Impact of Hormonal Replacement Therapy on Bone Mineral Density in Premature Ovarian Insufficiency Patients

Premature ovarian insufficiency (POI) is a type of hypergonadotropic hypogonadism caused by impaired ovarian function before the age of 40. Due to the hypoestrogenism, women with POI experience a variety of health complications, including an increased risk of bone mineral density loss and developing osteopenia and osteoporosis, which poses an important problem for public health. Purpose: The aim of this study was to evaluate and compare the values of bone mineral density (BMD), T-score and Z-score within the lumbar spine (L1-L4) using the dual energy X-ray absorptiometry method. The dual-energy X-ray absorptiometry (DXA) scans described in this original prospective article were performed at the time of POI diagnosis and after treatment with sequential hormone replacement therapy (HRT). Materials and methods: This study included 132 patients with a mean age of 31.86 ± 7.75 years who had been diagnosed with idiopathic POI. The control group consisted of 17 healthy women with regular menstrual cycles, with a mean age of 23.21 ± 5.86 years. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17-estradiol (E2), prolactin (PRL), testosterone (T), dehydroepiandrosterone sulfate (DHEA-S), thyroid-stimulating hormone (TSH), free thyroxine (fT4), insulin, and fasting serum glucose were measured. Lumbar spine (L1-L4) BMD was assessed by means of dual-energy X-ray absorptiometry. DXA scans were performed at the time of diagnosis and following treatment with sequential hormone replacement therapy (HRT) comprised of daily oral 2 mg 17-β-estradiol and 10 mg dydrogesterone. The mean time of observation was 3 ± 2 years. Results: Patients in the POI group presented with characteristic hypergonadotropic hypogonadism. They had a significantly decreased mean lumbar spine BMD when compared to healthy controls (1.088 ± 0.14 g/cm²) vs. 1.150 ± 0.30 g/cm²) (p = 0.04) as well as a decreased T-score (0.75 ± 1.167 vs. -0.144 ± 0.82) (p = 003). There was a significant increase in BMD (1.088 ± 0.14 vs. 1.109 ± 0.14; p < 0.001), T-score (-0.75 ± 1.17 vs. -0.59 ± 1.22; p < 0.001), and Z-score (-0.75 ± 1.12 vs. -0.49 ± 1.11; p < 0.001) after the implementation of HRT when compared to pre-treatment results. Conclusions: In conclusion, this study has demonstrated that patients with POI often have decreased bone mineral density and that the implementation of HRT has a significant and positive influence on bone mass. The implementation of full-dose HRT and monitoring of bone status is particularly important in these patients.