0000000000188484

AUTHOR

Gabriele Valli

showing 2 related works from this author

Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m)

2013

Context: High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels. Objectives: Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL). Results: Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these v…

AdultLeptinMaleVascular Endothelial Growth Factor Amedicine.medical_specialtyperiodic breathingPhysiologySettore MED/10 - Malattie Dell'Apparato RespiratorioBiologyNocturnalSettore BIO/09 - FisiologiaNOHypoxemiachemistry.chemical_compoundPhysiology (medical)Internal medicinemedicineHumanssleepExercisemaximal exercise testhypoxiaAltitudeHypoxia maximal exercise test metabolism periodic breathing sleepLeptinHypoxia; Maximal exercise test; Metabolism; Periodic breathing; Sleep; Adult; Exercise; Female; Humans; Hypoxia; Leptin; Male; Oxyhemoglobins; Vascular Endothelial Growth Factor A; Altitude; Healthy Volunteers; Physiology; Physiology (medical)hypoxia; maximal exercise test; sleep; periodic breathing; metabolismIntermittent hypoxiaGeneral MedicineHypoxia (medical)Effects of high altitude on humansHealthy VolunteersVascular endothelial growth factorEndocrinologychemistryOxyhemoglobinsPeriodic breathingFemalemedicine.symptommetabolismArchives of Physiology and Biochemistry
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Exercise intolerance at high altitude (5050 m): critical power and W'.

2011

Abstract The relationship between work rate (WR) and its tolerable duration (tLIM) has not been investigated at high altitude (HA). At HA (5050 m) and at sea level (SL), six subjects therefore performed symptom-limited cycle-ergometry: an incremental test (IET) and three constant-WR tests (% of IET WRmax, HA and SL respectively: WR1 70 ± 8%, 74 ± 7%; WR2 86 ± 14%, 88 ± 10%; WR3 105 ± 13%, 104 ± 9%). The power asymptote (CP) and curvature constant (W′) of the hyperbolic WR–tLIM relationship were reduced at HA compared to SL (CP: 81 ± 21 vs. 123 ± 38 W; W′: 7.2 ± 2.9 vs. 13.1 ± 4.3 kJ). HA breathing reserve (estimated maximum voluntary ventilation minus end-exercise ventilation) was also comp…

AdultMalePulmonary and Respiratory MedicinePhysiologyOxygen pulsepower-duration relationshipPhysical exerciseExercise intoleranceAltitude SicknessSettore BIO/09 - FisiologiaAnimal scienceExercise toleranceOxygen pulsemedicineHumansMaximum voluntary ventilationHypoxiaMathematicsAltitudeGeneral NeuroscienceHypoxia Exercise tolerance Power–duration relationship Lactate Oxygen uptake Oxygen pulsehypoxia; exercise tolerance; power-duration relationship; lactate; oxygen uptake; oxygen pulseMiddle AgedEffects of high altitude on humansIncremental testOxygen uptakeCritical powerExercise TestPhysical EnduranceBreathingLactateFemalePower–duration relationshipmedicine.symptomPulmonary Ventilation
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