A high workload-indexed systolic blood pressure slope in females was associated with lower peak oxygen uptake (1.7 vs. 2.1 L/min, p<0.001) and peak cardiac output (12.8 vs. 15.7 L/min).
Cross-Sectional (n=135)
Does workload-indexed systolic blood pressure (SBP/W-slope) correlate with cardiac output, vascular resistance, and cardiorespiratory fitness in females during exercise?
Workload-indexed SBP (SBP/W-slope) during exercise provides a better framework than maximal SBP alone for identifying females with impaired pressure-flow regulation, higher vascular resistance, and lower cardiorespiratory fitness.
p-value: p=<0.001
During exercise, vascular resistance – the ratio of arterial pressure to blood flow (i.e., cardiac output (CO)) – is an important component of the hemodynamic response determining peak oxygen uptake (V̇O 2peak ). However, how systolic blood pressure (SBP) responses reflect this pressure-flow relationship, and their association with V̇O 2peak remain incompletely understood. We performed cardiopulmonary exercise testing in 135 females (51±8 years) across a broad fitness spectrum to evaluate V̇O 2peak and SBP responses. SBP responses were stratified by maximal SBP (SBP max <190 mmHg or ≥190 mmHg) and workload-indexed SBP (SBP/W-slope; low vs. high based on sex- and age-specific median values). Peak CO (CO peak ) was quantified from exercise cardiac magnetic resonance imaging. SBP max ≥190 mmHg occurred in 74 participants (55%), high SBP/W-slope in 41 (30%), and 26 (19%) had both. A high SBP/W-slope was associated with lower V̇O 2peak (1.7±0.4 vs. 2.1±0.6 L/min, p<0.001), CO peak (12.8±2.3 vs. 15.7±3.5 L/min, p<0.001) and higher total peripheral resistance (TPR peak ; 11.2±2.3 vs. 9.0±2.0 mmHg·min/L, p<0.001). In contrast, a low SBP/W-slope despite SBP max ≥190 mmHg had the highest V̇O 2peak , CO peak , and larger reductions in TPR compared with high SBP/W-slope groups. SBP max ≥190 mmHg in isolation was associated with higher V̇O 2peak and CO peak , although it also identified females with low-fitness and CO peak . Thus, SBP/W-slope provides a framework for interpreting SBP relative to flow, with higher slopes indicating an unfavorable pressure-flow profile characterized by higher vascular resistance, lower CO peak and reduced V̇O 2peak . In contrast, SBP max reflects both flow and resistance. Incorporating SBP/W-slope may therefore improve identification of females with impaired pressure-flow regulation.
Janssens et al. (Wed,) conducted a cross-sectional in Broad fitness spectrum (n=135). High workload-indexed systolic blood pressure (SBP/W-slope) vs. Low SBP/W-slope was evaluated on Peak oxygen uptake (V̇O2peak) and peak cardiac output (COpeak) (p=<0.001). A high workload-indexed systolic blood pressure slope in females was associated with lower peak oxygen uptake (1.7 vs. 2.1 L/min, p<0.001) and peak cardiac output (12.8 vs. 15.7 L/min).