[Relationship between bone turnover markers and bone sound of speed in appropriate-for-gestational-age neonates].

OBJECTIVE

To investigate the correlation of gestational age (GA) with carboxyterminal propeptide of type I procollagen (PICP), deoxypyridinoline (DPD), and bone sound of speed (SOS) in appropriate-for-gestational-age (AGA) neonates, as well as the relationship between bone turnover markers and bone SOS.

METHODS

Sixty-five AGA neonates were included in the study. The neonates were divided into three groups: preterm infant (GA ≤3 4 weeks, 14 cases), late preterm infant (34 weeks<GA<37 weeks, 13 cases), and full-term infant (GA ≥ 37 weeks, 38 cases). Birth weight and length were measured in all cases, and Ponderal index (PI) was used to estimate their nutritional status. Venous blood was collected within 7 days after birth to measure blood PICP concentration. Urine was collected to measure urinary DPD and creatinine (Cr) levels. Omnisense 7000P ultrasound bone sonometer was applied to measure the SOS of the left tibia in all cases within 7 days after birth.

RESULTS

There were significant differences in GA (F=140.199, P<0.001), birth weight (F=47.042, P<0.001), birth length (F=46.877, P<0.001), and PI (F=11.898, P<0.001) between the three groups; the higher the GA, the higher the birth weigh, birth length, and PI. There were significant differences in PICP (F=30.384, P<0.001), DPD/Cr (F=21.761, P<0.001), and SOS (F=20.052, P<0.001) between the three groups; the higher the GA, the lower the PICP and DPD/Cr and the higher the bone SOS. PICP and DPD/Cr were negatively correlated with GA, birth weight and bone SOS (P<0.01), while bone SOS was positively correlated with GA and birth weight (P<0.01), which still held true after adjustment for GA and birth weight.

CONCLUSIONS

Among AGA neonates, bone turnover markers are negatively correlated with GA, birth weight and bone SOS. High bone turnover is bad for bone health in AGA neonates.