F. Labrie et al., MARKED DECLINE IN SERUM CONCENTRATIONS OF ADRENAL C19 SEX STEROID PRECURSORS AND CONJUGATED ANDROGEN METABOLITES DURING AGING, The Journal of clinical endocrinology and metabolism, 82(8), 1997, pp. 2396-2402
The present data show a dramatic decline in the circulating levels of
dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEA-S), an drost-5-ene-3
beta,17 beta-diol (5-diol), 5-diol-sulfate, 6-diol-fatty acid esters,
and androstenedione in both men and women between the ages of 30-80 y
r. In the 50- to 60-yr-old group, serum DHEA decreased by 74% and 70%
from its peak values in 20- to 30-yr-old men and women, respectively.
The serum concentrations of the conjugated metabolites of dihydrotesto
sterone (DHT), namely androsterone (ADT)-G, androstane-3 alpha,17 beta
-diol (3 alpha-diol-G), androstane-3 beta,17 beta-diol (3 beta-diol-G)
, and ADT-sulfate are the most reliable parameters of the total androg
en pool in both men and women, whereas serum testosterone and DHT can
be used as markers of testicular secretion in men and interstitial ova
rian secretion in women. The serum concentration of these various conj
ugated androgen metabolites: decreased by 40.8% to 72.8% between the 2
0- to 30-yr-old and 70- to 80-yr-old age groups in men and women, resp
ectively, thus suggesting a pal allel decrease in the total androgen p
ool with age. As estimated by measurement of the circulating levels of
these conjugated metabolites of DHT, it is noteworthy that women prod
uce approximately 66% of the total androgens found in men. In women, m
ost of these androgens originate from the transformation of DHEA and D
HEA-S into testosterone and DHT in peripheral intracrine tissues, wher
eas in men the testes and DHEA and DHEA-S provide approximately equal
amounts of androgens at the age of 50-60 yr. An additional potentially
highly significant observation is that the majority of the marked dec
line in circulating adrenal C-19 steroids and their resulting androgen
metabolites takes place between the age groups of 20- to 30-yr olds a
nd 50- to 60-yr-olds, with smaller changes are observed after the age
of 60 yr.