中高齢者における漸増運動負荷時の血圧応答と部位別脈波速度および左室拡張機能指標の関係

The Relationship between Exercise Blood Pressure Response and Regional Pulse Wave Velocity,Index of Left Ventricular Diastolic Function in Elderly Subjects

要旨　運動時の過剰な昇圧応答は，心血管病の発症に関連していることが指摘されている．本研究では，外来血圧正常者91例(平均年齢63±9歳，男性22例，女性69例)を対象として心肺運動負荷試験を施行し，最高収縮期血圧(Peak SBP)や嫌気性代謝閾値レベルの収縮期血圧(AT SBP)と動脈スティフネス指標(PWV)および左室拡張機能指標(E/E’)との関係について検討した．Peak SBPが男性で210mmHg以上，女性で190mmHg以上を示す群はそれ以外の群と比較してAT SBP，大動脈PWV(cfPWV)，下肢動脈PWV(faPWV)，E/E’が有意に高値を示した．AT SBPとPeak SBPの上昇度を従属変数とした重回帰分析ではE/E’とcfPWVが有意な独立変数として抽出された．また，E/E’はfaPWVとは有意な関係を示さなかったが，cfPWVとは有意な正相関を示した．中心動脈スティフネスの増加やそれに伴う左室拡張機能障害を有する中高齢者は，安静時血圧が正常であっても日常生活活動で過剰な血圧上昇を示す可能性がある．

　A hypertensive response to exercise has been reported to be associated with the development of cardiovascular diseases. We performed cardiopulmonary exercise tests in 91 normotensive outpatients(22 males and 69 females with a mean age of 63 years), and evaluated the association between the peak systolic blood pressure(Peak SBP)or systolic blood pressure at the anaerobic threshold(AT SBP)and the pulse wave velocity(PWV)reflecting arterial stiffness or the index of left ventricular diastolic function(E/E'). The male group with a peak SBP ≥210mmHg and the female group with a peak SBP ≥190mmHg showed a significantly higher AT SBP, carotid-femoral PWV(cfPWV), femoral-ankle PWV(faPWV), and E/E' than the other groups. As a result of multiple regression analysis using increases in AT SBP and Peak SBP as dependent variables, E/E' and cfPWV were extracted as significant independent variables. In addition, E/E' was not associated with faPWV, but there was a significant positive correlation between E/E' and cfPWV. There is a possibility that middle-aged and aged people with increased central artery stiffness and associated left ventricular diastolic dysfunction show hypertensive responses during activities of daily life even if their resting blood pressure is normal.