Background: Bone growth and mineralization during childhood are now recognized as important for bone health in adulthood, leading to renewed interest in identifying modifiable factors that impact bone mineral density (BMD) in childhood. Emerging data suggest that duration of breastfeeding may affect BMD in later childhood and adult life. However, such data are sparse and inconsistent.
Objectives: This study examined the relationship between the duration of breastfeeding and BMD in young Asian children.
Methods: 149 healthy children (73 girls, 76 boys; 81 Chinese, 45 Malay and 23 Indian) from the Growing up in Singapore Towards healthy Outcomes (GUSTO) mother-offspring cohort participated in this study. Children born from IVF pregnancies and twins were excluded. Duration of any breastfeeding (BF) regardless of exclusivity was categorized into 3 groups; never/short duration (never breastfed or breastfed till 3 months), intermediate duration (breastfed >36 months) and longer duration (breastfed >6 months). Dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine were performed (Hologic QDR discovery scanner) at age 6 years. Lumbar spine bone mineral apparent density (BMAD), i.e. volumetric BMD, was estimated from bone mineral content and bone area from L2-L4 (BMC/Ap3/2). BMAD, areal BMD (aBMD), standard deviation scores for BMAD (ZL-BMAD) and aBMD (ZaBMD) were used as outcomes. Co-variates related to childs BMD were adjusted for in linear regression analyses: ethnicity, maternal pre-pregnancy BMI, smoking, physical activity, plasma 25(OH) vitamin D status, gestational diabetes, and gestational age, childs sex and weight on the day of DXA scan.
Results: Compared to children who had never/short BF duration (N=67), those who were breastfed longer (N=53) had significantly lower ZL-BMAD and BMAD, b (95%CI) −0.356 (−0.694, −0.018), P=0.039 and −0.005 (−0.0089, −0.0002) g/cm3, P=0.039, respectively. The association between duration of BF and ZL-BMAD was significant only for boys −0.565 (1.079, −0.052) g/cm3 in a stratified analysis. The observed associations were independent of level of childs adiposity. However, these associations were non-significant when using lumbar spine aBMD and ZaBMD,, highlighting the importance of considering bone size when assessing BMD in children. The ZL-BMAD of children were similar between children who had short and intermediate BF (N=29) duration.
Conclusion: Duration of breastfeeding may have a long term impact on bone mass in young children. As society advocates for longer duration of breastfeeding, it may be important to determine interventions to enhance bone development in infants through a longer duration of breastfeeding.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology