Proper Estrogen Replacement in Turner Syndrome Adolescents
by Nelly Mauras, MD
The proper timing, dose and more recently route of estrogen replacement in females with Turner Syndrome have been better characterized. Although historically, conjugated equine estrogens (CEE) such as Premarin® had been the preferred method of estrogen replacement in Turner Syndrome and other disorders of ovarian function (hypogonadism), CEE contains over 100 forms of estrogens of different potencies and biological activity. When feminizing girls with different forms of hypogonadism, micronized 17βE2 should be now considered the first choice as, being identical to the product of the intact ovary, it is the most physiological and can be accurately measured in plasma. Most previous studies of the metabolic effects of the different routes of administration have also used different types of estrogen, making comparisons difficult. We recently studied the metabolic effects of the same form of estradiol, 17β£2 orally or transdermally in a group of 40 girls with Turner Syndrome in whom we titrated the doses based on estradiol (E2) concentrations obtained monthly measured by sensitive mass spectrometry assays. We aimed to achieve levels comparable to those of normally menstruating adolescents measured in the same assay in both groups. All subjects were cycled with progesterone monthly. After 12 months of treatment, although E2 concentrations were comparable, there were no differences in body composition, lean body mass, adiposity, bone mass accrual or energy expenditure, LH/FSH suppression and lipid concentrations between the groups. IGF-I concentrations (an indirect measure of growth hormone action) trended lower in the transdermal group, but still remained within normal range. However, there were considerable differences in the levels of estrone, estrone sulfate and total bioestrogen concentrations (measured using a recombinant cell bioassay), levels much higher in the oral group, creating an unphysiologic estrogen milieu. Both estrone and estrone sulfate can be stored in fat cells and in breast tissue and recycled back into E2 creating a reservoir of estrogen in the body. These results are important, given the compelling body of data that have accumulated on the increased thromboembolic effects of oral over transdermal estrogens in both post- and pre-menopausal women. Whether transdermal estrogen produces a greater accumulation of other estrogen metabolites that can cause DNA damage (genotoxic estrogens) awaits further study. We concluded that adolescent girls with Turner syndrome should be feminized at the normal physiologic time, preferably using transdermal estradiol which produces a more physiologic milieu in order to achieve normal levels in plasma. The therapeutic guidelines for estrogen replacement therapy in Turner Syndrome will be revised in the near future.
Nelly Mauras, MD
Chief, Division of Endocrinology, Diabetes & Metabolism
Nemours Children’s Clinic
& Professor of Pediatrics
Mayo College of Medicine
807 Children’s Way
Jacksonville, Florida 32207
Tel: 904 697 3674 (office)
904 803 3550 (cell)
Fax: 904 697 3948
Pharmacokinetics and Pharmacodynamics of Oral and Transdermal 17 Estradiol in Girls with Turner Syndrome read
Metabolic Effects of Oral Versus Transdermal17-Estradiol (E2): A Randomized Clinical Trial in Girls With Turner Syndrome read
Delayed Puberty and Sexual Development Require a Timely Intervention
The ovarian cells in females with Turner Syndrome undergo premature cell death. By 20 weeks gestation, 70% of ovarian germ cells were apoptotic in those with Turner Syndrome, compared to 3% in age-matched normal XX ovaries. The ovarian failure manifests itself as both estrogen deficiency as well as a lack of fertilizable ovum.
Girls with Turner Syndrome tend to have normal pubic and axillary hair development, as these are due to adrenal androgens, rather than ovarian estrogens. However, most girls with TS will not have full breast development nor menstrual cycles. Occasionally, there is enough residual ovarian function for breast development and/or menstrual periods. Because of the ovarian failure, natural fertilization is quite rare in women with TS.
The estrogen deficiency is treated with replacement estrogen, either as pills or estrogen patches. Studies show that estrogen patches have the advantage of not causing liver enzyme elevations and promote increased growth factor (IGF-1) levels. There are various estrogen replacement regimens that are used, but the common point among of all of them is to start with low dose estrogen, and slowly increase the dose over a couple of years. This allows for normal uterine and breast development.
Implications of a Delayed Puberty
It is psychologically beneficial for girls to experience puberty along with peer group. Girls who had not transitioned with peer group often experienced being teased and feeling left out. Shyness, social anxiety, and reduced self-esteem generally relate to the premature ovarian failure and fertility issues.
Since only a small percentage of girls will go into puberty without intervention, it is essential for the patient to discuss treatment options with their provider to coincide treatment in addition to growth hormone.
Puberty is a series of well defined stages controlled by connections between the hypothalamus, pituitary, and ovaries
• Spontaneous puberty can occur in Turner Syndrome
• More commonly, hormonal induction of puberty is required
• Treatment should be individualized for every girl
• Consideration of height and psychosocial benefits are critical in the decision-making process
• The likelihood of early ovarian failure should be discussed even with women who undergo spontaneous puberty and menarche for timely evaluation and intervention
Sexual Development Disorders
Connecticut Children’s Medical Center Multidisciplinary Clinic for Disorders of Sexual Development (DSD) brochure
Physician’s Referral Guide Fact Sheet
Accordalliance.org DSD Online Resource
DSD Resource List Fact Sheet