Health  Vol.6 No.12 , June 2014
Does Hypothyroidism Cause Hyponatremia?
Abstract: Background: According to most clinical guidelines hypothyroidism should be excluded as a cause in the analysis of euvolemic hyponatremia. Although this axiom has been well established in clinical practice, relatively little evidence supports a relation between hypothyroidism and hyponatremia. The current study was conducted to prove an association between hypothyroidism and the occurrence of hyponatremia. In addition, we sought to determine the effect of L-thyroxine replacement therapy on plasma sodium levels. Methods: Data from 2009 to 2011 were retrospectively reviewed. The database included blood samples in which both thyroid function and plasma sodium were determined. Regression analysis and ANOVA were performed to reveal an association between hypothyroidism and hyponatremia. Results: Linear regression analysis of plasma sodium on plasma TSH revealed no relationship (R2 = 0.005). The corresponding gradient belonging to the regression line was ﹣0.427 mmol/log plasma TSH (p = 0.22). No significant relation between plasma sodium and TSH concentration could therefore be found. 32 hypothyroid patients who were treated with L-thyroxine, were identified. No clear change in plasma sodium could be discerned with regression analysis (0.707 mmol/L per year, p = 0.147). Conclusion: Hypothyroidism is not a common cause of hyponatremia. Screening for thyroid function does not seem warranted in the initial analysis of a hyponatremic patient.
Cite this paper: Hunze, J. , IJsselstijn, L. , Wulkan, R. and van Alphen, A. (2014) Does Hypothyroidism Cause Hyponatremia?. Health, 6, 1453-1458. doi: 10.4236/health.2014.612179.

[1]   Marco Martinez, J. (2010) Hyponatremia: Classification and Differential Diagnosis. Endocrinología y Nutrición, 57, 2-9.

[2]   Iglesias, P. and Diez, J.J. (2009) Thyroid Dysfunction and Kidney Disease. European Journal of Endocrinology, 160, 503-515.

[3]   Schrier, R.W. (2008) Vasopressin and Aquaporin 2 in Clinical Disorders of Water Homeostasis. Seminars in Nephrology, 28, 289-296.

[4]   Laczi, F., Janaky, T., Ivanyi, T., Julesz, J. and Laszlo, F.A. (1987) Osmoregulation of Arginine-8-Vasopressin Secretion in Primary Hypothyroidism and in Addison’s Disease. Acta Endocrinologica (Copenhagen), 114, 389-395.

[5]   Skowsky, W.R. and Kikuchi, T.A. (1978) The Role of Vasopressin in the Impaired Water Excretion of Myxedema. American Journal of Medicine, 64, 613-621.

[6]   Chen, Y.C., Cadnapaphornchai, M.A., Yang, J., Summer, S.N., Falk, S., Li, C., et al. (2005) Nonosmotic Release of Vasopressin and Renal Aquaporins in Impaired Urinary Dilution in Hypothyroidism. American Journal of Physiology, Renal Physiology, 289, F672-F678.

[7]   Seif, S.M., Robinson, A.G., Zenser, T.V., Davis, B.B., Huellmantel, A.B. and Haluszczak, C. (1979) Neurohypophyseal Peptides in Hypothyroid Rats: Plasma Levels and Kidney Response. Metabolism, 28, 137-143.

[8]   Emmanouel, D.S., Lindheimer, M.D. and Katz, A.I. (1974) Mechanism of Impaired Water Excretion in the Hypothyroid Rat. The Journal of Clinical Investigation, 54, 926-934.

[9]   den Hollander, J.G., Wulkan, R.W., Mantel, M.J. and Berghout, A. (2005) Correlation between Severity of Thyroid Dysfunction and Renal Function. Clinical Endocrinology (Oxford), 62, 423-427.

[10]   Montenegro, J., Gonzalez, O., Saracho, R., Aguirre, R., Gonzalez, O. and Martinez, I. (1996) Changes in Renal Function in Primary Hypothyroidism. American Journal of Kidney Diseases, 27, 195-198.

[11]   Allon, M., Harrow, A., Pasque, C.B. and Rodriguez, M. (1990) Renal Sodium and Water Handling in Hypothyroid Patients: The Role of Renal Insufficiency. Journal of the American Society of Nephrology, 1, 205-210.

[12]   Vaamonde, C.A., Sebastianelli, M.J., Vaamonde, L.S., Pellegrini, E.L., Watts, R.S., Klingler Jr., E.L., et al. (1975) Impaired Renal Tubular Reabsorption of Sodium in Hypothyroid Man. Journal of Laboratory and Clinical Medicine, 85, 451-466.

[13]   Karanikas, G., Schutz, M., Szabo, M., Becherer, A., Wiesner, K., Dudczak, R., et al. (2004) Isotopic Renal Function Studies in Severe Hypothyroidism and after Thyroid Hormone Replacement Therapy. American Journal of Nephrology, 24, 41-45.

[14]   Kreisman, S.H. and Hennessey, J.V. (1999) Consistent Reversible Elevations of Serum Creatinine Levels in Severe Hypothyroidism. Archives of Internal Medicine, 159, 79-82.

[15]   Hanna, F.W. and Scanlon, M.F. (1997) Hyponatraemia, Hypothyroidism, and Role of Arginine-Vasopressin. Lancet, 350, 755-756.

[16]   Ojamaa, K., Balkman, C. and Klein, I.L. (1993) Acute Effects of Triiodothyronine on Arterial Smooth Muscle Cells. The Annals of Thoracic Surgery, 56, S61-S66.

[17]   Klein, I. and Ojamaa, K. (2001) Thyroid Hormone and the Cardiovascular System. The New England Journal of Medicine, 344, 501-509.

[18]   Ota, K., Kimura, T., Sakurada, T., Shoji, M., Inoue, M., Sato, K., et al. (1994) Effects of an Acute Water Load on Plasma ANP and AVP, and Renal Water Handling in Hypothyroidism: Comparison of before and after L-Thyroxine Treatment. Endocrine Journal, 41, 99-105.

[19]   Iwasaki, Y., Oiso, Y., Yamauchi, K., Takatsuki, K., Kondo, K., Hasegawa, H., et al. (1990) Osmoregulation of Plasma Vasopressin in Myxedema. The Journal of Clinical Endocrinology & Metabolism, 70, 534-539.

[20]   Asami, T. and Uchiyama, M. (2004) Sodium Handling in Congenitally Hypothyroid Neonates. Acta Paediatrica, 93, 22-24.

[21]   Baajafer, F.S., Hammami, M.M. and Mohamed, G.E. (1999) Prevalence and Severity of Hyponatremia and Hypercreatininemia in Short-Term Uncomplicated Hypothyroidism. Journal of Endocrinological Investigation, 22, 35-39.

[22]   Croal, B.L., Blake, A.M., Johnston, J., Glen, A.C. and O’Reilly, D.S. (1997) Absence of Relation between Hyponatraemia and Hypothyroidism. Lancet, 350, 1402.

[23]   Tran, H.A. and Petrovsky, N. (2005) Hypothyroidism and Hyponatraemia in the Hospital Setting. Pathology, 37, 179-181.

[24]   Warner, M.H., Holding, S. and Kilpatrick, E.S. (2006) The Effect of Newly Diagnosed Hypothyroidism on Serum Sodium Concentrations: A Retrospective Study. Clinical Endocrinology (Oxford), 64, 598-599.

[25]   Derubertis Jr., F.R., Michelis, M.F., Bloom, M.E., Mintz, D.H., Field, J.B. and Davis, B.B. (1971) Impaired Water Excretion in Myxedema. American Journal of Medicine, 51, 41-53.