Osteoporosis in Turner's syndrome and other forms of primary amenorrhoea

OBJECTIVE Osteopenia in Turner's syndrome is well recognized. This study is aimed to elucidate whether this is an intrinsic feature of the disorder, or is a nonspecific feature resulting from oestrogen deficiency. DESIGN Comparison of bone mineral density and fracture rate in Turner's patients and in 46,XX women with equivalent oestrogen deprivation from other causes. SUBJECTS One hundred and twenty women in the reproductive age range (16-45 years): 40 with Turner's syndrome, 40 with other forms of primary amenorrhoea, and 40 healthy controls matched to patients for duration of oestrogen usage. MEASUREMENTS Measurement of bone mineral density in the lumbar spine (and femoral neck in some subjects) by dual-energy X-ray absorptiometry, and reported history of fracture. RESULTS Vertebral bone mineral density was similar in women with Turner's syndrome (mean 0.84, SD 0.11 g/cm(2)) and those with other causes of primary amenorrhoea (mean 0.81, SD 0.11 g/cm(2); P = 0.26). Both groups had severe osteopenia compared with healthy controls (mean 1.06, SD 0.09 g/cm(2), P < 0.0005, confirmed after correction for height and weight). Fractures had been sustained by 45% (10/22) of Turner's patients for whom information was available, a high frequency compared with controls (P = 0.014); half of these were at 'osteoporotic' sites of fracture (wrist, vertebra, femoral neck). CONCLUSION Osteopenia in Turner's syndrome is not an intrinsic feature specific to this disorder, but results from extreme oestrogen deprivation. Early treatment with oestrogen is therefore recommended.