In May, the world of renal nutrition came together in Lausanne, Switzerland, for an intense meeting on renal nutrition.
The meeting, the International Congress on Nutrition and Metabolism in Renal Disease, featured topics ranging from the impact of lowering sodium in Finland to the impact of physical activity and nutrition on the kidney to vitamin D interventions. Interactive case studies were presented in both French and English by pairs of doctors and dietitians, and over 300 posters were presented.
This meeting is an excellent example of the synergistic work of renal dietitians and nephrologists. Each year the meeting draws well known names in renal nutrition such as Lilian Cuppari, Denis Fouque, Juan Carrero, Joel Kopple, Harold French, Jerrilynn Burrows, Kamyar Kalantar-Zadeh, Peter Stenvinkel, and Katrina Campbell, to name a few.
Due to her focus in renal nutrition, Jessie Pavlinac, president of the American Dietetic Association, this year presented a lecture on the renal dietitians’ perspective on providing renal diets. For clinicians who have not yet attended a meeting hosted by the International Society of Renal Nutrition and Metabolism, I strongly suggest attending the next meeting in Hawaii. Meeting information on this exciting program will soon appear here.
Among the sessions I found particularly interesting focused on keto acids and low protein diets, a topic that impacts many practitioners (nephrologists, internists, endocrinologist, urologists, and dietitians). Keto acids are a therapy used worldwide but have yet to become standard practice in the United States.
What are keto acids? To understand them, it is first important to remember that the body requires 20 amino acids for proper metabolic function. Of these 20, nine cannot be made endogenously and must be obtained from external sources. These nine are the essential amino acids and they must come from protein in the diet. Dietary protein can be derived from animal or plant sources but a specific amount must be eaten daily or protein malnutrition will occur.
The dietary protein recommendation for healthy adults is 0.8 g/kg body weight per day. Thus, if a man weighed 100 kg he would need 80 g of protein to maintain a healthy balance. However, when kidney function declines, protein recommendations are lowered to preserve kidney function and reduce uremic symptoms. In addition to reducing protein intake, amino and keto acid supplements can be given.
The supplements are manufactured and are free of phosphorus and other minerals or nutrients. Keto acids are metabolized by the body into essential amino acids and are thought to reduce the nitrogenous load on the kidneys. The supplements provide protein without overloading the diseased kidneys with too much phosphorus or urea that would come from foods.
At the meeting in Switzerland, researchers presented evidence from their studies supporting the use of keto acid supplementation. Bellizzi et al, demonstrated that elderly patients who are treated with very low protein diets that included keto acid supplements did not have an increased risk of death once initiating renal replacement therapy. Milovanov et al demonstrated that keto acid therapy in addition to a low protein diet (0.6g/kg/day) in CKD stages 3 and 4 had positive benefits on nutritional parameters.
These findings and others, in conjunction with previous work, substantiate the ESPEN guidelines that amino and keto acid supplementation can be benefical. However, in the United States, these supplements are expensive and not routinely cover by insurance companies.
Therefore, only patients who are able and willing to follow a low protein diet and can afford the amino and keto acid supplements will be able to follow the guideline recommendations. Most importantly, the patients who are placed on low protein diets must be followed regularly to ensure the nutritional parameters are maintained at adequate levels. In many of the studies used to establish the low protein guidelines, patients were seen by dietitians on a monthly basis.