Background: The European Thyroid Association recommends the treatment of
hypothyroidism in the elderly only if thyroid-stimulating hormone (TSH) levels are
consistently increased by >10 mU/l, as the available data does not suggest that the
same benefits of treatment apply to young and older patients. The aim of this study
was to prospectively investigate quality of life (QoL) and thyroid-related QoL in
younger (<40 years) and older patients (>60 years) with elevated TSH concentrations due to autoimmune thyroiditis, before and after levothyroxine (LT4) treatment. Material and Methods: Thyroid Study of Age in Germany (TSAGE): The study included male and female patients older than 18 years with newly diagnosed,
untreated, overt endogenous hyperthyroidism (TSH < 0.3 mU/l and elevated free T4 or free triiodothyronine (fT3)), endogenous hypothyroidism (TSH > 8 mU/l, free T4 <11.5 pmol/l or fT3 < 3.5 pmol/l), or subclinical hypothyroidism (TSH > 8 mU/l; free T4 and fT3 within reference range). Patients were evaluated by clinical assessment, blood sampling, and questionnaires that measured health-related QoL (SF-36 Version 2) and thyroid disease QoL (ThyPRO). Evaluations took place at the time of diagnosis (T1) and six months after initiation of treatment (intake of LT4), (T2).

Results: There were 43 patients with newly diagnosed subclinical hypothyroidism
who completed the ThyPRO and SF-36 (Version 2) at baseline (T1). 28 patients
completed the questionnaires six months after treatment initiation (> 60 years n = 11; <40 years n = 17). Significantly lower QoL in both young and old patients with
subclinical hypothyroidism (sHT) compared to age-matched healthy individuals was
found. All patients reported higher scores on follow-up for all SF-36 subscales,
irrespective of age, indicating better QoL on levothyroxine therapy. Analysis of the
ThyPRO questionnaire additionally showed an improvement, but thematic variation
existed for thyroid-specific QoL for young and old patients.
Conclusion: Impairment in general and disease-specific QoL is associated with sHT
in young and old age. These data confirm current recommendations for the initiation of LT4 substitution and underline that LT4 substitution should not be withheld in the treatment of elderly patients with TSH concentrations above 8–10 mU/l levels.