It is important to understand what causes malnutrition, what nutrients are most commonly deficient, how best to treat this complication and restore an acceptably healthy nutritional status.
Malnutrition occurs with a very high frequency in patients suffering with chronic liver disease and in almost 100% of patients needing liver transplantation. The morbidity and mortality rates increase for liver disease patients when malnutrition becomes part of the clinical picture and survival rates for liver transplant patients decrease if they are severely malnourished before the procedure. The prevalence of severe nutrient deficiencies in chronic liver disease patients and the poor prognoses that accompany this complication demand thorough nutritional assessment of all patients with chronic liver disease and appropriate interventions to treat the malnutrition component.
The difficulty arises when the compromised liver function creates impediments to nutrition, which leads to malnutrition – which further compromises liver function leading to more severe malnutrition and accelerating the degenerative process of the disease.
The most common cause of malnutrition is poor oral intake, probably resulting from multiple factors:
- Altered Taste Sensation – Food does not taste as good and is not as appetizing. This could be a result of vitamin A or zinc deficiency due to malabsorption.
- Early Satiety – Mechanical compression of the stomach due to ascites (abdominal edema); another theory is that elevated serum leptins which can occur in advanced liver disease suppress the appetite.
- Other Factors – Weakness, fatigue and low grade encephalopathy are thought to contribute to reduced oral intake.
Malabsorption is a common cause of malnutrition in this patient population. It leads to certain specific nutrient deficiencies through a number of mechanisms:
- Bile salt depletion leads to fat malabsorption. This results not only in macronutrient (fat) undernourishment, but also leads to the specific deficiency of fat soluble vitamins like A and D. Deficiency of these vitamins can cascade into other nutrient insufficiencies and their associated consequences, i.e. calcium deficiency and osteoporosis. This is especially problematical in cholestatic liver disease (liver disease with obstructed bile flow).
- Dysbiosis – Bacterial overgrowth due to poor small intestine motility inhibits nutrient absorption.
- Portal hypertension is thought to contribute specifically to the malabsorption of protein.
- Medications such as neomycin, which are administered to help manage the condition, can contribute to malabsorption syndrome.
Increased energy expenditure has received growing attention from researchers who believe that this hyper-metabolic state occurs in about one-third of liver disease patients and contributes specifically to protein-calorie malnutrition. The exact cause of hyper-metabolism is not known, but infection and ascites are the prime suspects in this case.
Protein-calorie malnutrition (PCM) is found in up to 90% of patients with advanced liver disease. It is characterized by body wasting subsequent to dietary deficiency of protein and calories. Poor absorption of fat calories leads to deficiencies in fat soluble vitamins and the nutrients they help the body absorb. Perhaps the most insidious effect is found in the micronutrient deficiencies that occur in these conditions. Thiamine, folate, magnesium, zinc and calcium are among the nutrients lost in chronic liver disease that have far reaching health effects that are not readily identified until the symptoms of severe insufficiency arise.
The primary objective of nutritional therapy is to improve protein and calorie absorption and to correct nutrient deficiencies. Oral ingestion is the preferred and most effective method for achieving these goals. Enteral (nasogastric tube) or parenteral (IV) nutrition are less desirable approaches and are utilized when patients are unable to maintain adequate levels of intake orally due to one or more of the complicating intake factors. Many experts believe that the most efficacious method for oral intake is via a well designed liquid protein supplement and liquid multi-vitamin nutrition. In liquid form, the nutrients are delivered in their most absorbable, balanced and highly bio-available state.
Overcoming the “catch-22” of liver disease and malnutrition requires early intervention through thorough nutritional assessment, ongoing strategic interventions to overcome the obstacles to nutrition, and continuing vigilance to ensure and maintain ongoing nutritional health.
http://ajcn.nutrition.org/content/85/5/1167.full, Malutrition and hypermetabolism in patients with liver cirrhosis, Manfred J Muller, Retrieved December 15, 2014, American Society for Nutrition, 2007.
http://www.nature.com/nrgastro/journal/v3/n4/full/ncpgasthep0443.html, Nutritional support in patients with chronic liver disease, Henkel, AS, Buchman, AL, Retrieved December 15, 2014, Nature Publishing Group, 2006.
http://livestrong.com/article/361699-malutition-cirrhosis/, Malnutrition and Cirrhosis, Carol Sarao, Retrieved December 15, 2014, Demand Media, Inc. 2014.