W5 - Correlates of endogenous sex hormone concentrations in WHI
This page provides study documentation for Core Study W5. For description of the specimen results, see Specimen Results Description (open to public). Data sets of the specimen results are included in the existing WHI datasets located on the WHI Data on this site (sign in and a completed Data Distribution Agreement are required; see details on the Data site).
Investigator Names and Contact Information
Core study approved by WHI Steering Committee
Introduction/Intent
Endogenous estrogens may be positively related to risk of breast cancer (1) and negatively related to risk of coronary heart disease and osteoporotic fractures (2,3). After menopause, the ovarian production of estrogen and progesterone ceases, while the production of various androgens continues. Most women continue to have detectable concentrations of circulating estrogen after menopause, however, the most prevalent being estrogen (4). After menopause, estrone is produced predominantly through the peripheral conversion, mostly in adipose tissue of adrenal androstenedione. Estradiol, the most metabolically active of the estrogens, is produced in postmenopausal women through the reduction of estrone through the aromatization of ovarian and adrenal testosterone (derived from the conversion of androstenedione and dephyroepiandrosterone). Only a small fraction of circulating estrogens persists in the "free' or unbound (thought to be more metabolically active ) state (less that 2% of total); the remainder is bound to either SHBG (55%) or albumin (45%) (5).
Circulating sex hormone concentrations have been found in several small series to be related to body weight, body mass index, age, exercise habits, and smoking and alcohol use (6-10). There had not been a simultaneous analysis of all of these variables in a large sample of postmenopausal women, as available in WHI. Nor has the concentration of endogenous sex hormones been compared between different racial and ethnic groups.
1. To examine the relationship between various factors and concentrations of endogenous sex hormones in a group of post menopausal women.
2. To examine the concentrations of sex hormones in different racial and ethnic groups
3. To compare relationships between these variable and these sex hormones in White, African-American, Hispanic , and Asian-American women..
Results/Findings
References
1. Tonolia P, Levitz. M, Zeleniuch-Jacquotte A, et al. A prospective study of endogenous estrogens and breast cancer in postmenopausal women. J Natl Cancer Inst 1995; 87: 190-197.
2. Colditz, GA, Willett WC, Stampfer MJ, et al. Menopause and the risk of coronary heart disease in women. N Engl J Med 1987; 316:1105-1110.
3. Cauley JA, Gutai JP, Sandler RB, et al. The relationship of endogenous estrogen to bone density and bone area in normal postmenopausal women. Am J Epidemiol 1986; 124:753-761.
4. Meldrum D, Davidson D, Tateryn, Judd HL. Changes in circulating steroids with aging in postmenopausal women. ObstetGynecol 1981; 57:624-628.
5. Siiteri PK, Murai JT, Hammond GL, et al. The serum transport of steroid hormones. Recent Program Hormones Res 1982; 38:457-510.
6. Nelson ME, Meredith CN, Dawson-Hughes B, et al. Hormone and bone mineral status in endurance-trained and sedentary postmenopausal women. J Clin Endocrinol Metab 1988; 66:927-933.
7. Cauley JA, Gutai JP, Kuller LH, et al. The epidemiology of serum sex hormones in postmenopausal women. Am J Epidemiol 1989; 129:1120-1131.
8. Kirschner MA, Samojlik E, Drejka M, et al. Androgen-estrogen metabolism in women with upper body vs. lower body obesity. J Clin Endocrinol Metab 1990; 70:473-479.
9. Kaye SA, Folsom AR, Soler JT, et al. Associations of body mass and fat distribution with sex hormone concentrations in postmenopausal women. Int J Epidemiol 1991; 20:151-156.
10. Newcomb PA, Klein R, Klein BEK, et al. Association of dietary and life-style factors with sex hormones in postmenopausal women. Epidemiology 1995; 6:318-321.