A prospective study was conducted on the somatic growth and fatty acid profiles of 60 preterm infants with a birthweight of 1000 to 1700g, submitted or not to 3 daily cutaneous applications of 4 mg/kg soybean oil each, for 30 days starting on the seventh day of life. Clinically stable preterm neonates were randomly assigned to the study (29 infants) or control group (31 infants) and fed human milk or formula. The study group consisted of 16 infants receiving human milk and 13 infants receiving formula, and the control group consisted of 15 infants receiving human milk and 16 receiving formula. The study was approved by the Ethics Committee of the University Hospital. None of the infants presented any clinical abnormality during the study.
Initial and final values for weight, length, head and arm circumference, tricipital and subscapular skinfolds were similar for both groups. The preterm infants submitted to cutaneous application of soy oil presented, after thirty days, a greater gain in weight (703 ± 129g vs 576 ± 140g, p=0.001), length (3.4 ± 0.57cm vs 3.14 ± 0.58cm, p=0.04), arm circumference (1.67 ± 0.42cm vs 1.37 ± 0.34cm, p= 0.004), tricipital skinfold (0.78 ± 0.17mm vs 0.56 ± 0.14mm, p<0.001) and subscapular skinfold (0.75 ± 0.20mm vs 0.59 ± 0.15mm, p=0.001).
The initial and final fatty acid profiles were similar for both groups. Both groups of infants presented significantly increased final percent plasma values of linoleic acid, with an increase from 18.35 ± 5.84% to 22.81± 4.36% in the control group, and from 16.28 ± 5.45% to 23.69± 3.51% in the study group. Final plasma arachidonic acid percent levels were significantly reduced in the control (from 10.14 ± 3.96% to 6.98 ± 2.56%) and study groups (from 9.43 ± 2.88% to 6.49± 2.39%) both receiving human milk and milk formula.
Cutaneous application of soy oil contributes to greater anthropometric growth. Further studies are needed for a better understanding of the mechanisms involved in this process.
(Spon by: Jaques Belik)