Effects of Promoting Longer Term and Exclusive Breastfeeding on Cardiometabolic Risk Factors at Age 11.5 Years: A Cluster-Randomized, Controlled Trial
Background—The duration and exclusivity of breastfeeding in infancy have been inversely associated with future cardiometabolic risk. We investigated the effects of an experimental intervention to promote increased duration of exclusive breastfeeding on cardiometabolic risk factors in childhood.
Methods and Results—We followed-up children in the Promotion of Breastfeeding Intervention Trial, a cluster-randomized trial of a breastfeeding promotion intervention based on the World Health Organization/United Nations Children's Fund Baby-Friendly Hospital Initiative. 17,046 breastfeeding mother-infant pairs were enrolled in 1996/7 from 31 Belarussian maternity hospitals and affiliated polyclinics (16 intervention vs 15 control sites); 13,879 (81.4%) children were followed-up at 11.5 years, with 13,616 (79.9%) fasted and without diabetes. The outcomes were blood pressure; fasting insulin, adiponectin, glucose and apolipoprotein A1; and presence of metabolic syndrome. Analysis was by intention to treat, accounting for clustering within hospitals/clinics. The intervention substantially increased breastfeeding duration and exclusivity compared with the control arm (43% vs. 6% and 7.9% vs. 0.6% exclusively breastfed at 3 and 6 months, respectively). Cluster-adjusted mean differences at 11.5 years between experimental vs control groups were: 1.0mmHg (95% CI: -1.1, 3.1) for systolic and 0.8mmHg (-0.6, 2.3) for diastolic blood pressure; -0.1mmol/l (-0.2, 0.1) for glucose; 8% (-3%, 34%) for insulin; -0.3μg/ml (-1.5, 0.9) for adiponectin; and 0.0g/l (-0.1, 0.1) for ApoA1. The cluster-adjusted odds ratio for metabolic syndrome, comparing experimental vs control groups, was 1.21 (0.85, 1.72).
Conclusions—An intervention to improve breastfeeding duration and exclusivity among healthy term infants did not influence cardiometabolic risk factors in childhood.
- Received July 22, 2013.
- Revision received October 3, 2013.
- Accepted October 15, 2013.