2013 ETA Guideline: Management of Subclinical Hypothyroidism.
Subclinical hypothyroidism (SCH) should be considered in two categories according to the elevation in serum thyroid-stimulating hormone (TSH) level: mildly increased TSH levels (4.0-10.0 mU/l) and more severely increased TSH value (>10 mU/l). An initially raised serum TSH, with FT4 within reference range, should be investigated with a repeat measurement of both serum TSH and FT4, along with thyroid peroxidase antibodies, preferably after a 2- to 3-month interval. Even in the absence of symptoms, replacement therapy with L-thyroxine is recommended for younger patients (<65-70 years) with serum TSH >10 mU/l. In younger SCH patients (serum TSH <10 mU/l) with symptoms suggestive of hypothyroidism, a trial of L-thyroxine replacement therapy should be considered. For such patients who have been started on L-thyroxine for symptoms attributed to SCH, response to treatment should be reviewed 3 or 4 months after a serum TSH within reference range is reached. If there is no improvement in symptoms, L-thyroxine therapy should generally be stopped. Age-specific local reference ranges for serum TSH should be considered in order to establish a diagnosis of SCH in older people. The oldest old subjects (>80-85 years) with elevated serum TSH ≤10 mU/l should be carefully followed with a wait-and-see strategy, generally avoiding hormonal treatment. If the decision is to treat SCH, then oral L-thyroxine, administered daily, is the treatment of choice. The serum TSH should be re-checked 2 months after starting L-thyroxine therapy, and dosage adjustments made accordingly. The aim for most adults should be to reach a stable serum TSH in the lower half of the reference range (0.4-2.5 mU/l). Once patients with SCH are commenced on L-thyroxine treatment, then serum TSH should be monitored at least annually thereafter.
Institute of Genetic Medicine, Newcastle University, UK ; Royal Victoria Infirmary, Newcastle upon Tyne, UK.
Simon H S
SH
Pearce
Medizinische Klinik I, Universitätsklinikum Schleswig-Holstein, Lübeck, Germany.
Georg
G
Brabant
Endocrine Unit, Evgenidion Hospital, University of Athens, Athens, Greece.
Leonidas H
LH
Duntas
Department of Clinical and Experimental Medicine, Università di Pisa, Pisa, Italy.
Fabio
F
Monzani
Rotterdam Thyroid Center, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
Robin P
RP
Peeters
Institute of Genetic Medicine, Newcastle University, UK ; Queen Elizabeth Hospital, Gateshead, UK.
Salman
S
Razvi
Clinique Endocrinologique Marc Linquette, CHU, Lille, France.
Jean-Louis
JL
Wemeau
Cognition; L-Thyroxine; Management; Subclinical hypothyroidism; Thyrotropin; Vascular risk