Effects of chronic hypoxia and exercise on plasma erythropoietin in high-altitude residents

The present study was performed to evaluate the effects of chronic inspiratory hypoxia and its combination with physical exercise on plasma erythropoietin concentration ([EPO]). Eight natives from the Bolivian Plateau were investigated at 3,600 m above sea level at rest as well as during and up to 48 h after exhaustive exercise (EE) and 60 min of submaximal (60%) cycle ergometer exercise (SE). Ten sea-level subjects were used as a control group for resting values. The mean resting plasma [EPO] of the high-altitude group (19.5 +/- 0.7 mU/ml) did not differ from that of the sea-level group (18.1 +/- 0.4 mU/ml) but was higher than would be expected from the relationship between [EPO] and hematocrit at sea level. Five hours after both types of exercise, [EPO] decreased by 2.1 +/- 0.8 (EE, P < 0.01) and 1.6 +/- 0.8 mU/ml (SE, P < 0.05); 48 h after SE, [EPO] increased by 2.6 +/- 0.9 mU/ml (P < 0.05). It is concluded that 1) high-altitude natives need relatively high [EPO] to maintain their high hematocrit and 2) exercise at low basal arterial PO2 does not directly increase plasma [EPO] in high-altitude residents but seems to exert suppressive effects.

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AltitudeOmics: impaired pulmonary gas exchange efficiency and blunted ventilatory acclimatization in humans with patent foramen ovale after 16 days at 5,260 m

Journal of Applied Physiology ◽

10.1152/japplphysiol.00879.2014 ◽

2015 ◽

Vol 118 (9) ◽

pp. 1100-1112 ◽

Cited By ~ 15

Author(s):

Jonathan E. Elliott ◽

Steven S. Laurie ◽

Julia P. Kern ◽

Kara M. Beasley ◽

Randall D. Goodman ◽

...

Keyword(s):

Gas Exchange ◽

High Altitude ◽

Sea Level ◽

Patent Foramen Ovale ◽

Acute Mountain Sickness ◽

Cycle Ergometer ◽

Pulmonary Gas Exchange ◽

Foramen Ovale ◽

Ergometer Exercise ◽

High Altitude Acclimatization

A patent foramen ovale (PFO), present in ∼40% of the general population, is a potential source of right-to-left shunt that can impair pulmonary gas exchange efficiency [i.e., increase the alveolar-to-arterial Po2 difference (A-aDO2)]. Prior studies investigating human acclimatization to high-altitude with A-aDO2 as a key parameter have not investigated differences between subjects with (PFO+) or without a PFO (PFO−). We hypothesized that in PFO+ subjects A-aDO2 would not improve (i.e., decrease) after acclimatization to high altitude compared with PFO− subjects. Twenty-one (11 PFO+) healthy sea-level residents were studied at rest and during cycle ergometer exercise at the highest iso-workload achieved at sea level (SL), after acute transport to 5,260 m (ALT1), and again at 5,260 m after 16 days of high-altitude acclimatization (ALT16). In contrast to PFO− subjects, PFO+ subjects had 1) no improvement in A-aDO2 at rest and during exercise at ALT16 compared with ALT1, 2) no significant increase in resting alveolar ventilation, or alveolar Po2, at ALT16 compared with ALT1, and consequently had 3) an increased arterial Pco2 and decreased arterial Po2 and arterial O2 saturation at rest at ALT16. Furthermore, PFO+ subjects had an increased incidence of acute mountain sickness (AMS) at ALT1 concomitant with significantly lower peripheral O2 saturation (SpO2). These data suggest that PFO+ subjects have increased susceptibility to AMS when not taking prophylactic treatments, that right-to-left shunt through a PFO impairs pulmonary gas exchange efficiency even after acclimatization to high altitude, and that PFO+ subjects have blunted ventilatory acclimatization after 16 days at altitude compared with PFO− subjects.

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Body water metabolism in high altitude natives during and after a stay at sea level

International Journal of Biometeorology ◽

10.1007/bf02184438 ◽

1981 ◽

Vol 25 (1) ◽

pp. 47-52 ◽

Cited By ~ 3

Author(s):

S. C. Jain ◽

Jaya Bardhan ◽

Y. V. Swamy ◽

A. Grover ◽

H. S. Nayar

Keyword(s):

High Altitude ◽

Sea Level ◽

Body Water ◽

Water Metabolism ◽

High Altitude Natives

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Energy expenditure during load carriage at high altitude

Journal of Applied Physiology ◽

10.1152/jappl.1981.51.1.14 ◽

1981 ◽

Vol 51 (1) ◽

pp. 14-18 ◽

Cited By ~ 10

Author(s):

