Abstract: Background　Due to the rise in obesity rates worldwide，the prevalence of cardiometabolic comorbidities (CMM) is increasing year by year. Body Roundness Index (BRI) is a new obesity measure of visceral adipose tissueand the risk of BRI and CMM in people with normal body weight has been poorly studied. Objective　To explore the relationship between BRI and high-risk CMM in normal body weight population，and to explore the role of triacylglycerol glucose product (TyG) index in this association. Methods　A total of 42 438 subjects with a body mass index (BMI) of 18.50~23.99 kg/m2 who participated in the early screening and comprehensive intervention project of high-risk groups of cardiovascular diseases in Anhui Province in 2017~2021 were selected. According to gender and CMM，the participants were divided into male non-CMM group (n=14 546)，male CMM group (n=2 741)，female non-CMM group (n=20 901) and female CMM group (n=4 249)，and they were divided into four levels according to the BRI quartile of different sexes (male: M1，M2，M3，M4; Females: F1，F2，F3，F4). The Bonferroni method was used to compare the differences in the prevalence of CMM among different genders and age groups，and a percentage stacking chart was drawn to show the age distribution of CMM populations of different genders. Multivariate logistic regression analysis was used to explore the relationship between BRI quartile level and CMM risk. The mediate function of R (version 4.4.2) software was used to explore the mediating effect of the association between BRI and CMM after adjusting for covariates，and the mediating effect of TyG index was analyzed by medsens function. Results　The proportion of age，education in high school or above，BMI，total cholesterol (TC)，triglycerides (TG)，low-density lipoprotein cholesterol (LDL-C)，RC，fasting blood glucose (FPG)，TyG index，BRI，SBP，diastolic blood pressure (DBP)，hypertension，diabetes mellitus，dyslipidemia，heart disease，and stroke in the CMM group were higher than those in the non-CMM group，and the proportion of smoking and high-density lipoprotein cholesterol (HDL-C) were lower than those in the non-CMM group (P<0.05). In the female group，the age，BMI，TC，TG，LDL-C，RC，FPG，TyG index，BRI，SBP，DBP，hypertension，diabetes，dyslipidemia，heart disease，and stroke in the CMM group were higher than those in the non-CMM group，and the proportion of education in high school or above and HDL-C in the female group were lower than those in the non-CMM group. There were statistically significant differences in the prevalence of CMM，alcohol consumption ratio，TC，TG，LDL-C，RC，FPG，TyG index，SBP and DBP among different genders (P<0.05)，and the prevalence of CMM increased with the increase of BRI level (P trend < 0.001 for males and <0.001 for females). The prevalence of CMM was different in different genders and age groups (P<0.001)，and the proportion of CMM population over 50 years old was much higher than that in 50 years old. Multivariate logistic regression showed that the risk of CMM at M2/F2，M3/F3，and M4/F4 levels was increased compared with BRI M1/F1 levels，regardless of whether confounders were adjusted for confounders (P<0.001). In the mediating analysis of the association between BRI and CMM，after adjusting for covariates such as gender，age，education，smoking and alcohol consumption，the proportion mediated by TyG index [54.62% (95%CI，50.19%，60.00%)] was much higher than that of RC [22.98% (95%CI，20.70%，26.00%)] and SBP [24.05% (95%CI，22.05%，27.00%)]. The association between BRI and CMM disease was more significantly mediated. Conclusion　In people with normal body weight，BRI levels were positively correlated with the risk of CMM，and the TyG index played a significant mediating role in this association.

Key words: body mass index, body roundness index, cardiometabolic comorbidities, triacylglycerol glucose product index, obesity

摘要： 背景　由于全球肥胖率的上升，心血管代谢性共病（CMM）的患病率逐年升高。身体圆度指数（BRI）是一种衡量内脏脂肪组织的新型肥胖指标，目前少有人研究在体质量正常人群中BRI与CMM的患病风险。目的　探讨在体质量正常人群中BRI与CMM高危风险的关系，探究三酰甘油葡萄糖乘积（TyG）指数在这种关联中的作用。方法　选取2017—2021年参与安徽省心血管疾病高危人群早期筛查与综合干预项目中体质指数（BMI）处于18.50～23.99 kg/m2的42 438名研究对象，经统一培训人员进行收集人群的一般资料、疾病史和相关生化指标。根据性别和是否患有CMM将研究对象分为男性非CMM组（n=14 546）、男性CMM组（n=2 741）、女性非CMM组（n=20 901）和女性CMM组（n=4 249），分别根据不同性别BRI四分位数将其分为四个水平（男性：M1、 M2、 M3、M4；女性：F1、F2、F3、 F4）。采用Bonferroni法比较不同性别及年龄段人群CMM患病率差异，并绘制百分比堆积图展示不同性别CMM人群的年龄段分布。采用多因素Logistic回归分析探究BRI四分位水平与CMM患病风险的关系。采用R（version 4.4.2）软件的mediate函数探究在调整协变量后的TyG指数、残余胆固醇（RC）以及收缩压（SBP）在BRI与CMM之间关联的中介效应，并通过medsens函数对TyG指数的中介效应进行了敏感性分析。结果　男性群体中CMM组年龄、学历在高中及以上比例、BMI、总胆固醇（TC）、甘油三酯（TG） 、低密度脂蛋白胆固醇（LDL-C）、RC、空腹血糖（FPG）、TyG指数、BRI、SBP、舒张压（DBP）、高血压、糖尿病、血脂异常、心脏病、脑卒中高于非CMM组，吸烟比例、高密度脂蛋白胆固醇（HDL-C）低于非CMM组（P＜0.05）。女性群体中CMM组年龄、BMI、TC、TG 、LDL-C、RC、FPG、TyG指数、BRI、SBP、DBP、高血压、糖尿病、血脂异常、心脏病、脑卒中高于非CMM组，学历在高中及以上比例、HDL-C低于非CMM组。不同性别的BRI四分位水平中CMM患病率、饮酒比例、TC、TG 、LDL-C、RC、FPG、TyG指数、SBP、DBP比较，差异均有统计学意义（P＜0.05），且CMM的患病率随BRI水平的升高而增加（男性P趋势＜0.001，女性P趋势 ＜0.001）。不同性别和年龄段CMM患病率不同（P＜0.001），且CMM人群中50岁以上占比远大于50岁以下。多因素Logistic回归显示，无论是否调整混杂因素，与BRI M1/F1水平相比，M2/F2、M3/F3和M4/F4水平的CMM患病风险均增加（P＜0.001）。在BRI与CMM患病之间关联的中介分析中，调整性别、年龄、学历、吸烟及饮酒等协变量后，TyG指数［54.62%（95%CI,50.19%,60.00%）］介导占比远高于RC［22.98%（95%CI,20.70%,26.00%）］和SBP［24.05%（95%CI,22.05%,27.00%）］，更加显著地介导了BRI与CMM患病之间的关联。结论　在体质量正常的人群中，BRI水平与CMM的患病风险呈正相关，而TyG指数对这种关联起着显著的中介作用。

关键词: 体质指数, 身体圆度指数, 心血管代谢性共病, 三酰甘油葡萄糖乘积指数, 肥胖。