Sex-hormone-binding globulin and the free androgen index are related to cardiovascular risk factors in multiethnic premenopausal and perimenopausal women enrolled in the Study of Women Across the Nation (SWAN).
BACKGROUND
Recent clinical trials have shifted attention away from estrogens and toward androgens and sex hormone-binding globulin (SHBG) as potential mediators of increasing cardiovascular (CV) risk in women at midlife.


RESULTS
The correlation between reproductive hormones and CV risk factors was evaluated in a multiethnic (white, black, Hispanic, Chinese, and Japanese) sample of 3297 premenopausal and perimenopausal women. Testosterone and estradiol (E2) were evaluated along with SHBG and the free androgen index (FAI), the amount of testosterone not bound by SHBG. Low SHBG and high FAI were strongly and consistently related to elevated CV risk factors (higher insulin, glucose, and hemostatic and inflammatory markers and adverse lipids) even after controlling for body mass index (P<0.001 for all). Low levels of E2 were associated with elevated CV risk factors to a lesser degree. These observations were consistent across the 5 ethnic groups. Compared with whites, blacks had higher levels of SHBG and lower levels of FAI, and Chinese had lower levels of SHBG and higher levels of FAI.


CONCLUSIONS
Low SHBG and high FAI are strongly associated with CV risk factors in racially diverse women, and thus, androgens likely play a role in the CV risk profile of perimenopausal women.
Sutton-Tyrrell
Kim
K
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, 127 Parran Hall/130 DeSoto St, Pittsburgh, PA 15261, USA. Tyrrell@edc.pitt.edu
Wildman
Rachel P
RP
Matthews
Karen A
KA
Chae
Claudia
C
Lasley
Bill L
BL
Brockwell
Sarah
S
Pasternak
Richard C
RC
Lloyd-Jones
Donald
D
Sowers
Mary Fran
MF
Torréns
Javier I
JI
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000428:Alcohol Drinking / Q000208:ethnology; D000728:Androgens / Q000097:blood*; D001213:Asian / Q000706:statistics & numerical data; D015415:Biomarkers; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology; D002681:China / Q000208:ethnology; D015331:Cohort Studies; D004958:Estradiol / Q000097:blood; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006487:Hemostasis; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D007328:Insulin / Q000097:blood; D007564:Japan / Q000208:ethnology; D008055:Lipids / Q000097:blood; D024821:Metabolic Syndrome / Q000097:blood / Q000208:ethnology; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D017697:Premenopause / Q000097:blood*; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D012907:Smoking / Q000208:ethnology; D013739:Testosterone / Q000097:blood; D044465:White People / Q000706:statistics & numerical data
D000728:Androgens; D015415:Biomarkers; D001786:Blood Glucose; D018836:Inflammation Mediators; D007328:Insulin; D008055:Lipids; D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D004958:Estradiol