The thyroid is a gland in the neck that regulates metabolism. Low thyroid function (hypothyroidism) can lead to diverse symptoms including weight gain, fatigue, sensitivity to cold, dry skin, dry hair, hair loss and constipation. In conventional medicine, the diagnosis of low thyroid function is usually made with a blood test. Here’s the classic picture:
Raised levels of ‘TSH’ (thyroid stimulating hormone, the hormone secreted by the pituitary gland at the base of the brain that stimulates the thyroid to produce thyroid hormones)
Low levels of thyroxine (one of the chief thyroid hormones – also known as ‘T4’)
My experience in practice tells me that the conventional way in which these blood tests are used to diagnose hypothyroidism is quite inadequate. The fact is, true hypothyroidism is not always reflected in a raised TSH and low thyroxine, and many individuals can suffer from hypothyroidism in the long term because their tests are ‘normal’. You can read about this here and here.
Even when tests yield abnormal readings, doctors can be reluctant to treat. For example, there is a recognised condition termed ‘subclinical hypothyroidism’ in which TSH levels are raised, but thyroxine levels are ‘normal’. Whether this condition should be treated with thyroid hormone is a moot point. Some doctors will treat. Many won’t, though, sometimes on the basis of the supposed risks associated with thyroid hormone treatment.
I was interested to read a recent study which looked women with subclinical hypothyroidism over time. Some of these women were treated with thyroxine, while some were not . The researchers then looked at the women’s risk for ‘ischaemic heart disease’ events (fatal and non-fatal heart attacks). In women aged 40-70, thyroid treatment was associated with a 39 per cent reduced risk of heart events. In women over the age of 70, treatment was not associated with a reduction in risk.
Now this study was epidemiological in nature, and cannot be used to conclude that thyroid treatment reduces risk of heart attacks in ‘younger’ women. However, this idea is not far-fetched, seeing as subclinical hypothyroidism is associated with an increased risk of heart disease.
The results of this study suggest that treatment of subclinical hypothyroidism may benefit heart health, and that diagnosing the issue and initiating treatment earlier might be better than ‘watching and waiting’.
As will all things, there are risks associated with treatment. However, what sometimes is forgotten in thyroid management is that there is often a heavy price to pay for not treating too.
Razvi S, et al. Levothyroxine Treatment of Subclinical Hypothyroidism, Fatal and Nonfatal Cardiovascular Events, and Mortality. Arch Intern Med. Published online 23 April 2012