Correlation between RBC changes and coagulation parameters in high altitude population

Dietary patterns related to attention and physiological function in high-altitude migrants

High altitude exposure negatively affects human attentional function. However, no studies have explored the regulation of attentional and physiological functions from a dietary perspective. A total of 116 Han Chinese students from Tibet University who were born and raised in a plain area and had been living in Tibet for > 2 years were recruited. All participants were male migrants. A food frequency questionnaire, complete blood count, and attention network test were performed on the participants. Pearson's correlation was applied to assess the reliability and validity of the food frequency questionnaire. Principal component analysis was utilized to extract dietary patterns. A linear mixed model was employed to account for individual differences. The results showed that the five main dietary patterns were coarse grain, alcohol, meat, protein, and snacking dietary patterns. Furthermore, individuals who adhered to the coarse grain dietary pattern and had high mean corpuscular hemoglobin showed better attentional performance. Individuals with high alcohol consumption and systemic immune-inflammation index levels exhibited worse attentional performance. These findings imply that high-altitude migrants should include more coarse grains in their daily diet and avoid excessive alcohol consumption to improve attention.

Contemporary tools for evaluation of hemostasis in neonates. Where are we and where are we headed?

The assessment of hemostatic disorders in neonates is crucial, but remains challenging for clinicians. Although the concept of developmental hemostasis is widely accepted among hemostasis specialists globally, it is probably under-recognized by clinicians and laboratory practitioners. In parallel with age-dependent hemostatic status maturation, comprehension of the differences between normal values is crucial for the accurate diagnosis of potential hemorrhagic and thrombotic disorders of the vulnerable neonatal population. This review outlines the basics of developmental hemostasis and the features of the available coagulation testing methods, with a focus on novel tools for evaluating the neonatal hemostatic profile. Common errors, issues, and pitfalls during the assessment of neonatal hemostasis are discussed, along with their impact on patient management. Current knowledge gaps and research areas are addressed. Further studying to improve our understanding of developmental hemostasis and its reflection on everyday clinical practice is warranted.

Retinal Manifestations in High Altitude

Dangi, Meenu, Arnab Sadhukhan, Poninder Kumar, S. Bandopadhayay, Vijay K. Sharma, V.K. Patra, Manu Chaudhary, and Vipin Rana. Retinal manifestations in high altitude. High Alt Med Biol. 24:296-301, 2023. Aim: To study the high altitude (HA)-related retinal manifestations among security personnel and thus to provide new insights into the characteristics and mechanisms of retinopathy. Materials and Methods: This was a multicentric, nonrandomized prospective observational and descriptive study. We studied 54 security personnel over 1 year, who were referred from HA areas of northern India and north-eastern India for ocular problems. Complete coagulation profile was performed among patients with vascular occlusion. Results: There were total of 54 patients with ages ranging from 22 to 55 years. HA retinopathy was noticed in 28 patients: central retinal vein occlusion (6 patients), branch retinal vein occlusion (4 patients), branch retinal artery occlusion (1 patient), central retinal artery occlusion (4 patients), ocular ischemic syndrome (1 patient), central serous chorioretinopathy (7 patients), acetazolamide-induced maculopathy (1 patient), and solar retinopathy (2 patients). Along with an increased hematocrit, serum homocysteine was raised in the majority of vascular occlusions. The mean age was 38.16 years, the mean altitude was 14,716 ft, and the mean duration of stay was 11.2 weeks. Conclusion: Hypobaric hypoxia due to HA is a potential risk for HA retinopathy and associated vascular occlusions. Aside from increased hematocrit, hyperhomocysteinemia is a potential cause of vascular occlusions.

A study on the correlation between hemoglobin concentration and the storage quality of suspended red blood cells prepared from the whole blood of Tibetan male residents

Background

Previous studies reported that the blood of Tibetans living at different altitudes may vary slightly. There is evidence that the harsh environmental conditions at high altitudes, such as low pressure and hypoxia, may affect the morphology and hemorheology of red blood cells (RBCs). Hypoxia would increase the levels of hemoglobin ([Hb]) and hematocrit (Hct), potentially increasing blood hyperviscosity and compromising blood collection and transfusions. Therefore, it is critical to investigate the in vitro storage quality of Tibetan RBCs.

Objectives

In this study, the in vitro quality of suspended RBCs (SRBCs) prepared from whole blood (WB) of Tibetan residents with varying Hb concentrations ([Hb]) was measured during storage, and the relationship between the major factors in RBC storage and [Hb] was studied.

