Santos Palacios S, Pascual-Corrales E, Galofré J C. Management of subclinical hyperthyroidism. Int J Endocrinol Metab. 2012;10(2):490-496.
The ideal approach for adequate management of subclinical hyperthyroidism (low levels
of thyroid-stimulating hormone [TSH] and normal thyroid hormone level) is a matter of
intense debate among endocrinologists. The prevalence of low serum TSH levels ranges
between 0.5% in children and 15% in the elderly population. Mild subclinical hyperthyroid
ism is more common than severe subclinical hyperthyroidism. Transient suppression of
TSH secretion may occur because of several reasons; thus, corroboration of results from
different assessments is essential in such cases. During differential diagnosis of hyperthy
roidism, pituitary or hypothalamic disease, euthyroid sick syndrome, and drug-mediated
suppression of TSH must be ruled out. A low plasma TSH value is also typically seen in
the first trimester of gestation. Factitial or iatrogenic TSH inhibition caused by excessive
intake of levothyroxine should be excluded by checking the patient’s medication history.
If these nonthyroidal causes are ruled out during differential diagnosis, either transient
or long-term endogenous thyroid hormone excess, usually caused by Graves’ disease or
nodular goiter, should be considered as the cause of low circulating TSH levels.
We recommend the following 6-step process for the assessment and treatment of this
common hormonal disorder: 1) confirmation, 2) evaluation of severity, 3) investiga
tion of the cause, 4) assessment of potential complications, 5) evaluation of the neces
sity of treatment, and 6) if necessary, selection of the most appropriate treatment.
In conclusion, management of subclinical hyperthyroidism merits careful monitoring
through regular assessment of thyroid function. Treatment is mandatory in older patients
(> 65 years) or in presence of comorbidities (such as osteoporosis and atrial fibrillation)