Contrary to the Guideline

Postulating over- or undertreatment independently of age and merely because a TSH concentration falls below or exceeds a TSH reference range (1) is in contradiction of the guideline “Raised TSH concentrations in general practice [Erhöhter TSH-Wert in der Hausarztpraxis]” compiled by the Association of the Scientific Medical Societies in Germany (AWMF) (2) and, also, to best practice in the treatment. Individual TSH concentrations need to be assessed in consideration of a patient’s life age, fT4 measurement, clinical symptoms, body mass index (BMI), medication, impairment to health related quality of life, and general health (acute illnesses/disorders, comorbidities). Disease mongering on the basis of a deviation from the reference range for TSH concentrations is unjustifiable. For low TSH concentrations this is equally true: the reference range is not the criterion for treatment, but clinical symptoms, etiology, comorbidities, and—where applicable—additional medication and laboratory variables have to be considered. When interpreting TSH measurements, dietary/nutritional, environmental, geographical, genetic as well as endogenous and exogenous factors have to be considered, including iodine intake, age, sex, biological variations, pregnancy, ethnic background, and testing method used. In older persons the upper threshold of the TSH reference range increases (3). According to (1), independently of age, asymptomatic elevated TSH≤ 10 mU/L should not be substituted and hormone substitution can be omitted in patients >75 years who have latent hypothyroidism up to <20 mU/L. The levothyroxine dose has to be guided in the individual case by thyroid readings determined in laboratory tests as well as subjective wellbeing or symptoms. It was shown that in patients ≥85 years, latent hypothyroidism is not associated with higher mortality and confers no survival advantage compared with TSH concentrations <4 mU/L.