The month's best new evidence on Thyroid Disease, August 2016
1. The ATA has issued 124 recommendations on diagnosis and treatment, covering management of Graves' disease, management of hyperthyroidism during pregnancy, how to prepare patients for surgery, and many other topics. See our essential synopsis of the article from Thyroid below.
2. You may be using the wrong reference range for your older patients, and that could lead to suboptimal management. For example, older patients exhibit higher thyrotrophin/TSH concentrations than younger patients. See our essential synopsis of the article from the Journal of Gerontology Biological Sciences and Medical Sciences below.
3. What's the connection between hypothyroidism and frozen shoulder? Apparently higher serum TSH levels are associated with bilateral and severe cases of FS. See our essential synopsis of the article from The Journal of Shoulder and Elbow Surgery below.
New ATA guidelines for hyperthyroidism
- A task force of experts from North America, South America, and Europe reviewed published research on the diagnosis and treatment of thyrotoxicosis.
- Funding: Study funded by the American Thyroid Association (ATA).
What's new in the guidelines
- A revised list of the most common causes of thyrotoxicosis.
- Evaluation of the etiology of the disease.
- Management of Graves' disease using antithyroid drugs.
- Management of hyperthyroidism during pregnancy.
- How to prepare patients for thyroid surgery.
- Expanded sections on rare causes of the disease.
Additional topics covered
- Initial diagnosis and management.
- The use of radioactive iodine, antithyroid drugs, or surgery in Graves' disease.
- Treatment of toxic multinodular goiter or toxic adenoma with radioactive iodine or surgery.
- Graves' disease in children, adolescents, or pregnant patients.
- Subclinical hyperthyroidism.
- Hyperthyroidism in patients with Graves' orbitopathy.
- How to manage other causes of thyrotoxicosis.
Why this matters
- Significant scientific advances in the field since the original guidelines were published in 2011 by the ATA and the American Association of Clinical Endocrinologists meant some current clinical issues were not addressed.
Reference intervals for TSH and FT4 in older men
Source: Journal of Gerontology Biological Sciences and Medical Sciences
- Of the men included in the analysis, the 2.5th and 97.5th centiles for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were 0.64-5.9 mIU/L and 12.1-20.6 pmol/L (0.94-1.60 ng/dL), respectively.
- Of the 411 very healthy men defined by excellent or very good self-rated health and absence of major medical comorbidities, 2.5th to 97.5th centiles for TSH and FT4 were 0.67-4.98 mIU/L and 12.1-20.5 pmol/L (0.94-1.59 ng/dL), respectively.
- TSH was not associated with mortality.
- Higher FT4 was associated with increased mortality.
- Applying intervals based on very healthy older men to the cohort led to reclassification of 310 men (8.0%).
- More men classified as hyperthyroid or hypothyroid, or having subclinical hyperthyroidism.
- Study included 3885 men aged 70-89 y.
- Baseline TSH and FT4 levels assayed.
- Conventional reference intervals for TSH and FT4 were 0.4-4.0 mIU/L and 10-23 pmol/L, respectively.
- Funding: Study funded by the Fremantle Hospital Medical Research Foundation, the Ada Bartholomew Medical Research Trust, University of Western Australia, and the National Health and Medical Research Council of Australia.
Why this matters
- Use of non-age-appropriate reference ranges could lead to suboptimal management.
- Thyroid axis matures during ageing; older adults exhibiting higher thyrotrophin/TSH concentrations compared with younger and middle-aged adults.
Hypothyroidism and frozen shoulder
Source: Journal of Shoulder and Elbow Surgery
- Prevalence of hypothyroidism diagnosis was significantly higher in the frozen shoulder (FS) group (27.2% vs 10.7%; P=.001).
- Tendency for higher prevalence of bilateral FS among patients with elevated thyroid-stimulating hormone (TSH) levels (P=.09).
- Mean serum TSH levels were higher in patients with bilateral FS compared with those with unilateral compromise (3.39 vs 2.28; P=.05) and higher in patients with severe FS compared with those with mild and moderate FS together (3.15 vs 2.21; P=.03).
- Multivariate analysis showed FS independently related to hypothyroidism (OR, 3.1; 95% CI, 1.5-6.4; P=.002).
- Trend toward independent association between high serum TSH levels and severe (OR, 3.5; 95% CI, 0.8-14.9; P=.09) and bilateral (OR, 11.7, 95% CI, 0.9-144.8; P=.05) compromise.
- Case-control study to compare patients with FS with patients who visited an orthopedic service for other conditions (control patients).
- FS diagnosed according to criteria based on anamnesis, physical examination, and shoulder radiographs.
- Questionnaire applied and measurements of serum TSH and free tetraiodothyronine performed in all patients.
- Authors evaluated 401 shoulders from 93 patients with FS and 151 control patients.
Why this matters
- Patients diagnosed with FS should be checked for changes to thyroid function.
- Control of TSH levels might also protect against FS.