Accuracy of calculated free testosterone differs between equations and depends on gender and SHBG concentration

Hackbarth, Jennifer S.; Hoyne, Jonathan; Grebe, Stefan K.; Singh, Ravinder J.

doi:10.1016/j.steroids.2010.08.008

Cited by 53 publications

(25 citation statements)

References 37 publications

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“…However, a single measurement of testosterone is considered reliable in the context of large-scale analyses (51). The Vermeulen method has been reported to both overestimate (24) and underestimate (25) free testosterone compared with laboratory measures, but direct measurement of free testosterone was impractical. Nonetheless, estimated free testosterone remains useful in the research context, although its application in other settings should be approached cautiously.…”

Section: Discussionmentioning

confidence: 99%

“…Free testosterone was estimated with Vermeulen's method (23). The total testosterone assay accounts for the majority of variance (Ͼ80%) in the free testosterone estimate; detailed analyses of its predictive accuracy have been published elsewhere (24,25). Serum glucose, high-density lipoprotein and low-density lipoprotein (LDL), total cholesterol, and triglycerides were assayed using a Roche Hitachi 917 analyzer (Roche Diagnostic GmbH, Mannheim, Germany).…”

Section: Biochemical Assessmentmentioning

confidence: 99%

See 1 more Smart Citation

Low Free Testosterone Predicts Mortality from Cardiovascular Disease But Not Other Causes: The Health in Men Study

Hyde

Norman²,

Flicker

et al. 2012

The Journal of Clinical Endocrinology & Metabolism

164

114

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Section: Discussionmentioning

confidence: 99%

Section: Biochemical Assessmentmentioning

confidence: 99%

Low Free Testosterone Predicts Mortality from Cardiovascular Disease But Not Other Causes: The Health in Men Study

Hyde

Norman²,

Flicker

et al. 2012

The Journal of Clinical Endocrinology & Metabolism

164

114

View full text Add to dashboard Cite

show abstract

“…Free testosterone, the fraction not bound to SHBG or albumin, was estimated with Vermeulen's method (18). The total testosterone assay accounts for the majority of variance (>80%) in the free testosterone estimate; detailed analyses of its predictive accuracy have been published elsewhere (19,20). Serum glucose, high-and low-density lipoprotein, total cholesterol, and triglycerides were assayed using a Roche Hitachi 917 analyzer (Roche Diagnostic GmbH).…”

Section: Laboratory Methodsmentioning

confidence: 99%

Associations between Testosterone Levels and Incident Prostate, Lung, and Colorectal Cancer. A Population-Based Study

Hyde

Flicker

McCaul

et al. 2012

Cancer Epidemiology, Biomarkers &Amp; Prevention

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Background: The relationship between testosterone and cancer is relatively unexplored. We sought to examine whether testosterone and related hormones are associated with incident prostate, lung, and colorectal cancer.Methods: This was a population-based cohort study. Demographic and clinical predictors of cancer, and testosterone, sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were measured between 2001 and 2004 in 3,635 community-dwelling men aged 70 to 88 years (mean 77 years). Cancer notifications were obtained via electronic record linkage until December 31, 2010.Results: During a mean follow-up period of 6.7 AE 1.8 years, there were 297, 104, and 82 cases of prostate, colorectal, and lung cancer. In adjusted competing risks proportional hazards models, each one SD increase in free testosterone was associated with a 9% increase in prostate cancer risk (95% confidence interval [CI], 1.00-1.18), but other hormones were not significantly associated. No significant associations were observed between hormonal parameters and colorectal cancer. Higher total testosterone was associated with lung cancer. Compared with the mean of 15 nmol/L, men with levels of 20 nmol/L were 1.38 times more likely to be cases (95% CI, 1.21-1.57), whereas those with levels of 30 nmol/L were 3.62 times more likely to be cases (95% CI, 2.53-5.18). Higher free testosterone was also associated with lung cancer, though SHBG and LH were not. Associations were maintained after exclusion of current smokers.Conclusions: Higher free testosterone was associated with incident prostate cancer. Higher testosterone levels may also be associated with lung cancer.Impact: Further studies should investigate whether these risks apply to men receiving testosterone therapy.

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“…Free or bioavailable testosterone would be preferable, but quantification is technically more difficult and costly. Formulas to calculate free testosterone using information on total testosterone, SHBG, and albumin are available, but the generalizability is complicated by large variations depending on the formula and the assays used [30]. Sample storage and processing issues additionally contribute to the difficulties of comparisons between studies.…”

Section: Modification Of Risk By Androgens In Heart Failurementioning

confidence: 99%

Androgen Deficiency in Heart Failure

Güder

Allolio

Angermann

et al. 2011

Curr Heart Fail Rep

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Androgen deficiency is a hormonal disorder that is frequently observed in advanced chronic conditions. A reduction of androgen blood levels may be cause or consequence of the disease, or both. Typical symptoms, such as fatigue or muscle weakness, may be particularly aggravated in heart failure, and disease severity may be indirectly affected by low levels of androgen. Recently, androgen replacement therapy has been suggested as a new treatment option of heart failure symptoms, and placebo-controlled pilot trials showed a modest improvement of physical performance. However, testosterone replacement in elderly patients is not without risks, and the benefit-risk ratio for such adjunct treatment is unclear. This review focuses on the general effects of androgens on the cardiovascular system and outlines expected benefits and suspected side effects of testosterone replacement therapy in patients with heart failure.

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Accuracy of calculated free testosterone differs between equations and depends on gender and SHBG concentration

Cited by 53 publications

References 37 publications

Low Free Testosterone Predicts Mortality from Cardiovascular Disease But Not Other Causes: The Health in Men Study

Low Free Testosterone Predicts Mortality from Cardiovascular Disease But Not Other Causes: The Health in Men Study

Associations between Testosterone Levels and Incident Prostate, Lung, and Colorectal Cancer. A Population-Based Study

Androgen Deficiency in Heart Failure

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