[Nephrotic syndrome and protein metabolism]

The adult protein turn-over daily affects 250 grammes, which is equivalent to four times the average daily protein intake. Regulation of synthesis and catabolism appears to occur by independent ways. These systems are altered during the nephrotic syndrome and ultimately lead to a loss of total body nitrogen and a risk for malnutrition. Indeed, during the nephrotic syndrome, muscle protein synthesis is further impaired as the urinary protein losses increase. This may suggest that anabolic compounds are lost in the urine of such patients. A moderate protein restriction (0.8 g/kg BW/day) allows a reduction in proteinuria, as well as pharmacological agents (ACE inhibitors) and should therefore slow the progressive renal insult.