Optimizing estrogen replacement treatment in Turner syndrome

Area of Science:

• Pediatric Endocrinology
• Growth Hormone Therapy
• Hormone Replacement Therapy

Background:

• Estrogen exhibits a biphasic effect on growth: stimulatory at low doses and inhibitory at high doses.
• Optimal sex hormone replacement in girls with Turner syndrome (TS) requires careful consideration of estrogen dose, form, route, and timing, especially when co-administered with growth hormone (GH).

Purpose of the Study:

• To evaluate the efficacy of a low-dose, systemically administered estradiol regimen for enhancing final height in girls with Turner syndrome (TS) undergoing growth hormone (GH) therapy.

Main Methods:

• A preliminary analysis involved 9 girls with TS treated with GH for ≥6 months.
• Depot estradiol was administered monthly intramuscularly, starting at 0.2 mg and escalating to 0.8 mg over time.
• Results were compared to a matched group of 37 TS patients receiving routine estrogen treatment alongside GH therapy.

Main Results:

• Patients treated with depot estradiol showed a 2.6 cm greater height gain over 2 years compared to those on routine estrogen.
• Bone age progression in the depot estradiol group was proportional to chronological age, indicating a potential increase in predicted adult height.

Conclusions:

• Very low doses of systemic estradiol, used to induce puberty before age 15 in girls with TS on GH therapy, can lead to increased final heights.
• This optimized estrogen replacement strategy offers a promising alternative to routine estrogen therapy for improving growth outcomes in Turner syndrome.