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The 24-h mean plasma concentration of total testosterone (T) was measured in 33 healthy, regularly cycling, nonobese women between 21 and 51 yr of age. Percent free T was measured in 17 of them. Plasma dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) were measured in 24 of them, and the DHEA-to-T and DHEAS-to-T ratios were calculated. It was found that the concentration of total T showed a steep decline with age; the regression equation was: T (nanomoles per L) = 37.8 x age-1.12 (r = -0.54; P < 0.003). According to this equation, the expected T concentration of a woman of 40 would be 0.61 nmol/L, about half that of a woman of 21 (1.3 nmol/L). The percent free T did not vary significantly with age, so free T concentration likewise showed a steep decline with age. The DHEA-to-T and DHEAS-to-T ratios were both age invariant, clearly because the levels of DHEA and DHEAS also decline steeply with age, as previously reported.
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
January 1999,
Journal of veterinary internal medicine,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
June 2005,
European journal of clinical pharmacology,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
December 1989,
Fertility and sterility,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
March 1984,
Taiwan yi xue hui za zhi. Journal of the Formosan Medical Association,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
October 1988,
Steroids,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
January 1981,
Journal of endocrinological investigation,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
June 1991,
Clinical science (London, England : 1979),
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
August 1980,
Endocrinologia japonica,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
September 1994,
Oncology reports,
B Zumoff, and
G W Strain, and
L K Miller, and
W Rosner
October 1996,
The British journal of ophthalmology,
