heart rate ↔ energy expenditure

Relations (1)

related 3.32 — strongly supporting 9 facts

Heart rate and energy expenditure are physiologically linked variables used together in multivariate models to predict changes in oxygen saturation under hypoxic conditions {fact:1, fact:8}. Furthermore, energy expenditure is mathematically defined as a function of heart rate, with specific sex-based formulas established to quantify this relationship {fact:9, fact:5}.

Facts (9)

Sources

Sex differences in respiratory and circulatory cost during hypoxic ... nature.com Nature 9 facts

claimWhen using multiple regression to predict changes in energy expenditure (ΔEE), both changes in minute ventilation (ΔV̇E) and changes in heart rate (ΔHR) were statistically significant predictors for both men and women.

claimThe study used sex-specific models to analyze changes in energy expenditure (EE), minute ventilation (V̇E), and heart rate (HR), which resulted in similar changes for both men and women.

measurementA multivariate model using energy expenditure (EE), minute ventilation (V̇E), and heart rate (HR) to predict hypoxia-induced reduction in peripheral oxygen saturation (ΔSpO2) achieved a very strong fit for both men (r2 = 0.900, P < 0.001) and women (r2 = 0.957, P < 0.001).

measurementThe relative contributions of energy expenditure (EE), ventilation (VE), and heart rate (HR) to the change in oxygen saturation (ΔSpO2) under hypoxic conditions differ by sex: in women, the effects of EE (28.1% vs 15.8% in men) and VE (4.1% vs 1.7% in men) were greater, while in men, the contribution of HR was greater (82.5% vs 67.9% in women).

procedureHypoxia-induced changes in energy expenditure (ΔEE), ventilation (ΔVE), and heart rate (ΔHR) are calculated by subtracting normoxic values from hypoxic values at the same walking speed, with calculations performed separately for men and women.

claimThe relative contributions of energy expenditure (EE), minute ventilation (V̇E), and heart rate (HR) to hypoxia-induced reduction in peripheral oxygen saturation (ΔSpO2) differ between sexes, with the contribution of EE and V̇E in women being about two-fold higher than in men, while the contribution of HR in men is greater than in women.

claimThe study hypothesized that women would experience greater arterial hypoxemia than men, and that the contribution rates of energy expenditure, ventilation, and heart rate in response to changes in oxygen saturation would differ between the sexes.

formulaEnergy expenditure (EE) increases as a function of heart rate (HR) at a rate of approximately 1 Watt for every 8.8 beats per minute in men and every 15 beats per minute in women, defined by the formulas ΔEE = 0.020 ± 0.004ΔHR2 - 0.061 ± 0.101ΔHR (r2 = 0.946, P < 0.001) for men and ΔEE = 0.010 ± 0.006ΔHR2 - 0.083 ± 0.159ΔHR (r2 = 0.812, P < 0.001) for women.

procedureThe researchers calculated changes in SpO2 with hypoxia and used multiple regression analysis to test for the independent, additive effects of energy expenditure (EE), ({\dot{{\rm{V}}}}{{\rm{E}}}), and heart rate (HR) on SpO2 after logarithmic transformation.