title: Plasma copeptin and therapeutic effectiveness of midodrine hydrochloride on postural tachycardia syndrome in children.
abstract: OBJECTIVE
  Midodrine hydrochloride is used clinically to treat children with postural tachycardia syndrome (POTS), but it is not effective in all patients. This study was designed to explore the changes in plasma copeptin and its predictive value in assessing the therapeutic efficacy of midodrine hydrochloride in children with POTS.
  
  
  METHODS
  The study included 33 children with POTS and 26 healthy children. The group with POTS received midodrine hydrochloride treatment for 1.5-3 months. The plasma copeptin was measured using a sandwich immunoluminometric assay. A receiver operating characteristic curve was used to explore the predictive value of plasma copeptin.
  
  
  RESULTS
  The plasma copeptin in the group with POTS was significantly higher than that of the control group (10.827±2.459 pmol/L vs 8.845±1.471 pmol/L, P<.001). The plasma copeptin in responders to midodrine hydrochloride was significantly higher than that of nonresponders (12.082±1.998 pmol/L vs 9.646±2.301 pmol/L, P=.003). Receiver operating characteristic analysis on the predictive value of plasma copeptin showed that the area under the curve was 0.800 with a 95% CI of 0.640-0.959. Using a plasma copeptin level of 10.482 pmol/L as the cutoff point produced both favorite sensitivity (81.3%) and specificity (76.5%) in predicting the efficacy of midodrine hydrochloride therapy in children with POTS.
  
  
  CONCLUSIONS
  Plasma copeptin may be considered as a predictive biomarker for the likelihood of successful treatment of children with POTS with midodrine hydrochloride.
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Physiology and Pathophysiology, Peking University Health Sciences Center, Beijing, P. R. China; Key Laboratory of Cardiovascular Sciences, Ministry of Education, Beijing, P. R. China.
authors.forename: Chaoshu
authors.initials: C
authors.lastname: Tang
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China. Electronic address: jinhongfang51@126.com.
authors.forename: Hongfang
authors.initials: H
authors.lastname: Jin
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China. Electronic address: junbaodu1@126.com.
authors.forename: Junbao
authors.initials: J
authors.lastname: Du
mesh_terms: D000293:Adolescent; D058646:Adrenergic alpha-1 Receptor Agonists / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006020:Glycopeptides / Q000097:blood*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008879:Midodrine / Q000627:therapeutic use*; D054972:Postural Orthostatic Tachycardia Syndrome / Q000097:blood / Q000188:drug therapy*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D058646:Adrenergic alpha-1 Receptor Agonists; D015415:Biomarkers; D006020:Glycopeptides; C048197:copeptins; D008879:Midodrine