Cardiac function and arteriovenous oxygen difference during exercise in obese adults

Abstract

The purpose of this study was to assess cardiac function and arteriovenous oxygen difference (a-vO(2) difference) at rest and during exercise in young, normal-weight (n = 20), and obese (n = 12) men and women who were matched for age and fitness level. Participants were assessed for body composition, peak oxygen consumption (VO(2peak)), and cardiac variables (thoracic bioimpedance)-cardiac index (CI), cardiac output (Q), stroke volume (SV), heart rate (HR), and ejection fraction (EF)-at rest and during cycling exercise at 65% of VO(2peak). Differences between groups were assessed with multivariate ANOVA and mixed-model ANOVA with repeated measures controlling for sex. Absolute VO(2peak) and VO(2peak) relative to fat-free mass (FFM) were similar between normal-weight and obese groups (Mean ± SEE 2.7 ± 0.2 vs. 3.3 ± 0.3 l min(-1), p = 0.084 and 52.4 ± 1.5 vs. 50.9 ± 2.3 ml kg FFM(-1) min(-1), p = 0.583, respectively). In the obese group, resting Q and SV were higher (6.7 ± 0.4 vs. 4.9 ± 0.1 l min(-1), p < 0.001 and 86.8 ± 4.3 vs. 65.8 ± 1.9 ml min(-1), p < 0.001, respectively) and EF lower (56.4 ± 2.2 vs. 65.5 ± 2.2%, p = 0.003, respectively) when compared with the normal-weight group. During submaximal exercise, the obese group demonstrated higher mean CI (8.8 ± 0.3 vs. 7.7 ± 0.2 l min(-1) m(-2), p = 0.007, respectively), Q (19.2 ± 0.9 vs. 13.1 ± 0.3 l min(-1), p < 0.001, respectively), and SV (123.0 ± 5.6 vs. 88.9 ± 4.1 ml min(-1), p < 0.001, respectively) and a lower a-vO(2) difference (10.4 ± 1.0 vs. 14.0 ± 0.7 ml l00 ml(-1), p = 0.002, respectively) compared with controls. Our study suggests that the ability to extract oxygen during exercise may be impaired in obese individuals.

Hemodynamic responses to an exercise stress test in Parkinson’s disease patients without orthostatic hypotension

“…This finding, while not significant, is in agreement with results reported by Kanegusuku et al (2016), which revealed lower SBP values in PD patients compared to CON at sub-maximal and peak intensities. During exercise, changes in SVI and CI were comparable to those of other studies using treadmills and cycling (Mile et al 1984, Thadani and Parker 1978, Vella et al 2011. It should be noted, however, that these studies included predominately younger subjects.…”

Cardiovascular and cerebral hemodynamics during exercise and recovery in obese individuals as a function of their fitness status

“…The C(a‐v)O 2 between our groups (OB, LF‐OB, HF‐OB and AMHC) was not different which is in disagreement with previous studies (Vella et al. , ; Fournier et al. ).…”

“…) but is inconsistent with results from two other studies (Vella et al. , ). The C(a‐v)O 2 between our groups (OB, LF‐OB, HF‐OB and AMHC) was not different which is in disagreement with previous studies (Vella et al.…”

“…) and muscle oxygen extraction (C(a‐v)O 2 ) (Vella et al. , ; Fournier et al. ) in obese subjects as compared to age‐matched nonobese healthy controls (AMHC) during incremental exercise.…”

Maternal low intensity physical exercise prevents obesity in offspring rats exposed to early overnutrition

“…Aerobic exercise increases blood flow and provides better delivery of nutrients and oxygen, allowing for a better overall growth rate of the fetus in later pregnancy 49 . The improvement of the VO 2max may induce an increase in blood supply to tissues leading to high diffusion of oxygen, improving the ability to extract oxygen from the blood into all tissues 50 .…”