A. Cymerman ◽

K. B. Pandolf ◽

A. J. Young ◽

J. T. Maher

Keyword(s):

Energy Expenditure ◽

High Altitude ◽

Sea Level ◽

Prediction Equation ◽

Cycle Ergometer ◽

Load Carriage ◽

Metabolic Rates ◽

Specific Exercise ◽

Upper Limit ◽

Predicted Values

To determine the applicability of a prediction equation for energy expenditure during load carriage at high altitude that was previously validated at sea level, oxygen uptake (Vo2) was determined in five young men at 4,300 m while they walked with backpack loads of 0, 15, and 30 kg at treadmill grades of 0,8, and 16% at 1.12 m.s-1 for 10 min. Mean +/- SE maximal Vo2, determined on the cycle ergometer, was 42.2 +/- 2.3 at sea level and 35.6 +/- 1.7 ml.kg-1 .min-1 at altitude. There were no significant differences in daily Vo2 at any specific exercise intensity on days 1, 5, and 9 of exposure, nor were there any differences in endurance times at the two most difficult exercise intensities. Endurance times for 15- and 30-kg loads at 16% grade were 7.3 and 4.2 min, respectively. Measured energy expenditure was compared with that predicted by the formula of Pandolf et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 43: 577–581, 1977) and found to be significantly different. The differences could be attributed to measurements at metabolic rates exceeding 730 W or 2.1 1.min-1 Vo2. These data indicate that the prediction equation can be used at altitude for exercise intensities not exceeding this upper limit. The observed deviations from predicted values at the high exercise intensities could possibly be attributed to the occurrence of appreciable oxygen deficits and the inability to achieve steady-state conditions.

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Exercise-induced VA/Q inequality in subjects with prior high-altitude pulmonary edema

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.2.922 ◽

1996 ◽

Vol 81 (2) ◽

pp. 922-932 ◽

Cited By ~ 57

Author(s):

A. Podolsky ◽

M. W. Eldridge ◽

R. S. Richardson ◽

D. R. Knight ◽

E. C. Johnson ◽

...

Keyword(s):

Standard Deviation ◽

Pulmonary Edema ◽

High Altitude ◽

Sea Level ◽

Control Group ◽

Pulmonary Capillary ◽

High Altitude Pulmonary Edema ◽

History Of ◽

Capillary Pressures ◽

Exercise Induced

Ventilation-perfusion (VA/Q) mismatch has been shown to increase during exercise, especially in hypoxia. A possible explanation is subclinical interstitial edema due to high pulmonary capillary pressures. We hypothesized that this may be pathogenetically similar to high-altitude pulmonary edema (HAPE) so that HAPE-susceptible people with higher vascular pressures would develop more exercise-induced VA/Q mismatch. To examine this, seven healthy people with a history of HAPE and nine with similar altitude exposure but no HAPE history (control) were studied at rest and during exercise at 35, 65, and 85% of maximum 1) at sea level and then 2) after 2 days at altitude (3,810 m) breathing both normoxic (inspired Po2 = 148 Torr) and hypoxic (inspired Po2 = 91 Torr) gas at both locations. We measured cardiac output and respiratory and inert gas exchange. In both groups, VA/Q mismatch (assessed by log standard deviation of the perfusion distribution) increased with exercise. At sea level, log standard deviation of the perfusion distribution was slightly higher in the HAPE-susceptible group than in the control group during heavy exercise. At altitude, these differences disappeared. Because a history of HAPE was associated with greater exercise-induced VA/Q mismatch and higher pulmonary capillary pressures, our findings are consistent with the hypothesis that exercise-induced mismatch is due to a temporary extravascular fluid accumulation.

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Relationship Between Salivary Nitric Oxide Concentration and Dental Caries in Children: A Systematic Review and Meta-Analysis

Iranian Journal of Pediatrics ◽

10.5812/ijp.107050 ◽

2020 ◽

Vol In Press (In Press) ◽

Author(s):

Nadia Elyassi ◽

Ali Malekzadeh Shafaroudi ◽

Pegah Nasiri ◽

Mahmood Moosazadeh ◽

Azam Nahvi

Keyword(s):

