scholarly journals Associations between arterial oxygen saturation, body size and limb measurements among high-altitude andean children

2013 ◽  
Vol 25 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Emma Pomeroy ◽  
Jay T. Stock ◽  
Sanja Stanojevic ◽  
J. Jaime Miranda ◽  
Tim J. Cole ◽  
...  
Keyword(s):  
Body Size ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen

P6480Asymmetric dimethylarginine (ADMA) predicts altitude-associated hypoxic pulmonary arterial hypertension

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R H Boeger ◽  
P Siques ◽  
J Brito ◽  
E Schwedhelm ◽  
E Pena ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Logistic Regression ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Pulmonary Arterial

Abstract Prolonged exposure to altitude-associated chronic hypoxia (CH) may cause high altitude pulmonary hypertension (HAPH). Chronic intermittent hypobaric hypoxia (CIH) occurs in individuals who commute between sea level and high altitude. CIH is associated with repetitive acute hypoxic acclimatization and conveys the long-term risk of HAPH. As nitric oxide (NO) is an important regulator of systemic and pulmonary vascular tone and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthesis that increases in hypoxia, we aimed to investigate whether ADMA predicts the incidence of HAPH among Chilean frontiers personnel exposed to six months of CIH. We performed a prospective study of 123 healthy male subjects who were subjected to CIH (5 days at appr. 3,550 m, followed by 2 days at sea level) for six months. ADMA, SDMA, L-arginine, arterial oxygen saturation, systemic arterial blood pressure, and haematocrit were measured at baseline and at months 1, 4, and 6 at high altitude. Acclimatization to high altitude was determined using the Lake Louise Score and the presence of acute mountain sickness (AMS). Echocardiography was performed after six months of CIH in a subgroup of 43 individuals with either good (n=23) or poor (n=20) aclimatization to altitude, respectively. Logistic regression was used to assess the association of biomarkers with HAPH. 100 study participants aged 18.3±1.3 years with complete data sets were included in the final analysis. Arterial oxygen saturation decreased upon the first ascent to altitude and plateaued at about 90% during the further course of the study. Haematocrit increased to about 47% after one month and remained stable thereafter. ADMA continuously increased and SDMA decreased during the study course, whilst L-arginine levels showed no distinct pattern. The incidence of AMS and the Lake Louise Score were high after the first ascent (53 and 3.1±2.4, respectively) and at one month of CIH (47 and 3.0±2.6, respectively), but decreased to 20 and 1.4±2.0 at month 6, respectively (both p<0.001 for trend). In echocardiography, 18 participants (42%) showed a mean pulmonary arterial pressure (mPAP) greater than 25 mm Hg (mean ± SD, 30.4±3.9 mm Hg), out of which 9 (21%) were classified as HAPH (mPAP ≥30 mm Hg; mean ± SD, 33.9±2.2 mm Hg). Baseline ADMA, but not SDMA, was significantly associated with mPAP at month 6 in univariate logistic regression analysis (R = 0.413; p=0.007). In ROC analysis, a cut-off for baseline ADMA of 0.665 μmol/l was determined as the optimal cut-off level to predict HAPH (mPAP >30 mm Hg) with a sensitivity of 100% and a specificity of 63.6%. ADMA concentration increases during long-term CIH. It is an independent predictive biomarker for the incidence of HAPH. SDMA concentration decreases during CIH and shows no association with HAPH. Our data support a role of impaired NO-mediated pulmonary vasodilation in the pathogenesis of high altitude pulmonary hypertension. Acknowledgement/Funding CONICYT/FONDEF/FONIS Sa 09I20007; FIC Tarapaca BIP 30477541-0; BMBF grant 01DN17046 (DECIPHER); Georg & Jürgen Rickertsen Foundation, Hamburg

scholarly journals Pulmonary artery pressure and arterial oxygen saturation in people living at high or low altitude: systematic review and meta-analysis

2016 ◽  
Vol 121 (5) ◽  
pp. 1151-1159 ◽  
Author(s):  
Rodrigo Soria ◽  
Matthias Egger ◽  
Urs Scherrer ◽  
Nicole Bender ◽  
Stefano F. Rimoldi
Keyword(s):  
Systematic Review ◽  
Pulmonary Artery ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Pulmonary Artery Pressure ◽  
Meta Analysis ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Low Altitude ◽  
Apparently Healthy

