Luo Qingfeng, Zhang Shiyong, Liang Zixin, Wang Danni, Zhong Yanlin, Xia Bin, Xie Peng, Wang Can, Yuan Jinqiu, Zhang Ziji, Li Xingsheng
Department of Gerontology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Chongqing Municipality Clinical Research Center for Geriatrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China.
BMC Geriatr. 2025 Jan 27;25(1):58. doi: 10.1186/s12877-025-05704-3.
The obesity paradox is common among older adults at risk for various diseases. Although this paradox has also been observed in the association between obesity and osteoporosis, the available evidence remains controversial. This study aimed to investigate the association between obesity and OP risk in an older population.
A cross-sectional and prospective study was conducted using data from 177,734 participants in the UK Biobank. The association of body mass index (BMI), waist circumference (WC), and fat percentage with BMD was examined using Spearman correlation analysis with baseline BMD data. Cox proportional hazards regression analysis was used to investigate the association between obesity and OP risk. Restricted cubic spline (RCS) were used to assess the nonlinear associations of BMI, WC, and fat percentage with OP.
Baseline cross-sectional analyses revealed a significant positive association between BMI, WC, and fat percentage with BMD in women, whereas this association was very weak in men. A total of 8,998 OP patients were identified during a median follow-up period of 13.7 years. Cox analyses showed that obesity as defined by BMI, WC, and fat percentage was associated with a 33%, 23%, and 31% reduction in the risk of OP in older women but not in men, respectively. Conjoint analysis showed that lower BMI was associated with increased risk of OP in older adults, whereas the lowest risk was observed in women with higher BMI and higher body fat. RCS revealed an inverse J-shaped nonlinear association between obesity metrics and OP risk in women.
Lower BMI is an independent risk factor for OP in older adults, and the obesity paradox for OP risk exists only in women.
肥胖悖论在有各种疾病风险的老年人中很常见。尽管在肥胖与骨质疏松症的关联中也观察到了这种悖论，但现有证据仍存在争议。本研究旨在调查老年人群中肥胖与骨质疏松症风险之间的关联。
使用英国生物银行中177734名参与者的数据进行了一项横断面和前瞻性研究。使用Spearman相关性分析和基线骨密度数据检查体重指数（BMI）、腰围（WC）和脂肪百分比与骨密度的关联。使用Cox比例风险回归分析来研究肥胖与骨质疏松症风险之间的关联。使用受限立方样条（RCS）来评估BMI、WC和脂肪百分比与骨质疏松症的非线性关联。
基线横断面分析显示，女性的BMI、WC和脂肪百分比与骨密度之间存在显著正相关，而男性的这种相关性非常弱。在中位随访期13.7年期间共确定了8998名骨质疏松症患者。Cox分析表明，根据BMI、WC和脂肪百分比定义的肥胖分别使老年女性骨质疏松症风险降低33%、23%和31%，但在男性中则不然。联合分析表明，较低的BMI与老年人骨质疏松症风险增加相关，而BMI较高和体脂较高的女性风险最低。RCS显示肥胖指标与女性骨质疏松症风险之间呈倒J形非线性关联。
较低的BMI是老年人骨质疏松症的独立危险因素，骨质疏松症风险的肥胖悖论仅存在于女性中。
