Determinants of sex hormone-binding globulin in normal postmenopausal women.
OBJECTIVE
To examine the factors influencing the levels of sex hormone-binding globulin (SHBG) in normal postmenopausal women by assessing the relationship between SHBG and measured anthropometric, metabolic and hormonal variables.


METHODS
Cross-sectional, observational study.


METHODS
Seventy normal postmenopausal women aged 47-71 years (mean 58 years), participated in the study. Information was collected on medical, reproductive and smoking history, alcohol use, dietary intake and physical activity. Body composition measurements using dual-energy absorptiometry, and analyses of biochemical and hormonal indices were performed.


RESULTS
Bivariate correlation coefficients indicated that SHBG was inversely related to body weight (r = - 0.44), fat mass (r = - 0.35), and abdominal obesity (r = - 0.42). It was also inversely related to the glucose and insulin levels during an oral glucose tolerance test (- 0.24 < r < - 0.40), serum oestradiol (r = - 0.26), and physical activity (r = - 0.24). Multiple regression analysis indicated that significant independent correlates of SHBG concentration were fat mass, physical activity, alcohol intake, serum oestradiol, and insulin-like growth factor-1, all having a negative impact on SHBG.


CONCLUSIONS
From these observed associations, it is concluded that maintenance of body weight, moderate alcohol consumption, and physical activity will tend to reduce SHBG concentrations in postmenopausal women, thereby increasing the levels of free oestradiol. This mechanism could mediate the beneficial effects of these factors in preventing the development of osteoporosis and cardiovascular disease.
Wu
F
F
Department of Medicine, University of Auckland, Auckland, New Zealand.
Ames
R
R
Evans
M C
MC
France
J T
JT
Reid
I R
IR
D000368:Aged; D000428:Alcohol Drinking; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D001835:Body Weight; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood; D015444:Exercise; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012044:Regression Analysis; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D012907:Smoking
D001786:Blood Glucose; D007328:Insulin; D012738:Sex Hormone-Binding Globulin; D004958:Estradiol; D007334:Insulin-Like Growth Factor I