Adriëtte Oostvogels

ABSTRACT Context: Maternal prepregnancy body mass index (pBMI) and offspring’s accelerated postnatal growth have adverse consequences for later cardiometabolic health, but it is unknown how these two factors interact. Objective: To assess the association between maternal pBMI and offspring’s metabolic profile at age 5-6 years and determine the role (independent/ mediating/moderating) of offspring’s postnatal growth in this association. Design/Participants: 1459 mother-child pairs from the prospective ABCD-study with known maternal pBMI, offspring’s postnatal growth (weight and weight- for-length gain) between age 1-3 months (Δ SDS-score). Main outcome measures: Offspring’s metabolic components at age 5-6 years: waist-to-height-ratio (WHtR), systolic/diastolic blood pressure (SBP/DBP), fasting glucose, triglyceride and HDL-cholesterol values, analysed individually (z-scores) and combined (sum z-scores; metabolic score). Results: Maternal pBMI was positively associated with offspring’s WHtR ( β =0.025; 95%CI:0.010-0.039), SBP ( β =0.020; 95%CI:0.005-0.0035), DBP ( β =0.016; 95%CI:0.000-0.031) and metabolic score ( β =0.078; 95%CI:0.039-0.118) after adjusting. Adding postnatal growth had no relevant impact on these effect sizes. Postnatal weight gain was independently associated with WHtR ( β =0.199; 95%CI:0.097-0.300), fasting glucose values ( β =0.117; 95%CI:0.008-0.227) and metabolic score ( β =0.405; 95%CI:0.128-0.682); weight-for-length gain with WHtR ( β =0.145; 95%CI:0.080-0.211) and metabolic score ( β =0.301; 95%CI:0.125-0.477). An interaction between maternal pBMI and postnatal weight gain was present in the association with SBP (p=0.021) and metabolic score (p=0.047), and between maternal pBMI and postnatal weight-for-length gain in the association with triglycerides (p=0.022) and metabolic score (p=0.042). Conclusions: Both high maternal pBMI and postnatal accelerated growth are associated with adverse metabolic components in early childhood. No evidence was found for a mediating role of postnatal growth, the combination of high maternal pBMI and postnatal accelerated growth amplified individual effects. 176 Chapter 7