scholarly journals Adaptation of ghrelin and the GH/IGF axis to high altitude

2012 ◽  
Vol 166 (6) ◽  
pp. 969-976 ◽  
Author(s):  
Stefan Riedl ◽  
Michael Kluge ◽  
Katharina Schweitzer ◽  
Thomas Waldhör ◽  
Herwig Frisch
Keyword(s):  
High Altitude ◽  
Acute Mountain Sickness ◽  
Well Being ◽  
Metabolic Effects ◽  
Igf Binding Proteins ◽  
Adaptive Processes ◽  
Igf Binding ◽  
Acid Labile Subunit ◽  
Mountain Sickness ◽  
The Impact

ObjectiveHigh altitude (HA) provokes a variety of endocrine adaptive processes. We investigated the impact of HA on ghrelin levels and the GH/IGF axis.DesignObservational study as part of a medical multidisciplinary project in a mountainous environment.MethodsThirty-three probands (12 females) were investigated at three timepoints during ascent to HA (A: d −42, 120 m; B: d +4, 3440 m; C: d +14, 5050 m). The following parameters were obtained: ghrelin; GH; GH-binding protein (GHBP); IGF1; IGF2; IGF-binding proteins (IGFBPs) -1, -2, and -3; acid-labile subunit (ALS); and insulin. Weight was monitored and general well being assessed using the Lake Louise acute mountain sickness (AMS) score.ResultsGhrelin (150 vs 111 pg/ml;P<0.01) and GH (3.4 vs 1.7 μg/l;P<0.01) were significantly higher at timepoint C compared with A whereas GHBP, IGF1, IGF2, IGFBP3, ALS, and insulin levels did not change. IGFBP1 (58 vs 47 μg/l;P<0.05) and, even more pronounced, IGFBP2 (1141 vs 615 μg/l;P<0.001) increased significantly. No correlation, neither sex-specific nor in the total group, between individual weight loss (females: −2.1 kg; males: −5.1 kg) and rise in ghrelin was found. Five of the subjects did not reach investigation point C due to AMS.ConclusionsAfter 14 days of exposure to HA, we observed a significant ghrelin and GH increase without changes in GHBP, IGF1, IGF2, IGFBP3, ALS, and insulin. Higher GH seems to be needed for acute metabolic effects rather than IGF/IGFBP3 generation. Increased IGFBP1 and -2 may reflect effects from HA on IGF bioavailability.

Optic nerve sheath diameter changes at high altitude and in acute mountain sickness: meta-regression analyses

2020 ◽  
pp. bjophthalmol-2020-317717
Author(s):  
Tou-Yuan Tsai ◽  
George Gozari ◽  
Yung-Cheng Su ◽  
Yi-Kung Lee ◽  
Yu-Kang Tu
Keyword(s):  
Optic Nerve ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Optic Nerve Sheath Diameter ◽  
Optic Nerve Sheath ◽  
Cochrane Library ◽  
Regression Analyses ◽  
Spline Regression ◽  
Nerve Sheath ◽  
Mountain Sickness

Background/aimsTo assess changes in optic nerve sheath diameter (ONSD) at high altitude and in acute mountain sickness (AMS).MethodsCochrane Library, EMBASE, Google Scholar and PubMed were searched for articles published from their inception to 31st of July 2020. Outcome measures were mean changes of ONSD at high altitude and difference in ONSD change between subjects with and without AMS. Meta-regressions were conducted to investigate the relation of ONSD change to altitude and time spent at that altitude.ResultsEight studies with 248 participants comparing ONSD from sea level to high altitude, and five studies with 454 participants comparing subjects with or without AMS, were included. ONSD increased by 0.14 mm per 1000 m after adjustment for time (95% CI: 0.10 to 0.18; p<0.01). Restricted cubic spline regression revealed an almost linear relation between ONSD change and time within 2 days. ONSD was greater in subjects with AMS (mean difference=0.47; 95% CI: 0.14 to 0.80; p=0.01; I2=89.4%).ConclusionOur analysis shows that ONSD changes correlate with altitude and tend to increase in subjects with AMS. Small study number and high heterogeneity are the limitations of our study. Further large prospective studies are required to verify our findings.

scholarly journals A Prospective Epidemiological Study of Acute Mountain Sickness in Nepalese Pilgrims Ascending to High Altitude (4380 m)

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e75644 ◽  
Author(s):  
Martin J. MacInnis ◽  
Eric A. Carter ◽  
Michael G. Freeman ◽  
Bidur Prasad Pandit ◽  
Ashmita Siwakoti ◽  
...  
Keyword(s):  
High Altitude ◽  
Epidemiological Study ◽  
Acute Mountain Sickness ◽  
Prospective Epidemiological Study ◽  
Mountain Sickness

Abstract 14359: Single Nucleotide Polymorphisms in Genes Involved in L-arginine / Dimethylarginine Metabolism Predispose for Pulmonary Hypertension and Acute Mountain Sickness at High Altitude

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Juliane Hannemann ◽  
Julia Zummack ◽  
PATRICIA SIQUES ◽  
JULIO BRITO ◽  
Rainer Boeger
Keyword(s):  
Pulmonary Hypertension ◽  
Relative Risk ◽  
Genetic Variability ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Minor Allele ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mountain Sickness ◽  
Study Participants

