Cushing's syndrome is a rare disorder that most commonly affects people between the ages of 20 and 50 years. It is caused by a hormone imbalance as a result of changes in the pituitary or adrenal glands. In addition to causing some significant health symptoms, Cushing's syndrome may result in muscle wasting as a byproduct of reduced protein metabolism. The hormones associated with this condition directly affect how your body uses protein.
Cushing's Syndrome
People who develop Cushing's syndrome may have skin changes such as stretch marks, color changes or easy bruising. They may gain weight, particularly in the upper body, while the extremities may remain thin. One characteristic symptom of Cushing's syndrome is a "moon face" in which the face becomes rounded and excess fat develops around the neck. Cushing's syndrome can develop among some people who already have autoimmune disorders, such as lupus or arthritis, who must take steroids to manage their conditions. These drugs cause an increase in cortisol in the body, which can have an effect on metabolism of nutrients, including protein.
Cortisol
Cortisol is a type of hormone that affects metabolism and supports immunity, regulates blood pressure and helps the body to manage stress. Cushing's syndrome can develop when there is too much cortisol in the body. The hypothalamus in the brain produces corticotropin-releasing hormone and sends it to the pituitary gland, which is also located in the brain and is responsible for releasing several different types of hormones. The pituitary then sends adrenocorticotropin hormone to the adrenal glands near the kidneys, which then release cortisol. The high levels of cortisol that occur with Cushing's syndrome can cause damage to the body systems such as infection, difficulties responding to stress and an inability to metabolize protein.
Effects on Protein
The cortisol secreted by the adrenal glands is a type glucocorticoid that has an effect on protein metabolism. During the digestive process, cortisol stimulates the body to break down protein into amino acids, increasing their overall concentration in the bloodstream. The liver then takes these proteins and converts them into a usable form for the cells to use as fuel in a process called gluconeogenesis. This works for energy, but in situations where the body produces too much cortisol, such as in the case of Cushing's disease, the protein that would be used for the muscles is depleted. This can cause extreme weakness, fatigue and muscle atrophy.
Diet
Your doctor may prescribe a specific diet or you may need to talk with a dietitian if you are diagnosed with Cushing's syndrome. With Cushing's, the types of food that you eat have an effect on your adrenal glands, as well as how the body metabolizes food by using cortisol. Throughout the day, you may need to add protein-rich foods to your meals and snacks to promote protein levels while you are going through treatment. You can gain extra protein in your diet to support your muscle mass by eating foods such as lean meats, beans, spinach, eggs, peanut butter, milk or cottage cheese. Consult your doctor about dietary instructions for adding protein if you have Cushing's disease.
