Low bone mineral density at axial and appendicular sites in amenorrheic athletes

Amenorrheic athletes have low axial bone-mineral density (BMD, g.cm-2). We compared 12 amenorrheic and 9 eumenorrheic women athletes to determine whether athletes with amenorrhea have lower BMD in other skeletal regions, including weight-bearing lower limbs. BMD was measured by dual energy x-ray and single photon absorptiometry. Both groups had similar age, body mass, and exercise quantity. Women with amenorrhea missed 86.3 +/- 58.3 menstrual periods since menarche. BMD was lower in the amenorrheic vs eumenorrheic subjects for the lumbar spine (0.928 +/- 0.056 vs 1.050 +/- 0.110, P < 0.005), whole body (1.032 +/- 0.05 vs 1.09 +/- 0.06, P < 0.05), most regions of the whole body (P < 0.05-0.001), all areas of the proximal femur (P < 0.005), and at the femoral mid-shaft (1.333 +/- 0.109 vs 1.491 +/- 0.088, P < 0.005). No significant differences were detected at the mid-radius and tibial shaft. The best predictors of BMD were years of regular menstruation for lumbar spine; and years of amenorrhea for hip, femoral mid-shaft, and whole body. We conclude that low BMD in athletes with amenorrhea is not limited to the axial skeleton but is also present in other regions including appendicular weight-bearing bones.