Objectives: To assess the long-term impact of prematurity on bone and body composition by using Dual-energy X-ray absorptiometry (DXA).
Methods: DXA scans were performed in 100 preterm (PT) (n=42F, n=58M, mean weeksgestation 31.5±2.6; range 26−36) and 51 born at term (BT) healthy infants (n=28F, n=23M). DXA measures of total body and lumbar spine mineral density (TB/L1-L4 BMD, g/cm2 and Z-score), bone mineral content (TB-BMC, g), fat mass (FM%, kg) and free-fat mass (FFM, kg) were obtained. Height (SDS), BMI (S.D.S.) and 25-Hydroxyvitamin D, PTH, CTx, BAP were measured. Twenty-seven subjects (n=21PT, n=6BT) were born IUGR, 55 PT underwent antenatal steroids and 43 (n=20PT, n=23BT) were breastfed.
Results: Median age at study was 6.7±1.3yrs (range 5−9). There were no significant differences in anthropometrics, DXA and biochemical markers between PT and BT children. However, positive correlations were found between gestational age or birth weight and BMC, BMD, BMD Z-score both at TB and L1L4. Steroids and breastfeeding were negatively (−0.16<rs<−0.39; all Ps<0.04) and positively (0.18<rs<0.29; all Ps<0.02), respectively, associated with all bone parameters. IUGR (17.9%) were shorter with significantly lower DXA BM (all Ps<0.05). In multiple regression analyses gestational age was predictive of BM (4.8%) in PT but not in BT children.
Conclusions: DXA and biochemical measurements represent a promising diagnostic tool for bone assessment in preterm children after the age of 5 years. Breastfeeding is associated with better bone health while gestational age, IUGR and antenatal steroids might represent long-lasting risk factors.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology