Several techniques are utilized for measurement of bone density. Generally, a decrease in bone density is caused by different factors like diseases, ageing etc. Therefore, a bone density graph with age and bone density as its two variables exhibits the effect of age on the bone density. Moreover, bone density tends to decrease with an increase in the age of individual.
Bone density tests are generally carried out for measuring bone density at your spine and hip. A DXA test measures the bone density of an individual and compares it with an established standard or norm which enables the calculation of your score. Despite the fact that a bone density test need not be completely accurate, DXA test remains an important predictor. It helps in detecting the susceptibility of an individual to fracture.
A bone density graph can also be plotted to highlight the deviation of your bone density from the established standard. Generally, the results of your DXA tests are compared with that of the peak or ideal bone density of an individual in the same age group. This helps in giving you a T-score. Let us understand how the graph is studied.
A score of 0 indicates that the bone density of the individual is equal to the standard for an average young adult. The difference between the bone density of an individual and that of a healthy young adult is measured in terms of units known as standard deviations. Therefore, if the standard deviation is below zero (i.e. negative standard deviation), it indicates a lower bone density and higher risk of fracture.