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Arterial stiffness response to exercise training: Unequivocal explanations?
International Journal of Cardiology 187 (2015) 598–599
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Arterial stiffness response to exercise training: Unequivocal explanations? David Montero a,⁎, Agnès Vinet b, Christian K. Roberts c a b c
Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Switzerland Avignon University, LAPEC EA4278, F-84000 Avignon, France Exercise Physiology and Metabolic Disease Research Laboratory, Translational Sciences Section, School of Nursing, University of California, Los Angeles, CA, United States
a r t i c l e
i n f o
Article history: Received 29 March 2015 Accepted 31 March 2015 Available online 1 April 2015 Keywords: Arterial stiffness Combined exercise training Aerobic exercise training
We thank Dr. Veiga Sardeli et al. [1] for their interest and enthusiasm regarding our recent meta-analysis with respect to the effect of combined aerobic and resistance training versus aerobic training on arterial stiffness (AS) [2]. Dr. Veiga Sardeli et al. importantly emphasize the different effects of combined training, compared with aerobic training, on central AS. In particular, carotid–femoral pulse wave velocity (c–f PWV) was improved by aerobic, but not combined training and furthermore, there was a significant difference when the two training modalities were compared [2]. We argue, however, that in contrast to what Dr. Veiga Sardeli et al. imply [1], combined training has a null impact not only on central (c–f PWV) but also on central–peripheral (b–a PWV) AS. In this regard, after data pooling, b–a PWV was not improved by combined training and there was no difference compared with c–f PWV (P = 0.18, data not shown) [2]. Of note, subgroup analyses likely had a limited statistical power due to the small number of studies and the presence of uncontrolled moderating/confounding factors [2]. Nevertheless, a previous meta-analysis showed an increase in b–a PWV following resistance training [3], thus it is not surprising that b–a PWV remained unchanged after combined training. In addition, whether the effect of exercise intervention on b–a PWV differs with combined versus aerobic training cannot be certainly established according to our meta-analysis, since only 1 study included aerobic training and assessed b–a PWV [2]. ⁎ Corresponding author at: Institute of Physiology, ZIHP, University of Zurich, Office 23 J 64, Winterthurerstrasse 190, 8057 Zurich, Switzerland. E-mail address: [email protected] (D. Montero).
http://dx.doi.org/10.1016/j.ijcard.2015.03.427 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
It is tempting to speculate that peripheral AS may be improved by resistance, and thereby combined aerobic and resistance training, because both exercise modalities enhance peripheral arterial dilator function [4]. However, the parallelism between the effects of exercise on peripheral AS and dilator function, albeit commonly observed with aerobic training, is not always apparent with resistance training [5]. There is also conflicting evidence on whether exercise (aerobic or resistance) training distinctly conditions central and peripheral AS [5,6]. In this respect, it is noteworthy that trained individuals present more enhanced local (i.e., within the primary trained limb) than systemic arterial dilator adaptations, while structural modifications of the arterial wall can be uniformly observed along central and peripheral arteries in trained and untrained limbs [7,8]. Taken together, the effect of exercise training on AS may not be primarily dependent upon adaptations in dilator function. Instead, such effect may result from the complex interplay among systemic and local factors including, but not limited to, sympathetic drive, blood pressure, inflammatory profile, arterial wall structure, concentration of vasoactive substances and arterial dilator/constrictor reactivity, each potentially influenced according to the modality and characteristics of exercise training as well as the study population [9]. In line with the aforementioned complexity, it can be speculated that the concomitant effects of aerobic and resistance training on AS might have an interactive besides an additive nature. For instance, the ‘stiffening’ impact of resistance training may be exacerbated by the enlargement of arterial lumen and reduction of wall thickness facilitated by aerobic training [8], resulting in enhanced arterial wall stress per a certain level of blood pressure [10]. Conversely, the high intramuscular pressure during resistance exercise contractions could be diminished by enhanced vascular conductance related to the aerobic training-induced increase in capillary density within microvascular units perfusing both active and inactive motor units. Overall, there could be multiple synergetic determinants of AS, thus adding variability to the widespread impact of combined training on central and peripheral arteries. Hence, the specific (central and/or peripheral) AS response to any compounded modification of the AS determinants cannot yet be predicted with accuracy and remains a challenge for future studies. Finally, the clinical outcome linked to the effect of exercise training on AS may depend, at least in part, on the singular composite of the underlying adaptations modulating AS, in addition to the resultant quantitative change in AS. Herein, caution should be exercised when interpreting the prognostic impact of resistance training on AS, since
D. Montero et al. / International Journal of Cardiology 187 (2015) 598–599
this modality of training may concurrently prompt, among others, a reduction in blood pressure [11]. In conclusion, we are grateful to the insightful comments of Dr. Veiga Sardeli et al., which provide for a rich vein of experimental inquiry into the impact of exercise training on AS. Funding None. Conflict of interest The authors have no conflicts to disclose. References [1] A. Veiga Sardeli, A. Fernandes Gáspari, M.P. Chacon-Mikahil, About the article: effect of combined aerobic and resistance training versus aerobic training on arterial stiffness, Int. J. Cardiol. (2015). http://dx.doi.org/10.1016/j.ijcard.2015.03.019. [2] D. Montero, A. Vinet, C.K. Roberts, Effect of combined aerobic and resistance training versus aerobic training on arterial stiffness, Int. J. Cardiol. 178 (2015) 69–76. [3] M. Miyachi, Effects of resistance training on arterial stiffness: a meta-analysis, Br. J. Sports Med. 47 (2013) 393–396.