Introduction: Chronic (CH) and chronic-intermittent (CIH) exposure to hypoxia at high altitude causes acute or chronic mountain sickness and elevation of mean pulmonary arterial pressure (mPAP). This is paralleled by increased plasma levels of ADMA, an endogenous inhibitor of NO synthesis. ADMA is cleaved by dimethylarginine dimethylaminohydrolase (DDAH1 and DDAH2), whilst symmetric dimethylarginine (SDMA) is cleaved by AGXT2. Arginase (ARG1 and ARG2) competes with endothelial NO synthase (NOS3) for L-arginine as substrate. We have shown previously that baseline ADMA (at sea level) determines mPAP after six months of CIH; cut-off values of 25 mm Hg and 30 mm Hg are being used to diagnose high altitude pulmonary hypertension. Hypothesis: We hypothesized that genetic variability in genes coding for core enzymes of ADMA, SDMA, and L-arginine metabolism may predispose individuals for high altitude disease and pulmonary hypertension. Methods: We genotyped 16 common single nucleotide polymorphisms in the NOS3, DDAH1, DDAH2, AGXT2, ARG1 and ARG2 genes of 69 healthy male Chilean subjects. Study participants adhered to a CIH regimen (5d at 3,550m, 2d at sea level) for six months. Metabolites were measured by LC-MS/MS; mPAP was estimated by echocardiography at six months, and altitude acclimatization was assessed by Lake Louise Score and arterial oxygen saturation. Results: Carriers of the minor allele of DDAH1 rs233112 had a higher mean baseline ADMA level (0.76±0.03 vs. 0.67±0.02 μmol/l; p<0.05), whilst the major allele of DDAH2 rs805304 was linked to an exacerbated increase of ADMA in hypoxia (0.10±0.03 vs. 0.04±0.04 μmol/l; p<0.02). Study participants carrying the minor allele of ARG1 rs2781667 had a relative risk of elevated mPAP (>25 mm Hg) of 1.70 (1.56-1.85; p<0.0001), and carriers of the minor allele of NOS3 rs2070744 had a relative risk of elevated mPAP (>30 mm Hg) of 1.58 (1.47-1.69; p<0.0001). The NOS3 and DDAH2 genes were associated with the incidence of acute mountain sickness. Conclusions: We conclude that genetic variability in the L-arginine / ADMA / NO pathway is an important determinant of high altitude pulmonary hypertension and acute mountain sickness. DDAH1 is linked to baseline ADMA, whilst DDAH2 determines the response of ADMA to hypoxia.

Blood rheology in acute mountain sickness and high-altitude pulmonary edema

1991 ◽  
Vol 71 (3) ◽  
pp. 934-938 ◽  
Author(s):  
W. H. Reinhart ◽  
B. Kayser ◽  
A. Singh ◽  
U. Waber ◽  
O. Oelz ◽  
...  
Keyword(s):  
Pulmonary Edema ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Blood Rheology ◽  
Plasma Viscosity ◽  
Erythrocyte Deformability ◽  
Erythrocyte Aggregation ◽  
High Altitude Pulmonary Edema ◽  
Mountain Sickness ◽  
Low Altitude

The role of blood rheology in the pathogenesis of acute mountain sickness and high-altitude pulmonary edema was investigated. Twenty-three volunteers, 12 with a history of high-altitude pulmonary edema, were studied at low altitude (490 m) and at 2 h and 18 h after arrival at 4,559 m. Eight subjects remained healthy, seven developed acute mountain sickness, and eight developed high-altitude pulmonary edema. Hematocrit, whole blood viscosity, plasma viscosity, erythrocyte aggregation, and erythrocyte deformability (filtration) were measured. Plasma viscosity and erythrocyte deformability remained unaffected. The hematocrit level was lower 2 h after the arrival at high altitude and higher after 18 h compared with low altitude. The whole blood viscosity changed accordingly. The erythrocyte aggregation was about doubled 18 h after the arrival compared with low-altitude values, which reflects the acute phase reaction. There were, however, no significant differences in any rheological parameters between healthy individuals and subjects with acute mountain sickness or high-altitude pulmonary edema, either before or during the illness. We conclude that rheological abnormalities can be excluded as an initiating event in the development of acute mountain sickness and high-altitude pulmonary edema.

scholarly journals Perforation Peritonitis at High Altitude

2018 ◽  
Vol 56 (210) ◽  
pp. 625-628 ◽  
Author(s):  
Bhawana Amatya ◽  
Paleswan Joshi Lakhey ◽  
Prativa Pandey
Keyword(s):  
High Altitude ◽  
Distal Gastrectomy ◽  
Acute Mountain Sickness ◽  
Emergency Laparotomy ◽  
Delay In Diagnosis ◽  
First Case ◽  
Life Threatening ◽  
Perforation Peritonitis ◽  
Proper Diagnosis ◽  
Mountain Sickness

Trekkers going to high altitude can suffer from several ailments both during and after their treks. Gastro-intestinal symptoms including nausea, vomiting, and abdominal pain are common in high altitude areas of Nepal due to acute mountain sickness or due to a gastro-intestinal illness. Occasionally, complications of common conditions manifest at high altitude and delay in diagnosis could be catastrophic for the patient presenting with these symptoms. We present two rare cases of duodenal and gastric perforations in trekkers who were evacuated from the Everest trekking region. Both of them had to undergo emergency laparotomy and repair of the perforation using modified Graham’s patch in the first case and distal gastrectomy that included the perforated site, followed by two-layer end-to-side gastrojejunostomy and two-layer side-to-side jejunostomy in the second case. Perforation peritonitis at high-altitude, though rare, can be life threatening. Timely evacuation from high altitude, proper diagnosis and prompt treatment are essential

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