Objective: To examine the association of exclusive breastfeeding (BF) duration on serum fibrinogen levels of children and adolescents from Estonia and Sweden, controlling for other potential confounding factors that could mediate in this relationship.
Design: Cross-sectional study.
Setting: Estonia and Sweden.
Participants: A total of 704 children (mean [SD] age, 9.5 [0.4] years) and 665 adolescents (15.5 [0.5] years).
Main exposure: Exclusive BF duration was reported by the mother and categorized in the following 5 categories: never, less than 1 month, 1 to 3 months, more than 3 to 6 months, and more than 6 months.
Main outcome measures: Fasting fibrinogen level. Age, sex, pubertal status, country, adiposity (sum of 5 skin-fold thicknesses), total cholesterol and triglyceride levels, blood pressure, physical activity (accelerometry), birth weight, maternal education, body mass index, and age were considered confounders in the analyses.
Results: Longer duration of exclusive BF was associated with lower fibrinogen levels regardless of confounders (P < .001). Mean (SD) fibrinogen levels were lower in youth who were breastfed for more than 3 months (after adjusting for all confounders, P < .01) in children (2.55 [0.04] vs 2.77 [0.03] g/L), adolescents (2.59 [0.06] vs 2.72 [0.03] g/L), boys (2.47 [0.04] vs 2.73 [0.04] g/L), and girls (2.60 [0.03] vs 2.75 [0.02] g/L), compared with groups who were not breastfed. The results did not change substantially after further adjustment for birth weight and maternal educational level.
Conclusions: Exclusive BF is associated with less low-grade inflammation, as estimated by serum fibrinogen levels, in healthy children and adolescents. These findings give further support to the notion that early feeding patterns could program cardiovascular disease risk factors later in life.