Nitric Oxide ◽

Nitrous Oxide ◽

Dental Caries ◽

Meta Analysis ◽

Control Group ◽

Analysis Study ◽

Oxide Concentration ◽

The Mean ◽

The Relationship ◽

Nitrous Oxide Concentration

Context: Conflicting results have been reported in the literature concerning the relationship between salivary nitrous oxide concentration and dental caries in children. Metaanalysis studies aim to combine different studies and reduce the difference between the parameters by increasing the number of studies involved in the analysis process. Objectives: Accordingly, this meta-analysis study aimed at determining the relationship between salivary nitrous oxide concentration and dental caries in children. Methods: Databases were searched using the keywords “nitric oxide”, “salivary”, “Caries”, “DMFT Index”, “children”, “early childhood caries” and OR, AND and NOT operators. Quality assessment was then performed based on the Newcastle-Ottawa scale (NOS) checklist. The standardized mean difference (SMD) of DMFT, dmft, and salivary nitric oxide (NO) concentration was estimated. Results: Seven studies made a comparison between the mean salivary NO concentration in children with dental caries and that in the control group. In four studies, the mean salivary NO concentration in children with dental caries was lower, as compared to that in the control group. This difference was significant in all four studies. Also, the mean standardized difference of the salivary NO index was also estimated to be -0.11 (CI 95%: -1.77, 1.55). Conclusions: This meta-analysis study demonstrated that salivary NO concentration was not significantly related to dental caries. Moreover, since salivary NO concentration is affected by various factors, it is not sufficient to determine the likelihood of the incidence of caries.

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Urine CA-2 as a biomarker for diagnosis urinary stone and prediction of its complications

10.21203/rs.3.rs-59394/v1 ◽

2020 ◽

Author(s):

Yuan-jing Leng ◽

Hai-bin Zhou ◽

Jiang-ling Fu ◽

Wen-juan Wang

Keyword(s):

Healthy Subjects ◽

Characteristic Curve ◽

Urinary Stone ◽

Urinary Stones ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Healthy Control ◽

The Mean ◽

The Difference ◽

The Relationship

Abstract PURPOSECarbonic anhydrase-2 (CA-2) plays a role in mineralization and calcification in organism. Strong evidence suggests that CA-2 is associated with urolithiasis. However, the relationship between CA-2 and urinary stone remains unclear. The study aimed to assess the association of urine CA-2 (uCA-2) level and the potential risk of urinary stone.METHODSFrom March 2017 to November 2019, a prospective cohort study was conducted on patients with urinary stones and healthy subjects to determine the pretreatment uCA-2 level detection by Enzyme linked immunosorbent assay (ELISA). The difference of uCA-2 level between patients with urinary stones and healthy subjects was compared. Then comparison between stone patients with complications and without complications was carried out as well as correlation analysis to detect factors associated with biomarker expression.RESULTS118 patients with urinary stones were into urinary stones group and 42 healthy subjects were into healthy control group. The mean pretreatment uCA-2 level was significantly higher in patients with urinary stones group than healthy controls group (P=0.028). Furthermore, The uCA-2 level was positive correlation with urinary stones complications (R=0.379, P=0.000), especially pain complications (R=0.524, P=0.000) and hematuria complications (R=0.374, P=0.000). Receiver operating characteristic curve (ROC) analysis that a uCA-2 level threshold of 10.94 ng/mL had 83.67% sensitivity and 68.12% specificity for predicting urinary stones complications. CONCLUSIONSExcessive uCA-2 excretion is a major risk factor for urinary stone. Our findings suggested that uCA-2 may be used as an unappreciated biomarker for the diagnosis urinary stone in patients and to predict its complications.

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An Investigation of the Relationship between Involvement Sites in Vitiligo Patients and Autoimmune Diseases and Hematological Parameters

International Journal of Innovative Research in Medical Science ◽

10.23958/ijirms/vol04-i10/769 ◽

2019 ◽

Vol 4 (10) ◽

Cited By ~ 1

Author(s):

Ebru KARAGUN

Keyword(s):

