈、全股骨和腰椎总骨量）的差异。采用线性回归模型来确定BMD与饮食之间的关联。统计模型针对重要因素进行了调整，即年龄、性别、种族/民族、吸烟状况、饮酒量、血清维生素D和钙浓度、腰围和BMI。
在针对年龄、性别、种族/民族、绝经状态和教育水平进行调整的统计模型中，素食者的BMD值显著低于非素食者（P < 0.001）。在对生活方式因素进行调整后，这些差异有所减弱，在对股骨颈（素食者与非素食者分别为0.77与0.79g/cm²，P = 0.10）和全股骨BMD（分别为0.88与0.90g/cm²，P = 0.12）的人体测量变量（BMI和腰围）进行调整后，差异变得无统计学意义。腰椎总骨量仍存在微小但具有统计学意义的差异（分别为1.01与1.04g/cm²，P = 0.005）。
这些发现表明，成年素食者较低的BMD在很大程度上可由较低的BMI和腰围来解释。
