Aims: Patients with chronic heart failure (CHF) have an increased catabolic state that affects both muscle and adipose tissue (AT), and may ultimately result in cardiac cachexia. Increased plasma levels of ANP might contribute to increased lipid mobilization and oxidation in CHF. We tested the hypothesis that increased plasma ANP levels are associated with an increased catabolic (lipolytic) state of white AT in patients with CHF.
Methods and results: After an overnight fast, AT metabolism was studied by microdialysis in patients with CHF and healthy controls of a similar age and body composition (both n = 8). AT glycolytic and lipolytic activities were assessed at rest (fasting) and after an oral glucose load (oGL). Fasting and post-prandial profiles of serum glucose, insulin, and free fatty acids and of dialysate glucose did not differ significantly between patients and controls. In contrast, fasting dialysate lactate and glycerol levels were two-fold higher in patients vs. controls (lactate, 0.51 ± 0.10 and 0.26 ± 0.06 mmol/L, P < 0.01; glycerol, 116 ± 18 and 50 ± 8 µmol/L, P < 0.001), indicating increased AT glycolytic and lipolytic rates in patients. After an oGL, dialysate lactate increased ∼2- and 2.5-fold, whereas dialysate glycerol decreased by ∼60% and 50% in patients vs. controls, but metabolite levels were always significantly higher in patients vs. controls (all P < 0.05). Plasma ANP levels were increased in patients and significantly correlated with adipose tissue dialysate glycerol.
Conclusion: In patients wiuth CHF, there is a direct correlation between plasma ANP levels and increased AT catabolic (lipolytic) state. This might contribute to AT wasting and the development of cardiac cachexia in patients with CHF.
Keywords: Cachexia; Glycolysis; Heart failure; Insulin resistance; Lipolysis; Metabolism; Microdialysis; Muscle; Natiuretic peptide.