Analysis of the predisposing factors to orthostatic dysregulation in the allergic children

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09670851
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Pediatrics
• Research Institution: Kansai Medical University
• Principal Investigator: KINO Minoru Kansai Medical University, Medicine Faculty, Assistant Professor, 医学部, 講師 (30153159)
• Project Period (FY): 1997 – 1998
• Keywords: allergic diseases / autonomic dysfunction / orthostatic dysregulation

Research Abstract

Orthostatic intolerance is a main autonomic dysfunction in adolescents. Using echography, the diameter of the inferior vena cava (IVC) and its decrease on erect standing(collapse index) were evaluated in patients with orthostatic dysregulation (OD). the IVC diameter in thirteen patients with OD significantlydecreased with postural change from 16.4 * 3.2 to 6.0 * 2.0mm (p<0.01, collapseindex ; 57.7 * 17.2%). Collapse indices of the OD patients significantly reducedafter the administration of a syrnpathomimetic agent. Our data suggest that the abdominal venous return is not sufficient on erect standing in patients with ODand that the postural changes of the IVC diameter evaluated by echography areuseful parameters to assess circulatory status in OD.We also measured postural changes in plasma noradrenaline(NA) and endothelin(ET) levels in patients with orthostatic OD.NA level was significantly increased in postural changes from supine to upright position. In contrast, there was no change in FT levels. NAand FT levels were not different between OD and control group, at rest orupright position. Our data suggest that postural changes in IVC diameter are more useful parameters with which to assess circulatory status in OD than plasma NA or ET levels. By a questionnaire survey of children with OD and/or allergic diseases, it is shown that more than half of OD patients have allergic diseases or family history of allergy and that asthma patients, on the other hand, are prone to have subjective symptom such as abdominal pain and motion sickness.Further studies are needed to elucidate the predisposing factor to autonomic dysfunction in the children with allergic diseases.