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Cited by 239Hormonal and reproductive studiesSperm and Testicular FunctionAdrenal Hormones and Disorders

Circadian variation in testosterone, sex hormone-binding globulin, and calculated non-sex hormone-binding globulin bound testosterone in healthy young and elderly men

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PLYMATE, STEPHEN R., TENOVER, JOYCE S., BREMNER, WILLIAM J.·1989·Journal of Andrology
DOI 10.1002/j.1939-4640.1989.tb00120.x
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Abstract

The circadian pattern in levels of serum total testosterone (T) in men becomes blunted with normal aging. However, because T not bound to sex hormone‐binding globulin (non‐SHBG‐T) is felt to be a better representative of biologically available T than is total T, the possibility of a 24‐h variation in non‐SHBG‐T in young men and the possibility that aging is associated with a blunting of that rhythm were investigated. Hourly blood samples were drawn on 10 normal young men (mean age 27.3 years) and 10 normal elderly men (mean age 70.7 years) over a 24‐h period and the serum was assayed for total T, sex hormone‐binding globulin (SHBG), and total protein; non‐SHBG‐T was calculated. SHBG was determined by radioimmunoassay as well as by a steroid‐binding assay. Young men had a significantly higher (p < 0.05) mean 24‐h level of non‐SHBG‐T (1.91 ± 0.62 nm/l) than did the elderly men (0.86 ± 0.01 nM/l). Also, each young man showed a significant circadian rhythm in non‐SHBG‐T, with a group mean daily variation of 1.42 ± 0.38 nM/l. In contrast, only 60% of the elderly men demonstrated a significant circadian rhythm in non‐SHBG‐T, and the group mean rhythm was blunted (maximum excursion 0.38 ± 0.07 nM/l) compared with that of the young men. SHBG and total protein levels demonstrated similar 24‐h variations in the two age groups. It was concluded that non‐SHBG‐T serum levels, similar to serum total T levels, demonstrate a circadian pattern in young men and this circadian rhythmicity becomes blunted with normal aging.

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  • A meta-analysis of weight loss studies found mean testosterone increases of 83 ng/dl with diet alone and 252 ng/dl with bariatric surgery, with greater improvements after bariatric surgery attributed to more extensive weight loss.

    “A meta-analysis of studies reviewing the effect of weight loss on T demonstrated mean T increases of 83 ng/dl (diet alone [2.9 nmol/L]) and 252 ng/dl (bariatric surgery [8.7 nmol/L]), with greater improvements in bariatric surgery attributed to the more extensive weight loss achieved.”

    From Challenges in Testosterone Measurement, Data Interpretation, and Methodological Appraisal of Interventional Trials (2016) · cites this paper as [71]

  • A 4-5 point increase in BMI is roughly equivalent to a 10-year decline in testosterone, while weight loss directly correlates with increasing testosterone.

    “A 4–5 point increase in BMI is roughly equivalent to a 10-year decline in T, while weight loss directly correlates with increasing T.”

    From Challenges in Testosterone Measurement, Data Interpretation, and Methodological Appraisal of Interventional Trials (2016) · cites this paper as [71]

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Authors
PLYMATE, S. R., TENOVER, J. S., & BREMNER, W. J.
Affiliations
  • Madigan Army Medical Center (US)
  • University of Washington (US)
Corresponding author
PLYMATE, STEPHEN R.
ORCID
Venue
Journal of Andrology
Publisher
Wiley
Published
1989-09-10
Volume
10
Issue
5
Pages
366-371
ISSN
  • 0196-3635 (ISSN-L)
  • 1939-4640
DOI
10.1002/j.1939-4640.1989.tb00120.x
OpenAlex
W1889567471
Semantic Scholar
a0c6ba380ca4bed7281807f37cac956faa1f58b6
Cited by
239
References
19
Citations by year
2026: 1 · 2025: 4 · 2024: 8 · 2023: 8 · 2022: 11 · 2021: 5 · 2020: 8 · 2019: 9 · 2018: 4 · 2017: 5 · 2016: 7 · 2015: 10 · 2014: 12 · 2013: 13 · 2012: 5
FWCI
2.03
Type
journal article
Language
en
Open access
Licence
onlinelibrary.wiley.com/termsAndConditions#vor (vor, 8515 d)
Locations
  • Journal of Andrology (publishedVersion)
  • PubMed (publishedVersion)
  • ResearchWorks at the University of Washington (University of Washington) (submittedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Adrenal Hormones and Disorders
Keywords
circadian rhythm, testosterone, sex hormone-binding globulin, free testosterone, aging, older men, young men, diurnal variation, total protein
MeSH terms
Adult, Aged, Aging, Blood Proteins, Circadian Rhythm, Humans, Male, Sex Hormone-Binding Globulin, Testosterone

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