More than 140 million people are living at high altitude worldwide. An increase of pulmonary artery pressure (PAP) is a hallmark of high-altitude exposure and, if pronounced, may be associated with important morbidity and mortality. Surprisingly, there is little information on the usual PAP in high-altitude populations. We, therefore, conducted a systematic review (MEDLINE and EMBASE) and meta-analysis of studies published (in English or Spanish) between 2000 and 2015 on echocardiographic estimations of PAP and measurements of arterial oxygen saturation in apparently healthy participants from general populations of high-altitude dwellers (>2,500 m). For comparison, we similarly analyzed data published on these variables during the same period for populations living at low altitude. Twelve high-altitude studies comprising 834 participants and 18 low-altitude studies (710 participants) fulfilled the inclusion criteria. All but one high-altitude studies were performed between 3,600 and 4,350 m. The combined mean systolic PAP (right ventricular-to-right atrial pressure gradient) at high altitude [25.3 mmHg, 95% confidence interval (CI) 24.0, 26.7], as expected was significantly (P < 0.001) higher than at low altitude (18.4 mmHg, 95% CI 17.1,19.7), and arterial oxygen saturation was significantly lower (90.4%, 95% CI 89.3, 91.5) than at low altitude (98.1%; 95% CI 97.7, 98.4). These findings indicate that at an altitude where the very large majority of high-altitude populations are living, pulmonary hypertension appears to be rare. The reference values and distributions for PAP and arterial oxygen saturation in apparently healthy high-altitude dwellers provided by this meta-analysis will be useful to future studies on the adjustments to high altitude in humans.

scholarly journals Angiotensin-Converting Enzyme Genotype and Arterial Oxygen Saturation at High Altitude in Peruvian Quechua

2008 ◽  
Vol 9 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Abigail W. Bigham ◽  
Melisa Kiyamu ◽  
Fabiola León-Velarde ◽  
Esteban J. Parra ◽  
Maria Rivera-Ch ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme Genotype

scholarly journals Relationship Between Arterial Oxygen Saturation and Hematocrit, and Effect of Slow Deep Breathing on Oxygen Saturation in Himalayan High Altitude Populations

2013 ◽  
Vol 10 (3) ◽  
pp. 30-34 ◽  
Author(s):  
Ojashwi Nepal ◽  
BR Pokharel ◽  
K Khanal ◽  
SL Mallik ◽  
BK Kapoor ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Carrying Capacity ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
P Value ◽  
Deep Breathing ◽  
Cross Sectional ◽  
Lower Altitude ◽  
Oxygen Carrying Capacity

Background The oxygen saturation of haemoglobin is reduced in high altitude-living organisms. Increase in the hematocrit is responsible for rise in the hemoglobin concentration so that the oxygen carrying capacity in the hypobaric hypoxic subject is elevated. Objectives To compare two different high altitude populations, in order to study the relationship between arterial oxygen saturation and hematocrit. Methods lIn the cross-sectional study of two populations residing at altitude of 2800 m and 3760 m are compared for the difference in hematocrit. The oxygen carrying capacity of arterial haemoglobin (SaO2) is determined by pulse oximetry. The sample is drawn from the natives of two small villages, Thini at Jomsom (2800 m) and Jharkot (3760 m) in Mustang district of Nepal. The natives at 2800 m are termed as lower high altitude population and local residents at 3760 m are said to be higher altitude population in this study. The sample blood was drawn by venipuncture and packed cell volume was determined by Wintrobe’s method. Results The hematocrit obtained from 3760 m altitude population and the lower high altitude population at altitude of 2800 m differ significantly with the p value < 0.0001and the SaO2 in both the population fails to show any difference with p value > 0.05. Deep breathing exercise in these populations however increased SaO2 significantly. Conclusion The higher altitude natives have greater arterial oxygen saturation than lower altitude population which is due to rise in red cell concentration. The slow deep breathing raises oxygen saturation irrespective of altitude. Kathmandu University Medical Journal | VOL.10 | NO. 3 | ISSUE 39 | JUL- SEP 2012 | Page 30-34 DOI: http://dx.doi.org/10.3126/kumj.v10i3.8014

scholarly journals Pregnancy at high altitude in the Andes leads to increased total vessel density in healthy newborns

