2013 ETA Guideline: Management of Subclinical Hypothyroidism

Abstract

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 <smlcap>L</smlcap>-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 <smlcap>L</smlcap>-thyroxine replacement therapy should be considered. For such patients who have been started on <smlcap>L</smlcap>-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, <smlcap>L</smlcap>-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 <smlcap>L</smlcap>-thyroxine, administered daily, is the treatment of choice. The serum TSH should be re-checked 2 months after starting <smlcap>L</smlcap>-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 <smlcap>L</smlcap>-thyroxine treatment, then serum TSH should be monitored at least annually thereafter.

Natural history of mild subclinical hypothyroidism in a middle-aged and elderly Chinese population: a prospective study

“…Positivity for TPOAb was considered when the serum mortality in those with higher TSH levels [13]. Other possible adverse consequences include depression, Alzheimer disease, the worsening of renal function in patients with chronic kidney diseases (CKD), symptomatic OH and disordered lipid metabolism, particularly elevation of total cholesterol (TC) [2,4]. It is widely agreed that L-thyroxine is necessary for severe SCH patients.…”

“…It is widely agreed that L-thyroxine is necessary for severe SCH patients. However, controversy exists for mild SCH patients [1,2,4].…”

MECHANISMS IN ENDOCRINOLOGY: Aging and anti-aging: a Combo-Endocrinology overview

“…In this context, SCH commonly manifests, when peripheral thyroid hormone levels are within the normal reference laboratory range but serum TSH levels are high, a condition which may progress to overt hypothyroidism and lead to impaired cardiac function (63). According to the recent Guidelines, patients with persistent SCH, whose TSH levels are greater than 10 IU/L and who test positive for antithyroid antibodies and/or are symptomatic, should be treated with l-thyroxine (LT4) to reduce the risk of progression to overt hypothyroidism, decrease the risk of adverse cardiovascular events and improve their quality of life (64,65). This is also substantiated by evidence showing that SCH is associated with an increased risk of cardiovascular mortality particularly in patients with a TSH concentration of 10 IU/L or above (66).…”

Subclinical Hypothyroidism: The Importance of Information to the Patient as Part of the Management

“…In the current clinical practice Levothyroxine therapy are recommended for patients with TSH persistently > 10 mIU/L, but controversy persist in cases of patients with concentrations ≤ 10 mIU/L [7,8]. …”