Poster Theater Flash Session
Aging and Chronic Disease
Objectives : Gastrointestinal symptoms are prevalent extracardiac systemic manifestations of Congestive Heart Failure (CHF). We developed a comprehensive panel of methods to unravel gut dysfunction in CHF and its impact on the anabolic response to feeding.
Methods : We recruited 14 clinically stable CHF patients (ejection fraction: 33.9±2.1, NYHA class: 2.3±0.2) and 17 healthy controls matched for age and gender. Stable tracers of L-phenylalanine (PHE)-[ring-2H5] and L-tyrosine (TYR)-[13C9,15N] were administered intravenously for 5 hours via primed constant and continuous infusion. After 2 hours, participants ingested a complete high protein meal containing L-PHE-[1-13C] and spirulina-[U-15N]. We sampled blood throughout the study to analyze enrichments by LC-MS/MS. We calculated the anabolic response to feeding before and after correction for changes in protein digestion and absorption, assessed by spirulina degradation ratio (L-PHE-[15N]/[1-13C]). Moreover, we measured small intestinal membrane integrity and active carrier-mediated glucose transport by urinary recovery of the orally ingested inert sugars lactulose, rhamnose, and 3-O-methyl-glucose. Disease severity was assessed by medical chart and history. Statistical analysis was performed by unpaired t-tests. Data are expressed as mean ± SEM.
Results : In CHF patients, protein digestion and absorption were reduced (0.66±0.04 vs. 0.82±0.04, p< 0.01), which further attenuated the anabolic response to feeding (28.3±3.8 vs. 54.0±5.5 μmol/kg FFM/meal, p< 0.001). Disturbances in protein digestion and absorption as well as anabolic response in CHF were independent of disease severity. Small intestinal permeability and active carrier-mediated glucose transport did not differ between the groups indicating a preserved enterocyte function in CHF patients.
We hypothesize that enhancing protein digestion and absorption in patients with CHF can improve the availability of nutrients and protein anabolism.
Funding Sources :
National Institutes of Health