Cachexia (pronounced kuh-KEK-see-uh) is a “wasting” disorder that causes extreme weight loss and muscle wasting, and can include loss of body fat. This syndrome affects people who are in the late stages of serious diseases like cancer, HIV or AIDS,COPD, kidney disease, and congestive heart failure (CHF).
The term “cachexia” comes from the Greek words “kakos” and “hexis,” which mean “bad condition.”
The difference between cachexia and other types of weight loss is that it’s involuntary. People who develop it don’t lose weight because they’re trying to trim down with diet or exercise. They lose weight because they eat less due to a variety of reasons. At the same time, their metabolism changes, which causes their body to break down too much muscle. Both inflammation and substances created by tumors can affect appetite and cause the body to burn calories more quickly than usual.
Researchers believe that cachexia is part of the body’s response to fighting disease. To get more energy to fuel the brain when nutritional stores are low, the body breaks down muscle and fat.
A person with cachexia doesn’t simply lose weight. They get so weak and frail that their body becomes vulnerable to infections, which makes them more likely to die from their condition. Simply getting more nutrition or calories isn’t enough to reverse cachexia.
Categories of cachexia
There are three main categories of cachexia:
- Precachexiais defined as a loss of up to 5 percent of your body weight while having a known illness or disease. It’s accompanied by appetite loss, inflammation, and changes in metabolism.
- Cachexiais a loss of more than 5 percent of your body weight over 12 months or less, when you’re not trying to lose weight and you have a known illness or disease. Several other criteria include loss of muscle strength, decreased appetite, fatigue, and inflammation.
- Refractory cachexiaapplies to individuals with cancer. It is weight loss, muscle loss, loss of function, plus a failure to respond to cancer treatment.
Up to
Tumor cells release substances that reduce appetite. Cancer and its treatments can also cause severe nausea or damage the digestive track, making it hard to eat and absorb nutrients.
As the body gets fewer nutrients, it burns fat and muscle. Cancer cells use what limited nutrients are left to help them survive and multiply.
Cachexia happens in the late stage of serious conditions like:
- cancer
- congestive heart failure (CHF)
- chronic obstructive pulmonary disease (COPD)
- chronic kidney disease
- cystic fibrosis
- rheumatoid arthritis
How common cachexia is differs based on the disease. It affects:
-
5 percent to 15 percent of people with congestive heart failure or COPD - Up to80 percentof people with stomach and other upper GI cancers
- Up to
60 percent of people with lung cancer
People with cachexia lose weight and muscle mass. Some people look malnourished. Others appear to be at a normal weight.
To be diagnosed with cachexia, you must have lost at least 5 percent of your body weight within the last 12 months or less, and have a known illness or disease. You also must have at least three of these findings:
- reduced muscle strength
- fatigue
- appetite loss (anorexia)
- low fat-free mass index (a calculation based on your weight, body fat, and height)
- high levels of inflammation identified by blood tests
- anemia(low red blood cells)
- low levels of the protein, albumin
There is no specific treatment or way to reverse cachexia. The goal of treatment is to improve symptoms and quality of life.
Current therapy for cachexia includes:
- appetite stimulants such as megestrol acetate (Megace)
- 药物,如dronabinol (Marinol),改善nausea, appetite, and mood
- medications that decrease inflammation
- diet changes, nutritional supplements
- adapted exercise
Cachexia can be very serious. It can complicate treatment for the condition that caused it and lower your response to that treatment. People with cancer who have cachexia are less able to tolerate chemotherapy and other therapies they need to survive.
As a result of these complications, people with cachexia have a lower quality of life. They also have a worse outlook.
There currently is no treatment for cachexia. However, researchers are learning more about the processes that cause it. What they have discovered has fueled research into new drugs to combat the wasting process.
A number of studies have investigated substances that protect or rebuild muscles and accelerate weight gain.