Whose Thyroid Hormone Replacement is it Anyway?

A. P. Weetman

Disclosures

Clin Endocrinol. 2006;64(3):231-233. 

As an adult she had her organs removed one by one. Now she is a mere shell with symptoms where her organs used to be. - William O. Abbot (1902-43)

Nothing seems more straightforward than treatment of hypothyroidism. We have robust assays to diagnose the condition and an effective replacement in the form of synthetic thyroxine. However, the field appears to be in some turmoil and clinical endocrinologists are under increasing pressure from disaffected patients who believe their symptoms indicate hypothyroidism despite normal thyroid function tests. Consider the following. A group of patients has just lodged a petition with a Member of Parliament and the UK General Medical Council, as 'a formal complaint against the clinical practice of the majority of the medical profession with regard to the diagnosis and management of hypothyroidism on four counts:

  1. Over-reliance on thyroid blood tests and a total lack of reliance on signs, symptoms, history of the patient and a clinical appraisal.

  2. The emotional abuse and blatant disregard by the majority of general practitioners and endocrinologists over the suffering experienced by untreated/incorrectly treated thyroid patients and their lack of compassion over the fate of these patients.

  3. Stubbornness of general practitioners and endocrinologists to treat patients suffering from hypothyroidism with a level of medication that returns the patient to optimum health. In addition the unwillingness to prescribe alternate thyroid treatment for patients on individual grounds... such as Armour thyroid.

  4. The ongoing reluctance to encourage debate or further research on hypothyroidism.'

This has led the Member of Parliament to take the matter up with the Royal College of Physicians of London.

Another patient group, Thyroid Patient Advocacy (www.tpa-uk.org.uk), currently lists on its website the campaigns it is mounting, which include pressing another Member of Parliament to table an early day motion calling on the Government 'to raise awareness of hypothyroidism and the dangers of misdiagnosing an under-active thyroid and to promote the use of a range of treatments including thyroxine to address the current inadequacy of testing, diagnosis and treatment of the condition.' The same web-site makes the startling assertion that approximately 25% of the total population of the UK suffers from hypothyroidism and also supports the wider use of Armour thyroid extract, as well as claiming that diagnosis of hypothyroidism by blood tests alone is insufficient. This is far from a UK phenomenon, and much of the impetus for the views of such patient organizations derives originally from Broda Barnes in the USA (see www.brodabarnes.org).

Fundamental to the diagnosis of hypothyroidism according to the Barnes's approach is the basal body temperature, and treatment is recommended with 'natural desiccated thyroid hormone', rather than 'synthetic thyroid hormones'. Readers' reviews of Barnes and Galton's still widely read 1976 book Hypothyroidism: The Unsuspected Illness include the following quotations: 'Get the book there has never been anything printed that will help you more' and 'The only reason the medical profession won't use this theory is money' (www.amazon.co.uk).

Moreover, such views on the futility of laboratory testing and the need for empirical, natural hormone replacement are not confined to the thyroid field. Some medical practitioners advocate the use of a variety of natural and synthetic steroids for the treatment of mild to moderate adrenal insufficiency which is alleged to coexist frequently with clinically diagnosed hypothyroidism: 'It is... perfectly practical and reasonable, to establish the diagnosis (of hypoadrenalism) on clinical grounds, and because the therapy given is of very low - physiological - doses, there is no possible risk to the patient, however long it is needed' (Durrant-Peatfield, quoted from www.tpa-uk.org.uk).

Why do some patients feel so dissatisfied with and so mistrustful of standard medical advice? There are two broad reasons. The first is experienced in virtually all specialities and stems from the fact that we are practicing in the age of postmodern medicine.[1] A cardinal feature of postmodernism is the derogation of objective facts which are the defining characteristic of science and the replacement of scientific certainty with the view that reality can have multiple meanings. Access to information by patients has increased vastly due to the Internet, whilst changes in health care have shifted the emphasis away from healing and towards rapid diagnosis and treatment. Patients perceive symptoms and want an explanation for them, but in the rush to satisfy targets most doctors have little time to understand both the patient and their experiences which have led, in a more complex fashion than we generally acknowledge, to the consultation in the first place.[2]

The majority of patients who demand thyroid hormone treatment for multiple symptoms, despite normal thyroid function tests, have functional somatoform disorders, which in the postmodern world can understandably be misdiagnosed as hypothyroidism. Yet we inside medicine are not even sure how best to classify somatoform disorders, let alone explain them to patients, and this broad diagnostic label has many shortcomings. In particular (i) the terminology is unacceptable to patients; (ii) the classification supports the Cartesian dualism that somatic symptoms can be either 'organic' or 'psychogenic'; (iii) these disorders do not form a single category, although some have argued that there is a significant overlap which may well have therapeutic if not aetiological relevance; (iv) such a diagnosis is socially and culturally dependent and (v) there is considerable unreliability and ambiguity in defining the diagnosis.[3] A paradigm shift in our categorization of somatoform disorders has been proposed recently, with a recommendation to return to a far less dualistic approach.[4] This shift is based on evidence that functional neurological changes can be identified in some patients with somatoform disorders, and there is therefore a compelling case for a different approach using a 'psychologically augmented medical consultation'.

