Blood Pressure Load: An Effective Indicator of Systemic Circulation Status in Individuals With Acute Altitude Sickness

Abstract

Background: Acute high altitude (HA) exposure results in blood pressure (BP) variations in most subjects. Previous studies have demonstrated that higher BP is potentially correlated with acute mountain sickness (AMS). The BP load may be of clinical significance regarding systemic circulation status.Objectives: This study aimed to examine HA-induced BP changes in patients with AMS compared to those in healthy subjects. Further, we provided clinical information about the relationship between variations in 24-h ambulatory parameters (BP level, BP variability, and BP load) and AMS.Methods: Sixty-nine subjects were enrolled and all participants ascended Litang (4,100 m above sea level). They were monitored using a 24-h ambulatory blood pressure device and underwent echocardiography within 24 h of altitude exposure. The 2018 Lake Louise questionnaire was used to evaluate AMS.Results: The AMS group comprised more women than men [15 (65.2%) vs. 13 (28.3%), P < 0.001] and fewer smokers [4 (17.4%) vs. 23 (50.0%), P = 0.009]. The AMS group exhibited significant increases in 24-h BP compared to the non-AMS group (24-h SBP variation: 10.52 ± 6.48 vs. 6.03 ± 9.27 mmHg, P = 0.041; 24-h DBP variation: 8.70 ± 4.57 vs. 5.03 ± 4.98 mmHg, P = 0.004). The variation of mean 24-h cBPL (cumulative BP load) (mean 24-h cSBPL: 10.58 ± 10.99 vs. 4.02 ± 10.58, P = 0.016; 24-h mean cDBPL: 6.03 ± 5.87 vs. 2.89 ± 4.99, P = 0.034) was also obviously higher in AMS subjects than in non-AMS subjects after HA exposure. 24-h mean cSBPL variation (OR = 1.07, P = 0.024) and 24-h mean cDBPL variation (OR = 1.14, P = 0.034) were independent risk factors of AMS. Moreover, variation of 24-h mean cSBPL showed a good correlation with AMS score (R = 0.504, P < 0.001).Conclusions: Our study demonstrated that patients with AMS had higher BP and BP load changes after altitude exposure than healthy subjects. Excessive BP load variations were associated with AMS. Thus, BP load could be an effective indicator regarding systemic circulation status of AMS.

The role of post-translational modifications in driving abnormal cardiovascular complications at high altitude

“…More recently, cardiac function parameters at sea level were used as predictors of HAHD occurrence by screening echocardiographic parameters of the left ventricle, right ventricle, and pulmonary circulation ( 29 ). Moreover, changes in blood pressure (BP) and BP load were clinically found to be higher in HAHD patients, suggesting that BP load can be an effective indicator to evaluate cardiovascular adaptation ability ( 30 ). Furthermore, study found subjects with low 25% of the pulmonary volume values at low altitude were shown to be susceptible to high levels of pulmonary arterial pressure ( 31 ).…”

Sleep loss effects on physiological and cognitive responses to systemic environmental hypoxia

“…Increased sympathoadrenal activity has been implicated in the pathogenesis of AMS; during an 8-h exposure to normobaric hypoxia (12% O 2 , equal to 4,600 m) subjects who developed AMS had significantly higher arterial epinephrine concentrations ( Kamimori et al, 2009 ). In addition, individuals with AMS, and not those without AMS, had higher BP levels and BP load changes after an ascent to 3,700 m altitude ( Chen et al, 2022 ). In this study, excessive BP load variations are associated with AMS, and BP load was suggested to be an effective indicator of systemic circulation status in AMS patients.…”