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The effects of exposure to moderate altitude on cardiovascular autonomic function in normal subjects

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Abstract

Cardiovascular responses to altitude have been studied on well-trained young subjects, generally at high altitudes (>4000 m). Less known are the effects of exposure to lower altitudes, easily reached by the general population. The aim of the study was to evaluate the effects of exposure to a moderate altitude (2950 m) on heart rate (HR), blood pressure (BP) profile, and cardiovascular autonomic function, and their correlation with hemoglobin oxygen saturation (HbO2S), in untrained subjects of a wide age range. Twenty-seven healthy normotensive subjects (age range 6–83; 8 children, 9 adults, and 10 elderly subjects) underwent a battery of noninvasive cardiovascular reflex tests and 24-h ambulatory BP monitoring. Corrected QT interval was also calculated. HbO2S was measured with a transcutaneous oxymeter. All measurements were performed at about 200 m (s.l.) and repeated at 2950 m. 24-h HR and systolic/diastolic BP mean values increased at 2950 m in children (% change respectively: 6.4±6.4, p<0.05; 6.5±4.0/13.5±6.9, p<0.05), adults (4.9±8.1, NS; 6.0±5.1/8.1±5.8, p<0.05), and elderly subjects (7.2±4.8, p<0.05; 5.1±2.3/2.8±4.1, p<0.05 for systolic BP only). Standard deviation of BP mean values increased during night-time in the adult group (p<0.05). All subjects scored normal cardiovascular test results and no differences were observed after exposure to 2950m, at both 1 hour and 24 hours from arrival. After exposure to altitude, HbO2S decreased significantly in the three groups, both on arrival and after 24 hours. No correlation was found between changes in HbO2S and BP/HR responses, and cardiovascular test results. In conclusion, exposure to moderate altitudes, easily and often reached by the general population, causes a small but significant increase in BP and HR in healthy untrained subjects of a wide age range (6–83 years). Some physiological factors (eg, lower environmental temperature and lifestyle modification) together with hypoxia, possibly more than altered cardiovascular reactivity, seem responsible for this cardiovascular change. In terms of end-organ damage, the clinical relevance of this increase in BP and BP variability for repeated exposure is not known.

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References

  1. Vogel JA, Hartley H, Cruz JC, Hogan RP. Cardiac output during exercise in sea-level residents at sea-level and high altitude.J Appl Physiol 1974; 36:169–172.

    Google Scholar 

  2. Klausen K. Cardiac output in man in rest and work during and after acclimation to 3800m.J Appl Physiol 1966; 21; 609–616.

    Google Scholar 

  3. Cunningham WL, Becker EJ, Kreuzer F. Catecholamines in plasma and urine at high altitude.J Appl Physiol 1965; 20:607–610.

    Google Scholar 

  4. Wolfel EE, Selland MA, Mazzeo RS, Reeves JT. Systemic hypertension at 4300m is related to sympatoadrenal activity.J Appl Physiol 1994; 76:1643–1650.

    Google Scholar 

  5. Vogel JA, Harris CW. Cardiopulmonary responses of resting man during early exposure to high altitude.J Appl Physiol 1967; 22:1124–1128.

    Google Scholar 

  6. Bender PR, Groves BM, McCullough RE et al. Oxygen transport to exercising leg in chronic hypoxia.J Appl Physiol 1988; 65:2592–2597.

    Google Scholar 

  7. Reeves JT, Mazzeo RS, Wolfel EE, Young AJ. Increased arterial pressure after acclimatization to 4300m: possible role of norepinephrine.Int J Sports Med 1992; 13:S18-S21.

    Google Scholar 

  8. Palatini P, Businaro R, Berton G, Mormino P, Rossi G et al. Effects of low altitude exposure on 24h blood pressure and adrenergic activity.Am J Cardiol 1989: 64:1379–1382.

    Google Scholar 

  9. Mazzeo RS, Wolfel EE, Butterfield GE, Reeves JT. Sympathetic response during 21 days at high altitude (4300m) as determined by urinary and arterial catecholamines.Metabolism 1994; 43:1226–1232.

    Google Scholar 

  10. Savonitto S, Cardellino G, Sardina M, Chebat E, Baldi G et al. Effects of a cable car trip on blood pressure and cardiovascular hormones in lowlander and highlander normotensives.Cardiologia 1991; 36:385–390.

    Google Scholar 

  11. Engel S, Eldridge M, Appenzeller P, Wood SC, Appenzeller O. Functional effects of age, altitude and rheologic properties of blood on some autonomic nervous system tests.Clin Autonom Res 1992; 2:2.

    Google Scholar 

  12. Ewing DJ, Martyn CN, Young RJ, Clarke BF. The value of cardiovascular autonomic function tests: 10 years experience in diabetes.Diab Care 1985; 8:491–498.

    Google Scholar 

  13. Cardone C, Paiusco P, Marchetti G, Burelli F, Feruglio M, Fedele D. Cough test to assess cardiovascular autonomic reflexes in diabetes.Diab Care 1990; 13:719–120.

    Google Scholar 

  14. Gonin JM, Kadrofske MM, Schmaltz S, Bastyr EJ III, Vinik AI. Corrected QT interval prolongation as diagnostic tool for assessment of cardiac autonomic neuropathy in diabetes mellitus.Diab Care 1990; 13:68–71.

    Google Scholar 

  15. Lake Louise Consensus on Definition and Quantification of Altitude Illness. In: Sutton JR, Coates G, Houston CS eds.Hypoxia: Mountain Medicine. Burlington, Vermont: Queen City Press; 1992:327–330.

  16. Pickering T, Harschfield G, Kleinert H, Blank S, Laragh J. Blood pressure during normal daily activity, sleep and exercise.JAMA 1982; 247:746–748.

    Google Scholar 

  17. Frattola A, Parati G, Cuspidi C, Albini F, Mancia G. Prognostic value of 24-hour blood pressure variability.J Hypert 1993; 11:1133–1137.

    Google Scholar 

  18. Tooke JE. Microvascular haemodynamic in diabetes mellitus.Clin Sci 1986; 70:119–125.

    Google Scholar 

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Veglio, M., Maule, S., Cametti, G. et al. The effects of exposure to moderate altitude on cardiovascular autonomic function in normal subjects. Clinical Autonomic Research 9, 123–127 (1999). https://doi.org/10.1007/BF02281624

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