The threshold effect analysis of the BRI on HGS.

BackgroundSarcopenic obesity is characterized by a combination of obesity and sarcopenia. Body round index (BRI) is a novel anthropometric index that can more accurately assess body and visceral fat levels than body mass index or waist circumference. This study used data from the National Health and Nutrition Examination Survey (NHANES) to explore the relationship between BRI and handgrip strength (HGS) and muscle quality index (MQI) in American adults aged 20 and over.MethodsThis study used cross-sectional data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES) with complete data on BRI, HGS, and MQI. We used multivariate linear regression models and smooth curve fitting methods to explore the relationship between BRI and HGS and MQI. In addition, subgroup analyses and interaction tests were performed to further analyze the potential association between these variables.ResultsA total of 5466 participants were finally included in this study, of whom 2807 were males and 2659 were females. The results showed that BRI was positively correlated with HGS and negatively correlated with MQI. In the fully adjusted model, the negative correlation between BRI and MQI was (β= −0.08, 95% CI = −0.08, −0.07), while the positive correlation with HGS was (β= 0.3 8, 95% CI = 0.29, 0.46), indicating that for every unit increase in BRI, MQI decreases by 0.08 units and HGS increases by 0.38 units (P ConclusionThe results showed that BRI was positively correlated with HGS and negatively correlated with MQI, meaning that higher BRI was associated with higher HGS and lower MQI. This highlights the importance of body fat distribution in muscle health and suggests that BRI can be used as an effective anthropometric indicator to predict grip strength and muscle mass.【背景】肌肉减少症肥胖（sarcopenic obesity）以肥胖与肌肉减少症并存为特征。体圆指数（Body Round Index, BRI）是一种新型人体测量学指标，相较身体质量指数（body mass index）与腰围，其可更精准地评估体脂与内脏脂肪水平。本研究借助美国国家健康与营养检查调查（National Health and Nutrition Examination Survey, NHANES）的数据，探究20岁及以上美国成年人的体圆指数与握力（handgrip strength, HGS）、肌肉质量指数（muscle quality index, MQI）之间的关联。【方法】本研究采用2011-2014年美国国家健康与营养检查调查的横断面数据，纳入所有体圆指数、握力与肌肉质量指数数据完整的受试者。我们运用多元线性回归模型与平滑曲线拟合法，分析体圆指数与握力、肌肉质量指数的关联；此外还开展亚组分析与交互检验，以进一步剖析上述变量间的潜在联系。【结果】本研究最终纳入5466名受试者，其中男性2807名，女性2659名。结果显示，体圆指数与握力呈正相关，与肌肉质量指数呈负相关。在完全调整模型中，体圆指数与肌肉质量指数的负相关系数为(β=-0.08, 95%置信区间（confidence interval, CI）=-0.08~-0.07)，而与握力的正相关系数为(β=0.38, 95%置信区间（confidence interval, CI）=0.29~0.46)，即体圆指数每升高1个单位，肌肉质量指数降低0.08个单位，握力升高0.38个单位（P。【结论】本研究结果表明，体圆指数与握力呈正相关、与肌肉质量指数呈负相关，即体圆指数越高，握力越高而肌肉质量指数越低。这凸显了体脂分布在肌肉健康中的重要性，同时提示体圆指数可作为有效的人体测量学指标，用于预测握力与肌肉质量。