[Significance of short-term blood pressure variation in health management]

Blood pressure is known to vary under the influence of many factors. Although this variation can also occur in the short term, the significance of short-term blood pressure variation remains to be explained. The purpose of this study was to study the significance of short-term blood pressure variation in health management. Blood pressure was measured on 505 railway employees using an automatic blood pressure recorder based on an oscillometric method. "Continual blood pressure measurement" in which 5 blood pressure measurements were made at one-minute intervals was used. The following conclusions were obtained. 1. Blood pressure gradually fell during the 5 measurements made at one-minute intervals. There was a significant variation between the 1st and 2nd measured blood pressures, but there was no significant variation between the 4th and 5th measured blood pressures in most cases. These results suggest that 4 measurements made at one-minute intervals are needed to obtain stable blood pressure. 2. According to analysis of covariance, both sex and age had an influence on short-term blood pressure variation, but the body mass index (BMI) did not. 3. According to cluster analysis using 8 blood pressure variations, all subjects were classified into 4 clusters. These clusters showed significant relationship to age for males and BMI for females.