Diurnal rhythms of serum total, free and bioavailable testosterone and of SHBG in middle‐aged men compared with those in young men

Diver, M. J.; Imtiaz, Komal; Ahmad, Aftab; Vora, Jiten; Fraser, William D.

doi:10.1046/j.1365-2265.2003.01772.x

Cited by 300 publications

(198 citation statements)

References 77 publications

(101 reference statements)

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“…Our results with regard to the diurnal rhythm of testosterone in boys in late puberty are similar to those in young men (19). Characterization of pubertal stages may be carried out in different ways (10,20,21).…”

Section: Discussionsupporting

confidence: 66%

Changes of diurnal rhythm and levels of total and free testosterone secretion from pre to late puberty in boys: testis size of 3 ml is a transition stage to puberty

Ankarberg‐Lindgren

Norjavaara

2004

European Journal of Endocrinology

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Objective: To establish levels for comparison for 24-h total and free serum testosterone in prepubertal boys and throughout pubertal development. Design: The study subjects were 55 healthy boys, aged 5.0-18.6 years, who underwent serial sampling one or more times during their pubertal development. Methods: Testicular volumes were determined by orchidometer. Serum testosterone was measured by a modified RIA (detection limit, 0.03 nmol/l). Free testosterone was calculated (calc-FT) using a formula derived from the law of mass action. Results: Significant increases in testosterone and calc-FT concentrations in boys were found between testis volumes of 1 ml to 2 ml, 2 ml to 3 ml, 6 ml to 8 ml, and 10 ml to 15 ml. No differences were found between testis volumes of 3, 4, 5 and 6 ml neither were there differences between 8 and 10 ml, or between 15, 20 and 25 ml. Boys who had reached their final height had higher calc-FT values than boys who had the same pubertal development but had not reached their final height. Based on the results, puberty was classified into six stages: pre1 (testis, 1 ml), pre2 (testis, 2 ml), early (testis, 3 -6 ml), mid (testis, 8-12 ml), late1 (testis,15 -25 ml, not reached final height) and late2 (testis, 15 -25 ml, reached final height). Serum testosterone was secreted with a diurnal variation in prepuberty and during puberty. The increase of testosterone in the morning hours started earlier in pubertal than in pre-pubertal boys. The most pronounced diurnal rhythm was found in early and in mid puberty. Conclusion: Using a sensitive method, and a pubertal reclassification, we have established levels for comparison of testosterone and calc-FT in prepubertal and pubertal boys. The existence of data for comparison forms the basis for future studies on pubertal disorders.

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Section: Discussionsupporting

confidence: 66%

Changes of diurnal rhythm and levels of total and free testosterone secretion from pre to late puberty in boys: testis size of 3 ml is a transition stage to puberty

Ankarberg‐Lindgren

Norjavaara

2004

European Journal of Endocrinology

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“…Blood samples were drawn within 4 hours of subjects' waking to reduce the effect of diurnal variation in hormone concentrations. 34 To counteract episodic hormone secretion, 35 two samples were obtained at each visit, 30 minutes apart, and were pooled in equal aliquots at the time of assay. Blood was centrifuged within 6 hours of study visit.…”

Section: Study Design and Data Collectionmentioning

confidence: 99%

“…Blood samples were drawn within 4 hours of subjects' waking to reduce the effect of diurnal variation in hormone concentrations. 34 To Total T was measured using radioimmunoassay kits from Diagnostic Products Corporation (Los Angeles, CA). Interassay coefficients of variation (CVs) were 8.0%, 9.0%, and 8.3% at T1, T2, and T3, respectively.…”

mentioning

confidence: 99%

The Natural History of Symptomatic Androgen Deficiency in Men: Onset, Progression, and Spontaneous Remission

Travison

Shackelton

Araujo

et al. 2008

J American Geriatrics Society

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OBJECTIVES-To describe the onset, progression, and remission of symptomatic androgen deficiency (SAD) using longitudinal data from the Massachusetts Male Aging Study (MMAS).DESIGN-A prospective, population-based study of men living in Boston, Massachusetts. Data were collected in three waves: T1 (1987/89), T2 (1995/97), T3 (2002/04). Onset, progression, and remission were defined in terms of transitions in SAD status from one wave to the next. SETTING-In-person, in-home interviews.PARTICIPANTS-Seven hundred sixty-six community-dwelling men aged 40 to 70 at baseline (T1) contributed data from T1 to T2 and 391 from T2 to T3. MEASUREMENTS-SADwas defined in terms of serum total and free testosterone (T) levels and symptoms associated with low circulating androgens. Total T and sex hormone-binding globulin (SHBG) were measured using radioimmunoassay. Free T was calculated from total T and SHBG measurements. RESULTS-At T2 or T3, the likelihood of SAD was markedly greater for subjects who had exhibited SAD at the previous wave (odds ratio = 3.8, 95% confidence interval = 1.9-7.4), overall 55% of subjects who exhibited SAD experienced remission by the next study wave. The probability of SAD was greater with older age and greater body mass index. Multivariate models demonstrated that the likelihood of remission was at least 50% for most subpopulations.CONCLUSION-Over approximately 15 years of follow-up, SAD did not represent a stable health state. The likelihood of SAD would remit exceeded the likelihood that it Keywords aging; men; androgen; population study Gradual decreases in serum testosterone (T) concentrations are generally believed to accompany male aging. 1-8 Low T levels have been shown to contribute to diabetes mellitus, Address correspondence to: Thomas G. Travison, PhD, New England Research Institutes, 9 Galen St., Watertown, MA 02474. ttravison@neriscience.com. HHS Public AccessAuthor manuscript J Am Geriatr Soc. Author manuscript; available in PMC 2017 August 15. Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript low bone and muscle mass, impaired sexual function, and frailty, 9-13 so interventions intended to slow or reverse age-related declines in T have attracted a great deal of attention.Whether there exists a threshold at which T levels should be considered "deficient" is still the subject of substantial debate. [14][15][16] Although it is known that comorbidity and health behaviors influence T, 8,17 concurrent changes in health do not appear to account for agerelated declines in T. 8,18 In addition, T levels exhibit substantial random variability over periods of weeks or months. 19,20 The presence or absence of true age-related hypogonadism is therefore difficult to determine. 21 For these reasons, it has been proposed that a composite measure of T levels and seemingly related symptoms, many of them having to do with mood and self-assessed well-being, may represent a more clinically meaningful assessment of male hormonal status. [22][23][24][25][26][27][28] Implicit in thi...

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“…A serum sample for TT determination should be obtained between 07.00 and 11.00 h [54] (Level 2a, Grade A).…”

Section: Recommendation 3: Laboratory Diagnosismentioning

confidence: 99%

Recommendations on the diagnosis, treatment and monitoring of late-onset hypogonadism in men – a suggested update

et al. 2013

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Diurnal rhythms of serum total, free and bioavailable testosterone and of SHBG in middle‐aged men compared with those in young men

Abstract: The study suggests that the diurnal rhythm in these indices of androgen status is maintained in fit, healthy men into the 7th decade of life.

Cited by 300 publications

References 77 publications

Changes of diurnal rhythm and levels of total and free testosterone secretion from pre to late puberty in boys: testis size of 3 ml is a transition stage to puberty

Changes of diurnal rhythm and levels of total and free testosterone secretion from pre to late puberty in boys: testis size of 3 ml is a transition stage to puberty

The Natural History of Symptomatic Androgen Deficiency in Men: Onset, Progression, and Spontaneous Remission

Recommendations on the diagnosis, treatment and monitoring of late-onset hypogonadism in men – a suggested update

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