Background: Heart failure (HF) is characterized by inflammation, insulin resistance, and progressive catabolism. We hypothesized that patients with advanced HF also develop adipose tissue inflammation associated with impaired adipokine signaling and that hemodynamic correction through implantation of ventricular assist devices (VADs) would reverse adipocyte activation and correct adipokine signaling in advanced HF.
Methods and results: Circulating insulin, adiponectin, leptin, and resistin levels were measured in 36 patients with advanced HF before and after VAD implantation and 10 healthy control subjects. Serum adiponectin was higher in HF patients before VAD implantation compared with control subjects (13.3±4.9 versus 6.4±2.1 μg/mL, P=0.02). VAD implantation (mean, 129±99 days) reduced serum adiponectin (7.4±3.4 μg/mL, P<0.05) and improved insulin resistance (Homeostasis Assessment Model of insulin resistance: 7.6±7.7-4.5±3.6; P=0.012). [corrected] Adiponectin expression in adipose tissue decreased after VAD implantation (-65%; P<0.03). Adiponectin receptor expression was suppressed in the failing myocardium compared with control subjects and increased after mechanical unloading. Histomorphometric analysis of adipose tissue specimens revealed reduced adipocyte size in patients with advanced HF compared with control subjects (2105±585 μm(2) [corrected] versus 5583±142 μm(2) in control subjects; P<0.05), which increased after VAD placement. Of note, macrophage infiltration in adipose tissue was higher in advanced HF patients compared with control subjects (+25%; P<0.01), which normalized after VAD implantation.
Conclusions: Adipose tissue inflammation and adiponectin resistance develop in advanced HF. Mechanical unloading of the failing myocardium reverses adipose tissue macrophage infiltration, inflammation, and adiponectin resistance in patients with advanced HF.