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Purpose: Ingestion of sildenafil citrate has performance-enhancing effects at high altitudes above 3800 m in able-bodied individuals. It is unknown whether it can improve the performance of athletes with spinal cord injury (SCI) at moderate altitudes (<2200 m), relevant to Paralympic competitions. As most men with SCI suffer from erectile dysfunction of neurologic origin and use sildenafil on a regular basis, it seems important to study the impact of sildenafil on exercise capacity. The outcome of this study is also relevant to the antidoping community. Methods: Twenty-seven healthy male wheelchair athletes with a motor-complete SCI participated in this prospective double-blind, randomized, placebo-controlled study. The participants performed arm cranking exercise to exhaustion at sea level and moderate altitude (2200 m) after ingestion of 50 mg sildenafil citrate or a placebo. Peak power output, peak oxygen uptake, peak heart rate, rating of perceived exertion, oxygen saturation, and lactate concentrations at exhaustion were measured. Results: Friedman analysis showed that peak power output at sea level was significantly higher (P = .004) under placebo treatment (median [minimum; maximum]: 120 W [35; 170]) compared with sildenafil (115 W [40; 165]). Blood oxygen saturation under sildenafil treatment at sea level (98% [81; 100]) was significantly higher (P = .006) compared with sildenafil treatment at moderate altitude (94% [85; 100]). All other parameters revealed no impact of sildenafil or altitude. Conclusions: In this study, the ingestion of sildenafil citrate in athletes with SCI demonstrated no positive effects on peak arm-cranking-exercise capacity compared with placebo either at sea level or at moderate altitude.

Perret and Strupler are with the Swiss Paraplegic Center, Inst of Sports Medicine, Nottwil, Switzerland. Van Biesen and Vanlandewijck are with the Dept of Rehabilitation Sciences, KU Leuven–University of Leuven, Leuven, Belgium. Pit-Grosheide is with the Medical and Scientific Dept, International Paralympic Committee, Bonn, Germany.

Perret (claudio.perret@paraplegie.ch) is corresponding author.
  • 1.

    Leoni LA, Leite GS, Wichi RB, Rodrigues B. Sildenafil: two decades of benefits or risks? Aging Male 2013;16:8591. PubMed ID: 23758451 doi:10.3109/13685538.2013.801952

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Croom KF, Curran MP. Sildenafil: a review of its use in pulmonary arterial hypertension. Drugs 2008;68:383397. PubMed ID: 18257613 doi:10.2165/00003495-200868030-00009

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Zhao L, Mason NA, Morell NW, et al. Sildenafil inhibits hypoxia-induced pulmonary hypertension. Circulation 2001;104:424428. PubMed ID: 11468204 doi:10.1161/hc2901.093117

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Hsu AR, Barnholt KE, Grundmann NK, Lin JH, McCallum SW, Friedlanger AL. Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. J Appl Physiol. 2006;100:20312040. PubMed ID: 16455814 doi:10.1152/japplphysiol.00806.2005

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Guazzi M, Tumminello G, Di Marco F, Fiorentini C, Guazzi MD. The effects of phosphodiesterase-5 inhibition with sildenafil on pulmonary hemodynamics and diffusion capacity, exercise ventilatory efficiency, and oxygen uptake kinetics in chronic heart failure. J Am Coll Cardiol. 2004;44:23392348. doi:10.1016/j.jacc.2004.09.041

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6.

    Faoro V, Lamotte M, Deboeck G, et al. Effects of sildenafil on exercise capacity in hypoxic normal subjects. Alt Med Biol. 2007;8:155163. doi:10.1089/ham.2007.1058

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Ghofrani HA, Reichenberger F, Kohstall MG, et al. Sildenafil increased exercise capacity during hypoxia at low altitudes and at Mount Everest base camp: a randomized, double-blind, placebo-controlled crossover trial. Ann Intern Med. 2004;141:169177. PubMed ID: 15289213 doi:10.7326/0003-4819-141-3-200408030-00005

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Ricart A, Maristany J, Fort N, Leal C, Pages T, Viscor G. Effects of sildenafil on the human response to acute hypoxia and exercise. High Alt Med Biol. 2005;6:4349. PubMed ID: 15772499 doi:10.1089/ham.2005.6.43

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Richalet JP, Gratadour P, Robach P, et al. Sildenafil inhibits altitude-induced hypoxemia and pulmonary hypertension. Am J Respir Crit Care Med. 2005;171:275281. PubMed ID: 15516532 doi:10.1164/rccm.200406-804OC

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10.

    Rodway GW, Lovelace AJ, Lanspa MJ, et al. Sildenafil and exercise capacity in the elderly at moderate altitude. Wilderness Environ Med. 2016;27:307315. PubMed ID: 27116921 doi:10.1016/j.wem.2016.01.006

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11.

    Kjaergaard J, Snyder EM, Hassager C, et al. Right ventricular function with hypoxic exercise: effects of sildenafil. Eur J Appl Physiol. 2007;102:8795. PubMed ID: 17909844 doi:10.1007/s00421-007-0560-2

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 12.

    Kressler J, Stoutenberg M, Roos BA, et al. Sildenafil does not improve steady state cardiovascular hemodynamics, peak power, or 15-km time trial cycling performance at simulated moderate or high altitudes in men and women. Eur J Appl Physiol. 2011;111:30313040. PubMed ID: 21451938 doi:10.1007/s00421-011-1930-3

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Jacobs KA, Kressler J, Stoutenberg M, Roos BA, Friedlander AL. Sildenafil has little influence on cardiovascular hemodynamics or 6-km time trial performance in trained men and women at simulated high altitude. High Alt Med Biol. 2011;12:215222. PubMed ID: 21962064 doi:10.1089/ham.2011.0011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14.

    Snyder EM, Olson TP, Johnson BD, Frantz RP. Influence of sildenafil on lung diffusion during exposure to acute hypoxia at rest and during exercise in healthy humans. Eur J Appl Physiol. 2008;103:421430. PubMed ID: 18369657 doi:10.1007/s00421-008-0735-5

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15.

    Toro-Salinas AH, Fort N, Torrella JR, Pages T, Javierre C, Viscor G. Sildenafil does not improve exercise capacity under acute hypoxia exposure. Int J Sports Med. 2016;37:785791. PubMed ID: 27414159 doi:10.1055/s-0035-1559774

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Stone AR. The sexual needs of the injured spinal cord patient. Probl Urol. 1987;3:529536.

  • 17.

    Theisen D. Cardiovascular determinants of exercise capacity in the Paralympic athlete with spinal cord injury. Exp Physiol. 2012;97:319324. PubMed ID: 22090064 doi:10.1113/expphysiol.2011.063016

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18.

    Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc. 1982;14:377381. PubMed ID: 7154893

  • 19.

    Bhambhani Y. Physiology of wheelchair racing in athletes with spinal cord injury. Sports Med. 2002;32:2351. PubMed ID: 11772160 doi:10.2165/00007256-200232010-00002

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Theisen D, Vanlandewijck Y. Cardiovascular responses and thermoregulation in individuals with spinal cord injury. Eur Bull APA. 2002;1:119.

    • Search Google Scholar
    • Export Citation
  • 21.

    Porcelli S, Ramaglia M, Bellistri G, et al. Aerobic fitness affects the exercise performance responses to nitrate supplementation. Med Sci Sports Exerc. 2015;47:16431651. PubMed ID: 25412295 doi:10.1249/MSS.0000000000000577

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
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