Starting age of oestrogen-progestin therapy is negatively associated with bone mineral density in young adults with Turner syndrome independent of age and body mass index.

ABSTRACT

OBJECTIVE: Osteoporosis is an important health issue in patients with Turner syndrome (TS), and oestrogen sufficiency has been implicated in increased bone mineral density (BMD); however, the impact of the starting age of hormone replacement therapy (HRT) on bone mineral density remains unclear, particularly during young adulthood. DESIGN: A retrospective study from three tertiary care hospitals in Japan. PATIENTS One hundred and three patients with TS aged between 18 and 30 years of age who underwent dual-energy X-ray absorptiometry. MEASUREMENTS Anthropometric parameters, lumbar bone mineral density (L-BMD), including areal BMD (aBMD) and volumetric BMD (vBMD), karyotypes, the presence of spontaneous menarche, the starting ages of oestrogen replacement therapy (ERT) and oestrogen-progestin therapy (EPT), and the duration between starting ages of oestrogen replacement therapy and oestrogen-progestin therapy were investigated. vBMD was calculated based on the Kröger method. RESULTS: aBMD was lower in young adults with TS than in an age-matched reference population. L-BMD positively correlated with weight and body mass index (BMI). L-BMD was higher in subjects with spontaneous menarche (N = 22) than in those without. A dose escalation regimen of oestrogen replacement therapy was used in 84% of subjects without spontaneous menarche (N = 81). The starting age of oestrogen replacement therapy and the duration between the starting ages of oestrogen replacement therapy and oestrogen-progestin therapy negatively and independently correlated with aBMD, but not with vBMD, after adjustment with age and BMI. The starting age of oestrogen-progestin therapy negatively correlated with L-BMD independent of age and BMI. CONCLUSIONS: Early introduction of hormone replacement therapy, particularly oestrogen-progestin therapy, is important to accrue better L-BMD in young adults with TS.