Definition
- Estrone (E1) is more potent than estriol (E3) but is less potent than estradiol (E2). Estrone is converted to estrone sulfate, and it acts as a reservoir that can be converted as needed to the more active estradiol. Estrone is the major circulating estrogen in postmenopausal women. In premenopausal women, estrone levels generally parallel those of estradiol, rising gradually during the follicular phase and peaking just prior to ovulation, with a secondary and smaller increase during the luteal phase. After menopause, estrone levels do not decline as dramatically as estradiol levels, possibly due to increased conversion of androstenedione to estrone.
- Normal range:
- Children: see Table 16.32.
- Adults: see Table 16.33.
TABLE 16 " 32Reference Intervals for Estrone in ChildrenView LargeTABLE 16 " 32Reference Intervals for Estrone in Children Boys (pg/mL) Girls (pg/mL) Tanner Stage <7 <27 I <11 1 " 39 II 1 " 31 8 " 117 III 2 " 30 4 " 109 IV and V Age (y) <7 <20 7 " 9 <11 1 " 40 10 " 12 1 " 30 8 " 105 13 " 15 1 " 32 4 " 133
TABLE 16 " 33Reference Intervals for Estrone in Adults*View LargeTABLE 16 " 33Reference Intervals for Estrone in Adults* Female Male Premenopausal 9 " 36 pg/mL " Early follicular: <150 pg/mL " Late follicular: 100 " 250 pg/mL " Luteal: <200 pg/mL Postmenopausal: 3 " 32 pg/mL *Eighteen years of age and older.
Use
- Diagnosis of precocious and delayed puberty
- Workup of suspected disorders of sex steroid metabolism
- In the fracture risk assessment of postmenopausal women
Interpretation
Increased In
- Possibly in polycystic ovarian syndrome, androgen-producing tumors, or estrogen-producing tumors.
- Possibly increased in postmenopausal vaginal bleeding due to peripheral conversion of androgenic steroids. Increased estrone levels may be associated with increased levels of circulating androgens and their subsequent peripheral conversion.
Decreased In
- Inherited disorders of sex steroid metabolism
- Testicular feminization
Limitations
- Significant diurnal variations in plasma levels
- Digoxin and estrogens increase in plasma levels