Contributions of cardiac output and total peripheral resistance to interindividual variability in peak exercise blood pressure in young adults.

Higher peak exercise systolic blood pressure was significantly correlated with higher peak exercise cardiac output but not total peripheral resistance.

• Peak SBP correlated with peak exercise cardiac output: r = 0.53, P < 0.001
• Peak SBP was not correlated with total peripheral resistance: r = -0.15, P = 0.29
• Study included 51 normotensive adults (28 females) undergoing graded maximal cycling tests
• Cardiac output was measured using the nitrous oxide rebreathe technique (Innocor; COSMED)
• Blood pressure was measured using automated auscultation (Tango M2 Monitor)

Higher SBP rise per metabolic equivalent (ΔSBP/MET) tended to be related to higher peak exercise total peripheral resistance but not cardiac output.

• ΔSBP/MET showed a trend toward correlation with peak exercise TPR: r = 0.26, P = 0.067
• ΔSBP/MET was not correlated with peak exercise cardiac output: r = 0.07, P = 0.65
• Exaggerated ΔSBP/MET was defined as ≥9 mmHg/MET
• 13 participants met the criterion for exaggerated ΔSBP/MET

Participants with an exaggerated peak systolic blood pressure had larger increases in cardiac output during exercise and greater relative peak oxygen uptake compared to those without exaggerated peak SBP.

• Exaggerated peak SBP was defined as ≥210 mmHg in males and ≥190 mmHg in females
• 20 of 51 participants had an exaggerated peak SBP
• Change in cardiac output during exercise: Δ+12.7 L/min (exaggerated) vs. Δ+10.2 L/min (non-exaggerated), P = 0.002
• Relative peak oxygen uptake (V̇o2peak) was greater in the exaggerated SBP group, P = 0.03
• The reduction in TPR during exercise did not differ between groups: Δ-8.62 vs. Δ-8.85 mmHg/L/min, P = 0.23

Participants with an exaggerated ΔSBP/MET had an attenuated reduction in total peripheral resistance during exercise, while the rise in cardiac output did not differ from those without exaggerated ΔSBP/MET.

• Reduction in TPR during exercise: Δ-6.47 mmHg/L/min (exaggerated) vs. Δ-9.24 mmHg/L/min (non-exaggerated), P = 0.03
• Rise in cardiac output during exercise did not differ: Δ+10.4 vs. Δ+11.6 L/min, P = 0.16
• 13 participants had an exaggerated ΔSBP/MET (≥9 mmHg/MET)
• Exaggerated ΔSBP/MET group also had reduced aerobic fitness

Sex appeared to modulate the relationship between hemodynamic variables and exaggerated exercise blood pressure.

• Sex-specific thresholds for exaggerated peak SBP were applied: males ≥210 mmHg, females ≥190 mmHg
• The study cohort included 28 females and 23 males
• The authors noted that 'sex also appears to modulate this relation in those with an exaggerated exercise BP'
• Specific sex-stratified hemodynamic data are reported but sex modulation was identified as a notable finding

The study used a graded maximal cycling protocol with simultaneous cardiac output and blood pressure measurement in 51 normotensive young adults.

• Fifty-one normotensive adults (28 females) participated
• Graded maximal cycling exercise test was performed
• Brachial blood pressure measured using automated auscultation (Tango M2 Monitor)
• Cardiac output measured using the nitrous oxide rebreathe technique (Innocor; COSMED)
• Participants were analyzed both as a whole cohort and stratified by exaggerated vs. non-exaggerated SBP and ΔSBP/MET