The liver is an organ that plays a very important role for digestion. The liver render possible the transformation of the ingested foods into the different nutrients and thus allows the body to perform its main functions. When the liver is chronically ill (cirrhosis), it can no longer ensure an optimal supply of nutrients to the body: the condition of malnutrition.
Malnutrition is the most common complication in people with chronic liver disease. Over time, several symptoms appear in the cirrhotic peole who suffers from malnutrition: muscular fatigue, general fatigue, infections, longer healing time, fragility of the skin, hair and nails and decreased concentration. Cirrhotic people who suffer from malnutrition are also more likely to have their liver disease worsened and thus to be hospitalized more frequently.
Another complication of liver disease is hepatic encephalopathy that affects cognitive and psychiatric functions. Hepatic encephalopathy is caused, among other things, by the accumulation of ammonia which is normally eliminated by the liver and the healthy muscles. In a malnourished cirrhotic patient, and the liver and muscles can not remove ammonia.
Strategies to improve muscle mass, good diet and exercise reduce the symptoms of hepatic encephalopathy and improve quality of life.
Definition and causes
Initially, sarcopenia was quantitatively defined by a muscle mass that was two standard deviations below the average of healthy young adults. More recently, although no consensus has been reached, it is increasingly defined by loss of muscle mass and loss of function or muscle strength. In addition, although it is associated with aging, it may also be present as a result of chronic and malignant diseases.
The causes of sarcopenia are multifactorial. Neurological decline, hormonal changes, activation of the inflammatory pathway, decreased activity, chronic disease, fatty infiltration and low-quality diet are contributing factors. Current interventions focus on nutrition and exercise.
Sarcopenia and cirrhosis
Sarcopenia is a major component of malnutrition and is a frequent complication of cirrhosis. It results from the cumulative decline of multiple physiological systems. Indeed, it occurs in 30 to 70% of the patients cirrhotic and negatively affects the clinical outcome of the affected subjects. This includes survival, quality of life and development of other complications of cirrhosis including hepatic encephalopathy. Thus, patients with sarcopenia or malnutrition have an increased risk of hepatic encephalopathy. Its consequences are also reflected in patients undergoing orthopedic liver transplantation, with sarcopenia having a negative impact on the post-transplant period.
Profile of cirrhotic patients with sarcopenia
Sarcopenia is not exclusively present in patients with underweight and is a hidden condition that may be present in cirrhotic patients with any BMI. Indeed, the epidemic of overweight and obesity in Western countries has given way to a whole new profile: sarcopenic obesity. Thus, patients with cirrhosis may develop a simultaneous loss of skeletal muscle and a gain in adipose tissue. Individuals caught in this situation could experience serious repercussions if they are not adequately screened and cared.
What role of muscles in cirrhosis?
Muscles have a role to play in preventing and developing hepatic encephalopathy. Indeed, skeletal muscles can reduce ammonia levels through glutamine synthetase (an enzyme removing ammonia), which reduces the levels of circulating ammonia and reduces the risks and manifestations of hepatic encephalopathy. Particular attention should be paid to the assessment of body composition and muscle mass in nutritional evaluation, treatment decision-making and clinical prognosis of cirrhotic patients.
Challenges to Assessing Body Composition
Assessment of body composition is challenging in cirrhotic patients in relation to fluid retention in the abdomen (ascites) and lower limbs (edema), which may impair the accurate measurement of body weight, BMI. In addition, the measurement of sarcopenia is independent of the retention of liquids.
Several techniques are currently available, such as two-photon X-ray absorptiometry (DEXA), magnetic resonance imaging (MRI), computed tomography (CT-Scan), bioelectrical impedance, etc. However, anthropometric bedside measurements are still the most frequently used techniques for evaluating these patients in routine evaluations. These include brachial muscular circumference (CMB), grip strength and skin folds. These measurements are simple, radiation-free, inexpensive and easy to use.
Piero Amodio, Chantal Bémeur, Roger Butterworth, Juan Cordoba, Akinobu Kato, Sara Montagnese, Misael Uribe, Hendrik Vilstrup, Marsha Y. Morgan (2013) The nutritional management of hepatic encephalopathy in patients with cirrhosis: International Society for Hepatic Encephalopathy and Nitrogen Metabolism Consensus. Hepatology, 58: 325-336. doi: 10.1002/hep.26370
Chantal Bémeur, Paul Desjardins, Roger F. Butterworth (2010) Role of nutrition in the management of hepatic encephalopathy in end-stage liver failure. J Nutr Metab, 2010: 489823. doi: 10.1155/2010/489823
Chantal Bémeur, Roger F. Butterworth (2013) Liver-brain proinflammatory signalling in acute liver failure: role in the pathogenesis of hepatic encephalopathy and brain edema. Metab Brain Dis, 28: 145-150. doi: 10.1007/s11011-012-9361-3
Aldo J. Montano-Loza, Judith Meza-Junco, Carla M. M. Prado, Jessica R. Lieffers, Vickie E. Baracos, Vincent G. Bain, Michael B. Sawyer (2012) Muscle wasting is associated with mortality in patients with cirrhosis. Clinical gastroenterology and hepatology, 10: 166-73, 173.e1. doi: 10.1016/j.cgh.2011.08.028
Aldo J. Montano-Loza (2014) Clinical relevance of sarcopenia in patients with cirrhosis. World journal of gastroenterology, 20: 8061-8071. doi: 10.3748/wjg.v20.i25.8061
Srinivasan Dasarathy, Manuela Merli (2016) Sarcopenia from mechanism to diagnosis and treatment in liver disease. Journal of hepatology, 65: 1232-1244. doi: 10.1016/j.jhep.2016.07.040