Materials and methods

The WB of Tibetan men was divided into three groups based on [Hb] levels (group A: 120 < Hb ≤ 185 g/L; group B: 185 < Hb ≤ 210 g/L; group C: Hb > 210 g/L). The SRBCs prepared from WB were examined aseptically on days 1, 14, 21, and 35 after storage.

Results

[Hb] was not correlated with mean corpuscular volume (MCV), adenosine triphosphate (ATP), pH, P50, and hemolysis. There was a moderate or strong negative association between platelets (PLT) and [Hb] from days 1 to 35, and the PLT number of group C was lower than group A during storage. Group C had the highest change rates of electrolytes, glucose, and lactate, and there were moderate or strong positive correlations between lactate and [Hb] (r = 0.3772, p = 0.0045), glucose and [Hb] (r = 0.5845, p < 0.0001), Na⁺ and [Hb] (r = 0.3966, p = 0.0027), and K⁺ and [Hb] (r = 0.4885, p = 0.0002). Group B had the highest change rates of 2,3-DPG on day 35, and there was a negative correlation between 2,3-DPG and [Hb] (r = -0.4933, p = 0.0001).

Conclusions

These new data on the [Hb] could have implications for researchers wishing to study the storage quality of Tibetan SRBCs, particularly in the context of erythrocyte metabolism, and we propose finding a new, suitable alternative solution for plateau SRBCs, particularly the blood with [Hb] greater than 185 g/L. Our results could have important implications for researchers wishing to study the potential framework of high-altitude-induced SRBC storage lesions.

Does living at high altitude increase the risk of bleeding events after total knee arthroplasty? A retrospective cohort study

OBJECTIVE

Post-operative bleeding after total knee arthroplasty (TKA) is a frequent cause of post-operative complications. This study compared blood loss and indicators of coagulation and fibrinolysis between TKA patients living at low or high altitudes.

METHODS

We retrospectively analyzed 120 patients at our institution who underwent primary TKA from May 2019 to March 2020, and we divided them into those living in areas about 500 m or > 3000 m above sea level. We compared the primary outcome of total blood loss between them. We also compared them in terms of several secondary outcomes: coagulation and fibrinolysis parameters, platelet count, reduction in hemoglobin, hidden blood loss, intra-operative blood loss, transfusion rate, and incidence of thromboembolic events and other complications.

RESULTS

Total blood loss was significantly higher in the high-altitude group than in the low-altitude group (mean, 748.2 mL [95% CI, 658.5-837.9] vs 556.6 mL [95% CI, 496.0-617.1]; p = 0.001). The high-altitude group also showed significantly longer activated partial thromboplastin time, prothrombin time, and thrombin time before surgery and on post-operative day one, as well as increased levels of fibrinogen/fibrin degradation product on post-operative days one and three. Ecchymosis was significantly more frequent in the high-altitude group (41.7 vs 21.7%; relative risk (RR) = 1.923 [95% CI, 1.091-3.389]; p = 0.019). The two groups showed similar transfusion rates, and none of the patients experienced venous thromboembolism, pulmonary embolism, or infection.

CONCLUSION

High altitude may alter coagulation and fibrinolysis parameters in a way that increases risk of blood loss after TKA. Such patients may benefit from special management to avoid bleeding events.

Hemostatic Effects of Bio-Zeolite Gauze and QuikClot Combat Gauze on Major Bleeding in Rabbits Acutely Exposed to High Altitude

Objective: Hemostatic gauze application is an effective way to control major bleeding, which is the most common cause of death in trauma in both civilian and military settings. Coagulation derangement after acute exposure to high altitude might alter the effects of hemostatic gauzes. The present study aimed to observe the hemostatic effects of bio-zeolite gauze (BZG) and QuikClot Combat Gauze® (QCG) on major bleeding in rabbits acutely exposed to high altitude.Methods: Sixty rabbits were randomly and evenly divided into six groups. Animal models of simulated blast- and fragment-induced inguinal major bleeding were prepared in lower altitude and high-altitude areas, and BZG, QCG, and ordinary gauze without hemostatic material were used to control bleeding. The primary outcomes included immediate hemostasis rate, blood loss, and survival rate, while the secondary outcomes included hemodynamic parameters, laboratory examinations, and coagulation-relevant markers.Results: The overall effects of BZG and QCG were better than those of ordinary gauze, with a higher immediate hemostatic rate, less blood loss, and higher survival rate at 90 min after gauze application and higher red blood cell and platelet counts and lower creatinine level at 30 min after gauze application in lower altitude. The concentrations of coagulation factor XII and factor X in rabbits acutely exposed to high altitude were significantly lower than those in lower altitude. At high altitude, the hemostatic effects of BZG did not decrease significantly compared to those in the lower altitude, whereas those of ordinary gauze and QCG decreased significantly at high altitude compared to those in the lower altitude.Conclusions: Coagulation derangement after acute exposure to high altitude has negative effects on ordinary gauze and QCG but has no significant negative hemostatic effects on BZG.

