Can steroids affect thyroid levels?

From the Guidelines

Yes, steroids can significantly affect thyroid levels, particularly in the context of immune-related adverse events associated with immune checkpoint inhibitor therapy, as evidenced by the most recent and highest quality study 1.

Key Points to Consider

• Corticosteroids, such as prednisone, dexamethasone, and hydrocortisone, can decrease TSH levels and alter the conversion of T4 to T3, leading to lower T3 levels while T4 levels may remain relatively unchanged 1.
• The effects of steroids on thyroid levels are more pronounced with higher doses and longer durations of treatment, and anabolic steroids used for bodybuilding can also disrupt thyroid function by affecting the hypothalamic-pituitary-thyroid axis 1.
• In managing hypophysitis, a condition where the pituitary gland is inflamed, steroids should always be started prior to thyroid hormone replacement to avoid precipitating an adrenal crisis, as recommended in the management guidelines for immune-related adverse events 1.
• Patients on long-term steroid therapy should have their thyroid function monitored periodically, especially if they develop symptoms like fatigue, weight changes, or temperature intolerance, to ensure timely intervention and prevent long-term sequelae 1.

Management Recommendations

• For grade 1 toxicities, holding immune checkpoint inhibitor therapy until the patient is stabilized on replacement hormones, offering hormonal supplementation as needed, and consulting endocrinology are recommended 1.
• For grade 2 to 4 toxicities, holding immune checkpoint inhibitor therapy, consulting endocrinology, and offering hormonal supplementation, including initial pulse dose therapy with prednisone if necessary, are recommended 1.
• It is crucial to start corticosteroids several days before thyroid hormone replacement and to follow FT4 for thyroid hormone replacement titration, as TSH is not accurate in central hypothyroidism 1.

From the FDA Drug Label

There is an enhanced effect of corticosteroids on patients with hypothyroidism The use of steroids can have an impact on patients with hypothyroidism, indicating that steroids can affect thyroid levels in these individuals.

• Key points:
  • Steroids can enhance their effect in patients with hypothyroidism 2
  • Similar effects are also observed in patients with cirrhosis
  • Corticosteroids should be used cautiously in patients with certain conditions, including hypothyroidism 3

From the Research

Effects of Steroids on Thyroid Levels

• Steroids can affect thyroid levels, with different types of steroids having varying effects on thyroid function 4, 5, 6, 7, 8.
• Anabolic steroids, in particular, have been shown to reduce thyroxine binding globulin (TBG), leading to decreases in total serum T3 and T4 levels 4, 7.
• Glucocorticoids, such as dexamethasone and prednisone, have been found to decrease TSH secretion and affect thyroid hormone levels, including reductions in serum T3 and T4 concentrations 5, 6, 8.
• The effects of steroids on thyroid levels can vary depending on the specific steroid, dosage, and individual susceptibility, with some studies suggesting that high-dose androgenic-anabolic steroid administration can lead to mild thyroidal impairment 7.

Mechanisms of Steroid-Induced Thyroid Changes

• The exact mechanisms by which steroids affect thyroid levels are not fully understood, but may involve changes in thyroid hormone synthesis, release, or peripheral conversion 5, 6, 7.
• Steroids may also affect the hypothalamic-pituitary-thyroid axis, leading to changes in TSH secretion and thyroid hormone production 6, 8.
• Further research is needed to fully elucidate the effects of steroids on thyroid function and the underlying mechanisms 4, 5, 6, 7, 8.

Clinical Implications

• The use of steroids, particularly anabolic steroids, can have significant effects on thyroid function, and individuals using these substances should be monitored for changes in thyroid hormone levels 4, 7.
• Glucocorticoids, such as prednisone, may also affect thyroid function, and patients receiving these medications should be aware of the potential for changes in thyroid hormone levels 5, 6, 8.
• Healthcare providers should consider the potential effects of steroids on thyroid function when evaluating patients with thyroid disorders or those using steroid medications 4, 5, 6, 7, 8.