Increased free testosterone but normal 5 alpha-reduced testosterone metabolites in obese premenopausal women.
OBJECTIVE
The aim of the study was to investigate whether the absence of increased 5 alpha-reductase activity explained the absence of hirsutism in premenopausal obese women with increased free testosterone (FT) levels.


METHODS
As in hyperandrogenicity there generally exists evidence for increased 5 alpha-reductase activity, we measured, as parameters of 5 alpha-reductase activity, plasma levels of 5 alpha-androstane-3 alpha,17 beta-diol glucuronide (ADG) and androsterone glucuronide (ADTG) as well as their precursor levels in obese women without hirsutism, obese hirsute women, non-obese hirsute women, and non-obese, non-hirsute women.


METHODS
Eighty-two premenopausal women (20-45 years old) were studied, in four age matched groups: 39 controls, 18 obese without hirsutism, 11 non-obese hirsute and 14 obese hirsute women.


METHODS
Blood samples were taken between days 5 and 7 of the menstrual cycle. Steroid hormone levels were measured by radioimmunoassay. Free testosterone levels were measured by equilibrium dialysis.


RESULTS
Compared to controls, mean free testosterone levels were increased (P less than 0.01) in obese, obese hirsute and hirsute patients, whereas mean DHEAS levels were increased in hirsute and obese hirsute (P less than 0.01), but not in obese, women. Mean androstanediol glucuronide levels were markedly increased in hirsute and obese hirsute patients (P less than 0.01), but not in obese women. Plasma androsterone glucuronide levels were increased in hirsute (P less than 0.01), in the normal range in obese hirsute, and decreased in obese women (P less than 0.01).


CONCLUSIONS
These results show that, despite the presence of higher free testosterone levels, neither 5 alpha-reductase activity (as suggested by normal androstanediol glucuronide levels) nor adrenal androgen precursor levels (DHEAS) are increased in obese women without hirsutism.
Giagulli
V A
VA
Institute of Internal Medicine, Endocrinology and Metabolic Diseases, University of Bari, Italy.
De Pergola
G
G
Giorgino
F
F
Cignarelli
M
M
Abbaticchio
G
G
Vermeulen
A
A
Giorgino
R
R
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000097:blood*; D000328:Adult; D015113:Androstane-3,17-diol / Q000031:analogs & derivatives / Q000097:blood; D000738:Androsterone / Q000031:analogs & derivatives / Q000097:blood; D003687:Dehydroepiandrosterone / Q000031:analogs & derivatives / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate; D005260:Female; D006628:Hirsutism / Q000097:blood / Q000150:complications; D006801:Humans; D009765:Obesity / Q000097:blood* / Q000150:complications; D013739:Testosterone / Q000097:blood*
C027927:androsterone glucuronide; D015113:Androstane-3,17-diol; C028895:androstane-3,17-diol glucuronide; D013739:Testosterone; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D000738:Androsterone; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase