Long Term Effects of Oral Versus Transdermal Estrogen Replacement Therapy in Turner Syndrome

This 14-month, phase IV, randomized controlled crossover trial aims to compare the effects of oral versus transdermal estrogen replacement therapy (ERT) in women with Turner syndrome (TS). The study's objectives are to clarify endocrine, metabolic, cardiovascular, and thromboembolic risk factors in TS after a wash-out period without estrogen (E2) treatment; compare the effects of oral versus transdermal (TD) ERT regimens; and examine the long-term effects of E2 administration via these two routes. The study involves 50 TS women aged 18-50 years and 50 control participants. TS participants are randomized to receive either oral or TD ERT for six months, followed by crossover to the alternate treatment for another six months. Prior to randomization, any existing ERT will be discontinued for a 1-month washout period. A second 1-month washout period will occur between the two 6-month treatment phases. Laboratory analyses and clinical investigations are performed after the first wash-out period, after the first six months of treatment, and after the last six months of treatment. We anticipate that this study may provide a basis for new and improved recommendations for sex hormone replacement therapy in TS.