Thyroid hormone and its metabolites in relation to quality of life in patients treated for differentiated thyroid cancer. (13th June 2016)

• Record Type: Journal Article
• Authors: Massolt, E.T.; van der Windt, M.; Korevaar, T.I.M.; Kam, B.L.R.; Burger, J.W.; Franssen, G.J.H.; Lehmphul, I.; Köhrle, J.; Visser, W.E.; Peeters, R.P.
• Is Part Of: Clinical endocrinology. Volume 85:Number 5(2016)
• Page Start: 781
• Page End: 788
• Publication Date: 2016-06-13
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.13101
• Languages: English
• ISSNs: 0300-0664

Abstract

Summary: Background: Levothyroxine (LT4) is the standard of care in patients with hypothyroidism. Despite this replacement therapy, quality of life (QoL) remains impaired in a substantial amount of patients. The reasons for this are still a matter of debate. Suggested causes include lack of endogenous T3 secretion by the thyroid, changes in other thyroid hormone metabolites and interference by autoimmune processes. Objective: To investigate the association between thyroid function tests (TFTs) and QoL in patients with a history of differentiated thyroid cancer on LT4 monotherapy. These patients lack endogenous thyroidal T3 secretion in the absence of autoimmune disease. Materials and Methods: This is a cross‐sectional study in 143 patients (69·2% female). Initial therapy consisted of total thyroidectomy followed by radioiodine ablation minimally one year before inclusion. We assessed health‐related QoL (RAND‐36), thyroid‐specific QoL (ThyPRO) and fatigue with the Multidimensional Fatigue Inventory. Extensive TFTs were assessed, including 3, 5‐diiodo‐L‐thyronine (3, 5‐T2). Results: Mean age was 50·2 years and mean time since diagnosis was 8·4 years. Median TSH was 0·042 mU/l, total T4 145·0 nmol/l, free T4 25·6 pmol/l, total T3 1·93 nmol/l, reverse T3 0·53 nmol/l and 3, 5‐T2 0·86 nmol/l. Multiple linear regression analyses did not show any association between QoL and the different TFTs, including T4/T3 and 3, 5‐T2/T3 ratios reflecting peripheral metabolism. Conclusion: We did not find any association between TFTs and QoL in athyreotic patients on LT4 monotherapy. Our data do not provide evidence that a slight increase in dose improves fatigue or well‐being in hypothyroid patients on LT4 therapy.