Identifying predictors of prolonged levothyroxine dose adjustment after thyroidectomy
Open accessAbstract
Background Levothyroxine (LT4) is one of the most prescribed drugs in the United States; however, many patients started on LT4 after thyroidectomy suffer from symptoms of hyper- or hypo-thyroidism before achieving euthyroidism. This study aims to describe the time required for dose adjustment before achieving euthyroidism and identify predictors of prolonged dose adjustment (PDA+) after thyroidectomy.Methods This is a single institution retrospective cohort study of patients who achieved euthyroidism with LT4 therapy between 2008 and 2017 after total or completion thyroidectomy for benign disease. Patients who needed at least three dose adjustments (top quartile) were considered PDA+. Binomial logistic regression was used to identify predictors of PDA+.Results The 605 patients in this study achieved euthyroidism in a median of 116 d (standard deviation 124.9) and one dose adjustment (standard deviation 1.3). The 508 PDA- patients achieved euthyroidism in a median of 101 d and one dose adjustment. The 97 PDA+ patients achieved euthyroidism in a median of 271 d and three dose adjustments. Iron supplementation (odds ratio = 4.4, 95% confidence interval = 1.4-13.5, P = 0.010) and multivitamin with mineral supplementation (odds ratio = 2.4, 95% confidence interval = 1.3-4.3, P = 0.004) were independently associated with PDA+. Age, gender, preoperative thyroid disease, and comorbidities did not independently predict PDA+.Conclusions After thyroidectomy, achieving euthyroidism can take nearly 4 mo. Iron and mineral supplementation are associated with PDA+. This information can inform the preoperative counseling of patients and suggests that this may expedite achieving euthyroidism.
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Iron supplements hinder reaching optimal TSH; in thyroidectomy patients, iron use increased the need for levothyroxine dose adjustment (OR 2.4, 95% CI 1.3-4.13, P=.004).
“The use of iron supplements also hampers achieving optimal TSH levels, as demonstrated in a study of patients that underwent thyroidectomy, where iron supplement use increased the need for LT4 dose adjustment (OR: 2.4, 95% CI: 1.3-4.13,P ¼ .004).53”
From Refractory hypothyroidism: unraveling the complexities of diagnosis and management (2023) · cites this paper as [53]
Pancreatic insufficiency in cystic fibrosis lowers lipase secretion to about 10% of normal, causing steatorrhea and increased fecal T4 excretion.
“Pancreatic insufficiency, occurring in cystic fibrosis, 53 reduces lipase secretion to approximately 10% of normal, resulting in steatorrhea and an increase in fecal excretion of T4. 3”
From Refractory hypothyroidism: unraveling the complexities of diagnosis and management (2023) · cites this paper as [53]
After total or completion thyroidectomy for benign disease, time needed to achieve euthyroid status (usually 3-4 months) was considerably longer and required more dose adjustments in patients taking calcium supplements.
“After total or completion thyroidectomy for benign disease, the time needed to achieve euthyroid status (usually 3–4 months) was considerably longer and required more dose adjustments in patients taking calcium supplements [ 64 ].”
From Factors influencing the levothyroxine dose in the hormone replacement therapy of primary hypothyroidism in adults (2022) · cites this paper as [64]
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- Authors
- Atruktsang, T. S., Zaborek, N. A., Imbus, J. R., Long, K., Pitt, S. C., Sippel, R. S., & Schneider, D. F.
- Affiliations
- University of Wisconsin–Madison (US)
- Corresponding author
- Atruktsang, Tenzin S.
- Venue
- Journal of Surgical Research
- Publisher
- Elsevier BV
- Published
- 2019-10
- Volume
- 242
- Pages
- 166-171
- ISSN
- 0022-4804 (ISSN-L)
- PMC
- PMC6682465
- OpenAlex
- W2943990186
- Cited by
- 13
- References
- 14
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 2 · 2023: 3 · 2022: 2 · 2021: 2
- FWCI
- 0.81
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Journal of Surgical Research (publishedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institutes of Health
- Topics
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Health Sciences › Medicine › Surgery › Thyroid and Parathyroid Surgery
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Cancer Diagnosis and Treatment
- Keywords
- levothyroxine, thyroidectomy, dose adjustment, euthyroidism, iron supplementation, benign thyroid disease
- MeSH terms
- Adult, Aged, Dose-Response Relationship, Drug, Female, Humans, Hyperthyroidism, Hypothyroidism, Male, Middle Aged, Prospective Studies, Retrospective Studies, Thyroidectomy, Thyroxine, Time Factors, Dietary Supplements, Hormone Replacement Therapy
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