Bone density in TGD AFAB individuals is comparable to that in their peers prior to GAHT and BO, but those subjects who underwent BO had a reduced Z-score at LS, FN, and TH after 5 years and at LS after 10 years of GAHT.
Key Findings
Results
At baseline, low bone density was found in a small proportion of TGD AFAB individuals, primarily at the lumbar spine.
Low bone density (Z-score < -2.0) was found in 2.5% (6/243) of subjects for lumbar spine (LS) at baseline.
Total hip (TH) and femoral neck (FN) Z-scores were within the normal female range at baseline.
Laboratory tests (hormonal and bone metabolism parameters) were also within the normal female range at baseline.
243 TGD AFAB people were included in the study overall.
Results
Physical activity was associated with significantly higher lumbar spine bone mineral density and Z-scores at baseline.
After stratifying by physical activity, the physically active group showed significantly higher LS BMD and Z-scores (p ≤ 0.05).
This comparison was made at baseline prior to GAHT initiation.
Results
After 5 years of GAHT, significant reductions in Z-scores were detected at all three bone sites.
A significant reduction in LS Z-scores was detected after 5 years (p ≤ 0.05).
A significant reduction in TH Z-scores was detected after 5 years (p ≤ 0.001).
A significant reduction in FN Z-scores was detected after 5 years (p ≤ 0.01).
75 subjects had completed data for 5 years of GAHT.
Significant reduction in Z-scores at all three bone sites was observed only in the subgroup that had undergone bilateral oophorectomy (BO).
Results
Bilateral oophorectomy was associated with significantly lower estradiol levels and greater bone density reductions after 5 years of GAHT.
After 5 years of GAHT, estradiol levels were significantly decreased compared to baseline (p ≤ 0.001).
Significantly higher estradiol levels were detected in the 5-year no-BO subgroup compared to the 5-year BO subgroup (p ≤ 0.001).
Significant reduction in Z-scores at all three bone sites (LS, FN, TH) was observed only in the subgroup that had undergone BO.
No significant reduction in Z-scores across all three sites was observed in the subgroup that had not undergone BO after 5 years.
Results
After 10 years of GAHT, significant reductions in lumbar spine and total hip Z-scores were observed, along with decreased estradiol levels.
A significant reduction in LS and TH Z-scores was observed after 10 years of GAHT.
Estradiol levels were significantly decreased compared to baseline at 10 years (p ≤ 0.01).
Only 19 subjects had completed data for 10 years of GAHT.
At 10 years, the BO subgroup showed significant reduction at LS.
Methods
The study was a single-center, longitudinal study with retrospectively collected data enrolling GAHT-naïve TGD AFAB individuals.
Participants underwent dual-energy X-ray absorptiometry (DXA) scans and laboratory tests at baseline and after 5 and 10 years of GAHT.
Laboratory tests included hormonal and bone metabolism parameters.
Testosterone is the basis of GAHT for TGD AFAB individuals.
Gender-affirming surgery options considered included hysterectomy, bilateral salpingectomy, bilateral oophorectomy, thorax masculinization, and phalloplasty.
243 TGD AFAB people were included, with 75 having complete 5-year data and 19 having complete 10-year data.
Sanna E, Lami A, Giacomelli G, Alvisi S, Paccapelo A, Seracchioli R, et al.. (2024). Bone health in transgender assigned female at birth people: effects of gender-affirming hormone therapy and gonadectomy.. Frontiers in endocrinology. https://doi.org/10.3389/fendo.2024.1416121