Habitual physical activity and arterial stiffness in normotensive and hypertensive subjects

Abstract

Arterial stiffness is associated with cardiovascular risk factors such as hypertension and sedentary lifestyle. The aim of this study was to evaluate the relationship between habitual physical activity and arterial stiffness in hypertensive (HT) and normotensive subjects (NT). In 190 subjects (age range: 21-73 years, 112 HT, 78 NT) augmentation index (AIX), a marker of arterial stiffness, was measured by pulse wave analysis (PWA) in the radial artery (SphygmocorR). Brachial artery diameter was measured by high resolution ultrasounds. Habitual physical activity was evaluated with a modified Baecke questionnaire, which assesses work activity score (WAS), sports activity score (SAS) and leisure time activity score (LAS). The total activity score (TAS) of habitual physical activity was calculated from the individual scores. In a subgroup of 40 subjects cardiorespiratory fitness (VO2 max) was assessed with a graded exercise (cycle ergometer) test. AIX (adjusted for heart rate) was higher in HT (26.0±9.8) (p<0.0001) as compared to NT (19.4±11.2). No significant differences were found in levels of habitual physical activity or VO2 max between these groups. VO2 max correlated with TAS (r=0.40, p=0.01) and SAS (r=0.47, p=0.005), but not with WAS or LAS. In NT, AIX correlated with TAS (r=-0.32, p=0.004) and SAS (r=-0.29, p=0.01), brachial artery diameter (r=-0.34, p=0.003), age (r=0.54, p<0.0001), systolic blood pressure (SBP) (r=0.26, p=0.02) and diastolic blood pressure (DBP) (r=0.38, p= 0.0007). In the multivariate analysis only age (p=0.0001), brachial artery diameter (p=0.0004) and SAS (p=0.02) resulted as significant predictors of AIX (R2=0.64). In HT, AIX correlated with TAS (r=-0.22, p=0.02) and SAS (r=-0.19, p=0.05), brachial artery diameter (r=-0.41, p<0.0001), age (r=0.27, p=0.005), SBP (r=-0.21, p=0.03), DBP (r=-0.22, p=0.02) and total cholesterol (r=-0.20, p=0.04). In the multivariate analysis only age (p=0.002), brachial artery diameter (p=0.0001) and DBP (p=0.01) resulted as significant predictors of AIX (R2=0.50). VO2 max was significantly related to AIX (r=-0.60, p= 0.004) in NT, whereas no relationship was found in HT. In conclusion, habitual physical activity is inversely related to arterial stiffness, this relationship is more pronounced in normotensive subjects than in hypertensive patients.