ANXA1 and Osteopenia: Annexin A1 exhibited the best trade-off of sensitivity against specificity of the three possible markers for all participants when nonosteoporotic controls were compared with osteoporosis (area under the curve, 0.893), with osteopenia (area under the curve, 0.805), or with osteopenia and osteoporosis combined (area under the curve, 0.833) or when only females over the age of 50 were included (areas under the curves, 0.809, 0.747, and 0.767, respectively).