Correlation between Vascular Compliance and Increase of Blood Pressure on Exercising in Normotensive Group

ABSTRACT

BACKGROUND AND OBJECTIVES: Vascular compliance is known to be decreased in hypertension, even at an early stage. The blood pressure response to exercise reflects the future risk of developing hypertension. A study was performed on the relationship between the vascular compliance and blood pressure response to exercise, to evaluate whether the vascular compliance is decreased in normotensive persons with a relatively higher future risk of developing hypertension. SUBJECTS AND METHODS: The subjects of the study were adults with normal blood pressure (SBP<120 mmHg, DBP<80 mmHg), who had undergone health screening and both echocardiography and treadmill test. Those patients with a history of diabetes mellitus or clinical cardiovascular diseases were excluded form the subjects. An index of overall vascular compliance (SVI/PP) was calculated using echocardiography. The relationship between the peak systolic blood pressure during exercise and vascular compliance was also investigated. RESULTS: The subjects were 77 patients, 54 male and 23 female, with a mean age of 47.6+/-7.7 years. The measured vascular compliance and average of peak systolic pressure on exercising were 1.08+/-0.24 L/m2/mmHg and 154+/-21 mmHg, respectively. The peak systolic pressure was correlated with the vascular compliance (r=-0.24, p<0.05). The peak systolic pressure at stage 3 was also correlated with the vascular compliance (r=-0.24, p<0.05). This relationship persisted after adjustment for age, gender, basal systolic blood pressure and maximal oxygen consumption (p<0.05). CONCLUSION: The vascular compliance was lower in subjects with a larger increase in blood pressure during exercise whose basal blood pressure was even below 120/80 mmHg. This finding may suggest that a decreased vascular compliance precedes the changes of hypertension. A longitudinal follow-up study is warranted.