Age- and gender-specific upper limits and reference equations for workload-indexed systolic blood pressure response during bicycle ergometry

Hedman, K; Lindow, T; Elmberg, V; Brudin, L; Ekstrom, M.

Eur J Prev Cardiol. 2020:2047487320909667.  Link to actual article.

BACKGROUND: Guidelines recommend considering workload in interpretation of the systolic blood pressure (SBP) response to exercise, but reference values are lacking.
DESIGN: This was a retrospective, consecutive cohort study.
METHODS: From 12,976 subjects aged 18-85 years who performed a bicycle ergometer exercise test at one centre in Sweden during the years 2005-2016, we excluded those with prevalent cardiovascular disease, comorbidities, cardiac risk factors or medications. We extracted SBP, heart rate and workload (watt) from >/= 3 time points from each test. The SBP/watt-slope and the SBP/watt-ratio at peak exercise were calculated. Age- and sex-specific mean values, standard deviations and 90th and 95th percentiles were determined. Reference equations for workload-indexed and peak SBP were derived using multiple linear regression analysis, including sex, age, workload, SBP at rest and anthropometric variables as predictors.
RESULTS: A final sample of 3839 healthy subjects (n = 1620 female) were included. While females had lower mean peak SBP than males (188 +/- 24 vs 202 +/- 22 mmHg, p < 0.001), workload-indexed SBP measures were markedly higher in females; SBP/watt-slope: 0.52 +/- 0.21 versus 0.41 +/- 0.15 mmHg/watt (p < 0.001); peak SBP/watt-ratio: 1.35 +/- 0.34 versus 0.90 +/- 0.21 mmHg/watt (p < 0.001). Age, sex, exercise capacity, resting SBP and height were significant predictors of the workload-indexed SBP parameters and were included in the reference equations. CONCLUSIONS: These novel reference values can aid clinicians and exercise physiologists in interpreting the SBP response to exercise and may provide a basis for future research on the prognostic impact of exercise SBP. In females, a markedly higher SBP in relation to workload could imply a greater peripheral vascular resistance during exercise than in males.