Cited by 469Hormonal and reproductive studiesDiabetes, Cardiovascular Risks, and LipoproteinsSperm and Testicular Function

The DOI matches its Crossref record; 37 of the 37 references it cites were found in a registry or an index; none of the 20 sources its claims cite is checked for support yet.

Low Testosterone Levels Are Common and Associated with Insulin Resistance in Men with Diabetes

Abstract

Context: Low testosterone levels are common in men with type 2 diabetes and may be associated with insulin resistance. Objective: We investigated prevalence of testosterone deficiency and the relationship between testosterone and insulin resistance in a large cohort of men with type 2 and type 1 diabetes. Design: The study was a cross-sectional survey of 580 men with type 2 diabetes and 69 men with type 1 diabetes. A subgroup of 262 men with type 2 diabetes was then reassessed after a median of 6 months. Results: Forty-three percent of men with type 2 diabetes had a reduced total testosterone, and 57% had a reduced calculated free testosterone. Only 7% of men with type 1 diabetes had low total testosterone. By contrast, 20.3% of men with type 1 diabetes had low calculated free testosterone, similar to that observed in type 2 diabetes (age-body mass index adjusted odds ratio = 1.4; 95% confidence interval = 0.7–2.9). Low testosterone levels were independently associated with insulin resistance in men with type 1 diabetes as well as type 2 diabetes. Serial measurements also revealed an inverse relationship between changes in testosterone levels and insulin resistance. Conclusions: Testosterone deficiency is common in men with diabetes, regardless of the type. Testosterone levels are partly influenced by insulin resistance, which may represent an important avenue for intervention, whereas the utility of testosterone replacement remains to be established in prospective trials.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In a single-center cross-sectional survey, testosterone deficiency was common in men with diabetes: 43% of men with type 2 diabetes had low total testosterone and 57% had low calculated free testosterone, while 20.3% of men with type 1 diabetes had low calculated free testosterone. Low testosterone indices were independently associated with insulin resistance in both diabetes types, and longitudinal changes in testosterone were inversely related to changes in insulin resistance in a type 2 diabetes subgroup.

Key findings

  • Among men with type 2 diabetes, 43% had low total testosterone (<10 nmol/L) and 57% had low calculated free testosterone (<0.23 nmol/L); among men with type 1 diabetes, 7% had low total testosterone but 20.3% had low calculated free testosterone, similar to age- and BMI-adjusted men with type 2 diabetes (adjusted odds ratio 1.4; 95% CI 0.7–2.9).
  • Low total testosterone in type 2 diabetes was independently associated with insulin resistance by HOMA-IR (odds ratio 1.2; 95% CI 1.0–1.4), and calculated free testosterone was independently associated with insulin sensitivity in type 2 diabetes (partial correlation coefficient −0.10; P = 0.02) and with eGDR in type 1 diabetes (P = 0.04).
  • In 262 men with type 2 diabetes reassessed after a median of 6 months, the change in total testosterone was inversely related to the change in HOMA-IR (P = 0.01), and the change in calculated free testosterone was inversely correlated with the change in HOMA-IR (P = 0.03).
  • The prevalence of low calculated free testosterone approximately doubled per decade of age in type 2 diabetes (adjusted odds ratio 2.0; 95% CI 1.4–2.4) and in type 1 diabetes (adjusted odds ratio 2.4; 95% CI 1.4–3.9).

Methods

  • Cross-sectional survey of 580 men with type 2 diabetes and 69 men with type 1 diabetes at a single clinic; 6 men with type 2 diabetes were excluded from statistical analysis, and a randomly selected subgroup of 262 men with type 2 diabetes was reassessed after a median of 6 months (range 1–15 months).
  • Fasting blood samples were drawn between 0800 and 1000 h; total testosterone was measured by Access assay, SHBG by Immulite, and calculated free testosterone was derived using Vermeulen’s formula. Low total testosterone was defined as <10 nmol/L and low calculated free testosterone as <0.23 nmol/L.
  • Insulin resistance was estimated by HOMA-IR in type 2 diabetes and by eGDR in type 1 diabetes; analyses used logistic regression, multiple regression, ANOVA, analysis of covariance, and nonparametric tests as appropriate.

Limitations

  • The paper states that it did not obtain a detailed symptomatology history, so the biochemical testosterone deficiency may not represent a true hypogonadal state; it also states that a single low testosterone level is inadequate for diagnosing hypogonadism because of variability, and on repeat testing 27% of men with low total testosterone and 33% with low calculated free testosterone had normal levels.
  • The paper states that longitudinal changes in testosterone in type 1 diabetes remain to be explored and that the utility of testosterone replacement remains to be established in prospective trials.
  • Evident from the text: the study was observational and single-center, with a tertiary referral cohort that had longstanding diabetes and high complication prevalence, which may limit generalizability and cannot establish causality.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1210/jc.2007-2177

Cites

37 of 37 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

0 of 20 cited sources checked · 0 supported · 0 flagged

Show all 42 claims

  • It may state two separate claims as one. 6
  • Probably not a substantial claim. 10
13 of 13
  • The paper relies on this without support.

    The cohort of men attending a single tertiary referral clinic is representative of men with diabetes generally.

    “in a large, unselected cohort of men with type 1 or type 2 diabetes presenting at a single center”
    “large unselected cohort of men presenting to a single tertiary referral center”
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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?

Self-check

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

Each contradiction between two passages listed here was confirmed by an independent check.

  • Overall hs-CRP median is below both reported subgroup medians

    Major

    The reported hs-CRP medians for men with and without low TT are 7.7 and 4.5, respectively. The overall type 2 diabetes median in Table 1 is 3.0, which cannot be below both subgroup medians if these are the same cohort.

  • Macrovascular disease prevalence differs from Table 1

    Minor

    The results describe macrovascular disease in one third of men with type 2 diabetes, but Table 1 reports 42% for that group.

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Metadata

Authors
Grossmann, M., Thomas, M. C., Panagiotopoulos, S., Sharpe, K., MacIsaac, R. J., Clarke, S., Zajac, J. D., & Jerums, G.
Affiliations
  • The University of Melbourne (AU)
  • Baker Heart and Diabetes Institute (AU)
Corresponding author
Grossmann, Mathis
Venue
The Journal of Clinical Endocrinology & Metabolism
Published
2008-05-01
Volume
93
Issue
5
Pages
1834-1840
ISSN
  • 0021-972X (ISSN-L)
  • 1945-7197
OpenAlex
W1975633687
Cited by
468
References
37
Citations by year
2026: 22 · 2025: 22 · 2024: 22 · 2023: 23 · 2022: 28 · 2021: 24 · 2020: 23 · 2019: 15 · 2018: 24 · 2017: 33 · 2016: 34 · 2015: 30 · 2014: 41 · 2013: 31 · 2012: 30
FWCI
15.97
Type
journal article
Language
en
Open access
closed
Locations
  • The Journal of Clinical Endocrinology & Metabolism (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Medical Research Council
  • National Health and Medical Research Council
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes, Cardiovascular Risks, and Lipoproteins
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
Keywords
androgen deficiency, insulin resistance, type 2 diabetes, type 1 diabetes, men, free testosterone, total testosterone, testosterone replacement therapy, prevalence
MeSH terms
Adult, Aged, Cross-Sectional Studies, Diabetes Mellitus, Diabetes Mellitus, Type 1, Diabetes Mellitus, Type 2, Humans, Insulin Resistance, Male, Middle Aged, Sex Hormone-Binding Globulin, Testosterone

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