We have located links that may give you full text access.
Journal Article
Research Support, Non-U.S. Gov't
Iron deficiency predicts impaired exercise capacity in patients with systolic chronic heart failure.
Journal of Cardiac Failure 2011 November
BACKGROUND: Iron is an indispensable element of hemoglobin, myoglobin, and cytochromes, and, beyond erythropoiesis, is involved in oxidative metabolism and cellular energetics. Hence, iron deficiency (ID) is anticipated to limit exercise capacity. We investigated whether ID predicted exercise intolerance in patients with systolic chronic heart failure (CHF).
METHODS AND RESULTS: We prospectively studied 443 patients with stable systolic CHF (age 54 ± 10 years, males 90%, ejection fraction 26 ± 7%, New York Heart Association Class I/II/III/IV 49/188/180/26). ID was defined as: serum ferritin <100 μg/L or serum ferritin 100-300 μg/L with serum transferrin saturation <20%. Exercise capacity was expressed as peak oxygen consumption (VO(2)) and ventilatory response to exercise (VE-VCO(2) slope). ID was present in 35 ± 4% (±95% confidence interval) of patients with systolic CHF. Those with ID had reduced peak VO(2) and increased VE-VCO(2) slope as compared to subjects without ID (peak VO(2): 13.3 ± 4.0 versus 15.3 ± 4.5 mL•min•kg, VE-VCO(2) slope: 50.9 ± 15.8 versus 43.1 ± 11.1, respectively, both P < .001, P < .05). In multivariable models, the presence of ID was associated with reduced peak VO(2) (β = -0.14, P < .01 P < .05) and higher VE-VCO(2) slope (β = 0.14, P < .01 P < .05), adjusted for demographics and clinical variables. Analogous associations were found between serum ferritin, and both peak VO(2) and VE-VCO(2) slope (P < .05).
CONCLUSIONS: ID independently predicts exercise intolerance in patients with systolic CHF, but the strength of these associations is relatively weak. Whether iron supplementation would improve exercise capacity in iron-deficient subjects requires further studies.
METHODS AND RESULTS: We prospectively studied 443 patients with stable systolic CHF (age 54 ± 10 years, males 90%, ejection fraction 26 ± 7%, New York Heart Association Class I/II/III/IV 49/188/180/26). ID was defined as: serum ferritin <100 μg/L or serum ferritin 100-300 μg/L with serum transferrin saturation <20%. Exercise capacity was expressed as peak oxygen consumption (VO(2)) and ventilatory response to exercise (VE-VCO(2) slope). ID was present in 35 ± 4% (±95% confidence interval) of patients with systolic CHF. Those with ID had reduced peak VO(2) and increased VE-VCO(2) slope as compared to subjects without ID (peak VO(2): 13.3 ± 4.0 versus 15.3 ± 4.5 mL•min•kg, VE-VCO(2) slope: 50.9 ± 15.8 versus 43.1 ± 11.1, respectively, both P < .001, P < .05). In multivariable models, the presence of ID was associated with reduced peak VO(2) (β = -0.14, P < .01 P < .05) and higher VE-VCO(2) slope (β = 0.14, P < .01 P < .05), adjusted for demographics and clinical variables. Analogous associations were found between serum ferritin, and both peak VO(2) and VE-VCO(2) slope (P < .05).
CONCLUSIONS: ID independently predicts exercise intolerance in patients with systolic CHF, but the strength of these associations is relatively weak. Whether iron supplementation would improve exercise capacity in iron-deficient subjects requires further studies.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app