A team from Regensburg, Germany, investigated screening for osteoporosis in patients with inflammatory bowel disease (IBD).
They conducted a prospective study of bone mineral density and biochemical markers of bone metabolism, like osteocalcin and urinary N-telopeptides.
In 72 IBD patients, they evaluated if one of these markers detects osteoporosis.
In addition, bone mineral density and N-telopeptides were analyzed retrospectively, in a second series of 93 IBD patients. This was in order to assess predictive values found in the first patient group in an independent sample.
Multiple linear regression showed that N-telopeptides and total white blood cell count correlated negatively with the bone mineral density of the lumbar spine.
Furthermore, only N-telopeptides correlated negatively with the bone mineral density of the femoral neck.
| N-telopeptides negatively correlated with lumbar spine and femoral neck BMD.
| European Journal of Gastroenterology & Hepatology |
N-telopeptide concentrations of > 40 nmol and > 30 nmol N-telopeptides/mmol creatinine were chosen as cut-off values to exclude osteoporosis at the lumbar spine and femoral neck, respectively.
Using these cut-off values, the researchers found a negative predictive value of 100% and a positive predictive value of 38% for osteoporosis at the lumbar spine, in the first group. These corresponding values were 100% and 28% for the femoral neck.
In the second, independent group of patients, negative predictive values of 95% and 96%, and positive predictive values of 16% and 23%, were identified for the lumbar spine and femoral neck, respectively.
Nicole Bregenzer, of the University of Regensburg, concluded on behalf of her group, "Our data suggest that N-telopeptide levels could be used as a tool for the screening of osteoporosis and for selecting those IBD patients where bone mineral density measurement is indicated."
In an accompanying Leading Article, Juliet E. Compston, of the University of Cambridge School of Clinical Medicine, Cambridge, England, commented, "These findings raise the possibility that N-telopeptide levels could be used to select IBD patients in whom bone densitometry is required."
"However, the value of this approach in predicting fracture risk remains unproven.
"Moreover, the relative contributions of clinical risk factors, biochemical markers of bone turnover, and bone mineral density measurements to fracture risk in patients with IBD require further study," she concluded.