Correlation Between Serum Total Bilirubin Levels and Blood Pressure Variability in Patients With Hypertension

Abstract

Background To investigate the effect of serum total bilirubin levels on blood pressure and its variability in patients with hypertension. Methods This study was a retrospective observational study. A total of 189 subjects were recruited from September 2019 to March 2020. All hypertensive patients were scheduled for ambulatory blood pressure and a 24-hour dynamic electrocardiography. Standard deviations of 24-hour systolic and diastolic blood pressure were used as blood pressure variability indicators. A multiple linear regression was used to analyze the relationship between total bilirubin serum levels and blood pressure variability in hypertensive patients. Results All patients were divided into 3 groups according to tertile values of total bilirubin: low (≤12.2 µmol/l, n = 64), moderate (12.3–16.7 µmol/l, n = 64), and high (>16.8 µmol/l, n = 62) total bilirubin groups. Compared with low total bilirubin group, 24-hour mean systolic and diastolic blood pressure, 24-hour systolic blood pressure standard deviation, systolic blood pressure coefficient of variability, and 24-hour systolic blood pressure load were reduced in the moderate and high total bilirubin groups (all P < 0.05). Multiple linear regression analysis showed that female (B = −1.408, P = 0.013), age (B = 0.043, P = 0.035), diabetes (B = 2.624, P < 0.001), and moderate and high bilirubin grouping (B = −1.582, −3.079; both P < 0.05) were influencing factors of 24-hour systolic pressure standard deviation. Serum total bilirubin levels had no effect on the standard deviation of 24-hour diastolic blood pressure(P > 0.05). Conclusions In hypertensive patients, the total bilirubin serum level is an influencing factor for 24-hour systolic blood pressure variability.