Abstract: Background　Frailty was an age-related geriatric syndrome，with its prevalence among Chinese older adults being notably high and demonstrating a rising trend over time. Obesity was closely associated with the development of numerous diseases，but its relationship with frailty remained controversial. This uncertainty was potentially attributable to limitations of conventional obesity indicators in characterizing adipose tissue distribution. Therefore，investigating the associations between multiple adiposity metrics and frailty was important for to advance the understanding of frailty pathogenesis and developing preventive interventions. Objective　This study investigates the relationship between various obesity indicators and frailty，providing a scientific basis for the early prevention and control of frailty in older adults. Methods　In this study，a total of 1，429 elderly people aged 60 years and above were surveyed in six rural villages in Jingyuan County，Gansu Province，from March to May 2023. After further exclusions，a final sample of 1 153 participants was included in the analysis. The FRAIL scale was utilized to assess the frailty status of the elderly. Based on Chinese obesity criteria，waist circumference and BMI were categorized，and waist-to-hip ratio（WHR），waist-to-height ratio（WHtR），body roundness index（BRI），and Chinese visceral adiposity index（CVAI）were grouped by quartiles. Multivariate Logistic regression，restricted cubic splines，and receiver operating characteristic（ROC）curve analysis were employed to explore the relationship between different obesity indicators and frailty. Results　This study included 1 153 elderly participants aged ≥ 60 years，comprising 474 males（41.11%）and 679 females（58.89%），with a mean age of 70.86±4.76 years. Based on FRAIL scale assessments，226 participants were identified as frail and 927 as non-frail，resulting in a frailty prevalence of 19.60%.The adjusted multivariate Logistic regression analysis revealed that central obesity，moderate to severe obesity（reference：normal BMI），Q3 and Q4（reference：Q1）levels of WHR，and Q4（reference：Q1）levels of WHtR，BRI，and CVAI were significant risk factors for frailty in the elderly population（P<0.05），with progressively increasing risks of frailty associated with elevated levels of waist circumference，BMI，WHR，WHtR，BRI，and CVAI（Ptrend<0.05）. The restricted cubic spline（RCS）curve indicated that waist circumference，BMI，WHtR，BRI，and CVAI were linearly and positively correlated with the risk of frailty in the elderly（Plinear<0.05）. The ROC curve analysis demonstrated that that the predictive capacity for frailty in the elderly was possessed by waist circumference，BMI，WHR，WHtR，BRI，and CVAI，with area under the curve（AUC）of 0.557（95%CI=0.515-0.598），0.570（95%CI=0.528-0.612），0.558（95%CI=0.515-0.600），0.610（95%CI=0.568-0.652），0.610（95%CI=0.568-0.652），and 0.586（95%CI=0.546-0.626），respectively（P<0.05）. Additionally，WHtR，BRI，and CVAI demonstrated better predictive ability compared to waist circumference（Z=-5.443，P<0.001；Z=-5.443，P<0.001；Z=-2.595，P=0.009），and both WHtR and BRI showed better predictive ability compared to BMI（Z=-2.885，P=0.004；Z=-2.884，P=0.004）. Conclusion　In rural communities of Northwest China，among the elderly population aged 60 and above，obesity indicators such as waist circumference，BMI，WHR，WHtR，BRI，and CVAI were positively correlated with the risk of frailty in the elderly. Among these indicators，WHtR and BRI showed better predictive ability for frailty.

Key words: Frailty, Obesity, Aged, Waist circumference, Body mass index, Waist-to-height ratio, Body roundness index, Chinese visceral adiposity index, Northwest rural area

摘要： 背景　衰弱是一种与年龄增长相关的老年综合征，我国老年人衰弱患病率较高且呈逐年上升趋势。肥胖与多种疾病的发生发展均密切相关，但其与衰弱间关联仍存在争议，这可能是由于传统肥胖指标在识别脂肪分布上存在一定的局限性。因此，探究多种肥胖指标与衰弱的关联，对进一步探索衰弱发病机制和制定预防干预措施具有重要意义。目的　本研究旨在探讨老年人多种肥胖指标与衰弱的相关性，为老年人衰弱的早期防控提供科学依据。方法　本研究于2023年3—5月在甘肃省靖远县的6个农村共调查了1 429名60岁及以上的老年人，经进一步排除，最终纳入了1 153人。使用FRAIL量表评估老年人的衰弱状况。根据中国肥胖标准对腰围和BMI进行分组，将腰臀比（WHR）、腰高比（WHtR）、躯体圆度指数（BRI）和中国内脏脂肪指数（CVAI）按四分位数分组，并使用多因素Logistic回归、限制性立方样条（RCS）和受试者工作特征（ROC）曲线探讨不同肥胖指标与衰弱的相关性。结果　本研究共纳入1 153名60岁及以上的老年人，其中男474名（41.11%），女679名（58.89%），平均年龄（70.86±4.76）岁。根据FRAIL量表评分，衰弱老年人226名，非衰弱老年人927名，衰弱患病率为19.60%。调整相关变量后多因素二元Logistic回归分析结果显示，中心性肥胖、中重度肥胖（以BMI正常为参照）、Q3和Q4水平的WHR以及Q4水平的WHtR、BRI和CVAI（均以Q1为参照）是老年人衰弱的危险因素（P<0.05）；且随着腰围、BMI、WHR、WHtR、BRI和CVAI水平的增加，老年人衰弱患病风险呈上升趋势（P趋势<0.05）。RCS曲线结果显示，老年人腰围、BMI、WHtR、BRI和CVAI与衰弱患病风险呈正相关（P线性<0.05）。ROC曲线分析结果显示，腰围、BMI、WHR、WHtR、BRI、CVAI预测衰弱风险的曲线下面积（AUC）分别为0.557（95%CI=0.515~0.598）、0.570（95%CI=0.528~0.612）、0.558（95%CI=0.515~0.600）、0.610（95%CI=0.568~0.652）、0.610（95%CI=0.568~0.652）、0.586（95%CI=0.546~0.626），对衰弱风险均存在预测价值（P<0.05）。其中，WHtR、BRI、CVAI预测衰弱风险的AUC高于腰围（Z=-5.443，P<0.001；Z=-5.443，P<0.001；Z=-2.595，P=0.009）；WHtR、BRI预测衰弱风险的AUC高于BMI（Z=-2.885，P=0.004；Z=-2.884，P=0.004）。结论　西北农村60岁及以上的老年人肥胖指标腰围、BMI、WHR、WHtR、BRI、CVAI与衰弱风险呈正相关，其中WHtR和BRI对老年人衰弱的预测能力较好。

关键词: 衰弱, 肥胖症, 老年人, 腰围, 体质指数, 腰高比, 躯体圆度指数, 中国内脏脂肪指数, 西北农村地区