The relationship between brachial ankle pulse wave velocity and complement 1 inhibitor

Abstract

Complement 1 (C1) inhibitor is an acute phase protein with anti-inflammatory properties. The aim of the present study was to elucidate the relationship between brachial ankle pulse wave velocity (baPWV), the parameter of arterial stiffness, and C1 inhibitor. One hundred subjects were randomly enrolled in this study. Data about baPWV, age, gender, hypertension, smoking, and body mass index (BMI) were measured. Blood tests for total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, hemoglobin A1c, erythrocyte sedimentation rate, C-reactive protein, complement 3, and C1 inhibitor were performed. Based on the Pearson correlation, the C1 inhibitor showed a positive relation to the baPWV (P<0.001). Multiple regression analysis revealed the significant predictors of baPWV were not only the conventional risk factors of arteriosclerosis and/or atherosclerosis, such as age (P<0.001), gender (P<0.001), hypertension (P<0.001), and BMI (P=0.006), but also the acute phase protein, C1 inhibitor (P=0.025). In conclusion, C1 inhibitor is associated with arterial stiffness through its association with increased inflammation.

Keywords: Complement 1 Inhibitor; Pulse Wave Velocity; Stiffness.

Fig. 1

Inter-observer and intra-observer reliability of measurements of the brachial ankle pulse wave velocity (cm/sec). (A) Inter-observer reliability (reproducibility) depicts the relationship between three independent measurements by three observers, r1 (observer 1), r2 (observer 2), and r3 (observer 3). The ICC value is 0.8783. (B) Intra-observer reliability (repeatability) shows the relationship between two different measurements by one observer. The ICC value is 0.8927.

Fig. 2

Linear regression graphs between baPWV and age in both males and females. (A) male, (B) female, baPWVs increase in proportion to the age in both males and females.

Fig. 3

Linear regression graph between baPWV and C1 inhibitor. Brachial ankle pulse wave velocity showed positive relationship to the serum level of C1 inhibitor. baPWV increases according to the increasing serum level of C1 inhibitor.