Low blood pressure and antihypertensive treatment are independently associated with physical and mental health status in patients with arterial disease: the SMART study

OBJECTIVE: To investigate the independent effects of antihypertensive treatment and blood pressure (BP) levels on physical and mental health status in patients with arterial disease. DESIGN AND SETTING: Cross-sectional analyses were conducted within the single-centre Secondary Manifestations of ARTerial disease (SMART) study, in a hospital care setting. SUBJECTS: A total of 5877 patients (mean age 57 years) with symptomatic and asymptomatic arterial disease underwent standardized vascular screening. MAIN OUTCOME MEASURE: The primary outcome was self-rated physical and mental health assessed using the 36-item short-form health survey. RESULTS: In the total population, antihypertensive drug use and increased intensity of antihypertensive treatment were associated with poorer health status independent of important confounders including BP levels; adjusted mean differences 95% confidence interval (CI) in physical and mental health between n = 0 and n ≥ 3 antihypertensives were -1.2 (-2.1; -0.3) and -3.5 (-4.4; -2.6), respectively. Furthermore, both lower systolic and lower diastolic BP levels were related to poorer physical and mental health status independent of antihypertensive treatment. Mean differences (95% CI) in physical and mental health status per SD decrease in systolic BP were -0.56 (-0.84; -0.27) and -0.32 (-0.61; -0.03) and per SD decrease in diastolic BP were -0.50 (-0.78; -0.23) and -0.08 (-0.36; 0.20), respectively. The association between low BP and poor health status was particularly present in patients with coronary artery disease. CONCLUSIONS: In a population of patients with asymptomatic and symptomatic arterial disease, antihypertensive treatment and lower BP levels are independently associated with poorer self-rated physical and mental health. These findings suggest that different underlying mechanisms may explain these independent associations.