Urinary N-telopeptide - A diagnostic Test or A Screening Test?

Abstract

Dual-energy X-ray absorptiometry (DEXA) scan is the gold standard investigation for diagnosing osteoporosis. The limitations of "gold standard" Dual-energy X-ray absorptiometry scan were many. The aim of this study is to find whether urinary n telopeptide can be used to diagnose osteoporosis — prospective cohort study done at Sri Ramachandra Medical University between August 2014 to December 2018. The study was done amongst the postmenopausal females and older males who came to the University hospital as an inpatient or an outpatient with suspected osteoporosis. We had 110 persons participated in the study. The patients were divided into two groups. Group I was cases whose Dexa scan was osteoporosis/osteopenia, and Group II was a control that had standard Dexa. The results from Dexa Scan are taken as the gold standard against urinary n telopeptide and a 2x2 table formed. Sensitivity, specificity, positive predictive value, likelihood ratio, area under ROC curve will be calculated. The mean value of urinary N Telopeptide in the case group was 182.5 and in control group was 49.8. The ROC curve was formed and cut off was calculated to be 71. Urinary N telopeptide can very well be considered as a diagnostic test and can’t be considered as a gold standard diagnostic test as there is some limitation as it is a bone resorption biomarker having some pre-analytical and biochemical variability which can alter the results. It can be used as an adjuvant and as a screening test along with gold standard Dexa in diagnosing osteoporosis.