599
[4] A.W. Ashor, J. Lara, M. Siervo, C. Celis-Morales, C. Oggioni, D.G. Jakovljevic, et al., Exercise modalities and endothelial function: a systematic review and dose–response meta-analysis of randomized controlled trials, Sports Med. 45 (2015) 279–296. [5] S.R. Collier, J.A. Kanaley, R. Carhart Jr., V. Frechette, M.M. Tobin, A.K. Hall, et al., Effect of 4 weeks of aerobic or resistance exercise training on arterial stiffness, blood flow and blood pressure in pre- and stage-1 hypertensives, J. Hum. Hypertens. 22 (2008) 678–686. [6] D.T. Beck, J.S. Martin, D.P. Casey, R.W. Braith, Exercise training reduces peripheral arterial stiffness and myocardial oxygen demand in young prehypertensive subjects, Am. J. Hypertens. 26 (2013) 1093–1102. [7] N.J. Rowley, E.A. Dawson, G.K. Birk, N.T. Cable, K. George, G. Whyte, et al., Exercise and arterial adaptation in humans: uncoupling localized and systemic effects, J. Appl. Physiol. 110 (2011) 1190–1195. [8] G. Walther, S. Nottin, L. Karpoff, A. Perez-Martin, M. Dauzat, P. Obert, Flow-mediated dilation and exercise-induced hyperaemia in highly trained athletes: comparison of the upper and lower limb vasculature, Acta Physiol. (Oxf.) 193 (2008) 139–150. [9] D. Montero, C.K. Roberts, A. Vinet, Arterial stiffness in obese populations: is it reduced by aerobic training? Int. J. Cardiol. 176 (2014) 280–281. [10] D. Montero, G. Walther, A. Perez-Martin, C.S. Mercier, E. Roche, A. Vinet, Leg arterial stiffness after weight loss in severely obese adolescents, Int. J. Cardiol. 168 (2013) 1676–1677. [11] D.M. Croymans, S.L. Krell, C.S. Oh, M. Katiraie, C.Y. Lam, R.A. Harris, et al., Effects of resistance training on central blood pressure in obese young men, J. Hum. Hypertens. 28 (2014) 157–164.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Arterial stiffness response to exercise training: Unequivocal explanations? David Montero a,⁎, Agnès Vinet b, Christian K. Roberts c a b c
Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Switzerland Avignon University, LAPEC EA4278, F-84000 Avignon, France Exercise Physiology and Metabolic Disease Research Laboratory, Translational Sciences Section, School of Nursing, University of California, Los Angeles, CA, United States
a r t i c l e
i n f o
Article history: Received 29 March 2015 Accepted 31 March 2015 Available online 1 April 2015 Keywords: Arterial stiffness Combined exercise training Aerobic exercise training
We thank Dr. Veiga Sardeli et al. [1] for their interest and enthusiasm regarding our recent meta-analysis with respect to the effect of combined aerobic and resistance training versus aerobic training on arterial stiffness (AS) [2]. Dr. Veiga Sardeli et al. importantly emphasize the different effects of combined training, compared with aerobic training, on central AS. In particular, carotid–femoral pulse wave velocity (c–f PWV) was improved by aerobic, but not combined training and furthermore, there was a significant difference when the two training modalities were compared [2]. We argue, however, that in contrast to what Dr. Veiga Sardeli et al. imply [1], combined training has a null impact not only on central (c–f PWV) but also on central–peripheral (b–a PWV) AS. In this regard, after data pooling, b–a PWV was not improved by combined training and there was no difference compared with c–f PWV (P = 0.18, data not shown) [2]. Of note, subgroup analyses likely had a limited statistical power due to the small number of studies and the presence of uncontrolled moderating/confounding factors [2]. Nevertheless, a previous meta-analysis showed an increase in b–a PWV following resistance training [3], thus it is not surprising that b–a PWV remained unchanged after combined training. In addition, whether the effect of exercise intervention on b–a PWV differs with combined versus aerobic training cannot be certainly established according to our meta-analysis, since only 1 study included aerobic training and assessed b–a PWV [2]. ⁎ Corresponding author at: Institute of Physiology, ZIHP, University of Zurich, Office 23 J 64, Winterthurerstrasse 190, 8057 Zurich, Switzerland. E-mail address: [email protected] (D. Montero).
