Abstract: Background　The relationship between serum uric acid （SUA） level and bone mineral density（BMD） has been extensively studied，but the effect of body fat indices on their relationship is not well defined. Objective　To explore the effect of body fat indices on the relationship between SUA and BMD of the lumbar spine and femoral neck in middle-aged and elderly individuals aged between 45-70 years. Methods　This study was conducted from January to December 2020. Participants were middle-aged and elderly physical examinees selected from Health Management Center，Affiliated Hospital of Guizhou Medical University，and were invited to attend a survey for investigating general demographics using Osteoporosis-related Factors Questionnaire. Body fat indices，BMD，and SUA were also collected. General demographics，body fat distribution，BMD，SUA and incidence of osteoporosis were compared by sex. The correlation between SUA and BMD was analyzed，and the influence of body fat indices on their relationship was explored. Results　Over all，the response rate of the distributed questionnaires was 94.27%（707/750）. The average age，BMI，waist circumference，hip circumference，and WHR of the 707 respondents（314 women and 393 men） were （55.3±6.6） years，（24.6±6.4） kg/m2，（84.0±9.0） cm，（94.1±6.0） cm，and（0.9±0.1），respectively. There were significant sex-based differences in prevalence of active and passive smoking，and drinking，milk consumption，vitamin D intake，calcium tablets intake，average BMI，waist circumference，hip circumference，WHR，lumbar spine BMD，femoral neck BMD，SUA，and incidence of osteoporosis （P<0.05）. Pearson correlation analysis showed that SUA was weakly but positively associated with lumbar spine BMD and femoral neck BMD （r=0.202，0.164，P<0.05）. Multiple linear regression analysis indicated that SUA was significantly associated with lumbar spine BMD as well as femoral neck BMD after controlling for some demographic covariates（β=0.160，0.035，P<0.05）. And it was also significantly associated with lumbar spine and femoral neck BMD after controlling for covariates including some demographics and BMI （β=0.103，0.095，P<0.05）. Further analysis based on quartiles of waist circumference （<77 cm，77-85 cm，86-90 cm，91-113 cm） revealed that a positive correlation was found between SUA and lumbar spine BMD in participants with waist circumference of <77 cm，or 77-85 cm （r=0.213，0.199，P<0.05）. SUA was positively correlated with BMD of femoral neck in participants with waist circumference of <77 cm（r=0.173，P<0.05）. Conclusion　This study revealed a strong simple correlation between serum SUA level and BMD of the lumbar spine or femoral neck in middle-aged and elderly individuals，which may be partially influenced by some body fat indices. The beneficial effect of SUA on preventing BMD loss was more manifested in those with waist circumference ≤85 cm.

Key words: Obesity, abdominal；Waist circumference；Uric acid；Bone density；Aged；Middle aged；Adipose tissue；Root cause analysis

摘要： 背景　血尿酸（SUA）水平与骨密度（BMD）之间的联系已被公认，但目前关于体脂指标对SUA和BMD关系的影响尚无明确定论。目的　探究45~70岁中老年人群体脂指标变化对SUA与腰椎、股骨颈BMD关系的影响，可为进一步预防中老年人群骨质疏松提供帮助。方法　选取2020年1—12月于贵州医科大学附属医院健康管理中心进行体检的中老年人群为研究对象。发放《骨质疏松健康因素调查表》进行基本资料的调查，测量体脂指标、BMD，并检测SUA。比较不同性别中老年人群基本资料、体脂分布、BMD、SUA及骨质疏松发生率，分析中老年人群SUA与BMD的相关关系，并探究体脂指标变化对SUA与BMD的影响。结果　共回收问卷750份，回收有效问卷707份，有效回收率为94.27%。707例研究对象中女314例、男393例，平均年龄（55.3±6.6）岁，平均体质指数（BMI）（24.6±6.4）kg/m2，平均腰围（84.0±9.0）cm，平均臀围（94.1±6.0）cm，平均腰臀比（WHR）（0.9±0.1）。不同性别中老年人群主动吸烟情况、被动吸烟情况、饮酒情况、喝牛奶情况、服用维生素D情况、服用钙片情况、BMI、腰围、臀围、WHR、腰椎BMD、股骨颈BMD、SUA、骨质疏松发生率比较，差异有统计学意义（P<0.05）。Pearson相关分析结果显示，SUA与腰椎BMD、股骨颈BMD均呈弱正相关（r值分别为0.202、0.164，P<0.05）。控制部分基本资料为协变量，多元线性回归分析结果显示，SUA是中老年人群腰椎、股骨颈BMD（β值分别为0.160、0.035）的影响因素（P<0.05）。控制部分基本资料及腰围为协变量，多元线性回归分析结果显示，SUA是中老年人群腰椎、股骨颈BMD（β值分别为0.103、0.095）的影响因素（P<0.05）。依据腰围四分位数将中老年人群分为Ⅰ组（腰围<77 cm）、Ⅱ组（腰围77~85 cm）、Ⅲ组（腰围86~90 cm）、Ⅳ组（腰围91~113 cm）。Ⅰ、Ⅱ组中老年人群SUA与腰椎BMD呈正相关（r值分别为0.213、0.199，P<0.05）；Ⅰ组中老年人群SUA与股骨颈BMD呈正相关（r=0.173，P<0.05）。结论　在45~70岁中老年人群中，血清SUA水平与腰椎、股骨颈BMD之间存在较强的单变量相关性，部分原因是肥胖指标的混杂作用，SUA对骨密度的有益作用更多表现在腰围≤85 cm的中老年人群。

关键词: 肥胖, 腹部；腰围；尿酸；骨密度；老年人；中年人；脂肪组织；影响因素分析