Peripheral tissue metabolism in man with varied disease states and similar weight loss.
Academic Article
Overview
abstract
The purpose of this study was to identify the effects of tumor burden and benign inflammatory disease on peripheral tissue metabolism independent of antecedent weight loss. This was accomplished by comparing forearm substrate flux profiles in cachectic cancer and benign disease patients to those of normal subjects before and after 10 days of total protein calorie depletion. Tumor-bearing patients (CA), benign disease patients (BD), and starved (ST) normal volunteers had similar weight loss. Resting energy expenditure was not significantly different between the study populations. Efflux of total amino acids (TAA [nmole/100 ml tissue-min]) decreased significantly (P less than 0.05) in the normals after 10 days of starvation (-886 +/- 185 postabsorptive (PA) vs -278 +/- 60 (ST]. CA patients had TAA efflux of -428 +/- 52 which was significantly (P less than 0.05) less than PA normals. In contrast, BD patients had a significantly (P less than 0.05) elevated TAA efflux of -895 +/- 165 compared to ST normals. CA patients had a significantly (P less than 0.05) elevated glucose uptake and lactate efflux compared to ST normals (glucose: +1.12 +/- 0.21 (CA) vs +0.11 +/- 0.09 (ST), lactate: -0.84 +/- 0.13 (CA) vs -0.38 +/- 0.13 (ST) [mumole/100 ml tissue-min]). The data suggest that tumor-bearing patients are able to maintain their peripheral tissue protein sparing adaptation to nutritional depletion in the presence of accelerated glucose utilization. However, clinically stable patients with benign disease do not demonstrate this adaptation and may be at greater risk for lean tissue dissolution than previously appreciated.
