Serum procollagen type 1 N propeptide: A novel diagnostic test for diabetic foot osteomyelitis – A case–control study

Abstract

Background: Te objective of the study was to determine whether serum levels of procollagen type 1 N propeptide (P1NP), a bone formation turnover marker, di?ers between diabetic foot ulcer with osteomyelitis (DFO) and diabetic foot ulcers without osteomyelitis serving as controls. It was also aimed to assess the usefulness of P1NP in diagnosing DFO compared to other common in?ammatory markers. Materials and Methods: A case–control study was designed comparing the aforementioned groups. Patients were classifed as osteomyelitis and controls based on the  International Working Group diagnostic criteria. Serum P1NP and three
other in?ammatory markers, namely, C?reactive protein (CRP), white blood cells (WBC), and platelets were analyzed on patients with DFO and  ontrols. Results: Te mean serum P1NP levels were signifcantly higher in the DFO group (n: 16), 10.5 ± 5.2 (ng/ml), than the control group (n: 11) 3.1 ± 2.8 (ng/ml), P = 0.001. P1NP showed the highest sensitivity/specifcity  86.7%/80% compared to 70.6%/80%, 56.2%/45.4%, and 50%/37% for CRP, WBC and platelets, respectively. Receiver operator characteristic curves showed the best value of area under the curve of 0.9 for P1NP compared to 0.85, 0.54, and 0.46 for CRP, WBC, and platelets. Conclusion: We found marked elevation of serum P1NP in diabetic foot ulcer with bone infection with potential value in using it to diagnose DFO.