Your scans indicate that you have osteoporosis. A T-score of of less than -2.5 is classed as osteoporosis. Bone density scans compare your bone density with the bone density expected of a young healthy adult (aged 20-35) and the difference is calculated as a standard deviation score. For example, if your bone density was completely average amongst this cohort, the T-score would be 0 (-1.0 or higher is classified as the normal range). A T-score of -4.5 (in your left total hip) is therefore comparatively low. It sounds like you have a good understanding of the underlying cause of your bone loss, the treatment of which is vital to your bone health. Your doctor may also prescribe you a medication to reduce your bone turnover and therefore strengthen your bones.