Correlation of PDGF and TXA2 expression with platelet parameters and coagulation indices in chronic altitude sickness (CMS) patients

NEW FINDINGS

What is the central question of this study?

ANSWER

Are PDGF and TXA2 expressions elevated in chronic altitude patients, and are they related to thrombosis in chronic altitude disease? What is the main finding and its importance?

ANSWER

The expression of PDGF and TXA2 both in the bone marrow and peripheral blood of patients with chronic altitude disease is elevated, which is considered to be involved in the mechanism of thrombosis in patients with chronic altitude disease.

ABSTRACT

Objective: The purpose of this study was to evaluate the expression of PDGF and TXA2 with platelet parameters and coagulation indices in chronic mountain sickness (CMS) patients and healthy individuals on a high-elevation plateau.

METHOD

The levels of PDGF and TXA2 were examined in 22 CMS patients and 25 healthy individuals, and the association between platelet parameters and coagulation indices was investigated.

RESULTS

The MPV, PLT, PCT, and FDP characteristics of the CMS group were statistically different in the CMS compared to the control group (P<0.001). The levels of PDGF and TXA2 in the bone marrow and peripheral blood of CMS patients were significantly different (P<0.01) in comparison to the control group. The two factors had no statistically significant relationship with platelet parameters or coagulation indices (P>0.159).

CONCLUSIONS

According to the current findings, platelets in CMS patients were activated, resulting in aberrant coagulation and PDGF and TXA2 expression, which could be due to physiological adjustments to the plateau's high altitude. To summarize, PDGF and TXA2 levels in CMS patients were not correlated with coagulation or platelet parameters, implying that the mechanism behind their increased expression warrants additional investigation. This article is protected by copyright. All rights reserved.

The Clinical Differences of Patients With Traumatic Brain Injury in Plateau and Plain Areas

Objective

Traumatic brain injury (TBI) is a leading cause of death and disability, which tends to have a worse clinical recovery if it occurs in plateau areas than in plain areas. To explore the underlying cause of this outcome preliminarily, this retrospective study was conducted to compare the clinical differences of patients with TBI in plateau and plain areas.

Methods

In this study, 32 patients with TBI in plateau areas (altitude ≥ 4,000 m) and 32 in plain areas (altitude ≤ 1,000 m) were recruited according to the inclusion and exclusion criteria from June 2020 to December 2021. The collected data and compared parameters include clinical features, head CT presentations and Marshall classifications, hematology profile, lipid profile, coagulation profile, and multiorgan (cardiac, liver, renal) function within 24 h of hospital admission, as well as the treatment method and final outcome.

Results

There were no obvious differences in demographic characteristics, including gender, age, height, and weight, between patients with TBI in plateau and plain areas (all P > 0.05). Compared to patients with TBI in plain areas, the time before hospital admission was longer, heartbeat was slower, systolic blood pressure (SBP) was lower, and hospital stays were longer in patients with TBI in plateau areas (all P < 0.05). More importantly, elevated red blood cells (RBCs) count and hemoglobin (HGB) level, enhanced coagulation function, and higher rates of multiorgan (cardiac, liver, and renal) injury were found in patients with TBI in plateau areas (all P < 0.05).

Conclusion

Patients with TBI in plateau areas presented with altered clinical characteristics, enhanced coagulation function, and aggravated predisposition toward multiorgan (cardiac, liver, and renal) injury, compared to patients with TBI in plain areas. Future prospective studies are needed to further elucidate the influences of high altitude on the disease course of TBI.

Time Course of Coagulo-Fibrinolytic Derangements During Acclimatization to High Altitude in Rabbits and a Preliminary Study on the Possible Mechanisms

