Normalization of bone density in a previously amenorrheic runner with osteoporosis

To examine changes in bone mineral density (BMD) and bone mineral content (BMC) in relation to pharmacological and nutritional interventions in a distance runner diagnosed with the female athlete triad of disordered eating, amenorrhea, and osteoporosis.

BMD of the lumbar spine (L2-L4) and total proximal femur were measured from ages 22.9 to 30.8 yr using dual x-ray absorptiometry (DXA).

At age 22.9, the patient presented with primary amenorrhea, low body weight (BMI: 15.8 kg.m(-2)), and low BMD in the spine (74% of normal, T score: -2.50) and hip (80% of normal, T score: -1.54). For the next 2 yr, the patient took oral contraceptives to induce menses, but continued to maintain a low weight. Her BMD remained unchanged. At age 25.1 yr, she decided to gain weight and improve her nutrition, resulting in small increases in spinal BMD (+1.1%), hip BMD (+1.6%), and total body BMC (+7.6%) in 4 months. From ages 25.4 to 30.8 yr, the patient continued to gain weight, eventually reaching a healthy BMI of 21.3 kg.m(-2); correspondingly, since baseline, her BMD had increased 25.5% in the spine and 19.5% in the hip, bringing her BMD to within normal values (spine: 94% of normal, hip: 96% of normal).

This case illustrates that even if skeletal development is interrupted in adolescence, there is still the potential for "catch-up" in BMD well into the third decade of life. Reversal of large bone density deficits in this patient can be attributed to improved nutrition and weight gain but not to hormone replacement.