Objective: Hyponatremia is observed in hypothyroidism, but it is not known if hypo- or hyperkalemia is associated with hypothyroidism. To study these questions, we determined serum potassium (K(+)) levels in thyroidectomized patients undergoing levothyroxine withdrawal before radioactive iodine (RAI) therapy for thyroid carcinoma.
Methods: We retrospectively studied the records of 108 patients who had undergone total thyroidectomy for thyroid carcinoma followed by levothyroxine withdrawal and then ablation with RAI at Nagasaki University Hospital from 2009-2013. Blood samples were analyzed for serum K(+) concentrations when patients were euthyroid just before levothyroxine withdrawal and hypothyroid 21 days after levothyroxine withdrawal. We determined the proportion of patients who developed hyperkalemia (K(+) ≥5 mEq/L) and hypokalemia (K(+) ≤3.5 mEq/L).
Results: Five (4.6%) patients developed hyperkalemia and 2 (1.9%) patients developed hypokalemia after levothyroxine withdrawal. The mean serum K(+) level after levothyroxine withdrawal was significantly higher than before levothyroxine withdrawal (4.23 ± 0.50 mEq/L vs. 4.09 ± 0.34 mEq/L; P<.001). After levothyroxine withdrawal, serum K(+) values were significantly correlated with age, serum sodium and creatinine levels, and the estimated glomerular filtration rate but not with serum free thyroxine or thyroid-stimulating hormone concentrations. The finding of an elevated serum K(+) of >0.5 mEq/L after levothyroxine withdrawal was more prevalent with age >60 years (odds ratio [OR], 4.66; P = .026) and with the use of angiotensin-II receptor blockers or angiotensin-converting enzyme inhibitors (OR, 3.53; P = .033) in a multivariate analysis.
Conclusion: Hyperkalemia develops in a small percentage of hypothyroid patients after thyroid hormone withdrawal, especially in patients over 60 years of age who are using antihypertensive agents that inhibit the reninangiotensin-aldosterone system.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.4158/EP14532.OR | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Stimulated Thyrotropin (TSH) Levels Were Inversely Correlated with Age.
Int J Gen Med
December 2024
Department of Geriatric Neurology, Shandong Provincial Hospital affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.
Purpose: Serum Thyrotropin (TSH) levels in the elderly have been reported to be inconsistent in different studies. One of the difficulties in determining the effect of aging on TSH levels is that TSH levels are influenced by various factors, including thyroid-related factors. Therefore, this study aimed to assess the effect of aging on TSH levels while controlling for thyroid factors.
View Article and Find Full Text PDFOldie but Goldie: The Fundamental Role of Radioiodine in the Management of Thyroid Cancer.
J Clin Med
October 2024
Endocrinology Unit, Department of Human Pathology of Adulthood and Childhood DETEV, University of Messina, 98125 Messina, Italy.
Article Synopsis
- Recent advancements in the management of differentiated thyroid cancer (DTC) emphasize the importance of careful postoperative disease assessment to determine if iodine-131 therapy is needed and to tailor treatment goals accordingly (ablative, adjuvant, or therapeutic).
- A comprehensive review of the literature highlights that personalized risk-based approaches to iodine-131 therapy significantly enhance early disease staging and response assessment, particularly for metastatic DTC patients.
- Diagnostic and theragnostic uses of iodine isotopes are crucial for improving postoperative risk stratification and enabling more effective evaluation of patient responses to initial treatments.
Predictors for thyroid dysfunction after discontinuation of levothyroxine in children and adolescents with Hashimoto thyroiditis.
Ann Pediatr Endocrinol Metab
October 2024
Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
Purpose: Few data on the clinical course after levothyroxine (L-T4) discontinuation in pediatric patients with Hashimoto thyroiditis (HT) are available. We investigated outcomes and predictors for successful withdrawal from L-T4 among children with HT.
Methods: Among 168 patients diagnosed with HT between January 2000 and March 2021 at Seoul National University Children's Hospital and in whom L-T4 therapy was initiated during childhood, we attempted to discontinue this therapy in 47, 3 boys and 44 girls.
A digital pathology model for predicting radioiodine-avid metastases on initial post-therapeutic I scan in patients with papillary thyroid cancer.
Sci Rep
November 2024
Henan Key Laboratory for Molecular Nuclear Medicine and Translational Medicine, Department of Nuclear Medicine, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, 450003, China.
Accurate postoperative assessment is critical for optimizing I therapy in patients with papillary thyroid cancer (PTC). This study aimed to develop a pathology model utilizing postoperative digital pathology slides to predict lymph node and/or distant metastases on post-therapeutic I scan after initial I treatment in PTC patients. A retrospective analysis was conducted on 229 PTC patients who underwent total or near-total thyroidectomy and subsequent I treatment after levothyroxine (LT4) withdrawal between January 2022 and August 2023.
View Article and Find Full Text PDFClinical course of congenital hypothyroidism with gland in situ and necessity of L-thyroxine therapy after re-evaluation.
J Clin Endocrinol Metab
July 2024
Department of Clinical and Experimental Medicine, Endocrine Unit, University of Pisa, Pisa 56124, Italy.
Context: Clinical course and need for long-term L-thyroxine (LT4) therapy of congenital hypothyroidism (CH) with gland in situ (GIS) remain unclear.
Objective: To describe the clinical history of CH with GIS and evaluate the proportion of patients who can suspend therapy during follow-up.
Design And Setting: Retrospective evaluation of patients followed at referral regional center for CH of Pisa.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!