Obesity and the metabolic response to severe multiple trauma in man.

Abstract

In the obese state profound metabolic disturbances exist and it is not known how this disrupted metabolism in obese subjects (body mass index greater than 30) may change their ability to respond to the superimposed, injury-induced stress. Understanding the mechanisms that modify the metabolic parameters in traumatized obese patients is essential in their nutritional assessment and further treatment. We have investigated in 7 obese and 10 nonobese multiple trauma patients, on a whole-body level, the energy metabolism, protein kinetics, and lipolysis in the early catabolic "flow phase" of severe injury when they were receiving maintenance fluids without calories or nitrogen. Traumatized obese patients mobilized relatively more protein and less fat compared with nonobese subjects. A relative block both in lipolysis and fat oxidation is experienced by injured obese patients that results in a shift to preferential use of proteins and carbohydrates. Reduced endogenous protein synthetic efficiency observed in obese patients implies increased protein recycling. Thus obese patients could not effectively use their most abundant fat fuel sources and have to depend on other fuel sources. The nutritional management of obese trauma victims should therefore be tailored towards provision of enough glucose calories to spare protein.

The equivocal metabolic response to endotoxaemia in type 2 diabetic and obese ZDF rats

“…In contrast with other studies [41,42], the obesity associated with diabetes in our experimental model of stress in ZDF rats appears not to be a cofactor of morbidity and mortality. In the studies cited [41,42], whole-body protein turnover and protein synthesis were higher in obese traumatised patients than non-obese traumatised patients, and daily muscle catabolism was also higher in the obese patients.…”

“…In the studies cited [41,42], whole-body protein turnover and protein synthesis were higher in obese traumatised patients than non-obese traumatised patients, and daily muscle catabolism was also higher in the obese patients. The metabolic response of our obese ZDF rats is probably more similar to the fair adaptation of obese subjects to starvation: these subjects had better nitrogen preservation than lean subjects and have been shown to be able to survive longer during hunger strike [43,44].…”

Energy expenditure in mechanically ventilated patients: The weight of body weight!

“…Measurements of lean body mass derived from routine CT-Scan obtained at the level of the third lumbar vertebra (L3), allows to calculate the total skeletal muscles area at this body level, but does not measure whole body composition, and it's capacity to predict the total body lean mass remains to be proven. Finally, BW does not take into account the impact on EE of preexisting metabolism alterations [24] as well as metabolic alterations secondary to the injury response [25].…”

Nutritional support in patients with oesophageal cancer

“…Moreover, despite the abundant stores of energy, obese patients experience after injury a relative block in both fat metabolism and utilisation which results in a significantly increased rate of protein catabolism to provide substrates for gluconeogenesis and finally in an increased nitrogen loss compared with equally injured non-obese patients [43].…”