Protein restriction in the conservative management of uremia.
Protein-restricted diets are widely used in the dietary management of uremia. These diets are undoubtedly effective in ameliorating many aspects of the uremic syndrome. However, there is no consensus as to whether diets providing less than 0.6 g/kg per day of protein are nutritionally adequate and capable of preventing the wasting syndrome. Wasting is common in the adult patient with renal insufficiency as is growth failure in the uremic child. There is some evidence that wasted patients do less well on hemodialysis and are more prone to infection. Experimental studies in uremic animals point ot diminihsed efficiency of utilization of protein, increased gluconeogenesis from animo acids, and increased catabolism of protein in the fasting state; in addition, the metabolism of a number of individual amino acids is altered in uremia. In view of these multiple abnormalities, it would seem unwise to routinely provide less than the Recommended Daily Allowances of protein. More recent developments, i.e., supplementation of essential amino acids and perhaps alpha keto acids, may provide useful alternatives. One important aspect of dietary management, i.e. prevention of hyperlipidemia, has attracted surprisingly little attention so far. Therapy with protein restricted diets in nondialyzed uremic patients has to compete with other modalities of treatment currently available, i.e., hemodialysis and transplantation, in providing optimal medical rehabilitaiton of the patient.