Adriëtte Oostvogels

Associations with maternal pBMI Few studies have examined the associations of maternal pBMI with all individual and combined measures of the metabolic components in childhood. In studies investigating individual components maternal obesity has been linked to increased obesity, 2,5,6 insulin resistance, 5,6 blood pressure 6,7 and an adverse lipid profile 6,8 in the offspring. We confirmed these earlier found associations with body size and blood pressure and, in addition we are the first study to assess the association between maternal pBMI and an increased overall metabolic score. However we were unable to show associations with fasting glucose and TG. These adverse outcomes might arise at a later age, since the age of offspring in our study is young compared with other studies. Associations with postnatal growth Except for Corvalan et al. 27 few studies examined the association of postnatal growth with all individual metabolic components and a combined measure in childhood. In studies with individual adverse components early postnatal growth was associated with BMI, 9,20 SBP 10 and insulin resistance 11 in childhood. In this study we also observed associations between postnatal growth with WHtR and the metabolic score at age 5-6 years, moreover we showed that accelerated weight gain between 1-3 months increased glucose levels in childhood. Although we hypothesized that we would find more effects for postnatal weight-for-length gain than for weight gain, being a better measure for adiposity, 13 we only found an association between postnatal weight gain and childhood glucose values. The effect for weight-for-length gain might be weakened because weight gain is usually attended by length gain. When analysing the Dutch group (n=1046) separately, we found in essence the same results, except for weight-for-length gain which was more strongly associated with offspring’s glucose values in the Dutch population than in the multi-ethnic population. This indicates that our results are robust, but heterogeneity might be introduced by using our multi-ethnic population resulting in residual confounding. We favoured the use of our multi-ethnic population over our homogeneous Dutch population for the generalizability of our study results. Mediating and moderating role of postnatal growth Our analyses suggest that postnatal growth does not mediate the association between maternal pBMI and the metabolic components, because no association was found between maternal pBMI and postnatal weight or weight-for-length gain in this 188 Chapter 7