How to determine hypothyroidism – Is TSH serum testing best?
For many years, physicians have determined the health of thyroid function based on TSH (thyroid stimulating hormone) serum test results. TSH testing has been considered the gold standard for diagnosing hypothyroidism, but researchers are questioning its accuracy. TSH is a pituitary hormone that has the primary function of stimulating thyroid hormone production. A high TSH level often means a patient has hypothyroidism, or a low functioning thyroid. This is indicated by a TSH level that is consistently around the upper limit of normal (4.0 to 5.0 ng/dL).
A study recently published in Clinics of Geriatric Medicine describes the difference between serum and tissue thyroid hormone levels; especially related to chronic and acute stress. The article outlines that physiological stress caused by aging or illness can show normal TSH levels, but that a patient may still have hypothyroid symptoms.
Measuring the peripheral tissue with T3 serum testing may be a better indication of thyroid health. Patients with hypothyroid symptoms may have normal TSH and T4 levels, but still have hypothyroid symptoms. Instead of prescribing a T4 preparation, a T3 thyroid therapy may have greater significance on improving fatigue, depression, weight gain, and cardiovascular conditions.
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References
Docter R, Krenning EP, de Jong M, et al. The sick euthyroid syndrome: changes in thyroid hormone serum parameters and hormone metabolism. Clin Endocrinol. 1993;39:499–518.
Iervasi G, Pinitore A, Landi P, et al. Low-T3 syndrome a strong prognostic predictor of death in patients with heart disease. Circulation. 2003;107:708–713.
Peeters RP, Wouters PJ, Kaptein E, et al. Reduced activation and increased inactivation of thyroid hormone in tissues of critically ill patients. J Clin Endocrinol Metab. 2003; 88:3202–3211.
Schwartz E, Morelli V, Holtorf K. Hormone replacement therapy in the geriatric patient: current state of the evidence and questions for the future–estrogen, progesterone, testosterone, and thyroid hormone augmentation in geriatric clinical practice: part 2. Clin Geriatr Med. 2011 Nov;27(4):561-575.
Smidt-Ott UM, Ascheim DD. Thyroid hormone and heart failure. Curr Heart Fail Rep.
2006;3:114–119.
