Does arterial stiffness affect orthostatic hypotension among high-altitude Tibetans?

ABSTRACT

Objective

This study aimed to investigate the association between arterial stiffness and orthostatic hypotension (OH) and orthostatic blood pressure (BP) changes among Tibetans living at high altitude.

Methods

A total of 630 high-altitude Tibetans were included (56.53 ± 10.16 years; 246 men). Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). OH was defined as a decrease in systolic BP (SBP) >20 mmHg or a decrease in diastolic BP (DBP) >10 mmHg after 1 min or 3 min of moving from supine to standing position.

Results

The prevalence of OH in this population was 6.3%. Compared with subjects without OH, the subjects with OH had a higher baPWV (P < 0.001). Multiple logistical regression found that baPWV was significantly associated with the occurrence of OH (OR 1.147, CI 95% 1.028–1.280, P = 0.014). Spearman correlation analysis showed that baPWV was negatively associated with orthostatic changes in SBP and DBP(r = −0.256, P < 0.001 and r = −0.194, P < 0.001, respectively). Further multiple stepwise linear regression analysis showed that baPWV was independently correlated with orthostatic BP changes (SBP: β = −0.599, P < 0.001; DBP: β = −0.333, P < 0.001). Moreover, increased baPWV was correlated with attenuation of orthostatic heart rate changes. No significant association was observed between hematocrit or hemoglobin concentration and OH.

Conclusion

BaPWV was significantly associated with the occurrence of OH and orthostatic changes in the SBP and DBP, which suggests that arterial stiffness may be a potential mechanism of impaired hemodynamic response to orthostatic challenges among high-altitude Tibetans.

KEYWORDS:

• Orthostatic hypotension
• high altitude
• Tibetan
• arterial stiffness

Acknowledgments

The authors thank the teams led by Dr.Renqian Lachu at Jiulong County People’s Hospital, Tibetan Autonomous Prefecture, China for their contributions to this study. We thank Hanne Gadeberg, PhD, from Liwen Bianji, Edanz Editing China (www.liwenbianji.cn/ac), for editing the English text of a draft of this manuscript.

Authorship confirmation statement

Xinran Li, Qingtao Meng and Xiaoping Chen designed the study. Xin Zhang, Xinran Li, Rufeng Shi recruited participants and collected clinical data and blood sample. Xinran Li completed data entry. Xinran Li and Rufeng Shi undertook the statistical analysis and wrote this manuscript. Xiaoping Chen revised the manuscript for important intellectual content and languages. All authors read and approved the final manuscript.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Disclosure of interest

The authors declare no conflict of interest

A reviewer on this manuscript has disclosed that they receive consulting fees from Lundbeck. Another reviewer is a Consultant to Medtronic Inc and a shareholder in Edwards Lifesciences Corp and Boston Scientific Inc. They are also a Member of the Speakers’ Bureau of Abbott Labs Corp. The other peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This study was funded by Science and Technology Pillar Programs in Sichuan Province (Grant no. 2017SZ0008).