Microcirculation characteristics and humoral factors of healthy people from different populations at high altitude (4 100 m) / 生理学报

ABSTRACT

The present study was aimed to observe the characteristics of sublingual microcirculation and the changes of humoral factors in healthy people of three different high altitude populations. Three groups of healthy subjects in Guoluo area of Qinghai province (4 100 m) were included Tibetan group 30 Tibetans, (45.62 ± 10.15) years old; Han group 22 two-generation of Han immigrants, (46.23 ± 8.59) years old; migrant group 23 migrants living at high altitude for 2-5 years, (43.45 ± 8.31) years old. Blood routine test was performed to determine white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB), hematocrit (HCT), platelet (PLT) count, and neutrophil (NEUT) count. The changes of serum humoral factors including endothelin-1 (ET-1), CD31, CD34, CD105, vascular endothelial growth factor (VEGF), nitric oxide (NO) and noradrenaline (NE) were detected by ELISA. Continuous noninvasive hemodynamics monitor was used to continuously measure the changes of systemic circulation indexes cardiac output (CO), cardiac index (CI), heart rate (HR), stroke volume (SV), pulse pressure variation (PPV), systemic vascular resistance index (SVRI), and mean arterial pressure (MAP). Blood oxygen was measured by pulse oximeter. Sublingual microcirculation indexes including total vascular density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI) were determined by sidestream dark field imaging. The results showed that there were no difference in systemic circulation among the 3 groups. Compared with Tibetan group, TVD and PVD of microcirculation in Han group and migrant group were significantly increased (P < 0.05). Compared with Tibetan group and Han group, WBC, RBC, HGB and HCT of migrant group were significantly increased (P < 0.05). Compared with Han group and Migrant group, PLT of Tibetan group was significantly increased (P < 0.05). Compared with the Tibetan group, the levels of serum humoral factors CD105 and VEGF were significantly higher in the migrant group (P < 0.05), while compared with Han and migration groups, NO in Tibetan group was significantly increased (P < 0.05). It is suggested that there were significant differences in microcirculation (TVD, PVD), blood routine (WBC, RBC, HGB, HCT) and humoral factors (CD105, VEGF) among different populations in high altitude area. Importantly, the increased microcirculation, erythrocytosis and increased pro-angiogenic factors due to hypoxic environment were observed in long-term residents and migrants, except for permanent residents. These physiological changes have clinical significance in the treatment of septic shock and chronic altitude sickness for different plateau populations.