APOLIPOPROTEIN-E POLYMORPHISM AND SERUM-LIPIDS IN A RANDOMIZED, PROSPECTIVE TRIAL OF AN INFANT DIET WITH REDUCED SATURATED FAT AND CHOLESTEROL

Background. The inherited apolipoprotein E (apoE) phenotype may determ ine effectiveness of dietary atherosclerosis prevention. This study an alyzes the effects of apoE phenotypes on changes in serum lipid concen trations in a 6-month prospective, randomized trial of a low-saturated -fat, low-cholesterol diet in infancy. Patients and Methods. One thous and sixty-two healthy infants were randomized to intervention and cont rol groups at the age of 7 months. Counseling was provided to the inte rvention families when the children's ages were 7, 8, and 10 months. D ietary goals were the child's intake of energy ad libitum, fat at 30% to 35% of energy, cholesterol at less than 200 mg/d, and saturated, mo nounsaturated, and polyunsaturated fatty acids at a 1:1:1 ratio, Contr ol families consumed an unrestricted diet. The apoE phenotype of 846 o f the infants was determined; serum lipid and lipoprotein concentratio ns were measured at 7 and 13 months of age; and nutrient intakes were analyzed using 3-day food records at 8 and 13 months of age. Results. At 7 months of age, serum cholesterol concentration was higher in apoE 4-positive infants (E2/E4, E3/E4, and homozygous E4) than in apoE4-neg ative infants (159 +/- 31 mg/dL [4.10 +/- 0.81 mmol/L] vs 150 +/- 29 m g/dL [3.89 +/- 0.74 mmol/L]). The high-density lipoprotein cholesterol concentration was slightly lower in apoE4-positive infants than in ap oE4-negative infants (34 +/- 8 mg/dL [0.88 +/- 0.20 mmol/L] vs 35 +/- 7 mg/dL [0.91 +/- 0.19 mmol/L]). Between 7 and 13 months of age, the s erum cholesterol concentration in infants in the intervention group wa s unchanged, apoB concentration increased slightly, and apoA1 concentr ation decreased. In the control infants, serum cholesterol concentrati on increased 9 +/- 25 mg/dL (0.24 +/- 0.65 mmol/L), apoB concentration increased markedly, and apoA1 concentration was stable. Changes in se rum Lipid and apo concentrations that resulted from the dietary interv ention were independent of the apoE phenotype. Conclusions. The apoE p henotype influenced serum cholesterol concentration markedly by 7 mont hs of age. Between the ages of 7 and 13 months, a reduced saturated fa t and cholesterol diet effectively prevented the age-associated increa ses in serum cholesterol and non-high-density cholesterol concentratio ns that were obvious in the control infants. The effects of the diet o ccurred in the infants independently of the apoE phenotype.