Zhong, Xin, Zhao Ye, Xiaolin Zhou, Renqing Jiang, Yijun Jia, Wenqiong Du, Haoyang Yang, Lin Zhang, Bai Lu, and Zhaowen Zong. Time course of coagulo-fibrinolytic derangements during acclimatization to high altitude in rabbits and a preliminary study on the possible mechanisms. High Alt Med Biol. 00:000-000, 2022. Background: Conflicting data exist regarding changes in the coagulation system during acclimatization to high altitude (HA), which makes the prevention of thromboembolic events difficult. The present study aimed at observing the dynamic changes in the coagulo-fibrinolysis system during acclimatization to HA and at exploring the possible mechanisms. Materials and Methods: Twenty rabbits of both sexes were randomly divided into two groups, including group A rabbits (healthy plain controls) and group B rabbits (acutely exposed to HA). A traditional coagulation test, thromboelastography analysis, and full blood cell count were used to assess the coagulo-fibrinolytic changes at different time points. Plasma was collected to examine the levels of relevant biomarkers. Results: Six hours and 1 day after acute exposure to HA, the coagulo-fibrinolytic system demonstrated a hypercoagulable state. Further, 3 days after exposure to HA, group B rabbits showed hypocoagulability, increased fibrinolysis, and lower clot firmness and 7 days after exposure to HA, delayed coagulation, decreased fibrinolysis, and increased clot firmness were observed. Subsequently, 14, 21, and 28 days after exposure to HA, we found increased clot firmness. Increased platelet counts and concentrations of fibrinogen and plasminogen activator inhibitor-1 contributed to this change. Conclusion: The coagulo-fibrinolytic derangements during acclimatization to HA in rabbits demonstrated a dynamic pattern.

Early Warning and Clinical Epidemiological Characteristics of Lung Injury in the Treatment of Infectious Staphylococcus aureus Sepsis by Vancomycin Based on Adaptive Niche Genetic Algorithm and Pulmonary Ultrasound Images

Adaptive niche genetic algorithm (ANGA) and lung ultrasound were combined, the death warning mathematical model was established for patients with sepsis-lung injury, and the epidemiological characteristics were analyzed to explore the efficacy of Vancomycin in the treatment of sepsis-lung injury. First, 88 sepsis patients with lung injury were selected as the research objects. General clinical data and pulmonary ultrasound results were collected. On this basis, epidemiological analysis was carried out, and the death warning model of patients with sepsis-lung injury was established based on ANGA algorithm. Then, the total cure rate, Staphylococcus aureus (SA) clearance rate, methicillin-resistant SA (MRSA) clearance rate, and the incidence of adverse reactions after intravenous infusion of Vancomycin were analyzed. The results showed that the ANGA mathematical model combined with the random forest (RF) classifier proposed had better classification effect and robustness relative to the traditional principal component analysis and NGA. The early warning accuracy of the proposed ANGA + RF mathematical model was higher than 95% in contrast to that of the APACHE-II score and the SOFA score. Compared with patients in the severe group, the MRSA infection rate and the levels of procalcitonin (PCT), C-reactive protein (CRP), and activated partial thromboplastin time (APTT) of SA sepsis-lung injury patients were greatly reduced, while thrombin time (TT) and D-D dimer in the death group were considerably increased (p < 0.05), and the PLT level was greatly reduced (p < 0.05). In addition, the total cure rate, SA clearance rate, and MRSA clearance rate of Vancomycin-treated SA sepsis-lung injury patients were significantly increased (p < 0.05) compared with patients in the conventional treatment control group. However, the probability of adverse reactions was increased notably (p < 0.05). ANGA combined with RF classifier can improve the accuracy of death warning in patients with sepsis-lung injury. Vancomycin can effectively eliminate MRSA infection rate in patients with sepsis-lung injury and improve the treatment effect of patients.

Platelets and High-Altitude Exposure: A Meta-Analysis

Wang, Yuliang, Xuewen Huang, Weibo Yang, and Qingxian Zeng. Platelets and high-altitude exposure: a meta-analysis. High Alt Med Biol. 23:43-56, 2022. Background: How high-altitude hypoxia influences platelets is controversial. We attempted to quantify the impact of high-altitude exposure on platelets through meta-analysis. Methods: We systematically searched electronic databases (PubMed, Embase, Web of Science, VIP, Wanfang, and CNKI) and identified articles reporting an association between platelet count (PC) or platelet indices (platelet distribution width, mean platelet volume [MPV], and plateletcrit) and high-altitude exposure. The mean and standard deviation were extracted, and the standard mean difference (SMD) was estimated using random-effects models. Stata 15.3 was used to analyze statistical data. Results: Thirty-two studies were ultimately included. For acute high-altitude hypoxia (1-14 days), no significant difference was detected, even in patients with acute mountain disease. For the chronic high-altitude hypoxia (≥1 month) group, a significant decrease in PC (SMD [95% confidence interval, CI] = -0.34 [-0.63 to -0.04]) and increase in MPV (SMD [95% CI] = 1.55 [0.60 to 2.49]) were detected compared with those in the control group. Subgroup analysis showed that the tendency was more obvious in the group with longer exposure (≥1 year). Moreover, the PC of the chronic mountain sickness group was less compared with the healthy altitude control group (SMD [95% CI] = -1.82 [-2.74 to -0.91]). Conclusion: A reduced PC and an increased MPV are associated with chronic exposure to high-altitude hypoxia. Moreover, acute high-altitude exposure has no significant influence on platelets.

