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L-Citrulline, Nitric Oxide, Fitness, Blood Pressure
Introduction: The aim of this study was to test the hypothesis that seven days of citrulline (CIT) supplementation would improve cardiovascular measures and functional performance in older active women.
Methods: Sixteen women (66.9±5.6yrs, 1.65±0.5m, 71.7±16.7kg) volunteered to participate in this randomized, double-blind, crossover-study. Participants underwent a series of functional fitness testing including a hand grip strength test, get-up and go, sit-to-stand, and a 6-minute walk test (6MWT). Heart rate and blood pressure (BP) were obtained at rest and following the 6MWT. Participants consumed 6g of citrulline or a placebo daily for seven days between pre- and post-testing in a counterbalanced fashion with a 14-day washout period between treatments. Data were analyzed via separate repeated measures analysis of variance.
Results: A significant time by treatment interaction was observed for resting diastolic BP (F = 5.34; p = 0.028) indicating lower resting diastolic BP values following seven days of CIT supplementation compared to placebo. No other differences in cardiovascular measures were observed. There were no significant (p>0.05) differences between CIT and placebo for any measure of functional performance following the interventions.
Conclusions: These results indicated that CIT did not influence functional performance, but CIT did improve resting diastolic blood pressure in older active female adults.
2. Gonzales JU, Raymond A, Ashley J, Kim Y. Does l-citrulline supplementation improve exercise blood flow in older adults? Exp Physiol. 2017;102(12):1661-1671.
3. Walsh T, Donnelly T, Lyons D. Impaired endothelial nitric oxide bioavailability: a common link between aging, hypertension, and atherogenesis? J Am Geriatr Soc. 2009;57(1):140-145.
4. Omer N, Rohilla A, Rohilla S, Kushnoor A. Nitric oxide: role in human biology. J Int J Pharm Sci Drug Res. 2012;4(2):105-109.
5. Ochiai M, Hayashi T, Morita M, et al. Short-term effects of L-citrulline supplementation on arterial stiffness in middle-aged men. Int J Cardiol. 2012;155(2):257-261.
6. Kim I-Y, Schutzler SE, Schrader A, et al. Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure. American Journal of Physiology-Endocrinology and Metabolism. 2015;309(11):E915-E924.
7. Bailey SJ, Blackwell JR, Lord T, Vanhatalo A, Winyard PG, Jones AM. l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans. J Appl Physiol (1985). 2015;119(4):385-395.
8. Bendahan D, Mattei J, Ghattas B, Confort-Gouny S, Le Guern M, Cozzone P. Citrulline/malate promotes aerobic energy production in human exercising muscle. Brit J Sports Med. 2002;36(4):282-289.
9. Figueroa A, Sanchez-Gonzalez MA, Perkins-Veazie PM, Arjmandi BHJ. Effects of watermelon supplementation on aortic blood pressure and wave reflection in individuals with prehypertension: a pilot study. Amer J Hyperten. 2011;24(1):40-44.
10. Vårvik FT, Bjørnsen T, Gonzalez AM. Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. Int J Sport Nutr Exer Metab. 2021;31(4):350-358.
11. Suzuki T, Morita M, Kobayashi Y, Kamimura AJ. Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study. J Int Soc Sports Nutr. 2016;13(1):6.
12. Aubertin-Leheudre M, Buckinx F. Effects of citrulline alone or combined with exercise on muscle mass, muscle strength, and physical performance among older adults: a systematic review. Curr Opin Clin Nutr Metab Care. 2020;23(1):8-16.
13. Buckinx F, Carvalho L, Marcangeli V, et al. High intensity interval training combined with L-citrulline supplementation: Effects on physical performance in healthy older adults. Exp Gerontol. 2020:111036.
14. Bouchard DR, Dionne IJ, Brochu M. Sarcopenic/obesity and physical capacity in older men and women: data from the Nutrition as a Determinant of Successful Aging (NuAge)—the Quebec Longitudinal Study. Obes Res. 2009;17(11):2082-2088.
15. Buckinx F, Gouspillou G, Carvalho LP, et al. Effect of High-Intensity Interval Training Combined with L-Citrulline Supplementation on Functional Capacities and Muscle Function in Dynapenic-Obese Older Adults. J Clin Med. 2018;7(12).
16. Milanović Z, Pantelić S, Trajković N, Sporiš G, Kostić R, James NJCiia. Age-related decrease in physical activity and functional fitness among elderly men and women. Clin Interv Aging. 2013;8:549.
17. Ashley J, Kim Y, Gonzales JU. Impact of l-citrulline supplementation on oxygen uptake kinetics during walking. Appl Physiol Nutr Metab. 2018;43(6):631-637.
18. Goron A, Lamarche F, Blanchet S, et al. Citrulline stimulates muscle protein synthesis, by reallocating ATP consumption to muscle protein synthesis. Journal of cachexia, sarcopenia and muscle. 2019;10(4):919-928.
19. Riebe D, Ehrman JK, Liguori G, Magal M, Medicine ACoS. ACSM's guidelines for exercise testing and prescription. Wolters Kluwer; 2018.
20. Glickman SG, Marn CS, Supiano MA, Dengel DR. Validity and reliability of dual-energy X-ray absorptiometry for the assessment of abdominal adiposity. J Appl Physiol (1985). 2004;97(2):509-514.
21. Villareal MO, Matsukawa T, Isoda H. l‐Citrulline Supplementation‐Increased Skeletal Muscle PGC‐1α Expression Is Associated with Exercise Performance and Increased Skeletal Muscle Weight. Mol Nutr Food Res. 2018;62(14):1701043.
22. Mitchell UH, Burton S, Gordon C, Mack GWJFip. The effect of being aerobically active vs. inactive on cutaneous vascular conductance during local heat stress in an older population. Front Physiol. 2017;8:859.
23. Casonatto J, Góes RC, Grandolfi K, Cavalari JV. Effects of L-citrulline malate oral supplementation on post-exercise hypotension. Manual Therapy, Posturology & Rehabilitation Journal. 2018;16.
24. Wickham KA, Spriet LL. No longer beeting around the bush: a review of potential sex differences with dietary nitrate supplementation. Appl Phys Nutr Metab. 2019;44(9):915-924.