COPD is a common respiratory disease, which is characterized by persistent airflow limitation. Its occurrence and development are closely related to the chronic inflammatory reaction caused by the exposure of airway and lung to toxic substances. Previous studies generally believed that COPD is related to the incidence of chronic bronchitis and obstructive pulmonary disease, but the pathogenesis of COPD is still unclear . The body of patients with COPD is in a state of hypoxia and the level of inflammatory factors increases, which leads to an increase in the level of vascular endothelial cell adhesion factors and a decrease in the elastic fibers of the blood vessel wall, causing arterial vascular disease, affecting the patient's heart function, and increasing the incidence of cardiovascular disease. About one-third of patients with COPD die of cardiovascular disease, so it is important to strengthen the early diagnosis of patients with COPD and take timely clinical intervention to reduce the incidence of COPD .
Arterial stiffness is a commonly used index for clinical prediction of carotid artery disease, which is a non-invasive examination. It was found that age, dyslipidemia, course of disease, V-type involvement and high mean arterial pressure were independent risk factors for increased arterial stiffness in patients with COPD [15, 16]. In this study, the level of RI and PI of the patients with COPD in the observation group were lower than those in the control group (P < 0.05); the IMT, total plaque area, and number of plaques in the observation group were higher than those in the control group ( P < 0.05); The arterial stiffness and ABI level of patients with COPD in the observation group were higher than those of healthy subjects in the control group (P < 0.05), indicating that the continuous development of COPD will lead to increased arterial stiffness and abnormal ultrasound examination. The main reason for this phenomenon is that the increased arterial stiffness is the early manifestation of arteriosclerosis, which can be effectively diagnosed by ultrasound. Measurement of arterial stiffness in high-risk groups of atherosclerosis can not only detect subclinical vascular structure changes in time, but also guide clinical treatment.
Patients with COPD have no typical clinical symptoms in the early stage of onset. With the development of the disease, it will lead to abnormal arterial function, metabolic disorders and other syndromes, which will lead to increased arterial stiffness and aggravation of the disease. At present, PWV is the main clinical examination for arterial stiffness, which has the advantages of simple operation, accurate results and non-invasive, which is suitable for large-scale screening of asymptomatic population . However, pulse wave propagation is affected by arterial stiffness. The greater the segmental arterial stiffness, the faster the pulse wave velocity . The detection of arterial stiffness is often affected by the nature and thickness of arterial wall, and the accuracy of prediction is closely related to the pathological state of patients. In order to reduce the influence of related factors in the process of arterial stiffness detection, this study further analyzed the relationship between arterial stiffness and ultrasound results in patients with COPD. The results showed that arterial stiffness and ABI levels were negatively correlated with RI and PI levels (P < 0.05), and positively correlated with IMT, total plaque area and plaque number (P < 0.05), indicating that there is a correlation between arterial stiffness in patients with COPD and the results of ultrasound examination, which can be used as an auxiliary detection index of arterial stiffness.