ESPE Abstracts (2015) 84 P-2-237

Intrauterine Growth Restriction, Gestational Age, Steroidal Prophylaxis and Breastfeeding Influence Bone Mass in Prepubertal Children

Annalisa Calcagnoa, Giovanna Palaa, Anna Elsa Maria Allegria, Flavia Napolia, Nadia Fratangelia, Maria Grazia Calevob, Mohamad Maghniea & Natascia Di Iorgia

aEndocrine Unit, Institute G. Gaslini, University of Genoa, Genoa, Italy; bDepartment of Epidemiology, Biostatistics and Ethical Committe, G. Gaslini Institute, Genoa, Italy

Background: The impact of prematurity on skeletal health later in life is not well elucidated.

Objective and hypotheses: In order to address this topic we evaluated bone mass in ex-preterm (PT) and born at term (BT) prepubertal children and potential risk factors for bone health.

Method: DXA measures of total body less head 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 in 100 PT (n=42 females, n=58 males, median age at study 6.7±1.3 years; gestational age-GA-range 26–36 weeks) and 51 BT (n=28 females, n=23 males) healthy children. Patients underwent height (HT SDS), BMI SDS and biochemical measures of 25OHD, PTH, CTx, BAP. 27 subjects (n=21 PT, n=6 BT) were intrauterine growth restriction (IUGR) and 55 PT underwent prenatal steroid prophylaxis. Forty-three children (n=20 PT and n=23 BT) were breastfed.

Results: There were no significant differences in anthropometrics, DXA parameters and bone markers between PT and BT children. However, positive correlations were found between GA or birth weight and BMC, BMD or BMD z-score both at the TB and the L1–L4. Steroid prophylaxis and breast feeding were respectively negatively (r’s between −0.16 and −0.39; all P’s<0.04) and positively (r’s between 0.18 and 0.29; all P’s<0.02) associated to all bone parameters. The IUGR group (17.9%) was shorter and presented significantly lower DXA bone measures (all P’s<0.05) compared to no IUGR children. Multiple regression analyses showed that, independently of age at visit, gestational age was predictive of bone mass (4.8%) in PT but not in BT children.

Conclusion: Our study demonstrates comparable bone mass parameters in PT and BT prepubertal children. Breastfeeding seems to have a positive impact on bone parameters, while gestational age, IUGR and steroid prophylaxis might represent long-lasting risk factors for bone health.