Evaluation of urinary N-telopeptide of type I collagen measurements in the management of osteoporosis in clinical practice
Osteoporosis International, 08/16/2012
Baxter I et al. – Treatment monitoring using urinary N–telopeptide of type I collagen/creatinine has a place in clinical practice for the early identification of non–compliance or presence of secondary osteoporosis.Methods
- A retrospective evaluation of data collected as part of the bone turnover marker monitoring service in the Metabolic Bone Centre, Sheffield, UK.
- Treatment compliance, underlying causes of osteoporosis, change in U-NTX/creatinine (Cr) at 4 months and change in spine and hip bone mineral density (BMD) by dual-energy X-ray absorptiometry were recorded.
- Treatment response was defined as either a change in U-NTX/Cr greater than a pre-defined least significant change (LSC) of 54 % or to within the lower half of a pre-defined pre-menopausal reference interval (≤30 nM BCE/mmol Cr).
- A greater decrease in U-NTX/Cr at 4 months was associated with a greater increase in spine BMD at 18 months (r = -0.33; P < 0.0001, Pearson’s correlation).
- The mean U-NTX/Cr at 4 months was higher in patients with secondary osteoporosis compared with those with primary osteoporosis (P < 0.01, ANOVA).
- A lesser response in U-NTX/Cr increased the likelihood of secondary osteoporosis or poor treatment compliance (P = 0.04, Fisher’s exact test).
- A lack of response in U-NTX/Cr to within the lower half of the reference interval was a better indicator of secondary osteoporosis and treatment non-compliance than a change in U-NTX/Cr greater than LSC.