The Relationship Between Orthostatic Intolerance Of Children And Serum 25-hydroxyvitamin D₃ And RAAS System

Objective:To observe the changes of serum 25-（OH）D₃ and RAAS concentrations in children with orthostatic intolerance,analyze the correlation between 25-（OH）D₃ levels and other laboratory parameters,and explore the relationship between 25-（OH）D₃ levels and other laboratory indicators,and explore the possible mechanisms of action For the early diagnosis and optimization of treatment,to determine the prognosis of orthostatic intolerance provide scientific basis.Methods:87 children with HUT/HUTT positive in the Department of Pediatric Cardiology of Lanzhou University Second Hospital were selected from January 2017 to May 2018 as the study subjects,including 45 males and 42 females,with a male to female ratio of 1.07:1.According to the results of HUT/HUTT test,the subjects were divided into 3 groups:29 patients with POTS group,8 patients with OHT group,50 patients in VVS group（5 patients with cardioinhibitory type of VVS,40 patients with vasoinhibitory type of,5 patients with mixed inhibitory type of VVS）.23 healthy children with the same age and gender were negative for HUT/HUTT as a control group.The concentrations of serum 25-（OH）D₃ and RAAS in each group were compared,and the correlation between 25-（OH）D₃ and RAAS system was analyzed.Results:1.The serum 25-（OH）D₃ level in OHT group was lower than that in VVS,POTS and negative group,while VVS-MI group was lower than the negative group,the difference was statistically significant（P<0.05）.2.The level of serum AngⅠ basis in OHT group were higher than VVS-VI,VVS-CI,POTS and negative group,the difference was statistically significant（P<0.05）.3.The serum ALD level of OHT group was lower than VVS-VI,POTS and negative group,the difference was statistically significant（P<0.05）;4.Rank correlation analysis between serum25-（OH）D₃ and AngⅠ activation,AngⅡ basis and AngⅡ activation level was negatively correlated（p<0.05）,and negative linear regression analysis with log（renin）was also negatively correlated（r=0.207,P=0.04）,while there is no correlation between serum 25-（OH）D₃ and RAAS in OHT group.Conclusion:Lack or deficiency of serum 25-（OH）D₃ may cause excessive activation of RAAS system,the higher level of serum renin,AngⅠ activation,AngⅡ basis and activation participate in the occurrence and identification of orthostatic intolerance in children,the lower serum 25-（OH）D₃ level has an early significant warning effect on children with OHT.