Hematological Parameters ◽

Fasting Blood Glucose ◽

Unknown Etiology ◽

Control Group ◽

Endocrine Disorders ◽

Positive Correlation ◽

Lymphocyte Ratio ◽

History Of ◽

The Mean ◽

The Relationship

Aim-Objectives: Vitiligo is an acquired idiopathic disease which progresses with melanocyte destruction and is clinically characterized by depigmented lesions of unknown etiology. Vitiligo may be coexistence with a autoimmune and endocrine disorders. This study examined the sT3, fT4, TSH, Anti-TPO, Anti-Tg, Vitamin B12 and fasting blood glucose (FBG) values, and thrombocyte-to-lymphocyte ratio(TLR), neutrophil-to-lymphocyte ratio(NLR), the mean platelet volume(MPV) the correlation of depigmented lesions with the extent of body involvement sites(IS). Materials and Method: The study enrolled 67 patients aged 0‒65 who were diagnosed with non-segmental generalized vitiligo and in whom an increase in lesions had been observed in the last six months. The IS of the lesions in the patients were evaluated as IS ˂10%(1st group), 10%‒20% (2nd group), 20% - 30%(3rd group), 30% - 40%(4th group), 40% ‒50 %(5th group), and ˃50%(6th group). The control group consisted of patients who had presented to the outpatient clinic having had no history of vitiligo detected in themselves nor in their families. Results: No significant correlation was found between IS and sT3, fT4, TSH, Anti-TPO, Anti-Tg, Vit. B12, PBG or MPV. A moderately positive correlation was found between IS and duration (p <0.05) and a mildly positive correlation between IS and NLR and TLR (p <0.05). Conclusion: This study show that every patient diagnosed with vitiligo, independent of the IS, should undergo examination for autoimmune disease. A mild positive correlation between VTA and NLO-TLO was found to be an indicator of increased inflammation in vitiligo patients as the extent of lesions increased.

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Effect of beta-adrenoceptor blockade on renin-aldosterone and alpha-ANF during exercise at altitude

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.1.141 ◽

1989 ◽

Vol 67 (1) ◽

pp. 141-146 ◽

Cited By ~ 23

Author(s):

P. Bouissou ◽

J. P. Richalet ◽

F. X. Galen ◽

M. Lartigue ◽

P. Larmignat ◽

...

Keyword(s):

High Altitude ◽

Sea Level ◽

Acute Mountain Sickness ◽

Plasma Renin ◽

Barometric Pressure ◽

Suppressive Effect ◽

Beta Blockade ◽

Plasma Norepinephrine ◽

Plasma Aldosterone Concentration ◽

Ergometer Exercise

The renin-aldosterone system may be depressed in subjects exercising at high altitude, thereby preventing excessive angiotensin I (ANG I) and aldosterone levels, which could favor the onset of acute mountain sickness. The role of beta-adrenoceptors in hormonal responses to hypoxia was investigated in 12 subjects treated with a nonselective beta-blocker, pindolol. The subjects performed a standardized maximal bicycle ergometer exercise with (P) and without (C) acute pindolol treatment (15 mg/day) at sea level, as well as during a 5-day period at high altitude (4,350 m, barometric pressure 450 mmHg). During sea-level exercise, pindolol caused a reduction in plasma renin activity (PRA, 2.83 +/- 0.35 vs. 5.13 +/- 0.7 ng ANG I.ml-1.h-1, P less than 0.01), an increase in plasma alpha-atrial natriuretic factor (alpha-ANF) level (23.1 +/- 2.9 (P) vs. 10.4 +/- 1.5 (C) pmol/1, P less than 0.01), and no change in plasma aldosterone concentration [0.50 +/- 0.04 (P) vs. 0.53 +/- 0.03 (C) nmol/1]. Compared with sea-level values, PRA (3.45 +/- 0.7 ng ANG I.ml-1.h-1) and PA (0.39 +/- 0.03 nmol/1) were significantly lower (P less than 0.05) during exercise at high altitude. alpha-ANF was not affected by hypoxia. When beta-blockade was achieved at high altitude, exercise-induced elevation in PRA was completely abolished, but no additional decline in PA occurred. Plasma norepinephrine and epinephrine concentrations tended to be lower during maximal exercise at altitude; however, these differences were not statistically significant. Our results provide further evidence that hypoxia has a suppressive effect on the renin-aldosterone system. However, beta-adrenergic mechanisms do not appear to be responsible for inhibition of renin secretion at high altitude.

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Antithyroid Effect of Chlorpropamide?

Human Toxicology ◽

10.1177/096032718300200112 ◽

1983 ◽

Vol 2 (1) ◽

pp. 149-153 ◽

Cited By ~ 1

Author(s):

J. Feely ◽

S. McLaren ◽

A.M.M. Shepherd ◽

D. Maclean ◽

I.H. Stevenson ◽

...

Keyword(s):

Matched Control ◽

Control Group ◽

Diabetic Patients ◽

Matched Control Group ◽

Serum Thyroxine ◽

Chronic Therapy ◽

The Mean ◽

Clinically Significant ◽

The Relationship ◽

Plasma Chlorpropamide

1 The relationship between plasma chlorpropamide concentration and thyroid function was examined in 87 maturity onset diabetic patients receiving chronic therapy. 2 Although plasma chlorpropamide concentration was weakly negatively correlated with serum thyroxine (r= 0.33, P< 0.01) the mean serum thyroxine and thyrotrophin (TSH) were not different from that of a matched control group of diabetics treated with diet alone. 3 Serum thyroxine was negatively correlated with the duration of diabetes in both groups. 4 These results suggest that chlorpropamide does not have a clinically significant antithyroid effect.

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