Responses to the postural change and orthostatic dysregulation symptoms: a population study on Japanese junior and senior high school students.

Unselected 580 male and 779 female junior and senior high school students were subjected to the tilting test and informations on 11 autonomic dysregulation symptoms and complaints were taken by interviews. Results of the analyses of the data are summarized as follows: 1) Number of symptoms and complaints possessed by each individual distributes continuously but nonrandomly among testees; that is, individuals having no symptom and those having 5 or more symptoms are significantly more numerous than those expected from random distribution, indicating accumulation of the symptoms into some individuals. 2) Some specific symptoms tend to coincide with each other. 3) Principal component analyses disclosed that the first principal component can explain only 16-20% of the observed variation in the presence or absence of symptoms and complaints, suggesting that numerous factors are responsible for the occurrence of the symptoms. 4) Measurements of the blood pressures and the pulse rate, and their responses to the postural change show continuous, normal distributions, and significantly correlate to each other. 5) The responses to the tilting test are increased with the increase of number of symptoms and complaints possessed by the testees.