2016 ◽  
Vol 121 (3) ◽  
pp. 709-715 ◽  
Author(s):  
Norina N. Gassmann ◽  
Hugo A. van Elteren ◽  
Tom G. Goos ◽  
Claudia R. Morales ◽  
Maria Rivera-Ch ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Dark Field ◽  
Vessel Density ◽  
Arterial Oxygen ◽  
Dark Field Imaging ◽  
Total Vessel Density

The developing human fetus is able to cope with the physiological reduction in oxygen supply occurring in utero. However, it is not known if microvascularization of the fetus is augmented when pregnancy occurs at high altitude. Fifty-three healthy term newborns in Puno, Peru (3,840 m) were compared with sea-level controls. Pre- and postductal arterial oxygen saturation (SpO2) was determined. Cerebral and calf muscle regional tissue oxygenation was measured using near infrared spectroscopy (NIRS). Skin microcirculation was noninvasively measured using incident dark field imaging. Pre- and postductal SpO2 in Peruvian babies was 88.1 and 88.4%, respectively, which was 10.4 and 9.7% lower than in newborns at sea level ( P < 0.001). Cerebral and regional oxygen saturation was significantly lower in the Peruvian newborns (cerebral: 71.0 vs. 74.9%; regional: 68.5 vs. 76.0%, P < 0.001). Transcutaneously measured total vessel density in the Peruvian newborns was 14% higher than that in the newborns born at sea level (29.7 vs. 26.0 mm/mm2; P ≤ 0.001). This study demonstrates that microvascular vessel density in neonates born to mothers living at high altitude is higher than that in neonates born at sea level.

Pulmonary circulation and gas exchange at exercise in Sherpas at high altitude

2014 ◽  
Vol 116 (7) ◽  
pp. 919-926 ◽  
Author(s):  
Vitalie Faoro ◽  
Sandrine Huez ◽  
Rebecca Vanderpool ◽  
Herman Groepenhoff ◽  
Claire de Bisschop ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Saturation ◽  
Aerobic Exercise ◽  
High Altitude ◽  
Exercise Capacity ◽  
Arterial Oxygen Saturation ◽  
Maximum Oxygen Uptake ◽  
Arterial Oxygen ◽  
Diffusing Capacity ◽  
Aerobic Exercise Capacity

Tibetans have been reported to present with a unique phenotypic adaptation to high altitude characterized by higher resting ventilation and arterial oxygen saturation, no excessive polycythemia, and lower pulmonary arterial pressures (Ppa) compared with other high-altitude populations. How this affects exercise capacity is not exactly known. We measured aerobic exercise capacity during an incremental cardiopulmonary exercise test, lung diffusing capacity for carbon monoxide (DlCO) and nitric oxide (DlNO) at rest, and mean Ppa (mPpa) and cardiac output by echocardiography at rest and at exercise in 13 Sherpas and in 13 acclimatized lowlander controls at the altitude of 5,050 m in Nepal. In Sherpas vs. lowlanders, arterial oxygen saturation was 86 ± 1 vs. 83 ± 2% (mean ± SE; P = nonsignificant), mPpa at rest 19 ± 1 vs. 23 ± 1 mmHg ( P < 0.05), DlCO corrected for hemoglobin 61 ± 4 vs. 37 ± 2 ml·min−1·mmHg−1 ( P < 0.001), DlNO 226 ± 18 vs. 153 ± 9 ml·min−1·mmHg−1 ( P < 0.001), maximum oxygen uptake 32 ± 3 vs. 28 ± 1 ml·kg−1·min−1 ( P = nonsignificant), and ventilatory equivalent for carbon dioxide at anaerobic threshold 40 ± 2 vs. 48 ± 2 ( P < 0.001). Maximum oxygen uptake was correlated directly to DlCO and inversely to the slope of mPpa-cardiac index relationships in both Sherpas and acclimatized lowlanders. We conclude that Sherpas compared with acclimatized lowlanders have an unremarkable aerobic exercise capacity, but with less pronounced pulmonary hypertension, lower ventilatory responses, and higher lung diffusing capacity.

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