Association between post-ischemic forearm blood flow and blood pressure response to maximal exercise in well trained healthy young men L. Aldo Ferrara a, * , Vittorio Palmieri a , Stefania Limauro a , Stefania Viola a , Emiliano Antonio Palmieri b , Emma Arezzi, Fabio Ferrara a , Serafino Fazio b , Aldo Celentano a,1 a Department of Clinical and Experimental Medicine, Federico 2nd University of Naples, Via Sergio Pansini n. 5 80131 Naples, Italy b Department of Internal Medicine and Cardiovascular Science, Federico 2nd University of Naples, Italy Received 25 May 2005; received in revised form 28 July 2005; accepted 6 August 2005 Available online 2 November 2005 Abstract Background: The relationship between peripheral circulation and blood pressure (BP) response to maximal exercise is an intriguing and not yet well defined topic. Aims: Aims of the present study were to investigate in well trained young healthy males the possible relationships between the endothelial or the smooth muscle component of the peripheral circulation and 1) the BP response to physical exercise on treadmill 2) the body mass composition. Subjects and methods: Fifteen subjects (18 – 36 years), regularly performing physical activity 3 times weekly underwent the following examinations: body composition by bioelectrical impedance analysis; measurement of the forearm blood flow (FBF) at rest and during post- ischemic hyperemia by strain-gauge plethysmography at the upper arm; measurement of brachial artery diameter (BAD) at rest and after 4- min ischemia by echography; BP response to maximal exercise on treadmill with the determination of maximal oxygen consumption and the measurement of lactic acid serum concentration. Results: BAD was significantly increased during post-ischemic hyperemia up to the 4th minute of observation with a peak at 60 s (+8.5%); FBF increased at 30 s after ischemia (+ 210%) and returned to baseline levels at the 2nd minute. In the linear correlation analysis, systolic BP increase at the end of the maximal exercise was significantly and inversely related to the increase in FBF (r = À 0.663, p < 0.01) and to the early FMD (r = 0.503, p <0.05). In the multiple regression analysis, however, only FBF independently affected SBP increase during exercise (t = À 3.268, p < 0.02). Systolic BP increase at the end of the maximal exercise was significantly related to the increase in FBF but not to that of BAD. Among parameters of body composition, fat-free mass was closely related to changes only in BAD. Conclusions: These data indicate that FBF, which depends on the smooth muscle component of the peripheral circulation, is closely related to BP response to exercise while the endothelial function, which has been determined as changes in BAD, is related to the fat-free mass of the body, possibly through the peripheral insulin sensitivity. D 2005 Elsevier Ireland Ltd. All rights reserved. Keywords: Peripheral blood flow; Flow-mediated vasodilatation; Blood pressure response to physical exercise; Body mass composition 1. Introduction Two main determinants of arterial function – the smooth muscle and the endothelial one – play an important role in the regulation of vascular tone and maintenance of cardiovascular homeostasis. Relaxation of the smooth muscle of the vessels is responsible for the increase in blood flow during the exercise but also endothelium 0167-5273/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2005.08.011 * Corresponding author. Tel.: +39 081 7462302; fax: +39 081 5466152. E-mail address: ferrara@unina.it (L. Aldo Ferrara). 1 Present address: Divisione di Cardiologia, Ospedale CTO, ASL NA 1, Italy. International Journal of Cardiology 111 (2006) 394 – 398 www.elsevier.com/locate/ijcard