Infant body composition as a predictor of childhood obesity, cardiovascular risk and inflammatory markers

Abstract

Background Childhood obesity is a growing epidemic associated with increased cardiometabolic disease risk in later life. Early detection and effective intervention are critical for preventing later obesity onset. Early life plays a key role in programming the development of later diseases. While birth weight is associated with poor health outcomes in later life, early body composition (fat mass [FM] vs. fat-free mass [FFM]) may be a better predictor. Aims The overarching aim of this study was to determine whether infant body composition is associated with later adverse health risk in childhood. Specifically, this study aimed to determine: (1) whether infant body composition is a better predictor of childhood obesity/cardiovascular risk/inflammatory markers than birth weight; and if so, (2) which infant body composition factors best predict childhood obesity/cardiovascular risk/inflammatory markers; and (3) what other early life and childhood factors are associated with childhood obesity/cardiovascular risk/inflammatory markers. It was hypothesised that increased infant adiposity would be a better predictor of later adverse health risk in childhood than birth weight. Methods This was an observational follow-up study of 131 children recruited as newborns at the Royal Brisbane and Women's Hospital (RBWH) between 2007 and 2010. Body composition had previously been measured by air displacement plethysmography (ADP) using the PEA POD ® Infant Body Composition System at four different timepoints during infancy: birth, 6 weeks, 3 months and 4.5 months of age. Maternal risk factors (e.g. pre-pregnancy body mass index [BMI] and gestational diabetes mellitus [GDM]) and infant feeding information were also recorded. During the childhood follow-up visit at 8 to 11 years of age, body composition was measured by ADP using the BOD POD ® Body Composition System to assess obesity. Childhood cardiovascular risk was assessed using multiple markers: carotid intima-media thickness (cIMT), retinal vasculature parameters (mainly arteriole-to-venule ratio [AVR]) and blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]). Urine samples were collected and assayed for four inflammatory markers: tumour iii necrosis factor-α (TNF-α), interleukin-6 (IL-6), α1-acid glycoprotein (AGP) and endothelin-1 (ET-1). Potential confounding factors including diet, physical activity and socioeconomic status (SES) were also recorded. Backward stepwise multiple regression analyses were used to identify significant predictors of childhood outcome variables. Statistical significance was accepted at p < 0.05. Results There was no association between childhood percentage fat (%Fat) and either birth weight or birth weight z-score in this cohort. Higher %Fat at 6 weeks was a significant predictor of increased childhood %Fat, as were higher maternal pre-pregnancy BMI and earlier exposure to formula feeding. For every additional 1% in %Fat at 6 weeks, childhood %Fat increased by 0.4%. For every 2.5 kg/m 2 increase in maternal pre-pregnancy...