During aging, among other physiological modifications, inactivity and insulin resistance cause a progressive muscle loss associated with a decrease in resting energy expenditure (REE). In cancer, loud inflammation background also provokes a decrease in muscle mass as well as in fat mass. However, previous studies reported an increased REE, termed hypermetabolism, probably linked to inflammation.
Data concerning response to aggression in the elderly patient is scarce and even inexistent when it comes to cancer. The investigators hypothesize that the mitochondrial dysfunction that comes with aging and that decreases the ATP rendering per unit of energy-producing nutrient oxidized increases the amount of nutrient to be consumed in order to sustain to energy needs. Therefore, in this situation, elderly patients could have a higher rate or degree of hypermetabolism than younger patients.
The primary objective of this study is to assess the effect of aging on the metabolic response to cancer assessed by resting energy expenditure measured by indirect calorimetry corrected by whole body fat free mass calculated from single slice CT imaging at the third lumbar vertebra.
The secondary objective of this study is to point out some inflammatory or endocrine determinants of these energy metabolism changes in the cancer patient.
Non-small cell lung carcinoma seems to be a relevant choice for this study because it is frequently associated with cachexia and the literature reports a high rate of hypermetabolism in this cancer.
