High-altitude erythrocytosis: mechanisms of adaptive and mal-adaptive responses

Physiology ◽  
2022 ◽  
Author(s):  
Francisco C. Villafuerte ◽  
Tatum S Simonson ◽  
Daniela Bermudez ◽  
Fabiola León-Velarde
Keyword(s):  
Red Blood Cells ◽  
High Altitude ◽  
Carrying Capacity ◽  
Blood Cells ◽  
Physiological Traits ◽  
Adaptive Responses ◽  
Chronic Mountain Sickness ◽  
Modest Increase ◽  
Mountain Sickness

Erythrocytosis, or increased production of red blood cells, is one of the most well-documented physiological traits that varies within and among in high-altitude populations. Although a modest increase in blood O2-carrying capacity may be beneficial for life in highland environments, erythrocytosis can also become excessive and lead to maladaptive syndromes such as Chronic Mountain Sickness (CMS).

Global REACH 2018: Volume regulation in high-altitude Andeans with and without chronic mountain sickness

2021 ◽  
Author(s):  
Andrew R. Steele ◽  
Michael M. Tymko ◽  
Victoria L. Meah ◽  
Lydia L Simpson ◽  
Christopher Gasho ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Plasma Renin Activity ◽  
High Altitude ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Plasma Renin ◽  
Renin Activity ◽  
Chronic Mountain Sickness ◽  
Plasma Aldosterone Concentration ◽  
Mountain Sickness

The high-altitude maladaptation syndrome known as chronic mountain sickness (CMS) is characterized by polycythemia and is associated with proteinuria despite unaltered glomerular filtration rate. However, it remains unclear if indigenous highlanders with CMS have altered volume regulatory hormones. We assessed N-terminal pro-B-type natriuretic peptide (NT pro-BNP), plasma aldosterone concentration, plasma renin activity, kidney function (urinary microalbumin, glomerular filtration rate), blood volume, and estimated pulmonary artery systolic pressure (ePASP), in Andean males without (n=14; age=39±11) and with (n=10; age=40±12) CMS at 4330 meters (Cerro de Pasco, Peru). Plasma renin activity (non-CMS: 15.8±7.9 vs. CMS: 8.7±5.4 ng/ml; p=0.025) and plasma aldosterone concentration (non-CMS: 77.5±35.5 vs. CMS: 54.2±28.9 pg/ml; p=0.018) were lower in highlanders with CMS compared to non-CMS, while NT pro-BNP was not different between groups (non-CMS: 1394.9±214.3 vs. CMS: 1451.1±327.8 pg/ml; p=0.15). Highlanders had similar total blood volume (non-CMS: 90±15 vs. CMS: 103±18 ml • kg-1; p=0.071), but Andeans with CMS had greater total red blood cell volume (non-CMS: 46±10 vs. CMS 66±14 ml • kg-1; p<0.01) and smaller plasma volume (non-CMS 43±7 vs. CMS 35±5 ml • kg-1; p=0.03) compared to non-CMS. There were no differences in ePASP between groups (non-CMS 32±9 vs. CMS 31±8 mmHg; p=0.6). A negative correlation was found between plasma renin activity and glomerular filtration rate in both groups (group: r=-0.66; p<0.01; non-CMS: r=-0.60; p=0.022; CMS: r=-0.63; p=0.049). A smaller plasma volume in Andeans with CMS may indicate an additional CMS maladaptation to high-altitude, causing potentially greater polycythemia and clinical symptoms.

Probing into the Oxygen Carrying Capacity of Red Blood Cells Using Raman Tweezers

2010 ◽  
Vol 39 (5) ◽  
pp. 907-912
Author(s):  
陈秀丽 CHEN Xiu-li ◽  
刘军贤 LIU Jun-xian ◽  
申卫东 SHEN Wei-dong ◽  
黎永青 LI Yong-qing ◽  
王桂文 WANG Gui-wen
Keyword(s):  
Red Blood Cells ◽  
Carrying Capacity ◽  
Blood Cells ◽  
Oxygen Carrying Capacity

Role of sex hormones in development of chronic mountain sickness in rats

1994 ◽  
Vol 77 (1) ◽  
pp. 427-433 ◽  
Author(s):  
L. C. Ou ◽  
G. L. Sardella ◽  
J. C. Leiter ◽  
T. Brinck-Johnsen ◽  
R. P. Smith
Keyword(s):  
Gender Differences ◽  
Pulmonary Hypertension ◽  
High Altitude ◽  
Sex Hormones ◽  
Systolic Pressure ◽  
Female Rats ◽  
Hypoxic Exposure ◽  
Chronic Mountain Sickness ◽  
Mountain Sickness

After chronic exposure to hypoxia, Hilltop Sprague-Dawley rats developed excessive polycythemia and severe pulmonary hypertension and right ventricular (RV) hypertrophy, signs consistent with human chronic mountain sickness; however, there were gender differences in the magnitude of the polycythemia and susceptibility to the fatal consequence of chronic mountain sickness. Orchiectomy and ovariectomy were performed to evaluate the role of sex hormones in the gender differences in these hypoxic responses. After 40 days of exposure to simulated high altitude (5,500 m; barometric pressure of 370 Torr and inspired Po2 of 73 Torr), both sham-gonadectomized male and female rats developed polycythemia and had increased RV peak systolic pressure and RV hypertrophy. The hematocrit was slightly but significantly higher in males than in females. Orchiectomy did not affect these hypoxic responses, although total ventricular weight was less in the castrated high-altitude rats. At high altitude, the mortality rates were 67% in the sham-operated male rats and 50% in the castrated animals. In contrast, ovariectomy aggravated the high-altitude-associated polycythemia and increased RV peak systolic pressure and RV weight compared with the sham-operated high-altitude female rats. Both sham-operated control and ovariectomized females suffered negligible mortality at high altitude. The present study demonstrated that 1) the male sex hormones play no role in the development of the excessive polycythemia, pulmonary hypertension, and RV hypertrophy during chronic hypoxic exposure or in the associated high mortality and 2) the female sex hormones suppressed both the polycythemic and cardiopulmonary responses in vivo during chronic hypoxic exposure.