http://dx.doi.org/10.1016/j.ijcard.2015.03.427 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
It is tempting to speculate that peripheral AS may be improved by resistance, and thereby combined aerobic and resistance training, because both exercise modalities enhance peripheral arterial dilator function [4]. However, the parallelism between the effects of exercise on peripheral AS and dilator function, albeit commonly observed with aerobic training, is not always apparent with resistance training [5]. There is also conflicting evidence on whether exercise (aerobic or resistance) training distinctly conditions central and peripheral AS [5,6]. In this respect, it is noteworthy that trained individuals present more enhanced local (i.e., within the primary trained limb) than systemic arterial dilator adaptations, while structural modifications of the arterial wall can be uniformly observed along central and peripheral arteries in trained and untrained limbs [7,8]. Taken together, the effect of exercise training on AS may not be primarily dependent upon adaptations in dilator function. Instead, such effect may result from the complex interplay among systemic and local factors including, but not limited to, sympathetic drive, blood pressure, inflammatory profile, arterial wall structure, concentration of vasoactive substances and arterial dilator/constrictor reactivity, each potentially influenced according to the modality and characteristics of exercise training as well as the study population [9]. In line with the aforementioned complexity, it can be speculated that the concomitant effects of aerobic and resistance training on AS might have an interactive besides an additive nature. For instance, the ‘stiffening’ impact of resistance training may be exacerbated by the enlargement of arterial lumen and reduction of wall thickness facilitated by aerobic training [8], resulting in enhanced arterial wall stress per a certain level of blood pressure [10]. Conversely, the high intramuscular pressure during resistance exercise contractions could be diminished by enhanced vascular conductance related to the aerobic training-induced increase in capillary density within microvascular units perfusing both active and inactive motor units. Overall, there could be multiple synergetic determinants of AS, thus adding variability to the widespread impact of combined training on central and peripheral arteries. Hence, the specific (central and/or peripheral) AS response to any compounded modification of the AS determinants cannot yet be predicted with accuracy and remains a challenge for future studies. Finally, the clinical outcome linked to the effect of exercise training on AS may depend, at least in part, on the singular composite of the underlying adaptations modulating AS, in addition to the resultant quantitative change in AS. Herein, caution should be exercised when interpreting the prognostic impact of resistance training on AS, since
D. Montero et al. / International Journal of Cardiology 187 (2015) 598–599
this modality of training may concurrently prompt, among others, a reduction in blood pressure [11]. In conclusion, we are grateful to the insightful comments of Dr. Veiga Sardeli et al., which provide for a rich vein of experimental inquiry into the impact of exercise training on AS. Funding None. Conflict of interest The authors have no conflicts to disclose. References [1] A. Veiga Sardeli, A. Fernandes Gáspari, M.P. Chacon-Mikahil, About the article: effect of combined aerobic and resistance training versus aerobic training on arterial stiffness, Int. J. Cardiol. (2015). http://dx.doi.org/10.1016/j.ijcard.2015.03.019. [2] D. Montero, A. Vinet, C.K. Roberts, Effect of combined aerobic and resistance training versus aerobic training on arterial stiffness, Int. J. Cardiol. 178 (2015) 69–76. [3] M. Miyachi, Effects of resistance training on arterial stiffness: a meta-analysis, Br. J. Sports Med. 47 (2013) 393–396.
599
[4] A.W. Ashor, J. Lara, M. Siervo, C. Celis-Morales, C. Oggioni, D.G. Jakovljevic, et al., Exercise modalities and endothelial function: a systematic review and dose–response meta-analysis of randomized controlled trials, Sports Med. 45 (2015) 279–296. [5] S.R. Collier, J.A. Kanaley, R. Carhart Jr., V. Frechette, M.M. Tobin, A.K. Hall, et al., Effect of 4 weeks of aerobic or resistance exercise training on arterial stiffness, blood flow and blood pressure in pre- and stage-1 hypertensives, J. Hum. Hypertens. 22 (2008) 678–686. [6] D.T. Beck, J.S. Martin, D.P. Casey, R.W. Braith, Exercise training reduces peripheral arterial stiffness and myocardial oxygen demand in young prehypertensive subjects, Am. J. Hypertens. 26 (2013) 1093–1102. [7] N.J. Rowley, E.A. Dawson, G.K. Birk, N.T. Cable, K. George, G. Whyte, et al., Exercise and arterial adaptation in humans: uncoupling localized and systemic effects, J. Appl. Physiol. 110 (2011) 1190–1195. [8] G. Walther, S. Nottin, L. Karpoff, A. Perez-Martin, M. Dauzat, P. Obert, Flow-mediated dilation and exercise-induced hyperaemia in highly trained athletes: comparison of the upper and lower limb vasculature, Acta Physiol. (Oxf.) 193 (2008) 139–150. [9] D. Montero, C.K. Roberts, A. Vinet, Arterial stiffness in obese populations: is it reduced by aerobic training? Int. J. Cardiol. 176 (2014) 280–281. [10] D. Montero, G. Walther, A. Perez-Martin, C.S. Mercier, E. Roche, A. Vinet, Leg arterial stiffness after weight loss in severely obese adolescents, Int. J. Cardiol. 168 (2013) 1676–1677. [11] D.M. Croymans, S.L. Krell, C.S. Oh, M. Katiraie, C.Y. Lam, R.A. Harris, et al., Effects of resistance training on central blood pressure in obese young men, J. Hum. Hypertens. 28 (2014) 157–164.