Laboratory Medicine ›› 2021, Vol. 36 ›› Issue (11): 1140-1145.DOI: 10.3969/j.issn.1673-8640.2021.11.010

Previous Articles     Next Articles

Clinical value of whole blood zinc in children and adolescents with neurally-mediated syncope

YANG Dan, HAN Lu, LONG Shuai, XU Jin, TIAN Hong()   

  1. National Children's Medical Center,Children's Hospital of Fudan University,Shanghai 201102,China
  • Received:2021-05-11 Online:2021-11-30 Published:2021-12-20
  • Contact: TIAN Hong

Abstract:

Objective To investigate the clinical value of whole blood zinc in children and adolescents with neurally-mediated syncope(NMS). Methods Totally,102 NMS children(NMS group) who underwent head-up tilt test(HUTT) and tested trace elements and vitamins(Vit) were enrolled. According to the results of HUTT,83 cases were classified into HUTT positive group,and 19 cases were classified into HUTT negative group. The HUTT positive group included 32 cases of vasovagal syncope(VVS) and 53 cases of postural orthostatic tachycardia syndrome(POTS). Two patients were diagnosed with both VVS and POTS. A total of 100 healthy age-matched children who tested trace elements and 100 healthy age-matched children who tested Vit were enrolled as control group A and control group B,respectively. The levels of zinc,calcium,copper,magnesium and iron in whole blood and the levels of Vit A,Vit B1,Vit B2,Vit B6,Vit B9,Vit C,Vit D and Vit E in serum were determined. Binary Logistic regression analysis was used to assess risk factors of NMS. Receiver operating characteristic(ROC) curve was used to evaluate the predictive value in diagnosing NMS and the predictive value in differentiating VVS and POTS. Results Compared with control group A,the differences of zinc,calcium and iron had statistical significance in NMS group(P<0.05). There was no statistical significance in the other items between NMS group and control groups(P>0.05). The levels of zinc,calcium and iron in HUTT positive group were lower than those in control group A(P<0.05). There was no statistical significance in trace element levels between HUTT negative group and HUTT positive group,control group A(P>0.05). The level of zinc in VVS group was lower than that in control group A(P<0.05). The levels of zinc,calcium,magnesium and iron in POTS group were lower than those in control group A(P<0.05). The level of magnesium in VVS group was higher than that in POTS group(P<0.05). Binary Logistic regression analysis showed that the decrease of zinc [odds ratio(OR)=0.726,95% confidence interval(CI) 0.652-0.807] increased the risk of NMS,and the decrease of calcium(OR=1.772,95%CI 0.639-4.909) and iron(OR=0.472,95%CI 0.090-2.476) had no statistical significance on the occurrence of NMS. When the cut-off value of zinc was 80.09 μmol/L,the area under curve(AUC)was 0.800,and the sensitivity and specificity for the diagnosis of NMS were 74.5% and 80.0%,respectively. When the cut-off value of magnesium was 1.33 mmol/L,the AUC was 0.631,and the sensitivity and specificity for the differential diagnosis between VVS and POTS were 67.9% and 59.4%,respectively. Conclusions Zinc deficiency may be related to children and adolescents with NMS. Magnesium may have a clinical value in the differential diagnosis of VVS and POTS.

Key words: Zinc, Trace element, Vitamin, Neurally-mediated syncope, Head-up tilt test, Child, Adolescent

CLC Number: