Biochemical bone markers for early detection of osteopaenia of prematurity

Abstract

Osteopaenia of prematurity (OOP) imposes the risk of fractures and growth failure to premature infants. Studies have investigated the validity of biochemical markers of osteopaenia but till date it is not established. So,this study was intended to examine the diagnostic performance of biochemical markers in early detection of osteopaenia of prematurity. This prospective study was conducted in the Neonatal Intensive Care Unit (NICU), Department of Neonatology, Bangabandhu Sheikh Mujib Medical Universityduring June 2013 to February 2014.A total of 100 premature infants with gestational age ≤ 34 weeks were consecutively included over 9 months period. Serum alkaline phosphatase, serum calcium and serum inorganic phosphates were measured from 1 week of chronological age until corrected term age. At corrected term age, radiologic examination was done for the assessment of osteopaenia. Of the enrolled infants, 36/78 (46%) developed radiological evidence of osteopaenia. Serum inorganic phosphate level was significantly less in osteopaenic infants than non-osteopaenic infants throughoutfirst two months of life (p<0.001). The area under ROC curve for serum inorganic phosphate was 85% (p=0.001). If the cut off value of serum inorganic phosphate was set at 3.6 mg/dl, then a sensitivity of 86% and a specificity of 49% were obtained.Low serum inorganic phosphate at 3 weeks of life can be used as a marker for earlydetection of osteopaenia of prematurity.