An Evaluation of Morphological Changes and Deformability of Suspended Red Blood Cells Prepared Using Whole Blood with Different Hemoglobin Levels of Tibetans

Background

The hypoxic environment stimulates the human body to increase the levels of hemoglobin (HGB) and hematocrit and the number of red blood cells. Such enhancements have individual differences, leading to a wide range of HGB in Tibetans' whole blood (WB).

Study Design

WB of male Tibetans was divided into 3 groups according to different HGB (i.e., A: >120 but ≤185 g/L, B: >185 but ≤210 g/L, and C: >210 g/L). Suspended red blood cells (SRBC) processed by collected WB and stored in standard conditions were examined aseptically on days 1, 14, 21, and 35 after storage. The routine biochemical indexes, deformability, cell morphology, and membrane proteins were tested.

Results

Mean corpuscular volume, adenosine triphosphate, pH, and deformability were not different in group A vs. those in storage (p > 0.05). The increased rate of irreversible morphology of red blood cells was different among the 3 groups, but there was no difference in the percentage of red blood cells with an irreversible morphology after 35 days of storage. Group C performed better in terms of osmotic fragility and showed a lower rigid index than group A. Furthermore, SDS-PAGE revealed similar cross-linking degrees of cell membrane protein but the band 3 protein of group C seemed to experience weaker clustering than that of group A as detected by Western Blot analysis after 35 days of storage.

Conclusions

There was no difference in deformability or morphological changes in the 3 groups over the 35 days of storage. High HGB levels of plateau SRBC did not accelerate the RBC change from a biconcave disc into a spherical shape and it did not cause a reduction in deformability during 35 days of preservation in bank conditions.

Effects of long-term high-altitude exposure on fibrinolytic system

OBJECTIVE

High altitude (HA), with the main feature of hypobaric hypoxia, is an independent risk factor for thrombosis. However, little is known on the alterations of fibrinolytic system in adaptation to HA. In this study, we investigated changes of fibrinolytic system parameters between individuals permanently living at HA and low altitude (LA) regions, and provided data for further studies on HA-induced thrombotic disease.

MATERIAL AND METHODS

A total of 226 eligible participants, including 103 LA participants, 100 healthy HA subjects and 23 high altitude polycythemia (HAPC) patients, were recruited in this study. Six fibrinolytic parameters, i.e. fibrinogen (Fbg), D-dimer (DDi), antithrombin III (AT-III), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) and plasminogen (PLG) were analyzed respectively. PAI-1 and tPA were performed by using bio-immuno-assays and an automated coagulation analyzer was used to conduct Fbg, DDi, AT-III and PLG tests.

RESULTS

Plasma levels of Fbg, DDi, PAI-1 and PLG were significantly higher in healthy HA group than in LA group (all p < 0.05), whereas tPA was significantly lower in healthy HA group. No significant difference in AT-III was observed between healthy HA and LA groups (p > 0.05). All these fibrinolytic parameters showed no significant distinctions between healthy HA subjects and HAPC patients (all p > 0.05). HGB showed no relationship with fibrinolytic parameters in HA cohort.

CONCLUSION

This study demonstrates that HA environment has a significant effect on fibrinolytic system and provides a foundation for further studies on HA hypobaric hypoxia-induced thrombotic disease.

Characteristics of Tibetan pig lung tissue in response to a hypoxic environment on the Qinghai-Tibet Plateau

To adapt to the plateau environment, Tibetan pigs' lungs have developed a unique physiological mechanism during evolution. The vascular corrosion casting technique and scanning electron microscopy were used to understand arterial architecture. Blood physiological index and quantitative real-time PCR (qRT-PCR) were used for assessing whether the lung can regulate the body through anatomical, physiological and molecular mechanisms to adapt to hypoxic environments. Our study showed that the lungs of Tibetan pigs were heavier and wider and that the pulmonary arteries were thicker and branched and had a denser vascular network than those of Landrace pigs. The hemoglobin (HGB), mean corpuscular hemoglobin concentration (MCHC) values of high-altitude pigs were significantly higher than those of low-altitude pigs. The expression levels of HIF- 1α , EPAS1, EPO and VEGF, but not those of eNOSand EGLN1, were significantly higher in the lungs of high-altitude pigs than in those from pigs at a lower altitude ( P<0.05 ). These findings and a comprehensive analysis help elucidate the pulmonary mechanism of hypoxic adaptation in pigs.