There is an increased risk of osteoporosis associated with KS/XXY, but the reasons for this are not fully understood.
Certainly low bone density is associated with low testosterone – and oestrogen- levels. However some studies have shown that reduced bone density also occurs in KS/XXY adults who have testosterone levels in the normal range.
There is some research which suggests that low bone density might also be an effect of the extra chromosome and that this might explain why testosterone replacement therapy is often not effective in improving bone density in KS/XXY.
Most endocrinologists feel that patients with KS/XXY should have bone density scans at some point during their assessment, although if testosterone is started early before levels become too low, this may not be strictly necessary. There is no automatic requirement for bone density assessment in patients with KS/XXY.
If the bone density is shown to within the normal range, the scan should be repeated every 5 to 10 years. If there are signs of osteopenia or osteoporosis, scans should be carried out every two years.