Sex Differences In Pulse Pressure Amplification Responses During Different Intensities Of Isometric Handgrip Exercise In Healthy Young Adults

Abstract

Pulse pressure amplification (PPA) refers to the elevated pulse pressure (PP) in the peripheral arteries relative to the central arteries and is the result of differences in vascular tone and time-dependent forward and reflected wave coupling within the arterial tree. PPA has been shown to predict sex differences in cardiovascular (CV) and all-cause mortality risk in middle-aged and older populations. Although PPA has been shown to increase during dynamic exercise in men, no study has investigated sex differences in PPA response to different intensities of isometric handgrip (IHG) exercise. METHODS: A total of 14 healthy young adults, 7 men (27 1 years) and 7 women (25 1 years) participated in the study. Each participant engaged in IHG exercises for 2-minutes at 20%, 30%, and 40% of their maximum voluntary contraction (MVC). Using a SphygmoCor device, radial artery tonometry was performed continuously throughout the experiment to collect PPA and other relevant peripheral and central hemodynamic data derived from the radial and estimated aortic waveforms. PPA is represented as a ratio of peripheral PP to central PP (radial PP/aortic PP). RESULTS: Baseline PPA values for all three intensities were not different between men and women (all P > 0.005). ΔPPA from baseline had significant group by time interaction during static HG exercise at 20% (P = 0.0418) and 30% (P = .0495) of MVC but not at 40% of MVC (P = 0.6701). Initially, ΔPPA increased in men and women from baseline to 30(s) at 20%, 30%, and 40% of MVC except in women at 30% of MVC. From 30(s) to 120(s), men and women had a decrease in ΔPPA for all HG intensities. The largest sex differences in ΔPPA observed at 120(s) at 20% and 30% of MVC trend toward significance (P = 0.1399 and P = 0.0517, respectively). CONCLUSIONS: The data support that there are intensity-dependent sex differences in PPA responses to static exercise. Supported by AHA Undergraduate Student Fellowship (Eckenrode), NIH P01 HL134609 (Sinoway), and UL1 TR002014 (Sinoway)