NEOCYTOLYSIS OF RED BLOOD CELLS FOLLOWING HIGH ALTITUDE EXPOSURE

2012 ◽  
Vol 16 (2) ◽  
pp. 75-78
Author(s):  
Guglielmo Antonutto ◽  
Angela Risso
Keyword(s):  
Red Blood Cells ◽  
High Altitude ◽  
Blood Cells ◽  
Altitude Exposure

scholarly journals Effect of Hypoxia in the Pharmacological Treatment of Chronic Mountain Sickness (monge sickness) in Native Residents of High Altitude

2020 ◽  
Vol 5 (12) ◽  
pp. 3-3
Author(s):  
Aquino Lopez Tatiana; Aylas Aylas ◽  
Lucero; Brian Talledo Flores; Correa ◽  
Munoz; Mishel Loayza Miranda Jesus Alexander; Mendoza Chuquillanqui ◽  
Lenin; Mercado Baltazar Maria de los Angeles; Quispe Hidalgo ◽  
Natalia; Quispe Tovar Consuelo Milagros; Ramos Lucas ◽  
...  
Keyword(s):  
High Altitude ◽  
Pharmacological Treatment ◽  
Chronic Mountain Sickness ◽  
Mountain Sickness

scholarly journals Pulmonary arterial pressure at rest and during exercise in chronic mountain sickness: a meta-analysis

2019 ◽  
Vol 53 (6) ◽  
pp. 1802040 ◽  
Author(s):  
Rodrigo Soria ◽  
Matthias Egger ◽  
Urs Scherrer ◽  
Nicole Bender ◽  
Stefano F. Rimoldi
Keyword(s):  
Arterial Pressure ◽  
High Altitude ◽  
Pulmonary Arterial Pressure ◽  
Meta Analysis ◽  
Right Heart Failure ◽  
Exercise Intolerance ◽  
Point Estimate ◽  
Chronic Mountain Sickness ◽  
Pulmonary Arterial ◽  
Mountain Sickness

Up to 10% of the more than 140 million high-altitude dwellers worldwide suffer from chronic mountain sickness (CMS). Patients suffering from this debilitating problem often display increased pulmonary arterial pressure (PAP), which may contribute to exercise intolerance and right heart failure. However, there is little information on the usual PAP in these patients.We systematically reviewed and meta-analysed all data published in English or Spanish until June 2018 on echocardiographic estimations of PAP at rest and during mild exercise in CMS patients.Nine studies comprising 287 participants fulfilled the inclusion criteria. At rest, the point estimate from meta-analysis of the mean systolic PAP was 27.9 mmHg (95% CI 26.3–29.6 mmHg). These values are 11% (+2.7 mmHg) higher than those previously meta-analysed in apparently healthy high-altitude dwellers. During mild exercise (50 W) the difference in mean systolic PAP between patients and high-altitude dwellers was markedly more accentuated (48.3 versus 36.3 mmHg) than at rest.These findings indicate that in patients with CMS PAP is moderately increased at rest, but markedly increased during mild exercise, which will be common with activities of daily living.

scholarly journals Autonomic cardiovascular function in high-altitude Andean natives with chronic mountain sickness

2003 ◽  
Vol 94 (1) ◽  
pp. 213-219 ◽  
Author(s):  
C. Keyl ◽  
A. Schneider ◽  
A. Gamboa ◽  
L. Spicuzza ◽  
N. Casiraghi ◽  
...  
Keyword(s):  
Beneficial Effect ◽  
High Altitude ◽  
Baroreflex Sensitivity ◽  
Cardiovascular Function ◽  
Supplemental Oxygen ◽  
Arterial Oxygen ◽  
Control Group ◽  
Chronic Mountain Sickness ◽  
Mountain Sickness ◽  
Spontaneous Baroreflex

We evaluated autonomic cardiovascular regulation in subjects with polycythemia and chronic mountain sickness (CMS) and tested the hypothesis that an increase in arterial oxygen saturation has a beneficial effect on arterial baroreflex sensitivity in these subjects. Ten Andean natives with a Hct >65% and 10 natives with a Hct <60%, all living permanently at an altitude of 4,300 m, were included in the study. Cardiovascular autonomic regulation was evaluated by spectral analysis of hemodynamic parameters, while subjects breathed spontaneously or frequency controlled at 0.1 and 0.25 Hz, respectively. The recordings were repeated after a 1-h administration of supplemental oxygen and after frequency-controlled breathing at 6 breaths/min for 1 h, respectively. Subjects with Hct >65% showed an increased incidence of CMS compared with subjects with Hct <60%. Spontaneous baroreflex sensitivity was significantly lower in subjects with high Hct compared with the control group. The effects of supplemental oxygen or modification of the breathing pattern on autonomic function were as follows: 1) heart rate decreased significantly after both maneuvers in both groups, and 2) spontaneous baroreflex sensitivity increased significantly in subjects with high Hct and did not differ from subjects with low Hct. Temporary slow-frequency breathing may provide a beneficial effect on the autonomic cardiovascular function in high-altitude natives with CMS.

Sign in / Sign up

Export Citation Format

Share Document