Skip Navigation
Skip to contents

Endocrinol Metab : Endocrinology and Metabolism


Author index

Page Path
Juan Carlo P. Dayrit  (Dayrit JCP) 1 Article
Clinical Study
Prevalence of Hyponatremia in Hypothyroid Patients during Radioactive 131I Ablation for Differentiated Thyroid Cancer: Single Institution Experience
Juan Carlo P. Dayrit, Elaine C. Cunanan, Sjoberg A. Kho
Endocrinol Metab. 2016;31(3):410-415.   Published online August 17, 2016
  • 3,787 View
  • 35 Download
  • 3 Web of Science
  • 2 Crossref
AbstractAbstract PDFPubReader   

Hyponatremia developing in hypothyroid patients has been encountered in clinical practice; however, its prevalence has not been well established.


Thirty patients diagnosed with differentiated thyroid cancer, rendered hypothyroid after surgery and levothyroxine withdrawal, and who are for radioactive iodine (RAI) ablation were included. Serum sodium concentrations were measured twice, at the time of admission for RAI ablation, and before discharge after increased oral fluid intake. The outcome measures were to determine the prevalence of hyponatremia among hypothyroid patients prior to RAI ablation and after oral hydration post-RAI, and to correlate the serum sodium levels pre-RAI and post-RAI with thyroid-stimulating hormone (TSH) concentration and age.


Thirty patients were included, with ages from 23 to 65 years old (median, 40). Two patients (6.7%) were hyponatremic prior to RAI ablation, and eight patients (26.7%) had mild hyponatremia (130 to 134 mEq/L) after RAI and hydration. There was no significant correlation between TSH levels and serum sodium levels prior to or after RAI. There was also no significant correlation between pre- and post-RAI sodium concentration and age.


The prevalence of hyponatremia pre-RAI was 6.7%, and 26.7% post-RAI. No significant correlation was noted between TSH concentration and age on pre- or post-RAI sodium concentrations. Routine measurement of serum sodium post-RAI/isolation is still not advised. Measurement of sodium post-RAI may be considered in patients who are elderly, with comorbid conditions or on medications.


Citations to this article as recorded by  
  • Is there a causal relationship between hypothyroidism and hyponatremia?
    Julie Chen
    Therapeutic Advances in Endocrinology and Metabolism.2023;[Epub]     CrossRef
  • Endocrinopathy-induced euvolemic hyponatremia
    Talia Diker-Cohen, Benaya Rozen-Zvi, Dana Yelin, Amit Akirov, Eyal Robenshtok, Anat Gafter-Gvili, Daniel Shepshelovich
    Internal and Emergency Medicine.2018; 13(5): 679.     CrossRef
Close layer

Endocrinol Metab : Endocrinology and Metabolism