Impact of acute whole-body cold exposure with concurrent isometric handgrip exercise on aortic pressure waveform characteristics.
OBJECTIVE
Adverse cardiovascular events are more prevalent during winter and in people that exercise/work in cold temperatures. Since pulse wave analysis indices, aortic systolic blood pressure (ASBP), augmentation index (AIx), and wasted left ventricular pressure energy (ΔE w), are stronger predictors of cardiovascular events and myocardial performance than brachial blood pressure (BP), we sought to evaluate the aortic hemodynamic responses during cold exposure with concurrent isometric handgrip exercise (IHG).


METHODS
In a crossover randomized fashion, 20 healthy normotensive men (22.1 ± 2 years) were evaluated, by means of radial applanation tonometry, inside an environmental chamber in the supine position at cold (4 °C) and temperate (24 °C) conditions. Following a 30-min equilibration period, measurements were performed during pre-exercise baseline (REST), in the last 90 s of a 3-min IHG at 30% maximal voluntary contraction, and 3 min immediately after the finalization of IHG bout (recovery, REC).


RESULTS
At REST, brachial systolic BP (BSBP) (12 ± 2 mmHg; P < 0.01), ASBP (14 ± 3 mmHg; P < 0.01), AIx (11 ± 3%; P < 0.05), and ΔE w (737 ± 128 dynes s/cm(2); P < 0.01) were higher in 4 °C compared to 24 °C trial. Compared to REST, IHG significantly increased (P < 0.01) BSBP, ASBP, AIx, and ΔEw, while BSBP and ASBP remained elevated during REC (P < 0.01). Compared to REST and temperate, AIx (11 ± 3%) and ΔE w (793 ± 145 dynes s/cm(2); P < 0.01) were higher during IHG and cold, while BSBP and ASBP were elevated during REC and cold. AIx and ΔE w returned to REST values in both trials, but AIx (11 ± 4%; P < 0.05) and ΔE w (656 ± 132 dynes s/cm(2); P < 0.05) were higher in the cold.


CONCLUSIONS
Cold exposure with concurrent IHG induces a significant increase in aortic hemodynamic markers, which may evoke adverse cardiovascular events.
Department of Biomedical Sciences, College of Medicine, The Florida State University, 1115 W Call Street BMS 2300-24, Tallahassee, FL, 32306, USA.
Andrew P
AP
Koutnik
Arturo
A
Figueroa
Alexei
A
Wong
Katherine J
KJ
Ramirez
Michael J
MJ
Ormsbee
Marcos A
MA
Sanchez-Gonzalez
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D003080:Cold Temperature / Q000009:adverse effects*; D018592:Cross-Over Studies; D015444:Exercise; D018737:Hand Strength; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D011897:Random Allocation