Aims: To assess factors associated with excess rates of fractures in women with Turner's syndrome (TS).
Outcome measures: History of bone fracture and treatment with oestrogen, growth hormone (GH), oxandrolone and thyroxine, anthropometry, blood measurements of calcium, vitamin D (25-hydroxycholecalciferol), parathyroid hormone and karyotype, pure tone audiometry and spinal bone mineral density (BMD).
Results: One hundred and seventy-seven consecutive women with TS, aged 19-60 years, were interviewed with respect to bone fracture history. BMD and hearing information were recorded from the medical notes. Karyotype was available in 94% of patients (55% monosomy 45X, 45% other X chromosome defects and mosaicism). Subjects had a mean (SD) height of 1.47 (0.07) m and BMI 25.8 (5.2) kg/m(2). The prevalence of fractures was 32% and hearing impairment 84% (18% conductive and 67% sensorineual, of whom 32% and 16%, respectively, used hearing aids). BMD T score was < -1 in 55% of women and < -2.5 in 9%. Fracture rates were higher in subjects with a combination of low BMD and hearing impairment (44% in conductive and 35% in sensorineural) than those with high BMD and normal hearing (25%) (P < 0.05). The duration of oestrogen deficiency was also longer in the former groups (P < 0.05). Multivariate logistic regression analysis (adjusted for age and karyotype) showed that increased risk of fracture was independently associated with low BMD (OR 3.2, 95% CI: 1.0 to10.5) and hearing impairment (conductive: OR 4.8, 95% CI: 1.2 to18.9, sensorineural: OR 3.6, 95% CI: 1.1 to11.8). Subgroup analysis showed that hearing impairment was associated with fractures only in those with low BMD (OR 9.0, 95% CI: 1.1-73.4). Further adjustments for weight, height, BMI, calcium levels, vitamin D concentrations, thyroxine use and oestrogen deficiency, previous use of oxandrolone or GH did not alter these relationships.
Conclusions: Women with TS who have low BMD and hearing impairment, particularly a conductive type, are at increased risk of bone fractures.