I read with interest the BTA's response to the petition to the Scottish Parliament.
Yesterday I came across a document written in 2006 by BTA, the Association for Clinical Biochemistry and the British Thyroid Association which seems to contradict some of their statements (I'm not sure I understand what is meant by 'non-thyroidal illness' - see below).
In the response to:
1. We ask for the inclusion of tests for Free T3 (FT3) and Reverse T3 (RT3) thyroid hormones, as these are the strongest indicators of cellular thyroid levels.
The BTF informs enquirers that these tests are not useful in the diagnosis of hypothyroidism. Our medical advisors inform us there is no reliable scientific evidence to the contrary.
Yet in their 2006 doc:
Diagnosis: The biochemical diagnosis of secondary hypothyroidism necessitates the use of a
combination of TSH with FT4. Plasma TSH can be low, within or mildly above the reference
range in these patients but combined with a low FT4 measurement is suggestive of secondary
Measurement of FT3 may be required to differentiate secondary hypothyroidism from non-
thyroidal illness especially in older patients where symptoms are often vague and non-specific.
Patients suspected of having secondary hypothyroidism may require referral to an
endocrinologist to accurately make the diagnosis and for additional pituitary function tests (PRL,
FSH, LH, ACTH/cortisol). Tests of adrenal function are mandatory in patients with a high index
of suspicion of hypopituitarism.
Measurement of TSH and FT4 is required to identify secondary hypothyroidism.
Secondary hypothyroidism can be distinguished from non-thyroidal illness on the basis
of clinical history, measurement of FT3 and tests of other anterior pituitary hormones.
Guiding Treatment: Patients with secondary hypothyroidism usually also be deficient in other
anterior pituitary hormones and the degree of hypopituitarism must be established before
commencing thyroxine replacement. In particular thyroid hormone replacement should not be
commenced in patients with cortisol deficiency as this could provoke an Addisonian crisis.
Glucocorticoid replacement should be started prior to the initiation of thyroxine therapy.
Thyroxine should be given in increasing 25 μg doses and optimised such that the thyroid
hormone concentration is within the upper third of the reference range.
The full document is called: Adapted Summary of UK Guidelines for the Use of Thyroid Function Tests (July 2006). Here is the Introduction:
The Use of Thyroid Function Tests Guidelines Development Group was formed in 2002 under
the auspices of the Association for Clinical Biochemistry (ACB), the British Thyroid Association
(BTA) and the British Thyroid Foundation (BTF). The purpose of the guidelines is to encourage
a greater understanding of thyroid function testing amongst all stakeholders with a view to the
widespread adoption of harmonised good practice in the diagnosis and management of patients
with thyroid disorders. This summary is adapted from the July 2006 guidelines.
The full doc can be read here:
Or have I misunderstood what they are saying?