Animal studies in chronic renal failure show that correcting metabolic acidosis improves protein metabolism, nitrogen balance, and growth. In the presence of metabolic acidosis, catabolism increases in uremia. Glucocorticoids speed up protein degradation in muscles, leading to loss of lean body mass. Low insulin levels also contribute to increased catabolism. Cellular mechanisms involved include the upregulation of specific pathways in muscles. These findings from rat studies have been confirmed in humans, showing that correcting metabolic acidosis can improve nutritional status and reduce protein breakdown.