ESPE Abstracts

Background and aims: Insight into which determinants associate with bone mineral density (BMD) is needed for targeted therapy in children with a low BMD for chronological age but also for preventive treatment on population level. Currently, studies investigating determinants of BMD in children aged <4 years are scarce. The primary aim of our study was to assess which determinants associate with BMD total body less head (BMD_TBLH) at around age 6 month, with a special focus to macro- and micronutrient composition of infant nutrition.

Methods: In 287 healthy term-born children of the Sophia Pluto birth cohort, we determined anthropometrics, and BMD_TBLH and body composition by Dual-energy-X-ray Absorptiometry (DXA) at age 6 months. Information regarding child’s characteristics and feeding type were collected. Macronutrients (protein, fat, carbohydrate) composition (g/100ml) were determined in breastmilk samples collected at infants’ age of 3 months from mothers who had been exclusively breastfeeding (EBF) their child (n = 87), and results were compared with formula feeding (n = 88). Regression analyses were performed to determine which variables associated with BMD_TBLH. Subgroup analyses were performed to investigate the association between the macronutrient composition of breastfeeding and formula feeding at age 3 months and BMD_TBLH at 6 months.

Results: At age 6 months, median BMD_TBLH was 0.287 g/cm² in boys and 0.283 g/cm² in girls (P = 0.32). Age (β = 0.14, P = 0.02), fat mass standard deviation score (SDS) (β=0.13, P = 0.02) and fat-free mass SDS (β=0.46, P <0.001), corrected for height SDS, were positively associated with BMD_TBLH. Subgroup analyses showed that, corrected for age, fat mass and fat-free mass, protein content was positively associated (β=0.22, P = 0.02) and carbohydrate tended to be negatively associated (β=-0.14, P = 0.13) with BMD_TBLH at age 6 months in children who received EBF for 3 months, but this was not found in children who received EFF. Fat was not associated with BMD_TBLH, independent of feeding type.

Conclusion: Fat-free mass SDS, corrected for height SDS, was the strongest determinant of BMD_TBLH at age 6 months. The amount of protein in breastmilk at age 3 months was positively associated with BMD_TBLH, this might suggest that protein-rich formula could serve as treatment for infants with low BMD.