The association between subclinical thyroid dysfunction and dementia: The Health, Aging and Body Composition (Health ABC) Study

The Health ABC Study

Research output: Contribution to journalArticle

Abstract

Objective: Data on the association between subclinical thyroid dysfunction and dementia are limited and conflicting. We aimed to determine whether subclinical thyroid dysfunction was associated with dementia and cognitive decline. Design: Population-based prospective cohort study. Patients: Adults aged 70-79 years with measured thyroid function, but no dementia at baseline, and Modified Mini-Mental State (3MS) at baseline and follow-up. Measurements: Primary outcome was incident-adjudicated dementia, based on 3MS, hospital records and dementia drugs. Secondary outcome was change in 3MS. Models were adjusted for age, sex, race, education and baseline 3MS, and then further for cardiovascular risk factors. Results: Among 2558 adults, 85% were euthyroid (TSH 0.45-4.49mIU/L), 2% had subclinical hyperthyroidism with mildly decreased TSH (TSH 0.10-0.44 mIU/L), 1% subclinical hyperthyroidism with suppressed TSH (TSH < 0.10 mIU/L with normal free thyroxine [FT4]) and 12% subclinical hypothyroidism (TSH 4.50-19.99 mIU/L with normal FT4). Over 9 years, 22% developed dementia. Compared to euthyroidism, risk of dementia was higher in participants with subclinical hyperthyroidism with suppressed TSH (HR 2.38, 95% CI = 1.13;5.04), while we found no significant association in those with mildly decreased TSH (HR 0.79, 95% CI = 0.45;1.38) or with subclinical hypothyroidism (HR 0.91, 95% CI = 0.70;1.19). Participants with subclinical hyperthyroidism with suppressed TSH had a larger decline in 3MS (−3.89, 95% CI = −7.62; −0.15). Conclusions: Among older adults, subclinical hyperthyroidism with a TSH < 0.10 mIU/L was associated with a higher risk of dementia and a larger cognitive decline, while subclinical hyperthyroidism with mildly decreased TSH or subclinical hypothyroidism were not.

Original languageEnglish (US)
Pages (from-to)617-626
Number of pages10
JournalClinical Endocrinology
Volume87
Issue number5
DOIs
StatePublished - Nov 1 2017
Externally publishedYes

Fingerprint

Body Composition
Dementia
Thyroid Gland
Hyperthyroidism
Health
Hypothyroidism
Sex Education
Hospital Records
Thyroxine
Cohort Studies
Prospective Studies
Pharmaceutical Preparations
Population

Keywords

  • cognitive ageing
  • cognitive decline
  • dementia
  • thyroid dysfunction

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism

Cite this

The association between subclinical thyroid dysfunction and dementia : The Health, Aging and Body Composition (Health ABC) Study. / The Health ABC Study.

In: Clinical Endocrinology, Vol. 87, No. 5, 01.11.2017, p. 617-626.

Research output: Contribution to journalArticle

@article{ba91e9c2b59449f4ad64ff57b32d6377,
title = "The association between subclinical thyroid dysfunction and dementia: The Health, Aging and Body Composition (Health ABC) Study",
abstract = "Objective: Data on the association between subclinical thyroid dysfunction and dementia are limited and conflicting. We aimed to determine whether subclinical thyroid dysfunction was associated with dementia and cognitive decline. Design: Population-based prospective cohort study. Patients: Adults aged 70-79 years with measured thyroid function, but no dementia at baseline, and Modified Mini-Mental State (3MS) at baseline and follow-up. Measurements: Primary outcome was incident-adjudicated dementia, based on 3MS, hospital records and dementia drugs. Secondary outcome was change in 3MS. Models were adjusted for age, sex, race, education and baseline 3MS, and then further for cardiovascular risk factors. Results: Among 2558 adults, 85{\%} were euthyroid (TSH 0.45-4.49mIU/L), 2{\%} had subclinical hyperthyroidism with mildly decreased TSH (TSH 0.10-0.44 mIU/L), 1{\%} subclinical hyperthyroidism with suppressed TSH (TSH < 0.10 mIU/L with normal free thyroxine [FT4]) and 12{\%} subclinical hypothyroidism (TSH 4.50-19.99 mIU/L with normal FT4). Over 9 years, 22{\%} developed dementia. Compared to euthyroidism, risk of dementia was higher in participants with subclinical hyperthyroidism with suppressed TSH (HR 2.38, 95{\%} CI = 1.13;5.04), while we found no significant association in those with mildly decreased TSH (HR 0.79, 95{\%} CI = 0.45;1.38) or with subclinical hypothyroidism (HR 0.91, 95{\%} CI = 0.70;1.19). Participants with subclinical hyperthyroidism with suppressed TSH had a larger decline in 3MS (−3.89, 95{\%} CI = −7.62; −0.15). Conclusions: Among older adults, subclinical hyperthyroidism with a TSH < 0.10 mIU/L was associated with a higher risk of dementia and a larger cognitive decline, while subclinical hyperthyroidism with mildly decreased TSH or subclinical hypothyroidism were not.",
keywords = "cognitive ageing, cognitive decline, dementia, thyroid dysfunction",
author = "{The Health ABC Study} and Aubert, {Carole E.} and Bauer, {Douglas C.} and {da Costa}, {Bruno R.} and Martin Feller and Carole Rieben and Simonsick, {Eleanor Marie} and Kristine Yaffe and Nicolas Rodondi",
year = "2017",
month = "11",
day = "1",
doi = "10.1111/cen.13458",
language = "English (US)",
volume = "87",
pages = "617--626",
journal = "Clinical Endocrinology",
issn = "0300-0664",
publisher = "Wiley-Blackwell",
number = "5",

}

TY - JOUR

T1 - The association between subclinical thyroid dysfunction and dementia

T2 - The Health, Aging and Body Composition (Health ABC) Study

AU - The Health ABC Study

AU - Aubert, Carole E.

