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See Dr Morton’s living with diabetes and thyroid problems and steroids save lives
Last week in clinic I saw a young school teacher who usually enjoyed great health but just recently had started losing weight. She had also found that, most unusually she had been feeling rather short-tempered in class, and that she had been feeling her heart racing at times. She had seen her GP about these symptoms as she was sure that something wasn’t quite right. The GP had noticed that as well as looking much thinner than usual, her pulse was fast and her eyes seemed to be a bit more prominent. The GP did a blood test that confirmed that she had Graves’ disease and asked our team to see her.
Graves’ disease is a condition where the immune system goes wrong and the antibodies that usually fight infection are instead directed at the thyroid. Normally the thyroid releases thyroid hormones into the blood, and the levels of these hormones are measured in the pituitary gland. If the levels get a bit low then the pituitary sends out a bit more of a hormone called thyroid stimulating hormone (TSH). If levels get a bit high less TSH is sent out. In Graves’ disease antibodies work in two ways some just stir up the thyroid and cause it to release its hormones. Mostly though antibodies are made that act on the receptors for TSH and the thyroid thinks it is being given the message to make more thyroid hormones. Either way too many thyroid hormones are released into the blood and the result is that you have the symptoms of an overactive thyroid. The pituitary gland responds by turning down or off the production of TSH.
It is nine times more common in women and can affect up to 2% of women at some stage in their life, but men get it too, why you develop it or what the trigger is nobody knows, but it can run in families, so if one person has it, other members of the family are more likely to be affected in their lifetime. This suggests that your genes make you more susceptible.
Weight loss (although an unlucky 10% of people gain weight because you also become very hungry), diarrhoea, shaky hands, racing pulse, a feeling of your heart beating too fast (palpitations), sweating and sensitivity or intolerance of the heat, tiredness, irritability or short temper, irregular periods. The other thing that can happen in Graves’ disease is that the antibodies can also cause the muscles that move the eye to swell, this is known as Graves’ eye disease. Unfortunately the eyeball sits like an egg in an egg cup like socket in our skull and so if these muscles swell, the eyeball can be pushed forwards. This is called proptosis or exophthalmos. If the eye muscles are badly affected they can stop working as well, so some people with Graves’ disease can get blurred or double vision. Rarely the eyeball is pushed so far forward that it is difficult to close the eyelids over it, and this can cause problems to the delicate surface of the eyeball.
Graves’ disease – three main treatment options
Well there are three main options. The first is to give a course of tablets for 1 year to 18 months. These tablets are called carbimazole or propylthiouracil. We usually use high doses to start off with and gradually wean the dose down, some centres continue on the high dose of these tablets and then add in some thyroid hormone tablets. Most will treat you with these tablets for around 18 months and then stop the tablets and see what happens. Up to about 50% of people will be cured this way and never have any trouble again. Unfortunately the other 50% get a recurrence and need a different type of treatment.
A second option is to remove all or most of the thyroid, this can be done surgically, or as the third option with radioactive iodine. With surgery the majority or all of the thyroid is removed, the downside of surgery is that you may need to take thyroid hormones for the rest of your life, and you are left with a scar on your neck. Surgery also has the other problems of needing a general anaesthetic and putting you at risk of bleeding and infection in and from the wound.
With radioiodine we aim to give a dose that is just enough to kill off enough thyroid cells to leave you with the correct levels of hormones, however this is tricky to get right and often people are left either still overactive, in which case they might need a second or even third dose, or underactive and needing thyroid hormones for the rest of their life. The radioactive iodine is only taken up by the thyroid and so the rest of the body is not at risk, however you are radioactive for a few days/weeks and so you need to take precautions about being too close to people for a while, so this is not a good treatment if you have young children, or are unable to sleep separately from your partner for example. The other disadvantage of radioiodine is that it can make the swelling of the eye muscles worse, and so we do not use it if the Graves’ eye disease is bad.
So which treatment is the right one? In the UK, we mainly use the tablet option first, and save the other options to use if this fails, but in the US they mostly use radioiodine or surgery. There is no correct answer for everyone, and usually the doctor will be happy to let the sufferer know all the options, and let them choose which is right for them.
The eye disease is usually treated by eye specialists, and the treatment can involve steroids, surgery or radiotherapy to the eye muscles.
Our schoolteacher decided that the tablets would be the right option for her, we could not have given her radioiodine because of her job (unless we had organised it for the school holidays), but anyway we didn’t want to make her eye disease worse.