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Cited by 130Hormonal and reproductive studiesHypothalamic control of reproductive hormonesSperm and Testicular Function

Decreased androgen levels in massively obese men may be associated with impaired function of the gonadostat

Lima, N, Cavaliere, H, Knobel, M, Halpern, A, Medeiros-Neto, G·2000·International Journal of Obesity
DOI 10.1038/sj.ijo.0801406
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Abstract

Objective In obese men, sex hormone-binding globulin (SHBG) as well as total testosterone (TT) levels are decreased. Data concerning serum free testosterone (FT) levels in obese men are discordant. FT levels are decreased in only some morbidly obese men, consistent with an impairment of the feedback regulatory mechanism. In this study we aimed to verify serum levels of TT and FT in two groups of obese men (BMI < 35.0 kg/m2 and BMI > 35.1 kg/m2) before and after weight loss.Design Two groups of obese men (group 1: BMI < or = 35 kg/m2; and group 2: BMI > or =35.1 kg/m2) were studied before and after 6 months of a low energy diet (1200 kcal/day). Every patient received a therapeutic prescription of dexfenfluramine (15 mg b.i.d.) that was maintained for 6 months.Subjects Thirty-seven obese men and 20 normal weight men.Measurements Serum sex hormones (TT and FT), serum luteinizing hormone (LH) and insulin were analyzed by RIA assays. Plasma insulin levels, serum TT, FT and LH concentrations were obtained before and after weight loss.Results Moderately obese men (BMI = 32.3+/- 1.9 kg/m2) presented significantly decreased TT levels (390+/-120ng/dl) as well as FT (mean+/-s.d.:16.0+/-4.8pg/ml) as compared with normal controls. FT serum levels had a significant and negative correlation with body mass index (BMI), whereas for TT concentrations this correlation was not significant. Serum LH concentrations (4.5+/-2.9mlU/ml) were normal. Insulin levels were elevated in all patients (46.3+/-30.1 microU/ml). After weight loss there was a significant (P< 0.01) increase in TT, FT and LH levels, whereas insulin concentrations significantly decreased. In massively obese men (BMI = 43.0 6.7 kg/m2), TT (320+/-110ng/dl), FT (11.0+/-2.1 pg/ml) and LH (3.1+/-1.3mlU/ml) were decreased and significantly lower as compared with the previous group and normal controls. As expected, after weight loss TT, FT and LH levels increased significantly while insulin concentrations decreased.Conclusions We concluded that FT levels are dependent on the degree of obesity, massively obese men (BMI > or =35.1 kg/m2) being considered as candidates for consistently low FT levels. A functional decrease of LH pulse amplitude and serum LH levels as well as a possible negative action of excess of circulating leptin on the steroidogenesis may be related to the decreased androgens levels in massively obese men.

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  • Over the past 10 years, mass spectrometry, particularly liquid chromatography tandem mass spectrometry, has become increasingly adopted because of high throughput, limited sample preparation, and high sensitivity and specificity at low and high testosterone concentrations.

    “However, over the past 10 years, MS, and in particular liquid chromatography tandem mass spectrometry (LC-MS/MS), has become increasingly adopted due to its high throughput, limited requirement for sample preparation, and high sensitivity/specificity at low and high T concentrations.”

    From Challenges in Testosterone Measurement, Data Interpretation, and Methodological Appraisal of Interventional Trials (2016) · cites this paper as [84]

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Authors
Lima, N., Cavaliere, H., Knobel, M., Halpern, A., & Medeiros-Neto, G.
Affiliations
Universidade de São Paulo (BR)
Corresponding author
Medeiros-Neto, G
ORCID
Venue
International Journal of Obesity
Publisher
Springer Science and Business Media LLC
Published
2000-11
Volume
24
Issue
11
Pages
1433-1437
ISSN
  • 0307-0565 (ISSN-L)
  • 1476-5497
DOI
10.1038/sj.ijo.0801406
OpenAlex
W2031161694
Cited by
130
References
15
Citations by year
2026: 1 · 2025: 1 · 2024: 2 · 2023: 4 · 2022: 8 · 2021: 8 · 2020: 3 · 2019: 3 · 2018: 4 · 2017: 4 · 2016: 3 · 2015: 5 · 2014: 9 · 2013: 10 · 2012: 10
FWCI
1.94
Type
journal article
Language
en
Open access
closed
Licence
www.springer.com/tdm (tdm)
Locations
  • International Journal of Obesity (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Reproductive Medicine › Hypothalamic control of reproductive hormones
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
Keywords
obesity, androgen deficiency, free testosterone, total testosterone, luteinizing hormone, insulin resistance, hypothalamic-pituitary-gonadal axis, weight loss, dexfenfluramine, sex hormone-binding globulin, body mass index, hypocaloric diet, hyperinsulinemia, hypogonadism
MeSH terms
Adult, Aged, Diet, Reducing, Humans, Insulin, Luteinizing Hormone, Male, Middle Aged, Obesity, Morbid, Radioimmunoassay, Testis, Testosterone, Cohort Studies, Weight Loss, Body Mass Index, Case-Control Studies, Dexfenfluramine

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