Endocrine Abstracts

Introduction: Patients with pituitary deficiencies suffer from impaired quality of life regardless of substitution therapy with hydrocortisone, thyroxine (T₄), sex hormones or GH. Central hypothyroidism (CH) is difficult to diagnose and treat because symptoms are non-specific and TSH-levels cannot be used for assessment. There is no consensus for the fT₄-goal of thyroxine-replacement in patients with CH.

Aim: To determine the impact of increased fT₄ on quality of life in patients with hypopituitarism.

Methods: Randomized, double-blind, placebo-controlled trial of additional T₄-supplementation. 40 patients (age 20–70 years) with hypopituitarism and fT₄-levels in the lowest third of normal reference range were included. Patients received placebo or T₄-titration aiming for fT₄ levels in the upper third of reference range, irrespective of TSH values. Total study duration 42 weeks (24 weeks dose adjustment, 18 weeks stable dose). Quality of life assessments (QoL) using four questionnaires (SF-36v2, PGWBS, EQ-5D, AGHDA) at baseline and end of study. Statistics were performed using an analysis of covariance.

Results: The increase in fT₄-values in the treatment group did not translate into significant changes in vitality score as assessed by SF-36v2 (estimated treatment effect 4.65 (95% CI −7.86, 17.15) or general health score (estimated treatment effect is 1.57 (−8.19, 11.33)), nor in any of the other questionnaires (PGWBS −1.11 (−8.80, 6.58); AGHD 0.88 (−2.77, 4.53); EQ5D-VAS −4.40 (−13.45, 4.65)).

Conclusion: The increase of fT₄ to the upper third of normal range did not significantly change the vitality score, general health or quality of life in hypopituitary patients and therefore does not provide support for the commonly used strategy of thyroxine-supplementation to the upper limit of normal. With 40 patients, however, the study may be underpowered to detect small effects. Other explanations for lack of effect include an inappropriately high or low fT₄ goal and further research is required.