Petek BJ; Gustus SK; Churchill TW; Guseh JS; Loomer G; VanAtta C; BaggishAL; Wasfy MM

Clinical Therapeutics. 44(1):11-22.e3, 2022 01.

PURPOSE: Although exercise testing guidelines define cutoffs for an
exaggerated exercise systolic blood pressure (SBP) response, SBPs above
these cutoffs are not uncommon in athletes given their high exercise
capacity. Alternately, guidelines also specify a normal SBP response that
accounts for metabolic equivalents (METs; mean [SD] of 10 [2] mm Hg per
MET or 3.5 mL/kg/min oxygen consumption [Vo2]). SBP and Vo2 increase less
during exercise in females than males. It is not clear if sex-based
differences in exercise SBP are related to differences in Vo2 or if
current recommendations for normal increase in SBP per MET produce
reasonable estimates using measured METs (ie, Vo2) in athletes. We
therefore examined sex-based differences in exercise SBP indexed to Vo2 in
athletes with the goal of defining normative values for exercise SBP that
account for fitness and sex.

METHODS: Using prospectively collected data from a single sports
cardiology program, normotensive athlete patients were identified who had
no relevant cardiopulmonary disease and had undergone cardiopulmonary
exercise testing with cycle ergometry or treadmill. The relationship
between DELTASBP (peak – rest) and DELTAVo2 (peak – rest) was examined in
the total cohort and compared between sexes.

FINDINGS: A total of 413 athletes (mean [SD] age, 35.5 [14] years; 38%
female; mean [SD] peak Vo2, 46.0 [10.2] mL/kg/min, 127% [27%] predicted)
met the inclusion criteria. The DELTASBP correlated with unadjusted
DELTAVo2 (cycle: R2 = 0.18, treadmill: R2 = 0.12; P < 0.0001). Female
athletes had lower mean (SD) peak SBP (cycle: 161 [15] vs 186 [24] mm Hg;
treadmill: 165 [17] vs 180 [20] mm Hg; P < 0.05) than male athletes.
Despite lower peak SBP, mean (SD) DELTASBP relative to unadjusted DELTAVo2
was higher in female than male athletes (cycle: 25.6 [7.2] vs 21.1 [7.3]
mm Hg/L/min; treadmill: 21.6 [7.2] vs 17.0 [6.2] mm Hg/L/min; P < 0.05).
When Vo2 was adjusted for body size and converted to METs, female and male
athletes had similar mean (SD) DELTASBP /DELTAMET (cycle: 6.0 [2.1] vs 5.8
[2.0] mm Hg/mL/kg/min; treadmill: 4.7 [1.8] vs 4.8 [1.7] mm Hg/mL/kg/min).

IMPLICATIONS: In this cohort of athletes without known cardiopulmonary
disease, observed sex-based differences in peak exercise SBP were in part
related to the differences in DELTAVo2 between male and female athletes.
Despite lower peak SBP, DELTASBP/unadjusted DELTAVo2 was paradoxically
higher in female athletes. Future work should define whether this finding
reflects sex-based differences in the peripheral vascular response to
exercise. In this athletic cohort, DELTASBP/DELTAMET was similar between
sexes and much lower than the ratio that has been proposed by guidelines
to define a normal SBP response. Our observed DELTASBP/DELTAMET, based on
measured rather than estimated METs, provides a clinically useful estimate
for normal peak SBP range in athletes.