Neonatal amygdala microstructure mediates the relationship between gestational glycemia and offspring adiposity

INTRODUCTION: To determine if variations in the neonatal amygdala mediate the association between maternal antenatal glycemia and offspring adiposity in early childhood. RESEARCH DESIGN AND METHODS: 123 non-obese pregnant women with no pregnancy complications aside from gestational diabetes underwent a 75 g 2-hour oral glucose tolerance test at 26–28 weeks’ gestation. Volume and fractional anisotropy (FA) of the neonatal amygdala (5–17 days old) were measured by MRI. The Body Mass Index (BMI) z-scores and sum of skinfold thickness (subscapular and triceps) of these children were tracked up to 60 months of age (18, 24, 36, 48, 54 and 60 months). RESULTS: Maternal fasting glucose levels were positively associated with the offspring’s sum of skinfold thickness at age 48 months (β=3.12, 95% CI 0.18 to 6.06 mm) and 60 months (β=4.14, 95% CI 0.46 to 7.82 mm) and BMI z-scores at 48 months (β=0.94, 95% CI 0.03 to 1.85), 54 months (β=0.74, 95% CI 0.12 to 1.36) and 60 months (β=0.74, 95% CI 0.08 to 1.39). Maternal fasting glucose was negatively associated with the offspring’s FA of the right amygdala (β=−0.019, 95% CI −0.036 to −0.003). Right amygdala FA was negatively associated with the sum of skinfold thickness in the offspring at age 48 months (β=−56.95, 95% CI −98.43 to −15.47 mm), 54 months (β=−46.18, 95% CI −88.57 to −3.78 mm), and 60 months (β=−53.69, 95% CI −105.74 to −1.64 mm). The effect sizes mediated by right amygdala FA between fasting glucose and sum of skinfolds were estimated at β=5.14 (95% CI 0.74 to 9.53) mm (p=0.022), β=4.40 (95% CI 0.08 to 8.72) (p=0.049) mm and β=4.56 (95% CI −0.17 to 9.29) mm (p=0.059) at 48, 54 and 60 months, respectively. CONCLUSIONS: In the offspring of non-obese mothers, gestational fasting glucose concentration is negatively associated with neonatal right amygdala FA and positively associated with childhood adiposity. Neonatal right amygdala FA may be a potential mediator between maternal glycemia and childhood adiposity.