Whilst such analyses are undoubtedly changing our perception of patients' symptoms and ways of tackling them, progress is slow and not helped by the rise of 'healthism', which has been characterized by the following features: 'high health awareness and expectations, information seeking, self-reflection, distrust of doctors and scientists, healthy and often alternative lifestyle choices, and a tendency to explain illness in terms of folk models of invisible germ-like agents and malevolent science.'[5] Although this has been most frequently described in healthy and well-informed middle-class individuals who present with a variety of inexplicable symptoms, it is clear that healthism is affecting the whole spectrum of patients. The advance of healthism has its roots in postmodernism and accounts for the increasing number of bilaterally unsatisfactory consultations with patients who have an unshakeable self-diagnosis or a demand for a 'natural' rather than 'synthetic' treatment.

Many high-profile, alleged health hazards such as the MMR vaccine have engendered considerable fear and an ever-increasing distrust of science as a result of the healthism phenomenon. The scale of the problem has been eloquently described by Marcia Angell in her 1996 Shattuck Lecture on the purported health risks of silicone breast implants.[6] There is also a striking parallel between that saga and the present one of thyroid hormone replacement in euthyroid individuals. Women with implants who claimed a connection with connective tissue disease sought to prove their case by stating 'we are the evidence'. As Angell observed, this argument seemed 'reasonable to many people although... logically meaningless', and it distils what the Broda Barnes school of thought really is: if you have the symptoms of hypothyroidism, you must, reasonably, have that disease.

The second, more specific reason for the unhappiness of these patients is that any innate sense of disbelief in science has been heightened by the lack of consensus amongst endocrinologists, particularly with regard to the diagnosis of subclinical hypothyroidism, its importance, and the need for treatment. A healthy debate on whether subclinical hypothyroidism is mild thyroid failure and should be treated[7,8] appears welcome but can readily be understood to create anxiety or confusion in some patients with a TSH of, say, 8 mU/l who access these papers from the Web. Recent attempts to produce a comprehensive scientific review and guidelines for the diagnosis and management of subclinical thyroid disease[9] provoked a dissenting set of comments from members of the same organizations that had sponsored the original guidelines.[10] In turn, this spawned an editorial wondering whether we could achieve a consensus about the consensus![11] The difficulty we face as clinicians in formulating guidelines, or more commonly in judging how to apply them to our own practice, stems from our individual perceptions of benefit and risk. For instance, in the guidelines just mentioned, treatment of subclinial hypothyroidism with a TSH level below 10 mU/l was not recommended, largely based on the concern that more patients than we might suspect would end up with a suppressed TSH as a result of over-treatment, and this risk was deemed unacceptable in the face of so little evidence of benefit.[12] If one's own practice is such that the rates of over-treatment are very low, thus minimizing any risk, then the balance would shift, in my view at least, towards treatment in a symptomatic patient with a TSH that is elevated but below 10 mU/l.

Another concern for patients has been the recent debate over narrowing the TSH reference range.[13,14] As with the treatment of subclinical hypothyroidism, this is a complex area, demanding a sophisticated knowledge of laboratory medicine and clinical endocrinology to interpret and translate the current state of play into everyday clinical practice. In assessing these arguments, however, we should not be surprised that patients question our reliance on TSH levels when they have read such publications themselves.

What can be done? Obviously the scientific debate must continue and will undoubtedly lead to more definitive research that will answer these questions, although such studies will be hugely demanding and difficult to fund. Two papers published in November last year are examples of the further information we are now accruing on the risks of subclinical hypothyroidism and provide reassurance that subjects with TSH levels in the range of 2-7 mU/l show no increased incidence of cardiovascular disease over a 4- to 20-year follow-up period, in turn indicating that mild subclinical hypothyroidism does not require treatment, at least with regard to any concern over cardiovascular risk.[15,16] In addition, we must communicate areas of uncertainty in an open manner which allows for the range of educational, social and cultural differences that can exist between doctor and patient.

Dealing with someone who has many hypothyroid symptoms yet clearly normal thyroid function tests may be challenging, but physicians can do more than at present. Most patients with functional somatoform disorders are given explanations which are experienced as either a rejection of the reality of the symptoms or a simple collusion and acquiescence to the patient's own biomedical theory.[17] Both types of explanation are, not surprisingly, perceived to be unsatisfactory, whereas empowering explanations can improve patients' well-being directly and can reduce the demands they make on health services. Communication lies at the heart of managing patients whose health problems cannot be explained and the focus should be on the patient's concerns, the relief of symptoms and the avoidance of alienation.[18] Finally, we should retain our own sense of perspective, scepticism and humility. As functional somatoform disorders are dissected further, new ways of managing these common and troublesome disorders will undoubtedly become established. In the meantime we must avoid endocrinological collusion as a strategy, which in turn requires the avoidance of thyroid hormone treatment of euthyroid individuals, a robust defence of the biochemical basis for the diagnosis of hypothyroidism and institution of replacement with synthetic thyroxine as the standard, rather than Armour thyroid extract.


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