Association of exclusive breastfeeding duration, body mass index trajectories, and cardiometabolic risk in preschool children.

PURPOSE: This prospective cohort study aimed to examine the associations among exclusive breastfeeding duration, body mass index (BMI) growth trajectories, and cardiometabolic risk in children at 5 years of age. METHODS: Maternal pre-pregnancy BMI, infant feeding practices, and anthropometric measurements were prospectively collected at regular intervals. At 5 years of age, the children's cardiometabolic risk z-scores were calculated using five metabolic components. One-way analyses of variance and logistic regression analysis were performed to assess associations between exclusive breastfeeding duration, children's BMI trajectories, and metabolic variables, as well as to identify predictors of high cardiometabolic risk z-scores. RESULTS: In total, 242 children with 5-year follow-up were included, of whom 35.1% had ≥1 metabolic risk factor. Longer exclusive breastfeeding duration was associated with slower increases in BMI z-scores from 0 to 5 years and lower body fat percentages at outcome assessments; however, these associations were no longer significant after adjustment for confounders. Logistic regression analyses showed that maternal pre-pregnancy overweight or obesity (adjusted OR = 3.12, P = 0.007) and greater BMI z-score gain between 1 and 3 years (adjusted OR = 1.90, P = 0.001) and 3-5 years of age (adjusted OR = 3.04, P < 0.001) were independent predictors of high cardiometabolic risk. CONCLUSION: Maternal pre-pregnancy overweight or obesity and greater BMI z-score gain after 1 year of age were associated with a higher cardiometabolic risk at 5 years. Evidence supporting the protective effect of longer exclusive breastfeeding on cardiometabolic risk in preschool-aged children is insufficient, and further studies are warranted.