Correlation Analysis Of Body Mass Index,Heart Rate And Blood Pressure Coefficient Variation In Children With Orthostatic Intolerance

Objective By exploring the relationship between body mass index,heart rate variability coefficient,blood pressure coefficient of variation and Orthostatic Intolerance(OI)in children,we were able to find convenient and easy-to-obtain autonomic function evaluation indicators to predict the occurrence of OI,and quickly identify OI children based on clinical data.Methods In this study,143 children who underwent a head-up tilt test(HUTT)in our hospital after excluding other diseases were selected from January 2019 to December 2022who were treated in Inner Mongolia Maternal and Child Health Hospital due to symptoms of orthostatic intolerance.Among them,there were 58 children with vasovagal syncope(VVS),26 children with Postural tachycardia syndrome(POTS)and 59 children with negative disease.At the same time,40 healthy children without symptoms of orthostatic intolerance were selected as the healthy control group.All subjects completed the upright test and the basic upright tilt test,and symptomatic children were required to continue to complete the sublingual nitroglycerin upright tilt test.The general data(sex,age),clinical data(main symptoms,accompanying symptoms,triggers,history of motion sickness,family history,symptoms during HUTT,ECG T wave changes during HUTT),height,weight,blood pressure and heart rate values at different time points during the test were collected for statistical analysis.At the same time,the coefficient of variation of body mass index,heart rate and blood pressure were calculated and compared between the four groups to determine their diagnostic value for children with OI.Statistical analysis using SPSS 26.0(SPSS Inc.,Chicago,USA)software.Results 1.There was a statistically significant difference in syncope between the main symptoms of VVS,POTS and negative groups(P=0.034),and there was no difference between the remaining main complaint symptoms between the three groups(all P>0.05).The comparison of the incidence of concomitant symptoms between the three groups showed that except for nausea/vomiting/abdominal pain,there were differences in the symptoms between the three groups(all P<0.05).The comparison of the incidence of symptoms during HUTT between the three groups showed that there were differences in the symptoms between the three groups(all P<0.05).The comparison of triggers between the three groups showed that there was a difference between the three groups of persistent standing(P=0.043),and there was no difference between the three groups(all P>0.05).2.There was a significant difference in the history of motion sickness between VVS group,POTS group and negative group(P<0.001),and the comparison between the groups showed that the VVS group was meaningful with the negative group,and between the VVS group and the POTS group.There was no significant difference in family history between the three groups(P=0.859).The difference between the three groups of T wave amplitude change during HUTT was statistically significant(P=0.018),and the pairwise comparison between the groups showed that the VVS group was meaningful with the negative group,and the VVS group and the POTS group.3.The BMI difference between VVS,POTS,negative group and control group was statistically significant(P=0.039),and the pairwise comparison between the groups showed that the POTS group was meaningful with the VVS group,the POTS group and the negative group,and the POTS group and the control group.BMI predicted that the ROC curve results of POTS showed that the area under the curve was 0.70(95% CI:0.58-0.82),and the sensitivity of diagnosing POTS was 67.24% and the specificity was65.38% when the BMI was 15.97 kg/m2.4.The differences between VVS group,POTS group,negative group and control group were statistically significant(all P<0.001)between the VVS group,the negative group and the control group(all P<0.05)。 The area under the ROC curve in the recumbent tilt HRCV prediction positive group was 0.72(95% CI:0.63-0.80),the sensitivity of the positive group was 77.38% and the specificity was 61.02%when the HRCV in the recumbent tilt HRCV was 13.64%,the area under the curve in the recumbent HRCV prediction positive group was 0.70(95% CI: 0.61-0.79),and the sensitivity of the positive group was 82.14% when the truncated value was 18.34%,The specificity is50.85%.Conclusion 1.BMI has auxiliary diagnostic value for rapid identification of OI and identification of VVS and POTS children,the lower the BMI,the more likely to develop OI,when the BMI is less than 15.97Kg/m2,the possibility of POTS is greater.2.HRCV and BPCV can be used to evaluate the autonomic function of children with OI,and HRCV in the recumbent position and HRCV in the recumbent inclination position are valuable for the diagnosis of positive children,and the positive children can be quickly identified when the HRCV in the recumbent inclined position is greater than 13.64% and the HRCV in the recumbent position is greater than 18.34%.3.Common symptoms of children with OI are syncope and dizziness,and children with VVS are more likely to have a history of motion sickness and changes in the T wave amplitude of ECG during HUTT than children with POTS and negative children.