Aims: Maternal systemic inflammation is associated with poorer child health outcomes. Previous studies have reported associations between maternal dietary inflammatory index (DII®) and either child bone density (BMD) or lean mass. However, no study has examined whether these associations are independent of one another. Thus, we aimed to determine if, within our cohort, there were any associations between maternal DII score and child BMD and lean mass, and whether associations with BMD remained independent of lean mass.
Methods: Data were collected as part of the Vitamin D in Pregnancy study. There were 186 mother-child pairs that had complete data. Energy-adjusted maternal DII (E-DIITM) score was calculated from the Cancer Council Food Frequency Questionnaire during early (<16 weeks) and late (28-32 weeks) gestation. Total body less head (TBLH) and spine BMD, and fat-free mass index (FFMI) were derived from dual energy X-ray absorptiometry scans at 11 years of age (Lunar).
Results: In regression modelling there was an offspring sex interaction with maternal DII in early pregnancy and BMD outcomes whereby early maternal E-DII was associated with BMD (TBLH: β -0.01[95%CI:-0.02,-0.001]; Spine: β -0.02[95%CI-0.04,-0.002]) in girls but not in boys. There were sex interactions with FFMI, whereby maternal DII (early) was associated with FFMI in girls but not boys (β -0.19[95%CI-0.36,-0.02]). No associations were detected between maternal DII in late pregnancy and child outcomes. All significant associations with early maternal E-DII were not attenuated after adjustment for maternal factors (age, smoking, socioeconomic status, BMI); however, associations with BMD were attenuated after adjustment for FFMI (BMD (TBLH: β -0.005[95%CI:-0.01,0.01]; Spine: β -0.01[95%CI-0.03,0.01]).
Conclusion: Maternal E-DII in early, but not late, pregnancy is associated with offspring BMD and lean mass at 11 years of age. Associations appear to be time and sex specific and associations with BMD could be explained by increased FFMI.