What is Cachexia?
Cachexia is a complex health condition linked to another existing disease. It is marked by the loss of muscle mass, with or without the loss of body fat. It is commonly connected with a loss of appetite, inflammation, resistance to insulin (a hormone that regulates the amount of sugar in our bodies), and an increase in protein turnover (the process of protein breakdown and replacement). This condition is often associated with serious illnesses and can make treatment more complicated.
What Causes Cachexia?
Cachexia leads to weight loss and a higher chance of death. The main reason behind this is an excess of substances in the body known as cytokines. Other factors that contribute to cachexia include a shortage of testosterone and a protein called insulin-like growth factor-I, too much of another protein called myostatin, and an overabundance of a type of hormone called glucocorticoids.
Risk Factors and Frequency for Cachexia
Cachexia, a condition often seen in cancer patients, is a prevalent issue – 40% of individuals exhibit this condition at the time of their cancer diagnosis, and 70% show symptoms when the disease is advanced. It’s important to note that cachexia can lead to death in 20% to 25% patients who have advanced solid tumors and can substantially decrease the median survival time by up to 30%. While primarily associated with cancer, cachexia also plays a role in other chronic illnesses, including lung disease (COPD), heart failure, kidney disease, and chronic diseases involving infection and inflammation like AIDS. Unfortunately, those with advanced cancer and cachexia typically have a shorter lifespan compared to those without cachexia.
- Cachexia appears in 40% of people at the time of their cancer diagnosis and in 70% of individuals with advanced stage cancer.
- In 20% to 25% of advanced solid tumor patients, cachexia is considered the cause of death and can decrease average survival time by up to 30%.
- Cachexia is also associated with many chronic diseases such as COPD (lung disease), heart failure, kidney disease, and AIDS.
- Patients with advanced cancer and cachexia usually have a shorter life span than those without cachexia.
Signs and Symptoms of Cachexia
Cachexia, often seen in patients with advanced cancer, is usually accompanied by significant weight loss and loss of appetite. It can result in reduced quality of life due to increased fatigue and a decreased ability to carry out day-to-day activities. There’s a correlation between cachexia and an increase in multiple symptoms like lack of appetite, dry mouth, vomiting, altered taste, feeling full early, and diarrhea.
Cachexia can also worsen symptoms that may not seem obviously related, such as pain, excessive tiredness, loss of energy, trouble sleeping, and anxiety. These heightened symptoms occur regardless of the patient’s age, the stage of their cancer, or the type of treatment they’re receiving.
The criteria used to diagnose cachexia is a weight loss of 5% within a year, or a body mass index of under 20 kg/m2, in the presence of a known chronic illness. At the same time, the patient should also have at least three of the following signs:
- Loss of muscle mass
- Asthenia (weakness)
- Loss of body fat
- Signs of inflammation, such as albumin under 3.2 g/dL or increased C-reactive protein (a type of protein the liver makes when there’s inflammation in the body)
Physical examination may not show specific signs of cachexia, especially in the early stages of the disease. In later stages, things like thinning of the muscles on the temples, shrinking of the muscles above the collarbone, and an overall reduction in muscle definition may be observed.
Testing for Cachexia
Supporting lab tests for this condition might show certain results. For instance, albumin, a protein that helps keep fluid in your bloodstream so it doesn’t leak into other tissues, may be less than 3.2 g/L. Pre-albumin, another protein that the liver creates, may be less than 10 mg/dL. Transferrin, which is a protein that helps transport iron in your body, may be less than 100 mg/dL. Finally, the C-reactive protein, which is produced by your liver when there is inflammation in your body, might be elevated.
Treatment Options for Cachexia
Cachexia is a complex condition often associated with severe weight loss, muscle loss, and fatigue. It often affects patients suffering from illnesses like cancer or heart disease. The stages of cachexia are categorized into three:
1. Pre-cachexia, during which the patient loses more than 1kg but less than 5% of their starting weight.
2. Cachexia, where weight loss is more than 5%, or more than 2% if the patient’s Body Mass Index (BMI – a measure of body weight for height) is less than 20kg/m^2.
3. Refractory cachexia, where weight loss exceeds 15% and BMI is less than 23kg/m^2, or weight loss exceeds 20% with a BMI less than 27 kg/m^2.
Although we can’t directly predict patient outcomes based on these stages, it’s been suggested that addressing cachexia early on can lessen the damaging effects of the condition on the body.
The current research goal is a multi-pronged treatment approach. This includes improving appetite, reducing the inflammatory response, improving outcomes, and enhancing the quality of life. No single therapy has been found to meet all these objectives. Most research efforts focus on boosting appetite and ensuring adequate nutrition. However, simply increasing the intake of protein and calories doesn’t necessarily reverse the metabolic imbalance seen in cachexia. Therefore, the emphasis is also on addressing tumor-related factors and inflammation levels.
One contributor to inflammation in patients with cachexia is a protein called interleukin-6. Current treatments and those under investigation aim to influence the inflammation process and balance abnormal hormone responses and metabolism.
Physical activity has been found to help counteract cachexia’s effects by encouraging protein synthesis, reducing protein degradation, and increasing sensitivity to insulin, a hormone that regulates blood sugar. Aerobic and resistance exercise, especially when combined with certain amino acids found in some foods (branched-chain amino acids), have proven beneficial.
Medication is another potential treatment approach. Megestrol acetate enhances appetite and improves quality of life. However, its side effects can include adrenal issues and an increased risk of developing deep vein thrombosis (a dangerous clot). Corticosteroids also boost appetite but due to side effects, are only suitable for short-term use.
Other medicines being investigated include cannabinoids, non-steroidal anti-inflammatory drugs, and omega-3 fatty acids. The latter can be a useful addition for patients who are likely to live more than 8 weeks.
In patients with heart problems leading to cachexia, the beta-blocker medication carvedilol can potentially reverse the cachexia. This seems to be due to its effect on the rapid metabolic state seen in cachexia.
What else can Cachexia be?
Here is a list of various conditions:
- Celiac disease
- Crohn’s disease
- Cystic fibrosis
- Dementia
- Mercury poisoning
- Motor neuron disease
- Multiple sclerosis
- Multiple system atrophy
- Parkinson’s disease
- Rheumatoid arthritis
