Association between arterial stiffness and pulmonary function in hypertensive patients

Arterial stiffness, assessed by cardio-ankle vascular index (CAVI), is clinically used to assess arteriosclerosis. Recently, pulmonary age, as determined by pulmonary function test, has been proposed by the Japanese Respiratory Society as a diagnostic measure for chronic obstructive pulmonary disease (COPD). This study aims to examine the association between CAVI and pulmonary function and to elucidate the correlation between vascular stiffness and pulmonary age in hypertensive patients. We enrolled a total of 45 hypertensive patients (70±9 years) who had been taking antihypertensive medications for at least 1 year. Pulmonary function was measured by the percentage of predicted forced vital capacity (FVC) and the ratio of forced expiratory volume in 1?s (FEV(1)) to FVC (FEV(1)/FVC ratio). Pulmonary age was determined by the equation proposed by the Japanese Respiratory Society. CAVI was measured at the same clinic visit. In the simple correlation analysis CAVI correlated with the FEV(1)/FVC ratio (r=-0.399, P=0.007) and pulmonary age (r=0.559, P<0.001). Multiple linear regression analysis revealed that CAVI was independently associated with FEV(1)/FVC ratio (β=-0.418, P=0.014) and pulmonary age (β=0.514, P=0.002). In addition, CAVI was significantly higher in patients with increased pulmonary age (9.4±1.4) than in those with normal pulmonary age (8.4±0.9) (P=0.011). The present study indicates that an increased CAVI is independently associated with reduced pulmonary function and increased pulmonary age. Hypertensive patients with high CAVI may need to be monitored for the progression of COPD.