Relationship of socioeconomic status to arterial stiffness: comparison between medical aid beneficiaries and National Health Insurance beneficiaries.

BACKGROUND: There is no general agreement on underlying pathophysiology explaining the high burden of cardiovascular disease on people at low socioeconomic status. This study was conducted to investigate the association between healthcare systems and arterial stiffness. METHODS: A total of 8929 subjects (60 years old and 55% were male) who underwent brachial-ankle pulse wave velocity (baPWV) measurement were retrospectively analyzed. There were 8237 National Health Insurance (NHI) beneficiaries (92.2%) and 692 medical aid (MA) beneficiaries (7.8%). The median value of baPWV was 1540 cm/s. RESULTS: Subjects with higher baPWV values (≥ 1540 cm/s) were older, and more frequently had cardiovascular risk factors and unfavorable laboratory findings than those with lower values baPWV (< 1540 cm/s). The baPWV values were significantly higher in MA beneficiaries than in NHI beneficiaries (1966 ± 495 vs. 1582 ± 346 cm/s, P < 0.001). The proportion of MA beneficiaries was significantly higher in subjects with higher baPWV than those with lower baPWV (13.1% vs. 2.3%, P < 0.001). In multivariable analysis, MA beneficiaries were significantly associated with higher baPWV values even after controlling for potential confounders (odds ratio, 4.46; 95% confidence intervals, 3.36-5.92; P < 0.001). CONCLUSIONS: The baPWV values were significantly higher in MA beneficiaries than in NHI beneficiaries. The result of this study provides additional evidence on the association between low socioeconomic status and arterial stiffening.