Chronic Kidney Disease at High Altitude

Luks, Andrew M.; Johnson, Richard J.; Swenson, Erik R.

doi:10.1681/asn.2007111199

Cited by 76 publications

(45 citation statements)

References 90 publications

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“…The inability of the kidney to respond to tissue hypoxia, resulting from defects within the kidney itself such as enhanced oxidative stress and oxygen utilization, could plausibly result in a cascade of hypoxia-induced renal damage with no physiological brake. Our findings may also provide a mechanistic basis for the apparent increased risk of end-stage renal disease (21) and exacerbated diabetic nephropathy (38) in patients living at high altitude (31). Reductions in arterial oxygen content of 5-8% or more, which we show here can significantly reduce kidney tissue PO 2 , are likely experienced at least acutely by those ascending to altitudes Ͼ2,000 meters.…”

Section: Perspectivesmentioning

confidence: 53%

“…Body temperature was maintained between 37.0 and 38.0°C throughout the surgery and subsequent experiment by means of a heated table and infrared heating lamp. Baseline arterial PO2 (90 -110 mmHg) and PCO2 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40) were maintained within the desired ranges by altering respiratory rate and volume and the level of positive end-expiratory pressure. Arterial hemoglobin saturation was monitored continuously by pulse oximetry (model 8600V; Nonin, Plymouth, MN).…”

Section: Animalsmentioning

confidence: 99%

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Factors that render the kidney susceptible to tissue hypoxia in hypoxemia

Evans

Goddard

Eppel

et al. 2011

American Journal of Physiology-Regulatory, Integrative and Comp

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Evans RG, Goddard D, Eppel GA, O'Connor PM. Factors that render the kidney susceptible to tissue hypoxia in hypoxemia. Am J Physiol Regul Integr Comp Physiol 300: R931-R940, 2011. First published January 19, 2011 doi:10.1152/ajpregu.00552.2010To better understand what makes the kidney susceptible to tissue hypoxia, we compared, in the rabbit kidney and hindlimb, the ability of feedback mechanisms governing oxygen consumption (V O2) and oxygen delivery (DO 2 ) to attenuate tissue hypoxia during hypoxemia. In the kidney (cortex and medulla) and hindlimb (biceps femoris muscle), we determined responses of whole organ blood flow and V O2, and local perfusion and tissue PO2, to reductions in DO2 mediated by graded systemic hypoxemia. Progressive hypoxemia reduced tissue PO2 similarly in the renal cortex, renal medulla, and biceps femoris. Falls in tissue PO2 could be detected when arterial oxygen content was reduced by as little as 4 -8%. V O2 remained stable during progressive hypoxemia, only tending to fall once arterial oxygen content was reduced by 55% for the kidney or 42% for the hindlimb. Even then, the fall in renal V O2 could be accounted for by reduced oxygen demand for sodium transport rather than limited oxygen availability. Hindlimb blood flow and local biceps femoris perfusion increased progressively during graded hypoxia. In contrast, neither total renal blood flow nor cortical or medullary perfusion was altered by hypoxemia. Our data suggest that the absence in the kidney of hyperemic responses to hypoxia, and the insensitivity of renal V O2 to limited oxygen availability, contribute to kidney hypoxia during hypoxemia. The susceptibility of the kidney to tissue hypoxia, even in relatively mild hypoxemia, may have important implications for the progression of kidney disease, particularly in patients at high altitude or with chronic obstructive pulmonary disease. hyperemia; hypoxia; ischemia; kidney circulation; oxygen tension; skeletal muscle ONE OF THE GREAT PARADOXES of physiology is the susceptibility of the kidney to tissue hypoxia. The kidneys are among the most highly perfused organs in the body, receiving approximately one-quarter of the cardiac output at rest yet comprise Ͻ1% of total body weight (14). Thus renal oxygen delivery (DO 2 ) greatly exceeds oxygen consumption (V O 2 ). Yet the kidney is extremely susceptible to hypoxic damage, which in turn appears to be a crucial event in the pathogenesis of chronic kidney disease (8,19,32,35) and acute kidney injury (7, 20, 24) of diverse etiology. Therefore, it is imperative that we improve our understanding of the structural and functional characteristics of the kidney that make it susceptible to development of hypoxia.Most organs respond to a reduction in oxygenation by increasing local blood flow and so DO 2 (14). The increased DO 2 then acts to increase tissue oxygenation and so attenuate development of hypoxia and tissue injury. In this regard, the control of blood flow to the kidney is unique in that it appears to be dominated by the func...

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Section: Perspectivesmentioning

confidence: 53%

Section: Animalsmentioning

confidence: 99%

Factors that render the kidney susceptible to tissue hypoxia in hypoxemia

Evans

Goddard

Eppel

et al. 2011

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Acetazolamide therapy for the prophylaxis of acute mountain sickness (AMS) and high-altitude cerebral edema (HACE) (see below) can be used in patients with chronic kidney disease, provided that the patient does not have pre-existing metabolic acidosis and has an estimated glomerular filtration rate of .50 mL/min. Further advice regarding the use of medication at altitude has been reviewed in detail elsewhere (7)(8)(9).…”

Section: Renal Effectsmentioning

confidence: 99%

Physical Activity at Altitude: Challenges for People With Diabetes

Mol

Vries²,

Koning

et al. 2014

Diabetes Care

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A growing number of subjects with diabetes take part in physical activities at altitude such as skiing, climbing, and trekking. Exercise under conditions of hypobaric hypoxia poses some unique challenges on subjects with diabetes, and the presence of diabetes can complicate safe and successful participation in mountain activities. Among others, altitude can alter glucoregulation. Furthermore, cold temperatures and altitude can complicate accurate reading of glucose monitoring equipment and storage of insulin. These factors potentially lead to dangerous hyperglycemia or hypoglycemia. Over the last years, more information has become available on this subject. PURPOSETo provide an up-to-date overview of the pathophysiological changes during physical activity at altitude and the potential problems related to diabetes, including the use of (continuous) blood glucose monitors and insulin pumps. To propose practical recommendations for preparations and travel to altitude for subjects with diabetes. DATA SOURCES AND SYNTHESISWe researched PubMed, medical textbooks, and related Internet sites, and extracted human studies and data based on relevance for diabetes, exercise, and altitude. LIMITATIONSGiven the paucity of controlled trials regarding diabetes and altitude, we composed a narrative review and filled in areas lacking diabetes-specific studies with data obtained from nondiabetic subjects. CONCLUSIONSSubjects with diabetes can take part in activities at high, and even extreme, altitude. However, careful assessment of diabetes-related complications, optimal preparation, and adequate knowledge of glycemic regulation at altitude and altitude-related complications is needed.An increasing number of subjects with diabetes reside at high altitude for short periods of time, partly for work, but mainly for recreational purposes such as skiing, trekking, and climbing. Exercise under conditions of hypobaric hypoxia poses some unique challenges for subjects with diabetes and could potentially lead to dangerous situations such as unexpected hypoglycemia and hyperglycemia, inaccurate

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“…12 But controlled studies in experimental animals are warranted because such an approach may well provide insights into the mechanistic links between hypoxia and the progression of chronic kidney disease.…”

Section: November 2013mentioning

confidence: 99%