Pituitary insufficiency

The Adult Endocrinology Clinic provides diagnosis and follow-up for adult patients with an endocrine problem, i.e. a condition affecting the secretion of a hormone (excessive or insufficient secretion) and/or the gland that secretes it. The department manages conditions affecting the thyroid, parathyroid glands, adrenal glands, gonads (ovaries and testicles), and pituitary gland.

Since 2016, the Erasme Hospital Endocrinology Department, together with the Queen Fabiola Children’s University Hospital (HUDERF) for paediatric care, has been part of the ENDO-ERN network (European Reference Network for Rare Endocrine Conditions), the European Reference Network for rare endocrine diseases.

The mission of this network is to improve access to high-quality care for patients with rare endocrine disorders. It supports clinical research and contributes to the creation of registries listing patients receiving follow-up for rare conditions, in order to promote knowledge sharing and improve clinical practice.

The management of rare endocrine diseases is multidisciplinary. Regular consultations are organised to discuss complex cases with numerous specialists within our institution, as well as through virtual consultations with recognised European experts via the ENDO-ERN network or during international multidisciplinary consultation meetings (France).
Some endocrine diseases begin at birth or during childhood and require lifelong treatment and follow-up. Transition consultations have been provided for many years with our paediatric colleagues at HUDERF to ensure the smoothest possible transition from paediatric to adult care.

The pituitary gland is a pea-sized gland located at the base of the brain, behind the nose. It acts as the conductor of most of the body’s other glands. It produces several hormones that regulate the secretion of hormones by other glands (the thyroid, ovaries or testes, and adrenal glands). It also produces growth hormone and releases prolactin, which plays an important role during pregnancy and breastfeeding, as well as vasopressin, a hormone involved in maintaining the body’s water balance.

Some people have a pituitary gland that does not function, either partially or completely, and consequently have deficiencies in hormone secretion. Depending on which hormones are affected, their functions, and the age at which the insufficiency develops, the symptoms experienced by patients may vary: growth retardation and/or delayed puberty in children and adolescents, fatigue, hypoglycaemia, dizziness, a drop in blood pressure, abdominal pain, nausea, unexplained weight loss or gain, libido disorders, cessation of menstruation, etc. Vasopressin deficiency causes the kidneys to eliminate large amounts of water; patients urinate excessively both during the day and at night. As a result, they are very thirsty and drink a great deal to compensate.

Pituitary diseases may be caused by congenital conditions (abnormal development of the gland) that are present from birth, but are most often related to conditions acquired later in life. These conditions may be tumours (most often benign), inflammatory, haemorrhagic or, more rarely, infectious. Pituitary hormone deficiencies may also occur following treatment of tumours located in this region, through surgery and/or radiotherapy.
 

Pituitary disease is often investigated based on the patient’s symptoms (headaches, vomiting, hypoglycaemic episodes, abnormal weight gain or loss, menstrual disorders, reduced libido, etc.) or as part of an assessment of delayed growth or puberty in children. Hormonal deficiencies are systematically investigated after surgery or radiotherapy to the pituitary region. A simple blood test is usually sufficient to diagnose pituitary insufficiency. However, other tests, known as “dynamic” tests, may sometimes be required to confirm the diagnosis: a substance is administered by infusion to stimulate hormone secretion; in cases of insufficiency, the level of the hormone in question will not rise appropriately.

These tests are performed on an outpatient basis, usually during one morning, with a specialist nurse, in a dedicated room in the Endocrinology consultation building.  
A magnetic resonance scan of the pituitary gland completes the assessment to determine the cause of the insufficiency. In some cases, genetic testing is also offered, as well as other laboratory or radiological examinations depending on the suspected cause.

Regardless of the cause of pituitary insufficiency, hormone replacement therapy is offered. The missing hormone is replaced by daily capsules and/or tablets, with a dose adjusted to each patient’s needs (thyroid hormone, adrenal hormone = cortisol, sex hormones). Some hormones are administered by injection, such as growth hormone or testosterone. Vasopressin can be taken orally or administered as a nasal spray. If the cause is a tumour, surgery is usually offered, particularly if the tumour is large and may cause other complications.
 

It is very important to take the thyroid hormone and adrenal hormone (cortisone) correctly every day. Cortisone is an essential hormone for feeling well and energetic, maintaining good blood pressure and having energy, but also for responding to situations that put the body under stress (infection, fever, gastroenteritis, surgery, anaesthesia, trauma). The doses are adjusted according to the blood test results, but also according to the patient’s own feelings and experience and the clinical examination, particularly in the case of cortisone (level of fatigue, weight, blood pressure, etc.). 

The cortisone dose must be increased in situations that put the body under stress. In the event of repeated vomiting preventing proper oral administration, cortisone may be administered intramuscularly by a family member or an on-call doctor.  In situations of major stress, such as surgery, anaesthesia or a serious infection, cortisone must be administered at a higher dose intravenously.  Patients with cortisol deficiency and their families are informed about situations requiring an increase in the doses. A nurse shows them how to inject cortisone intramuscularly when necessary. They all carry a card in their wallet indicating their cortisol deficiency and the need to increase the doses in the event of stress. They are encouraged to show this card to the doctors caring for them, particularly in the event of surgery or a visit to the Emergency Department. 

Growth hormone is administered every evening by daily subcutaneous injection, most often in the abdomen, using a pen that must be kept in the refrigerator. The dose is adjusted according to the blood test results and the child’s growth progression. In adults, it no longer plays a role in growth but may improve quality of life and have a beneficial effect on body composition (the ratio of fat to muscle). 
 

During adolescence, a gradual preparation for the transition to adult care is organised. This step helps strengthen the young patient’s autonomy, ensure continuity of medical follow-up and transfer all the necessary information to the specialised adult service. The transition is planned in collaboration with the patient, their family, and the paediatric and adult teams.

Patients are treated by a licensed adult endocrinologist. Hormone assays and genetic tests are performed in a specialised laboratory. We work closely with the radiology and neurosurgery departments. Magnetic resonance imaging is of high quality and can be supplemented by functional imaging (methionine PET, choline PET). The neurosurgeons are experts in pituitary surgery. Patients requiring additional treatment after surgery may benefit from a targeted radiotherapy technique, the gamma knife, which is available in only a few hospitals in Belgium.

Complex pituitary cases are discussed during monthly multidisciplinary meetings with expert neurosurgeons and neuroradiologists. An on-call service is available 24 hours a day. Our centre is actively committed to improving knowledge and care for patients with rare endocrine diseases. A local registry has been established and feeds into a European ERN database dedicated to the pituitary gland. The aim is to optimise follow-up practices and compare the management of patients between different specialised centres.

Particularly rare and/or complex cases are also discussed with international experts. The team receives ongoing training, participates in conferences and seminars, initiates and collaborates on studies, and publishes in the field of pituitary medicine. It also provides training and teaching for students and doctors in training.