Hypopituitarism

Hypopituitarism is when a person has a short supply (deficiency) of one or more pituitary hormones.

A benign (non-cancerous) pituitary tumour called an adenoma, causes acromegaly in 98% of cases. The tumour produces GH, leading to an excess level of the hormone in your bloodstream. The GH in turn triggers the liver to produce an important metabolic hormone called Insulin like growth factor -1 (IGF-1). When IGF-1 levels are consistently high, it leads to abnormal bone and tissue enlargement. The high levels of GH can also promote insulin resistance, leading to diabetes.

In most cases, acromegaly isn’t inherited, although there are on-going genetic studies on the condition. We still don’t know what triggers the adenoma.

Acromegaly gradually causes excessive bone, tissue and organ growth. Over time, this leads to changes in your appearance and health. However, in the early stages, you can mistake symptoms, such as tiredness and skin changes, for ageing or other common conditions.

Swollen hands and feet are one of the most common symptoms. You may have noticed your shoes and rings no longer fit. You also might begin to notice your face is changing shape: your jaw and brow are beginning to protrude, your lips are thickening and nose and tongue are getting bigger. You teeth may have changed position and your “bite “ is no longer the same. Other common symptoms include: sweating, headache, sleep apnoea and arthritis. Acromegaly also places you at risk of diabetes, heart disease and respiratory disorders as well as thyroid and colon cancers.

Given the list of symptoms, it makes sense that if left untreated, acromegaly can lead to serious illness and even become life threatening.

You will need to be referred to an endocrinologist who specialises in hormonal disorders. They will send you for diagnostic tests for acromegaly which include

  • A morning fasting blood test for hormone measurements.
    IGF1, GH, prolactin, thyroid function tests reproductive hormones, adrenal/cortisol hormones and check of kidney, liver, metabolic function as well as full blood count
  • Your endocrinologist may request a glucose tolerance test. This is a 2 hour test that can also be used to diagnose diabetes. You would be asked to fast overnight, a blood test is taken, you are given a sweet glucose drink then several blood tests over the next 2 hours are taken. These include GH and glucose.
  • The imaging scan usually performed for the pituitary is a Magnetic Resonance Imaging (MRI). If you can’t have an MRI then computer tomography (CT) scan is used.
  • Your vision should be formally checked and should include a visual field check by the ophthalmologist or optometrist.

Following diagnosis, the aim of treatment is to normalise your GH production. This could include surgery, medication, radiation therapy or a combination of these.

In some cases, eg when the tumour is larger than 1cm diameter, surgery may not cure acromegaly, so following the initial treatment you may need long-term medication to manage the disease or halt its progression. However, in the months following the beginning of treatment your symptoms will reduce – and in some cases even reverse – including facial disfigurations. The same also goes for your health risks. In most cases the soft tissue swelling disappears.

Unfortunately, any bone changes are irreversible. eg enlarged lips and nose may reduce in size but a protruding jaw bone or enlarged forehead would not change so much. Soft tissue in the feet and hands can decrease but may never return to their original size. Position of teeth would not change. Having dental , orthodontic work or orthognathic surgery ( breaking the jaw and resetting it into a new, pre-determined, place). These procedures would not be performed while Acromegaly is still active and treatment is ongoing.

For some people surgery is the only treatment necessary however for some, to achieve the best outcome, requires long-term medical management. Your doctor will monitor your IGF-1 levels to ensure they don’t begin to rise again. ElevatedGF-1 for some individuals may increase the risk of bowel cancer, so your doctor will also request you have a colonoscopy every three to five years to check for any changes in your bowel.

Sometimes the tumour or the treatments (ie surgery of radiotherapy) can damage the pituitary gland. This can lead to underactivity in the following glands:

  • thyroid
  • adrenal gland
  • testes(men) / ovaries ( women)
  • posterior pituitary gland

If this happens, you’ll need ongoing hormone replacement * for these conditions.

Fortunately, there’s a lot of research into acromegaly and new medications are emerging. Internationally, endocrinologists regularly meet to update the guidelines on the diagnosis and treatment of acromegaly complications.