Historically, evaluation of bone mineral density through conventional means (urinary OH-PRO excretion rates, serum hydroxyproline levels, and bone density scans) are time consuming and have not been entirely accurate in predicting hip and vertebral fractures (Engelen, Com, & Deutz, 2014). This is because these tests take an overall look at hydroxyproline levels and whole body density scans. The urinary test required a 24 hour collection period and the serum test required a collagen-free diet prior to testing.
This study evaluates the infusion of a stable isotope to measure actual production of hydroxyproline at the time of infusion and is not affected by acute changes in serum hydroxyproline and does not require a collagen-free diet at the time of testing (Engelen, Com, & Deutz, 2014). Fifteen cystic fibrosis patients and seventeen health patients were used in the study showed an accurate assessment of whole-body collagen breakdown as compared with previous methods of testing without the time consuming process or restrictive diets of the