A study of longitudinal measurements in the screening for osteopenia of prematurity

Abstract

Aim: To investigate the biochemical parameters and bone “speed of sound” (SoS) values used in the screening for osteopenia of prematurity (OP). Material and Methods: Serial measurements of tibial bone SoS and concomitant serum calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels of preterm infants in postnatal week 1, 3, and 6 were studied retrospectively. Results: Fifty premature infants ≤ 35 weeks of gestational age were included in the study. A positive correlation was detected between serum P levels and SoS values at 1st and 6th week (r = 0.55, P = 0.0001 and Rho = 0.67, P = 0.0001, respectively). SoS values in postnatal week 3 were correlated with SoS values in week 1 and week 6 (Rho = 0.67, P = 0.0001 and Rho = 0.65, P = 0.0001, respectively). Serum Ca, P, and ALP levels measured in postnatal week 1 and 3 were not predictive of the subsequent risk of osteopenia. The SoS value in week 3 (≤ 2940 m/s) was predictive of the risk of osteopenia in week 6, with sensitivity of 85% and specify of 73% (Area under the curve [AUC] = 0.80, p = 0.001). Conclusions: Serum P levels were correlated with bone SoS values. Bone SoS measurements in postnatal week 3 rather than biochemical parameters was predictive of the risk of osteopenia in postnatal week 6. For this reason, screening for osteopenia can be started at postnatal week 3 in newborn units where quantitative ultrasonography (QUS) is used.