Hypoxemia as a potential risk factor of endothelial dysfunction and arterial stiffness in patients with chronic obstructive pulmonary disease

Abstract

Summary. This study was aimed at evaluation of role of hypoxemia in development of endothelial dysfunction (ED) and arterial stiffness (AS) in patients with COPD. AS of large vessels and ED were measured by photoplethysmography. Stiffness index (SI) and reflection index (RI) were calculated: The SI indicates the pulse wave velocity in large arteries. The RI is primarily related to small vessel tonus. ED was assessed using the RI dynamics following inhalation of salbutamol (Δ RISLB). Hypoxemia was evaluated using blood gas analysis, night-time pulse oximetry, basal oxygen saturation (SpO2), duration of periods with SpO2 60 mm Hg (0 [–1.7–1.3] % vs 2.00 [0.35–12.35] %; р ≤ 0.04). Therefore, increased hypoxemia in COPD patients was accompanied by a significant decrease in lung function. AS was related to hypoxemia in 6MWT. The lower minimal SpO2 and the longer periods with SpO2 < 88 % in 6MWT were, the higher photoplethysmographic SI was. The results support the crucial role of hypoxemia in arterial wall mechanical disorders and ED in patients with COPD.