What is the Cushing’s threshold?
Cushing’s syndrome describes a group of symptoms caused by an excessive level of cortisone in the blood. The symptoms are, for example, the development of diabetes mellitus, or a full moon face, trunk obesity, stretch marks on the stomach or osteoporosis. The most common reason for the occurrence of Cushing’s syndrome is the excessive intake of drugs such as cortisone or similarly acting substances, which all belong to the group of so-called glucocorticoids.
This is the reason for the Cushing’s threshold for these drugs. It indicates the maximum daily dose that can be taken of the drug in question. If this dose, i.e. the Cushing’s threshold, is exceeded, the Cortion level in the blood rises and the risk of developing Cushing’s syndrome increases.
The Cushing’s threshold for the intake of cortisone in adults is about 30mg per day. Artificially produced glucocorticoids that act in the same way as cortisone are for example prednisolone or dexamethasone. When taking prednisolone, the Cushing’s threshold is 7.5mg per day, and with dexamethasone it is 1.5mg per day. For children, depending on age and weight, about a quarter of this dose is considered the Cushing’s threshold.
Symptoms of Cushing’s syndrome
Among the symptoms that occur in people suffering from Cushing’s syndrome is weight gain with a distribution of fat that is typical of Cushing’s syndrome: often the patient gains weight mainly on the trunk, the face becomes round and fat pads form on the neck and above the collarbone (bull’s neck). The skin also shows symptomatic changes, reddening of the face, acne, poor wound healing and dark red stripes (striae) on the skin can occur. In women, male hair growth can be observed on the face, chest and back due to the altered hormone situation caused by Cushing’s syndrome.
Patients with Cushing’s syndrome often suffer from osteoporosis at a young age and complain of bone pain. Similarly, muscle weakness and muscle pain are common symptoms of Cushing’s syndrome. The patients feel powerless and lacking in drive.
The following signs of the disease can be seen on the skin: Wound healing in injuries is poor and the skin thins, which can be seen especially on the back of the hand. The patients also have red stretch marks on the skin (striae). Patients with hypercortisolism (too much cortisol) often develop diabetes (diabetes mellitus), as cortisol causes the release of sugar into the bloodstream, which can lead to high blood sugar levels.
Cushing’s patients have high blood pressure in 85% of cases. The development of depression is a not uncommon symptom in Cushing’s syndrome. Changes in the blood count can also be observed in Cushing’s syndrome: The platelet and red blood cell counts and total white blood cell count are elevated, while for special forms of white blood cells, eosinophils and lymphocytes, the counts are lower.
The development of endocrine hypertension (hormone-induced high blood pressure) can also be caused by an increased amount of cortisol, a hormone of the adrenal glands, in the blood. In women, Cushing’s syndrome can cause symptoms such as menstrual disorders and acne formation. It can also lead to masculinisation (androgenisation).
In 80% of cases, men with Cushing’s syndrome have erectile dysfunction and both sexes lose their libido. When children are affected by Cushing’s syndrome, growth disturbances and a delay in development occur. The Cushing’s triad is a combination of three symptoms, also described as the Cushing reflex.
These are: They’re all caused by an increase in intracranial pressure, which can occur for a variety of reasons. The Cushing’s Triad is not necessarily related to Cushing’s syndrome, but it can be caused by it. The increase in intracranial pressure, which can be caused by water retention, cerebral haemorrhage or brain tumours, leads to reduced blood flow to the brain.
In order for the nerve cells to be supplied with sufficient blood, the blood pressure is raised reflexively to enormously high values, whereupon the cerebral pressure can increase due to further oedemas. This increase in intracranial pressure also causes irregular breathing and slow heartbeat, but can also be accompanied by dizziness and loss of consciousness, neurological deficits of all kinds and later also coma. – increased high blood pressure
- Slowed down heartbeat and
- Irregular breathing.
Full moon face is a classic symptom of Cushing’s syndrome. It is caused by the fact that the high cortisone level in the blood has a great influence on the human metabolism. It also leads to a redistribution of fat throughout the body.
This usually reduces the fat pads on arms and legs. In return, more fat is stored on the trunk, neck and face. Thus the full moon face is created.
In addition, less salt is excreted. The salts then attract water in the body and lead to water retention. These also make the patient appear swollen and fuller.
