Zhang Jianqiang, Zhang Huifeng
Department of Medical Intensive Care Unit, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China.
Department of Neurology, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China.
Lipids Health Dis. 2025 Jan 30;24(1):30. doi: 10.1186/s12944-025-02450-8.
The relationship between body roundness index (BRI), a new obesity index, and frailty has not been established. This study aims to compare the associations of traditional obesity index body mass index (BMI) and BRI with frailty and the risk of all-cause mortality.
The clinical data of 15,157 participants over 40 years old from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018 were analyzed. Based on weighted logistic regression, COX regression and restricted cubic spline, the associations of BRI and BMI with the odds of frailty and the risk of all-cause mortality were estimated. The receiver operating characteristic curve (ROC) and concordance index were used to evaluate the ability of BRI and BMI to predict frailty and survival.
Weighted logistic regression showed that the odds of frailty showed a trend of increasing with the increase of BRI and BMI (P for trend < 0.0001, respectively). After adjusting for all confounding factors, the association between BRI and frailty was stronger (OR: 1.20, 95% CI: 1.13-1.27, P < 0.0001), and the association between BMI and frailty was slightly weaker (OR: 1.14, 95% CI: 1.08-1.21, P < 0.0001). ROC showed that the area under the curve (AUC) of BRI for predicting frailty was 0.628, while the AUC of BMI was 0.603, and the difference between the two was significant (P < 0.001). In addition, in survival analysis, BRI and BMI showed a significant U-shaped association with the risk of all-cause mortality. Piecewise regression based on the inflection point shows that when BRI < 7.33, an increase in BRI reduces the risk of all-cause mortality (HR: 0.85, 95% CI: 0.78-0.92, P < 0.0001), while when BRI ≥ 7.33, an increase in BRI increases the risk of all-cause mortality (HR: 1.19, 95% CI: 1.03-1.38, P = 0.02); when BMI < 33.57, an increase in BMI reduces the risk of all-cause mortality (HR: 0.84, 95% CI: 0.78-0.91, P < 0.0001), and when BMI ≥ 33.57, an increase in BRI increases the risk of all-cause mortality (HR: 1.18, 95% CI: 1.04-1.34, P = 0.01). Moreover, the time-dependent c-index curve showed that the ability of BRI to predict the risk of all-cause mortality in frail people was comparable to that of BMI.
In the American population over 40 years old, both BRI and BMI are independently and positively associated with frailty. Moreover, BRI has a stronger ability to predict frailty than BMI. In addition, both BRI and BMI have a U-shaped association with the risk of all-cause mortality in frail individuals, and the two have comparable abilities to predict the risk of all-cause mortality.
新型肥胖指数身体圆润度指数（BRI）与衰弱之间的关系尚未确立。本研究旨在比较传统肥胖指数体重指数（BMI）和BRI与衰弱及全因死亡风险的关联。
分析了2003年至2018年美国国家健康与营养检查调查（NHANES）中15157名40岁以上参与者的临床数据。基于加权逻辑回归、COX回归和限制性立方样条，估计了BRI和BMI与衰弱几率及全因死亡风险的关联。采用受试者工作特征曲线（ROC）和一致性指数评估BRI和BMI预测衰弱及生存的能力。
加权逻辑回归显示，衰弱几率随BRI和BMI的增加呈上升趋势（趋势P值均<0.0001）。调整所有混杂因素后，BRI与衰弱的关联更强（比值比：1.20，95%置信区间：1.13 - 1.27，P<0.0001），BMI与衰弱的关联稍弱（比值比：1.14，95%置信区间：1.08 - 1.21，P<0.0001）。ROC显示，BRI预测衰弱的曲线下面积（AUC）为0.628，而BMI的AUC为0.603，两者差异有统计学意义（P<0.001）。此外，在生存分析中，BRI和BMI与全因死亡风险呈显著的U型关联。基于拐点的分段回归显示，当BRI<7.33时，BRI升高降低全因死亡风险（风险比：0.85，95%置信区间：0.78 - 0.92，P<0.0001），而当BRI≥7.33时，BRI升高增加全因死亡风险（风险比：1.19，95%置信区间：1.03 - 1.38，P = 0.02）；当BMI<33.57时，BMI升高降低全因死亡风险（风险比：0.84，95%置信区间：0.78 - 0.91，P<0.0001），当BMI≥33.57时，BRI升高增加全因死亡风险（风险比：1.18，95%置信区间：1.04 - 1.34，P = 0.01）。此外，时间依赖性c指数曲线显示，BRI预测衰弱人群全因死亡风险的能力与BMI相当。
在40岁以上的美国人群中，BRI和BMI均与衰弱独立正相关。此外，BRI预测衰弱的能力强于BMI。此外，BRI和BMI与衰弱个体的全因死亡风险均呈U型关联，且两者预测全因死亡风险的能力相当。
