Abnormalities of vascular function in resistant hypertension

We aimed to evaluate markers of vascular dysfunction in patients with resistant hypertension (RH). A group of 144 patients (61 years, 42% women) with essential RH were divided in two groups based on ambulatory blood pressure monitoring (ABPM). True RH (72%) was considered when 24-h blood pressure (BP) was ≥ 130 and/or 80 mmHg. Otherwise, patients were classified as white coat RH (28%). Hyperemia-induced forearm vasodilation (HIFV), serum inflammatory biomarkers (hs-CRP, s-ICAM-1, s-VCAM-1, e-selectin, p-selectin and MCP-1) and large (C1) and small arterial (C2) compliance (HDI/Pulse Wave CR 2000) were determined in all individuals. In comparison with patients with white coat RH, and after adjustment for age, office systolic BP and diabetes status, those with true RH had a more impaired HIFV (201 ± 159 vs 436 ± 157%; p < 0.001), increased e-selectin (53.1 ± 29.8 vs 40.7 ± 23.5 ng/ml; p = 0.035), and MCP-1 (445 ± 120 vs 386 ± 126 ng/ml; p = 0.027). No significant differences were observed in arterial compliance. Maximal HIFV inversely correlated with urinary albumin excretion (Rho: - 0.278; p = 0.004) and with some inflammatory biomarkers (MCP-1: - 0.441; p < 0.001, e-selectin: - 0.468; p < 0.001 and p-selectin: - 0.329; p = 0.001). We conclude that true RH, diagnosed by ABPM, is associated with a more severe degree of vascular dysfunction, as measured by HIFV and serum biomarkers, whereas other types of vascular alterations, such as compliance, are not directly linked with the level of BP.