Nutrition Support Blog: Markers of Nutritional Status
September 1, 2011
It is amazing to me how persistent certain nutrition myths can be, regardless of how much data accumulates that debunks them. The use of serum proteins as markers of nutrition status seems to be one of the most persistent of these nutritional legends. There has been some headway in educating medical professionals about the limitations of albumin, but listserv posts and discussions during our training programs suggest that many practitioners continue to check prealbumin, and what is more concerning, base practice on it!
One of the remarkable things we have uncovered while looking at the original research is how limited and poor quality the data is that originally supported the use of prealbumin as a nutrition indicator--the most amazing thing is that it was ever proposed as a nutrition marker to begin with. Furthermore, research over the last several years has documented that although prealbumin correlates (inversely) with C-reative protein, it does not correlate with adequacy of nutrition support in hospitalized patients (see October 2006 article @ www.GInutrition.virginia.edu under Practical Gastroenterology series).
In 2004, an excellent review article in Journal of the American Dietetics Association1 made a compelling argument against the use of serum proteins as nutrition indicators and eloquently stated, “Substantial literature on the inflammatory process and its effects on hepatic protein metabolism has replaced previous reports suggesting that nutritional status and protein intake are the significant correlates with serum hepatic protein levels.” Unfortunately, 6 years later we still see new graduates leaving their undergraduate education being taught about prealbumin as a marker of nutrition status. A new study that is soon to be published in JPEN (available OnlineFirst http://pen.sagepub.com/content/early/recent ) adds to the data documenting that prealbumin is not a useful indicator of the adequacy of nutrition provided.2 Hopefully as the data continues to accumulate, we will begin to see the information about prealbumin get back to those teaching future nutrition professionals. Look for our evaluation of the new JPEN article in a future e-journal club.
The National Institutes of Health has recognized the problem of a lack of sensitive and specific indicators of nutrition status and has started a new program with the goal of developing nutrition biomarkers that would assist researchers and clinicians. The Biomarkers of Nutrition for Development (BOND) Program is a collaborative effort from a number of organizations with the NIH. The initial goal of the group is to evaluate markers of micronutrient status (folic acid, iodine, iron, vitamin A, vitamin B12, and zinc). I think that any interest and funds from the NIH to support nutrition research is a GOOD thing, and hopefully future efforts will include overall calorie and protein provision in sick patients. Check out the link below for more information on the BOND program: http://www.nih.gov/news/health/jul2011/nichd-06.htm
1. Patricia Fuhrman MP,, Charney P, Mueller CH. Hepatic proteins and nutrition assessment Journal of the American Dietetic Association. 2004;104 (8):1258-1264.
2. Davis CJ, Sowa D, Keim KS, et al. The Use of Prealbumin and C-Reactive Protein for Monitoring Nutrition Support in Adult Patients Receiving Enteral Nutrition in an Urban Medical Center. JPEN J Parenter Enteral Nutr. 2011 Jul 28.
“The great enemy of the truth is very often not the lie--deliberate, contrived and dishonest--but the myth--persistent, persuasive and unrealistic.” ~ John F. Kennedy