The Endocrine Society of Australia
Recommendations from the Endocrine Society of Australia on thyroid tests, testosterone therapy, insulin sensitivity tests & blood glucose self-monitoring. The Endocrine Society of Australia (ESA) is a national non-profit organisation of scientists and clinicians who conduct research and practice in the field of Endocrinology. The society was founded in 1958 and incorporated in 1986 in the State of Victoria.
5.
Don’t order a total or free T3 level when assessing thyroxine dose in hypothyroid patients.
T4 (thyroxine) is converted into T3 at the cellular level in virtually all organs. Intracellular T3 levels regulate pituitary secretion and blood levels of thyroid-stimulating hormone (TSH), as well as the effects of thyroid hormone in multiple organs; a normal TSH indicates an adequate T4 dose. Conversion of T4 to T3 at the cellular level may not be reflected in the T3 level in the blood. Compared to patients with intact thyroid glands, patients with hypothyroidism taking T4 may have higher blood T4 and lower blood T3 levels. Thus the blood level of total or free T3 may be misleading (low normal or slightly low); in most patients a normal TSH indicates a correct dose of T4.
Supporting evidence
- Garber JR. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Thyroid 2012; 22(12):1200-35.
How this list was made
The Medical Affairs sub-committee of the Endocrine Society of Australia (ESA) collaborated with the Royal Australasian College of Physicians (RACP) to compile a list of 44 possible low-value interventions using desktop research.
The list was examined and refined down to 8 interventions: comprising 6 that were deemed sufficiently common or important to warrant consideration and two additional practices identified by the committee. A review of the evidence for these 8 was completed and circulated to the whole ESA membership for feedback via an on-line survey. Based on the results of the survey, which attracted 146 respondents, a top 5 was identified.
- 1 Don’t routinely order a thyroid ultrasound in patients with abnormal thyroid function tests if there is no palpable abnormality of the thyroid gland.
- 2 Don’t prescribe testosterone therapy unless there is evidence of proven testosterone deficiency.
- 3 Do not measure insulin concentration in the fasting state or during an oral glucose tolerance test to assess insulin sensitivity.
- 4 Avoid multiple daily glucose self-monitoring in adults with stable type 2 diabetes on agents that do not cause hypoglycaemia.
- 5 Don’t order a total or free T3 level when assessing thyroxine dose in hypothyroid patients.