Skip to main content
Article thumbnail
Location of Repository

Review of the risks and/or benefits of thyroxine treatment in ‘mild’ subclinical hypothyroidism

By Rachel Agius


Subclinical hypothyroidism (SCH) is a form of mild thyroid failure and is a commonly encountered condition in clinical practice. It denotes the presence of a raised serum thyroid stimulating hormone (TSH) and normal serum free thyroid hormone concentrations (tri-iodothyronine [T3] and thyroxine [T4]). ‘Mild’ subclinical hypothyroidism is associated with a TSH level between 4.5-9mIU/L (0.4-4.2) whereas patients with a serum TSH level ?10mIU/L are classified as having the ‘severe’ form. The clinical significance of this condition has aroused a lot of interest over the last decade, especially its effects on various health outcomes (namely cardiovascular disease, lipid metabolism, fertility, pregnancy outcomes and fetal neurocognitive function). \ud Unfortunately the unavailability of adequately powered, double-blind randomised controlled studies precludes the availability of clear cut guidelines as to how one should treat subclinical hypothyroidism. This review looks at the available evidence for and against treatment of SCH with levothyroixine. Most authors agree on the use of clinical judgement as well as individualising management based on the underlying unique patient characteristics when it comes to formulating a management plan for this condition

Topics: Hypothyroidism -- Disease management, Hypothyroidism, Thyroxine -- Therapeutic use
Publisher: Malta Medical Journal
Year: 2013
OAI identifier:
Provided by: OAR@UM

Suggested articles


  1. (2002). Examination Survey (NHANES III). doi
  2. (2012). Natural history, diagnosis and management of subclinical thyroid dysfunction. doi
  3. (2001). The Treatment of Subclinical Hypothyroidism Is Seldom Necessary. doi
  4. (2010). How should we manage patients with mildly increased serum thyrotropin concentrations? Clinical Endocrinology doi
  5. (2000). The Colorado thyroid disease prevalence study. Archives of Internal Medicine. doi
  6. (2001). Subclinical hypothyroidism is mild thyroid failure and should be treated. doi
  7. (2010). Thyroid and obesity: an intriguing relationship. doi
  8. (2002). Prospective study of the spontaneous course of subclinical hypothyroidism: prognostic value of thyrotropin, thyroid reserve, and thyroid antibodies. doi
  9. Subclinical hypothyroidism and the risk of coronary heart disease and mortality. doi
  10. (1995). The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey. Clin Endocrinol (Oxf) doi
  11. (2007). Serum thyrotrophin measurements in the community: five-year follow-up in a large network of primary care physicians.
  12. (2005). Consensus Statement: Subclinical thyroid dysfunction: a joint statement on management from the American Association of Clinical Endocrinologists, the American Thyroid Association, and The Endocrine Society. doi
  13. (2004). Spontaneous Subclinical Hypothyroidism in Patients Older than 55 Years: An Analysis of Natural Course and Risk Factors for the Development of Overt Thyroid Failure. doi
  14. (2008). Subclinical thyroid dysfunction, cardiac function, and the risk of heart failure. The Cardiovascular Health Study. doi
  15. (2003). Subclinical hypothyroidism: the case against treatment. doi
  16. (2000). Subclinical hypothyroidism is an independent risk factor for atherosclerosis and myocardial infarction in elderly women: the Rotterdam study. Ann Intern Med doi
  17. (2007). Thyroid disease and the heart. Circulation doi
  18. (2004). Virdis A et al. Effect of levothyroxine replacement on lipid profile and intima-media thickness in subclinical hypothyroidism. doi
  19. (2008). The influence of age on the relationship between subclinical hypothyroidism and ischemic heart disease: A meta-analysis. doi
  20. (2002). Effects of Subclinical Thyroid Dysfunction on the Heart. Ann Intern Med. doi
  21. (2010). The incidence of ischemic heart disease and mortality in people with subclinical hypothyroidism: Reanalysis of the Whickham survey cohort. doi
  22. (2000). Effect of thyroxine therapy on serum lipoproteins in patients with mild thyroid failure: a quantitative review of the literature. doi
  23. (2000). Low-density lipoprotein cholesterol in subclinical hypothyroidism. Thyroid doi
  24. (2000). Clinical and metabolic effects of thyroxine replacement in patients with mild thyroid failure: results from a double-blind placebo-controlled study.
  25. (2002). A 6-month randomized trial of thyroxine treatment in women with mild subclinical hypothyroidism. doi
  26. (2012). Association and predictive accuracy of high TSH serum levels in first trimester and adverse pregnancy outcomes. J clin Endocrinol Metab doi
  27. (2011). Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid doi
  28. (2005). Subclinical hypothyroidism and pregnancy outcomes. Obstetrics and Gynecology doi
  29. (2002). Garcia A and Levalle O. Overt and subclinical hypothyroidism complicating pregnancy. Thyroid doi
  30. (1999). Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child. doi
  31. (1998). Subclinical thyrotoxicosis. Endocrin Metab Clin North Am doi
  32. Adrenal insufficiency should be excluded before thyroxine replacement is started. doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.