EFFECT OF WEANING ON SERUM LIPOPROTEIN(A) CONCENTRATION - THE STRIP BABY STUDY

Risk for coronary heart disease is increased in adult Caucasians with high serum lipoprotein(a) [Lp(a)] concentration. In adults the concent ration is mainly regulated by genetic factors. Our previous study sugg ests that breast milk has a beneficial effect on serum Lp(a) concentra tion in infants. Now we analyzed the influence of weaning by measuring serum Lp(a) and cholesterol in 414 infants at 7, 13, 24, and 36 mo of age. At 7 mo the infants received, in addition to solid food, only br east milk (n = 148), breast milk and formula (n = 74), or formula only (n = 191). Median (range) serum Lp(a) concentrations were then 25 (le ss than or equal to 12-743) mg/L, 35 (less than or equal to 12-1188) m g/L, and 45 (less than or equal to 12-577) mg/L in the three feeding g roups, respectively (p = 0.0013). Breast milk and formula were changed to cow's milk in all infants before 12 mo of age. At 13 mo serum Lp(a ) concentration had increased more in infants who were weaned from bre ast milk than in those who had been fed both breast milk and formula, or formula only (median increases 37, 26, and 20 mg/L, respectively; p = 0.0062). Thus the serum Lp(a) concentration was similar in all feed ing groups at 13 mo. This finding was also observed at 24 and 36 mo, T he increase in serum Lp(a) concentration was independent of the baseli ne Lp(a) level, apolipoprotein E phenotype, gender, and weight gain of the infants between 7 and 13 mo, The results imply that weaning from breast milk influences markedly serum Lp(a) concentration, suggesting the presence of a Lp(a) lowering factor in breast milk.