非観血的携帯用血圧測定装置による高血圧患者の血圧日内変動および諸種負荷に対する反応性の検討

Circadian rhythm of blood pressure (BP) and BP responses to daily activities:Using a noninvasive automatic pressure recording device (Avionics)

　血圧の重症度の如何にかかわらず，外来にて種々の投薬を行っても目的とする値まで降圧し得なかった患者が，入院後特別の治療なしで，正常範囲まで降圧してしまうことを時折経験する。このように入院後血圧が正常域を示す患者と，持続的に高血圧を示す患者の病態，血圧変動性，日常生活上の行動や諸種ストレスに対する昇圧反応等^1）の相違を明らかにすることは意味あることと思われる。

　本研究の目的は，本態性高血圧症の入院患者について，入院後，非観血的無拘束で測定した24時間平均血圧値が150／90mmHg以下に降圧した群と，入院後も持続的に高血圧を示した群の血圧，心拍数の日内変動および諸種ストレスや日常行動に対する血圧反応性の相違を明らかにしようとしたものである。

Circadian rhythm of BP and BP responses to daily activities were studied in 40 essential hypertensives (HT) and 6 normotensives (NT), using a non-invasive auto-matic pressure-recording device (Avionics). Hyperten-sion was defined as systolic blood pressure (SBP) > 160 mmHg and/or diastolic blood pressure (DBP) > 95 mmHg in the physician's office. BP and heart rate (HR) were recorded every 15 minuites from 6: 00 to 21: 00, and every 30 minuites from 21: 00 to 6: 00. These readings were analyzed for four situations; ie morning, afternoon, evening and mid-night. During daytime, bicycle ergometer and mental arithmetic were performed. HT group were devided into two groups by the average value of 24hr-SBP and DBP ; namely patients who had average 24hr-BP of lower than 150/ 90mmHg was classified as HT₁ group, and the others was classified as HT₂ group. Both hypertensive groups showed no difference in age, sex, casual SBP and severity of HT, Average 24hr-BP were lower than casual BP in the three groups (ΔSBP/ΔDBP; NT: 14±4.3/6±4.9 HT₁: 52±7.4/19±4.5 HT₂: 32±6.7/15±2.9mmHg). Although HT₁ had almost similar high blood pressure as HT2 in the physician's office, their average 24hr-BP were significantly lower than that of HT₂ and were within normal range, but were still significantly higher than that of NT subject. BP and HR response to stress of HT₁ were greater than NT and HT₂ subjects. BP variability, HR variability (Standarddeviation, Coefficient variance), and urinary excretion of epinephrine were higher in HT1 compared with HT2. It is suggested that HT₁ subjects may have imbalance of central nervous control systems of blood pressure, and this will results in labile hypertension.