These data suggest that IGF-1 levels, reflecting acute directional changes in nitrogen balance and dietary energy, may represent a potential marker of nitrogen losses, useful for monitoring changes in protein metabolism In a study of malnourished patients with renal failure, IGF-1 was found to be a more sensitive indicator of malnutrition than classical nutritional markers such as albumin, pre-albumin, transferrin, and retinol-binding protein [38]. Here, IGF1 is linked to malnutrition.