CoChat
Sign Up
Cited by 239Thyroid Disorders and TreatmentsHormonal and reproductive studiesThyroid and Parathyroid Surgery

High Frequency of and Factors Associated with Thyroid Hormone Over-Replacement and Under-Replacement in Men and Women Aged 65 and Over

Open access
Somwaru, Lily L., Arnold, Alice M., Joshi, Neha, Fried, Linda P., Cappola, Anne R.·2009·The Journal of Clinical Endocrinology & Metabolism
DOI 10.1210/jc.2008-1696PMC PMC2682480
Open this paper in CoChat — free accountOpen PDF

Abstract

CONTEXT: Thyroid hormone use is common in older populations, but the frequency of over- or under-replacement is debated. OBJECTIVE: We sought to describe the frequency of and factors associated with thyroid hormone over- or under-replacement in a population of older men and women. DESIGN: Participants were 3678 U.S. community dwelling individuals aged 65 yr or older enrolled in the Cardiovascular Health Study who had thyroid function tests in 1989-1990. Thyroid hormone users (n = 339) were identified and classified into low TSH (<0.45 mU/liter), euthyroid (0.45-4.5 mU/liter), and high TSH (>4.5 mU/liter). RESULTS: Of the 339 thyroid hormone users, 41% had a low TSH, 16% had a high TSH, and 43% were in the euthyroid range. In multivariable analyses, lower weight (P < 0.001) was independently associated with low TSH status. For every 10 kg lower weight, the likelihood of having low TSH increased by 65% [odd ratio (OR) 1.65; 95% confidence interval (CI) 1.31-2.07]. Those with renal insufficiency were less likely to have low TSH levels (P = 0.02). The presence of diabetes was independently associated with having low (OR 3.35; 95% CI 1.46-7.65) and high TSH levels (OR 2.66; 95% CI 1.14-6.21). CONCLUSIONS: There is a very high prevalence of thyroid function testing abnormalities in older people taking thyroid hormone preparations, particularly in those of low weight or with diabetes. Because of potential adverse cardiovascular and skeletal effects from over-replacement, older people represent a key population for increased TSH monitoring on therapy.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1210/jc.2008-1696

Cites

17 of 17 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Nine studies over nearly 30 years across five different countries show that only 50%-70% of patients prescribed levothyroxine maintain serum TSH within reference range.

    “nine studies over nearly 30 years across five different countries show that only 50% -70% of patients prescribed levothyroxine maintain serum TSH within reference range. 20,30 -34”

    From Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement (2023) · cites this paper as [33]

    The Results and Discussion report that many thyroid-hormone users had TSH outside the reference range. But this is one U.S. cohort of adults aged 65 or older, not nine studies across five countries; Figure 1 reports 46.0% in the euthyroid range among those taking T4 alone, below the claimed 50%–70%. (LLM, conf=0.87)

    Experimental — accuracy not yet measured

  • Levothyroxine has a narrow therapeutic index, and both under-treatment (TSH above reference range) and over-treatment (TSH below reference range) are common, with cross-sectional studies consistently showing that 30%-50% of patients on levothyroxine have TSH values outside of the laboratory reference range.

    “Levothyroxine has a narrow therapeutic index, however, and both under -treatment (TSH above the reference range) and over -treatment (TSH below the reference range) are common, with cross -sectional studies consistently showing that 30% -50% of patients on levothyroxine have TSH values outside of the laboratory reference range. 20,30 -34,65”

    From Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement (2023) · cites this paper as [33]

    Split into 2 atoms — 0 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 1 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

  • Among patients with hypothyroidism taking levothyroxine, studies have reported a cumulative incidence of low thyrotropin levels in 5% to 41% and high thyrotropin levels in approximately 5% to 21%, with varying incidence depending on the population, clinical setting, and criteria used to define abnormal thyrotropin levels.

    “Among patients with hypothyroidism taking levothyroxine, studies 67-70 have reported a cumulative incidence of low thyrotropin levels in 5% to 41% and high thyrotropin levels in approximately 5% to 21%, with varying incidence depending on the population, clinical setting, and criteria used to define abnormal thyrotropin levels.”

    From Hypothyroidism: A Review (2025) · cites this paper as [68]

    Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

  • The larger risk of fracture in women than men may be related to differences in body size and pharmacokinetics between the sexes.

    “This may be related to differences in body size and pharmacokinetics between the sexes.14 28 61”

    From Levothyroxine dose and risk of fractures in older adults: nested case-control study (2011) · cites this paper as [14]

    The Discussion (page not specified) suggests that women’s lower weight accounts for their greater representation in the low-TSH group. Clinical implications (page not specified) notes potential skeletal effects of excess thyroid hormone. The paper does not establish a greater fracture risk in women than men or attribute such a difference to sex-specific pharmacokinetics. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
Somwaru, L. L., Arnold, A. M., Joshi, N., Fried, L. P., & Cappola, A. R.
Affiliations
  • University of Pennsylvania (US)
  • University of Washington (US)
  • Columbia University (US)
Corresponding author
Cappola, Anne R.
ORCID
Venue
The Journal of Clinical Endocrinology & Metabolism
Publisher
The Endocrine Society
Published
2009-04-01
Volume
94
Issue
4
Pages
1342-1345
ISSN
  • 0021-972X (ISSN-L)
  • 1945-7197
DOI
10.1210/jc.2008-1696
PMC
PMC2682480
OpenAlex
W2161444360
Cited by
239
References
17
Citations by year
2026: 11 · 2025: 18 · 2024: 18 · 2023: 21 · 2022: 14 · 2021: 22 · 2020: 19 · 2019: 23 · 2018: 15 · 2017: 14 · 2016: 17 · 2015: 4 · 2014: 8 · 2013: 11 · 2012: 8
FWCI
5.81
Type
journal article
Language
en
Open access
Locations
  • The Journal of Clinical Endocrinology & Metabolism (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Columbia Academic Commons (Columbia University)
Funders
  • University of Pennsylvania
  • National Institutes of Health (n01hc085079-024, n01hc015103-009, n01hc085086-022, n01hc035129-010)
  • National Institute on Aging (K23AG19161, K23AG019161)
  • National Heart, Lung, and Blood Institute (N01 HC085086, N01HC15103, N01 HC085079, N01 HC85086, N01 HC035129, N01 HC015103, N01-HC-85079 through N01-HC-85086, N01-HC85079, N01HC35129)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Surgery › Thyroid and Parathyroid Surgery
Keywords
thyroid hormone replacement, TSH levels, older adults, underweight, diabetes mellitus, renal failure, thyroid function tests, TSH monitoring, Cardiovascular Health Study
MeSH terms
Aged, Body Weight, Diabetes Mellitus, Dose-Response Relationship, Drug, Drug Therapy, Combination, Female, Humans, Male, Risk Factors, Thyroid Diseases, Thyroid Hormones, Thyrotropin, Thyroxine, Triiodothyronine, Body Mass Index, Multivariate Analysis, Hormone Replacement Therapy, Renal Insufficiency

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review