Plasma catecholamines and blood volume in native Andeans during hypoxia and normoxia

Gamboa, Alfredo; Gamboa, Jorge L.; Holmes, Courtney; Sharabi, Yehonatan; León‐Velarde, Fabiola; Fischman, Gary J.; Appenzeller, Otto; Goldstein, David S.

doi:10.1007/s10286-006-0305-z

Cited by 27 publications

(16 citation statements)

References 32 publications

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“…Arterial wall stiffness is greater and blood pressures are higher [51, 52]. High altitude residents, both healthy subjects and patients with chronic mountain sickness (see below) have higher catecholamine levels when measured at altitude than following descent to sea level [20]. Baroreceptors, however, appear to function normally at altitude [5].…”

Section: Autonomic Function In High Altitude Residentsmentioning

confidence: 99%

The autonomic nervous system at high altitude

2007

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IntroductionHigh altitude places are amongst the most inhospitable on earth. According to WHO [70] in 1966 there were approximately 140 million people living at altitudes over 2,500 m and there are several areas of permanent habitation at over 4,000 m. These are in three main regions of the world: the Andes of South America, the highlands of Eastern Africa, and the Himalayas of South-Central Asia. This review is concerned with the effects of the altitude on visitors and the ways by which the permanent high altitude dwellers have adapted to their environment.The two main challenges to life at high altitude come from hypobaric hypoxia and the low ambient temperatures. Temperature decreases about 1°C for each 150 m elevation, so that at 4,500 m temperature is roughly 30°C lower than at sea level. Barometric pressure falls progressively with increasing altitude. Up to about 2,500 m there are few if any effects of hypoxia. Above 3,000 m some effects of hypoxia are likely to be experienced and above 4,000 m adverse effects would be experienced by most unacclimatized visitors. However, many people live and work at altitude with no apparent adverse effects. One such example is Cerro de Pasco a busy mining town of Roger Hainsworth Mark J. Drinkhill Maria Rivera-ChiraThe autonomic nervous system at high altitude j Abstract The effects of hypobaric hypoxia in visitors depend not only on the actual elevation but also on the rate of ascent. Sympathetic activity increases and there are increases in blood pressure and heart rate. Pulmonary vasoconstriction leads to pulmonary hypertension, particularly during exercise. The sympathetic excitation results from hypoxia, partly through chemoreceptor reflexes and partly through altered baroreceptor function. High pulmonary arterial pressures may also cause reflex systemic vasoconstriction. Most permanent high altitude dwellers show excellent adaptation although there are differences between populations in the extent of the ventilatory drive and the erythropoiesis. Some altitude dwellers, particularly Andeans, may develop chronic mountain sickness, the most prominent characteristic of which being excessive polycythaemia. Excessive hypoxia due to peripheral chemoreceptor dysfunction has been suggested as a cause. The hyperviscous blood leads to pulmonary hypertension, symptoms of cerebral hypoperfusion, and eventually right heart failure and death. j

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Section: Autonomic Function In High Altitude Residentsmentioning

confidence: 99%

The autonomic nervous system at high altitude

2007

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“…Occasionally, this position is supported by the results of studies in recent years [70][71][72]. But over the past decade, a number of studies received the data which are contrary to this popular point of view [73][74][75][76]. So, Otsuka K et al [75] showed higher diastolic pressure and thicker walls of arteries in highaltitude residents (Leh, Ladakh) compared with sea-level residents.…”

Section: Hypertension Risk Of Acute Mountain Sickness and Other Advmentioning

confidence: 74%

Hypertension at High Altitude

Sarybaev

Mulajkar

Sikri

et al. 2014

Translational Research in Environmental and Occupational Stress

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Systemic hypoxia is associated with conditions like anemia, lung diseases, sleep disorders, breathing, and exposure to high altitude. The physiological responses including blood pressure regulation to acute, chronic, intermittent normobaric, and hypobaric hypoxia have been under intense investigation for the past many years; however, the regulatory mechanisms are incompletely understood. The available literature indicates a differential response to hypoxia in pulmonary versus systemic circulation. Multiple physiological and metabolic changes contribute towards high-altitude acclimatization; yet, in some individuals, exposure to high altitude could be life threatening due to maladaptation. There are a few studies on the prevalence of hypertension in high-altitude natives and sea-level dwellers exposed to high altitude (acute and chronic). Elevated blood pressure is an established risk factor for different cardiovascular disease and the evidence suggests that the blood pressure rises to a modest extent in patients with mild to moderate hypertension upon acute ascent to high altitude (Luks et al., Congenit Heart Dis 5:220-232, 2010), but there is no clear evidence on increased risk of complications due to increased systemic blood pressures. This book chapter reviews available literature on systemic blood pressure responses to high altitude. A. Sarybaev (*)

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“…Gamboa et al [ 111 ] reported higher plasma levels of noradrenaline, dopamine and the noradrenaline metabolite dihydroxyphenylglycol (DHPG) in Andeans at their resident altitude compared to data obtained following descent to sea level, suggesting sympathetic activation at altitude. Other studies suggest that, unlike following acute exposure to hypoxia where there is down-regulation of β -adrenoceptors in response to sympathetic overactivity [ 86 ], in Andeans chronically exposed to hypoxia there is no such change [ 116 ], and no evidence for adrenergic desensitivity in either healthy altitude dwellers or those with CMS.…”

Section: Changes In Catecholamine Levelsmentioning

confidence: 94%

“…Heart rate is signifi cantly higher in altitude dwellers at their resident altitude than following descent to sea level [ 109 ]. This effect is more pronounced in those with CMS who also have increased arterial wall stiffness [ 110 ], increased circulating catecholamine levels, particularly noradrenaline [ 111 ] and altered barorefl ex control (see below). This tendency to higher blood pressures and sympathetic activation may predispose to the increased cardiovascular morbidity in these populations.…”

Section: Effects On the Cardiovascular Systemmentioning

confidence: 97%