Relationships among blood pressures obtained using different measurement methods in the general population of Ohasama, Japan

To examine the relationships between casual, ambulatory and home blood pres sure measurements in the general population, these measurements were obtain ed in 1,695 of 3,744 subjects aged 20 yr or older in Ohasama, Japan. Of the se 1,695 subjects, 1,207 measured their home blood pressure more than 14 ti mes in each of the morning and evening (881 untreated subjects including no rmotensives and untreated hypertensives, 56.4 +/- 11.5 yr of age; 326 treat ed subjects, 66.0 +/- 9.2 yr of age). We analyzed data in these 1,207 subje cts, examining the distribution of each measurement, the relationships amon g measurements, and the factors affecting the blood pressure differences am ong the measurements. For systolic pressure, the casual measurement was the highest among the methods examined. The daytime ambulatory measurement was significantly higher than morning and evening home measurements. Morning h ome measurements were significantly higher than those in the evening. For d iastolic pressure, however, the morning home measurement was the highest am ong the methods examined. Short-term pressure variability (standard deviati on and variation coefficient of ambulatory measurements) was greater than l ong-term pressure variability (standard deviation and variation coefficient of home measurements). The pressure variability in treated subjects was gr eater than that in untreated subjects. The correlation between casual press ure and the other pressures was not as strong (r < 0.567). Among the relati onships between ambulatory and home measurements, the strongest correlation was observed between the 24-h ambulatory measurement and the morning home measurement (r = 0.738) in untreated subjects. The morning home measurement was highly correlated with the evening home measurement (r > 0.814). The d ifferences among the methods examined were affected by blood pressure level and age. It should be noted that in elderly and treated subjects, blood pr essure measurement using one method does not necessarily correlate with tha t obtained using the other methods. This information is useful for the esti mation of the value of one type of blood pressure measurement from values o btained with other methods.