TY - JOUR
T1 - Incidence and Determinants of Spontaneous Normalization of Subclinical Hypothyroidism in Older Adults
AU - Van Der Spoel, Evie
AU - Van Vliet, Nicolien A.
AU - Poortvliet, Rosalinde K.E.
AU - Du Puy, Robert S.
AU - Den Elzen, Wendy P.J.
AU - Quinn, Terence J.
AU - Stott, David J.
AU - Sattar, Naveed
AU - Kearney, Patricia M.
AU - Blum, Manuel R.
AU - Alwan, Heba
AU - Rodondi, Nicolas
AU - Collet, Tinh Hai
AU - Westendorp, Rudi G.J.
AU - Ballieux, Bart E.
AU - Jukema, J. Wouter
AU - Dekkers, Olaf M.
AU - Gussekloo, Jacobijn
AU - Mooijaart, Simon P.
AU - Van Heemst, Diana
N1 - Publisher Copyright:
© 2023 The Author(s). Published by Oxford University Press on behalf of the Endocrine Society.
PY - 2024/3/1
Y1 - 2024/3/1
N2 - Context: With age, the prevalence of subclinical hypothyroidism rises. However, incidence and determinants of spontaneous normalization remain largely unknown. Objective: To investigate incidence and determinants of spontaneous normalization of TSH levels in older adults with subclinical hypothyroidism. Design: Pooled data were used from the (1) pretrial population and (2) in-trial placebo group from 2 randomized, double-blind, placebo-controlled trials (Thyroid Hormone Replacement for Untreated Older Adults With Subclinical Hypothyroidism Trial and Institute for Evidence-Based Medicine in Old Age thyroid 80-plus thyroid trial). Setting: Community-dwelling 65+ adults with subclinical hypothyroidism from the Netherlands, Switzerland, Ireland, and the United Kingdom. Participants: The pretrial population (N = 2335) consisted of older adults with biochemical subclinical hypothyroidism, defined as ≥1 elevated TSH measurement (≥4.60 mIU/L) and a free T4 within the laboratory-specific reference range. Individuals with persistent subclinical hypothyroidism, defined as ≥2 elevated TSH measurements ≥3 months apart, were randomized to levothyroxine/placebo, of which the in-trial placebo group (N = 361) was included. Main Outcome Measures: Incidence of spontaneous normalization of TSH levels and associations between participant characteristics and normalization. Results: In the pretrial phase, TSH levels normalized in 60.8% of participants in a median follow-up of 1 year. In the in-trial phase, levels normalized in 39.9% of participants after 1 year of follow-up. Younger age, female sex, lower initial TSH level, higher initial free T4 level, absence of thyroid peroxidase antibodies, and a follow-up measurement in summer were independent determinants for normalization. Conclusion: Because TSH levels spontaneously normalized in a large proportion of older adults with subclinical hypothyroidism (also after confirmation by repeat measurement), a third measurement may be recommended before considering treatment. Trial registration: ClinicalTrials.gov, NCT01660126 and Netherlands Trial Register, NTR3851.
AB - Context: With age, the prevalence of subclinical hypothyroidism rises. However, incidence and determinants of spontaneous normalization remain largely unknown. Objective: To investigate incidence and determinants of spontaneous normalization of TSH levels in older adults with subclinical hypothyroidism. Design: Pooled data were used from the (1) pretrial population and (2) in-trial placebo group from 2 randomized, double-blind, placebo-controlled trials (Thyroid Hormone Replacement for Untreated Older Adults With Subclinical Hypothyroidism Trial and Institute for Evidence-Based Medicine in Old Age thyroid 80-plus thyroid trial). Setting: Community-dwelling 65+ adults with subclinical hypothyroidism from the Netherlands, Switzerland, Ireland, and the United Kingdom. Participants: The pretrial population (N = 2335) consisted of older adults with biochemical subclinical hypothyroidism, defined as ≥1 elevated TSH measurement (≥4.60 mIU/L) and a free T4 within the laboratory-specific reference range. Individuals with persistent subclinical hypothyroidism, defined as ≥2 elevated TSH measurements ≥3 months apart, were randomized to levothyroxine/placebo, of which the in-trial placebo group (N = 361) was included. Main Outcome Measures: Incidence of spontaneous normalization of TSH levels and associations between participant characteristics and normalization. Results: In the pretrial phase, TSH levels normalized in 60.8% of participants in a median follow-up of 1 year. In the in-trial phase, levels normalized in 39.9% of participants after 1 year of follow-up. Younger age, female sex, lower initial TSH level, higher initial free T4 level, absence of thyroid peroxidase antibodies, and a follow-up measurement in summer were independent determinants for normalization. Conclusion: Because TSH levels spontaneously normalized in a large proportion of older adults with subclinical hypothyroidism (also after confirmation by repeat measurement), a third measurement may be recommended before considering treatment. Trial registration: ClinicalTrials.gov, NCT01660126 and Netherlands Trial Register, NTR3851.
KW - follow-up studies
KW - older adults
KW - subclinical hypothyroidism
KW - thyrotropin
UR - https://www.scopus.com/pages/publications/85195061120
U2 - 10.1210/clinem/dgad623
DO - 10.1210/clinem/dgad623
M3 - Article
C2 - 37862463
AN - SCOPUS:85195061120
SN - 0021-972X
VL - 109
SP - e1167-e1174
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 3
ER -