Reduced skeletal muscle oxidative capacity and impaired training adaptations in heart failure

Physiological Reports

William M. Southern¹  Terence E. Ryan²  Kirsten Kepple³  Jonathan R. Murrow¹  Kent R. Nilsson¹ 

[1] University of Georgia, Athens, Georgia;East Carolina University, Greenville, North Carolina;Georgia Regents University, Athens, Georgia

关键词: Exercise training;    heart failure;    mitochondria;    near‐infrared spectroscopy;    skeletal muscle;   

DOI  :  10.14814/phy2.12353

来源: Wiley

【 摘 要 】

Abstract

Systolic heart failure (HF) is associated with exercise intolerance that has been attributed, in part, to skeletal muscle dysfunction. The purpose of this study was to compare skeletal muscle oxidative capacity and training-induced changes in oxidative capacity in participants with and without HF. Participants with HF (n = 16, 65 ± 6.6 years) were compared with control participants without HF (n = 23, 61 ± 5.0 years). A subset of participants (HF: n = 7, controls: n = 5) performed 4 weeks of wrist-flexor exercise training. Skeletal muscle oxidative capacity was determined from the recovery kinetics of muscle oxygen consumption measured by near-infrared spectroscopy (NIRS) following a brief bout of wrist-flexor exercise. Oxidative capacity, prior to exercise training, was significantly lower in the HF participants in both the dominant (1.31 ± 0.30 min⁻¹ vs. 1.59 ± 0.25 min⁻¹, P = 0.002; HF and control groups, respectively) and nondominant arms (1.29 ± 0.24 min⁻¹ vs. 1.46 ± 0.23 min⁻¹, P = 0.04; HF and control groups, respectively). Following 4 weeks of endurance training, there was a significant difference in the training response between HF and controls, as the difference in oxidative training adaptations was 0.69 ± 0.12 min⁻¹ (P < 0.001, 95% CI 0.43, 0.96). The wrist-flexor training induced a ~50% improvement in oxidative capacity in participants without HF (mean difference from baseline = 0.66 ± 0.09 min⁻¹, P < 0.001, 95% CI 0.33, 0.98), whereas participants with HF showed no improvement in oxidative capacity (mean difference from baseline = −0.04 ± 0.08 min⁻¹, P = 0.66, 95% CI −0.24, 0.31), suggesting impairments in mitochondrial biogenesis. In conclusion, participants with HF had reduced oxidative capacity and impaired oxidative adaptations to endurance exercise compared to controls.

【 授权许可】

CC BY   
© 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

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