Abstract: Objective To analyze the statistical distribution of body mass index (BMI) in children with postural tachycardia syndrome (POTS) and children with vasovagal syncope (VVS), and to explore the application value of BMI in distinguishing the two diseases. Methods A total of 260 children and adolescents who complained of unexplained syncope were enrolled in this study from June 2015 to December 2019, and were divided into POTS group (n=110) and VVS group (n=150) after definite diagnosis by HUTT. Meanwhile, 82 subjects who took physical examination were selected as the control group. The data of BMI was collected after measuring the height and weight of all subjects in the same room, and its statistical difference among the three groups above was described. Then the receiver operating characteristic (ROC) curve was used to evaluate the value of BMI in distinguishing POTS and VVS. Results The average BMI of children in control group, POTS group and VVS group were (20. 51±2. 91) kg/m², (18. 17±3. 12)kg/m² and (19. 91±3. 69)kg/m², respectively. The BMI of children in POTS group was significantly lower than that in control group and VVS group (P＜0. 001). However, there was no statistically significant difference between VVS group and control group (P＝0. 195). As for the BMI difference among the three VVS subtypes, the statistically difference was significant(F＝3. 229,P＝0. 042). The area under the ROC curve of BMI was 0. 644 (95%CI: 0. 577-0. 711, P＜0. 001). Taking 19. 30 kg/m² as threshold BMI for VVS children and adolescents, the predicted sensitivity and specificity were 56. 0% and 71. 8%, respectively. Conclusions Children and adolescents with POTS have the significantly lower BMI than those with VVS. Thus, BMI is an acceptable auxiliary method to discriminate POTS and VVS combined with medical history, physical examination and other auxiliary examinations.

Key words: postural tachycardia syndrome, vasovagal syncope, body mass index, children and adolescents

摘要： 目的 分析体重指数(BMI)在体位性心动过速综合征(POTS)患儿和血管迷走性晕厥(VVS)患儿中的分布差异,并探讨其在上述两种疾病鉴别中的应用价值。方法 选取2015年6月至2019年12月在儿科门诊纳入以“不明原因晕厥”就诊的患儿260例,依据直立倾斜试验结果对患儿分组(POTS组110例,VVS组150例),并将同期行健康体检的82例儿童青少年作为对照组。所有受试者接受统一的身高及体重测量。计算BMI,对比分析各组间BMI分布差异,并采用受试者工作特征(ROC)曲线预测用BMI鉴别POTS和VVS患儿的诊断价值。 结果 对照组、POTS组和VVS组BMI均值分别为(20.51±2.91)kg/m²、(18.17±3.12)kg/m²和(19.91±3.69)kg/m²,其中POTS组患儿BMI较对照组和VVS组均显著降低(P＜0.001),但VVS组患儿BMI分布和对照组相比差异无统计学意义(P＝0.195)。三种VVS亚型间BMI分布差异亦有统计学意义(F＝3.229,P＝0.042)。利用ROC曲线分析BMI鉴别POTS患儿和VVS患儿的价值,结果显示ROC曲线下面积为0.644(95%CI:0.577~0.711,P＜0.001),当BMI＞19.30 kg/m²时,其预测某晕厥患儿是VVS的灵敏度和特异度分别为56.0%和71.8%。 结论 POTS患儿较VVS患儿BMI明显降低,BMI在二者的鉴别诊断中具有一定的应用价值,可结合病史、体格检查和其他辅助检查作为临床初步诊断依据。

关键词: 体位性心动过速综合征, 血管迷走性晕厥, 体重指数, 儿童青少年