AU - Bauer, Douglas C.

AU - da Costa, Bruno R.

AU - Feller, Martin

AU - Rieben, Carole

AU - Simonsick, Eleanor Marie

AU - Yaffe, Kristine

AU - Rodondi, Nicolas

PY - 2017/11/1

Y1 - 2017/11/1

N2 - Objective: Data on the association between subclinical thyroid dysfunction and dementia are limited and conflicting. We aimed to determine whether subclinical thyroid dysfunction was associated with dementia and cognitive decline. Design: Population-based prospective cohort study. Patients: Adults aged 70-79 years with measured thyroid function, but no dementia at baseline, and Modified Mini-Mental State (3MS) at baseline and follow-up. Measurements: Primary outcome was incident-adjudicated dementia, based on 3MS, hospital records and dementia drugs. Secondary outcome was change in 3MS. Models were adjusted for age, sex, race, education and baseline 3MS, and then further for cardiovascular risk factors. Results: Among 2558 adults, 85% were euthyroid (TSH 0.45-4.49mIU/L), 2% had subclinical hyperthyroidism with mildly decreased TSH (TSH 0.10-0.44 mIU/L), 1% subclinical hyperthyroidism with suppressed TSH (TSH < 0.10 mIU/L with normal free thyroxine [FT4]) and 12% subclinical hypothyroidism (TSH 4.50-19.99 mIU/L with normal FT4). Over 9 years, 22% developed dementia. Compared to euthyroidism, risk of dementia was higher in participants with subclinical hyperthyroidism with suppressed TSH (HR 2.38, 95% CI = 1.13;5.04), while we found no significant association in those with mildly decreased TSH (HR 0.79, 95% CI = 0.45;1.38) or with subclinical hypothyroidism (HR 0.91, 95% CI = 0.70;1.19). Participants with subclinical hyperthyroidism with suppressed TSH had a larger decline in 3MS (−3.89, 95% CI = −7.62; −0.15). Conclusions: Among older adults, subclinical hyperthyroidism with a TSH < 0.10 mIU/L was associated with a higher risk of dementia and a larger cognitive decline, while subclinical hyperthyroidism with mildly decreased TSH or subclinical hypothyroidism were not.

AB - Objective: Data on the association between subclinical thyroid dysfunction and dementia are limited and conflicting. We aimed to determine whether subclinical thyroid dysfunction was associated with dementia and cognitive decline. Design: Population-based prospective cohort study. Patients: Adults aged 70-79 years with measured thyroid function, but no dementia at baseline, and Modified Mini-Mental State (3MS) at baseline and follow-up. Measurements: Primary outcome was incident-adjudicated dementia, based on 3MS, hospital records and dementia drugs. Secondary outcome was change in 3MS. Models were adjusted for age, sex, race, education and baseline 3MS, and then further for cardiovascular risk factors. Results: Among 2558 adults, 85% were euthyroid (TSH 0.45-4.49mIU/L), 2% had subclinical hyperthyroidism with mildly decreased TSH (TSH 0.10-0.44 mIU/L), 1% subclinical hyperthyroidism with suppressed TSH (TSH < 0.10 mIU/L with normal free thyroxine [FT4]) and 12% subclinical hypothyroidism (TSH 4.50-19.99 mIU/L with normal FT4). Over 9 years, 22% developed dementia. Compared to euthyroidism, risk of dementia was higher in participants with subclinical hyperthyroidism with suppressed TSH (HR 2.38, 95% CI = 1.13;5.04), while we found no significant association in those with mildly decreased TSH (HR 0.79, 95% CI = 0.45;1.38) or with subclinical hypothyroidism (HR 0.91, 95% CI = 0.70;1.19). Participants with subclinical hyperthyroidism with suppressed TSH had a larger decline in 3MS (−3.89, 95% CI = −7.62; −0.15). Conclusions: Among older adults, subclinical hyperthyroidism with a TSH < 0.10 mIU/L was associated with a higher risk of dementia and a larger cognitive decline, while subclinical hyperthyroidism with mildly decreased TSH or subclinical hypothyroidism were not.

KW - cognitive ageing

KW - cognitive decline

KW - dementia

KW - thyroid dysfunction

UR - http://www.scopus.com/inward/record.url?scp=85032175963&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85032175963&partnerID=8YFLogxK

U2 - 10.1111/cen.13458

DO - 10.1111/cen.13458

M3 - Article

C2 - 28850708

AN - SCOPUS:85032175963

VL - 87

SP - 617

EP - 626

JO - Clinical Endocrinology

JF - Clinical Endocrinology

SN - 0300-0664

IS - 5

ER -