Abstract 11968: Serum Myostatin Levels Are Independent Determinant of Skeletal Muscle Wasting in Patients With Heart Failure
Background: It has been reported that skeletal muscle mass and strength are decreased in patients with heart failure (HF), and this decrease is associated with both reduced exercise capacity and adverse clinical outcomes. Myostain and follistatin are members of the transforming growth factor-β superfamily maintaining tissue homeostasis. Myostatin has been known as a negative regulator of muscle growth, follistatin as the myostatin antagonist. We thus determined whether serum myostatin levels are decreased in HF patients and are associated with skeletal muscle wasting.
Methods and Results: Forty one consecutive HF patients (58±15 years old, New York Heart Association class I-III, left ventricular ejection fraction 32±11%) and 30 age-matched healthy subjects as controls (53±8 years old) were studied. Causes of HF were ischemic in 27% and non-ischemic in 73%. Serum myostatin levels, measured by ELISA, were significantly lower in HF patients than control subjects (18.7±7.4 vs. 23.6±5.2 ng/mL, P≤0.001). Circumference of the thickest part of right thigh was significantly small (468±72 vs. 559±37 mm, P=0.001) and lower extremity muscular strength by isokinetic dynamometer was lower in patients with HF compared to control (129±55 vs. 219±52 Nхm, P≤0.001). Moreover, maximal oxygen uptake, evaluated by cardiopulmonary exercise test, was lower in HF patients than controls(17±3 vs. 29±7 ml/kg/min, P≤0.001). Fourteen HF patients (34%) had muscle wasting, defined as smaller muscle mass and lower muscle strength than 2 standard deviations of their means in control subjects. By univariate analysis, higher age (OR=1.06, 95%CI [1.01, 1.14], P=0.04), higher serum follistatin (OR=2.28, 95%CI [1.20, 5.80], P=0.04), and lower serum myostatin (OR=0.76, 95%CI [0.62, 0.88], P≤0.01) were significantly associated with the presence of muscle wasting. By multivariate analysis, serum myostatin levels were identified as an independent determinant of muscle wasting (OR=0.77, 95%CI [0.58, 0.93], P=0.02).
Conclusion: Serum myostatin levels were significantly decreased in HF patients and associated with lower extremity muscle wasting, suggesting that myostatin may be important factor for maintaining skeletal muscle mass and strength in this disease state.
- © 2013 by American Heart Association, Inc.