The effect of testosterone aromatization on high-density lipoprotein cholesterol level and postheparin lipolytic activity.

Metabolism. 1993 Apr;42(4):446-50.

The effect of testosterone aromatization on high-density lipoprotein cholesterol
level and postheparin lipolytic activity.

Zmuda JM, Fahrenbach MC, Younkin BT, Bausserman LL, Terry RB, Catlin DH, Thompson
PD.

Department of Medicine, Miriam Hospital, Providence, RI.

Stanozolol, an oral 17 alpha-alkylated androgen, increases hepatic triglyceride
lipase activity (HTGLA) and decreases high-density lipoprotein cholesterol
(HDL-C) levels, whereas intramuscular testosterone has comparatively little
effect. In the present study, we tested the hypothesis that aromatization of
androgen to estrogen blunts the lipid and lipase effects of exogenous
testosterone. Fourteen male weightlifters received testosterone enanthate (200
mg/wk intramuscularly), the aromatase inhibitor testolactone (250 mg four times
per day), or both drugs together in a randomized cross-over design. Serum
testosterone level increased during all three drug treatments, whereas estradiol
level increased only with testosterone alone (+47%, P < .05), demonstrating that
testolactone effectively inhibited testosterone aromatization. Testosterone
decreased HDL-C(-16%, P < .05), HDL2-C(-23%, NS), and apoprotein (apo) A-I (-12%,
P < .05) levels, effects that were consistently but not significantly greater
with simultaneous testosterone and testolactone administration (HDL-C, -20%;
HDL2-C, -30%; apo A-I, -15%; P < .05 for all). In contrast, both testosterone
regimens decreased HDL3-C levels by 13% (P < .05 for both). HTGLA increased 21%
during testosterone treatment and 38% during combined testosterone and
testolactone treatment (P < .01 for both). Lipoprotein lipase activity (LPLA)
increased only during combined testosterone and testolactone treatment (+31%, P <
.01), suggesting that estrogen production may counteract the effects of
testosterone on LPLA. Testolactone alone had little effect on any lipid,
lipoprotein, apoprotein, or lipase concentration.(ABSTRACT TRUNCATED AT 250
WORDS)