Exercise Dose-Response of the (V) over dot(E)/(V) over dotCO(2) Slope in Postmenopausal Women in the DREW Study

Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
Medicine and science in sports and exercise (Impact Factor: 3.98). 05/2009; 41(5):971-6. DOI: 10.1249/MSS.0b013e3181930009
Source: PubMed

ABSTRACT Being overweight/obese, having hypertension, and being postmenopausal are risk factors for the development of congestive heart failure (CHF). A characteristic of CHF is an abnormal V(E)/VCO(2) slope, which is predictive of mortality in patients with CHF. Although the V(E)/VCO(2) slope is well established in CHF patients, little is known regarding interventions for "at-risk" populations.
We examined the V(E)/VCO(2) slope in 401 sedentary, overweight, moderately hypertensive women randomized to 6 m of nonexercise (control) or 4 kcal x kg(-1) x wk(-1) (KKW), 8 KKW, or 12 KKW of exercise at an intensity corresponding to 50% of baseline VO(2max). We examined trends in exercise treatment dose versus change in mean V(E)/VCO(2) slope using a linear regression model (KKW vs V(E)/VCO(2) slope) and a linear mixed model.
Regression analysis showed a significant trend for a reduction in the V(E)/VCO(2) slope from baseline (mean +/- SD: 32.6 +/- 6.3; P < 0.004). When expressed as mean change (95% confidence interval (CI)) from baseline, we observed significant reductions in the V(E)/VCO(2) slope for the 8-KKW (-1.14; 95% CI, -1.5 to -0.2) and 12-KKW (-1.67; 95% CI, -2.3 to -0.3) groups. No significant effect was noted for the 4-KKW (-0.4; 95% CI, -1.2 to 0.15) group.
Moderate-intensity aerobic exercise at doses of 8 KKW or greater seems to present an adequate dose of exercise to promote small but significant reductions in the V(E)/VCO(2) slope in postmenopausal women who exhibit risk factors associated with the development of CHF.

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Available from: Conrad P. Earnest, Oct 29, 2014
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