Acta Paediatr 81: 774-8. 1992
Lipoproteins in preterm and small-for-gestational-age infants during the first week of life JM Morillas2, L Molto', R Robles', A Gi12and A Sanchez-Pozo2 Department of Neonatology'. Maternal-Infant Hospital of Granada and Department of Biochemistry2, University of Granada. Spain
Morillas JM, Molto L, Robles R, Gil A, Sanchez-Pozo A. Lipoproteins in preterm and small-forgestational-age infants during the first week of life. Acta Pzdiatr 1992;81:774-8. Stockholm. ISSN 0803-5253 Plasma lipoprotein levels and composition have been determined in preterm and small-for-gestationalage (SGA) infants, and compared to full-term infants, during the first week of life. Significantly lower levels of HDL and higher levels of VLDL were found in both preterm and SGA infants in comparison to full-term healthy infants. These results suggest a low capacity to metabolize VLDL. Preterm infants showed a behaviour similar to full-term infants with regard to the changes in lipoprotein composition. Small-for-gestational-age infants showed a higher lipoprotein lipid content than preterm infants. A low ratio of cholesteryl ester to free cholesterol (CE/FC) was found in both preterm and SGA infants suggesting a reduced lecithin :cholesterol acyl transferase (LCAT) activity. In preterm infants we observed no changes in the CE/FC ratio during the first week of life, whereas in SGA infants this ratio increased after birth. 0 Lipoproteins, preterm infants, small-for-gestationaI-ageinfants A Sanchez-Pozo. Departamento de Bioquimica, FacuItad de Farmacia. Campus Cartuja, 18071Granada, Spain
Plasma lipid and lipoprotein patterns in newborns are significantly different from those observed in adults, both in concentration and composition. Shortly after birth, the plasma-lipid-transport system changes rapidly. An abundance of data is available on cord blood lipoprotein levels and on postnatal changes in healthy full-term infants (1-6). Postnatal changes in lipoproteins in low-birth-weight infants are less known. Both weight and gestational age seem to affect significantly the lipoprotein metabolism in the earliest neonatal period (7). Lipid levels of preterm infants have been described for various stages of postnatal life (8-10); however, few data are available concerning the small-for-gestational-age (SGA) infants (1 I). Many studies consider the SGA infants together with the preterm infants, despite the possible differences in their lipid metabolism, and confusion could result from this. Therefore, in this work the influences of birth weight and gestational age on the plasma lipoproteins during the first week of life are studied separately.
Methods Subjecrs Three groups of infants were studied (Table 1). The protocol was approved by the Committee for Research on Human Subjects of Granada Maternal-Infant Hospital and informed consent was obtained from parents.
Table I . Characteristics of the study groups. TI =full-term infants; PTI = preterm infants; SGAI = small-for-gestational-age infants. Data are presented as meanfSD. Birthweight was considered as 100%,.
TI
PTI
SGAI
39.2k 1.0 3391k113
34.4k0.8 1988+101
39.2+ 1.2 2164+53
100k13
100+10
97_+13 10
100+9
95+7 105k7 12
~
Gestational age (weeks) Birth weight (g) Weight change (%) 0-3 days 3-7 days Number of infants
~
II
Infants suffering any kind of pathology and those showing formula intolerance were excluded. The data were evaluated from the following groups of infants: 10 healthy full-term; 1 1 preterm with birth weight adequate for gestational age; and 12 full-term, small-for-gestational-age.
Diets
All infants were fed exclusively on formulas following the ESPGAN recommendations (12, 13). Full-term infants were fed on formula 1 and preterm and SGA infants on formula 2. The composition of the formulas is given in Table 2.
Low-birth-weight-infanl lipoproteins
ACTA PEDIATR 8 I ( 1992)
Tuble 2. Main composition of the formulas. Values are given per 100 kcal.
Formula Component Proteins (g) (caseinlwhey proteins) Lipids (g) (milk fatlvegetable fat) Carbohydrates (9) (dextrinmaltose/lactose) Minerals and vitamins Humidity (g)
1
2
2.4 40160 5.1
2.9 40160 5.4 25/75 9.9 54/46 0.6 0.6
50/50
11.1 25/75 0.5 0.6
Sample collection Blood samples were taken at delivery, and on postnatal days 3 and 7 immediately before feeding. Blood was collected in tubes containing EDTA (1 mg/ml) and centrifuged, and the resulting plasma was kept at - 20°C until analysis.
775
electrophoresis according to Maguire et a]. (17). Apo AI was determined with specific antibodies by the Sebia Hydragel electro-immune-diffusion kit (France). Statistical analysis
Comparisons between groups were made by a two-way analysis of the variance and by the multiple a posteriori comparison tests of Tukey and Student-NewmanKeuls, both methods using the BMDP statistics software package (UCLA, CA, USA). A value of p
Lipoproteins in preterm and small-for-gestational-age infants during the first week of life JM Morillas2, L Molto', R Robles', A Gi12and A Sanchez-Pozo2 Department of Neonatology'. Maternal-Infant Hospital of Granada and Department of Biochemistry2, University of Granada. Spain
Morillas JM, Molto L, Robles R, Gil A, Sanchez-Pozo A. Lipoproteins in preterm and small-forgestational-age infants during the first week of life. Acta Pzdiatr 1992;81:774-8. Stockholm. ISSN 0803-5253 Plasma lipoprotein levels and composition have been determined in preterm and small-for-gestationalage (SGA) infants, and compared to full-term infants, during the first week of life. Significantly lower levels of HDL and higher levels of VLDL were found in both preterm and SGA infants in comparison to full-term healthy infants. These results suggest a low capacity to metabolize VLDL. Preterm infants showed a behaviour similar to full-term infants with regard to the changes in lipoprotein composition. Small-for-gestational-age infants showed a higher lipoprotein lipid content than preterm infants. A low ratio of cholesteryl ester to free cholesterol (CE/FC) was found in both preterm and SGA infants suggesting a reduced lecithin :cholesterol acyl transferase (LCAT) activity. In preterm infants we observed no changes in the CE/FC ratio during the first week of life, whereas in SGA infants this ratio increased after birth. 0 Lipoproteins, preterm infants, small-for-gestationaI-ageinfants A Sanchez-Pozo. Departamento de Bioquimica, FacuItad de Farmacia. Campus Cartuja, 18071Granada, Spain
Plasma lipid and lipoprotein patterns in newborns are significantly different from those observed in adults, both in concentration and composition. Shortly after birth, the plasma-lipid-transport system changes rapidly. An abundance of data is available on cord blood lipoprotein levels and on postnatal changes in healthy full-term infants (1-6). Postnatal changes in lipoproteins in low-birth-weight infants are less known. Both weight and gestational age seem to affect significantly the lipoprotein metabolism in the earliest neonatal period (7). Lipid levels of preterm infants have been described for various stages of postnatal life (8-10); however, few data are available concerning the small-for-gestational-age (SGA) infants (1 I). Many studies consider the SGA infants together with the preterm infants, despite the possible differences in their lipid metabolism, and confusion could result from this. Therefore, in this work the influences of birth weight and gestational age on the plasma lipoproteins during the first week of life are studied separately.
Methods Subjecrs Three groups of infants were studied (Table 1). The protocol was approved by the Committee for Research on Human Subjects of Granada Maternal-Infant Hospital and informed consent was obtained from parents.
Table I . Characteristics of the study groups. TI =full-term infants; PTI = preterm infants; SGAI = small-for-gestational-age infants. Data are presented as meanfSD. Birthweight was considered as 100%,.
TI
PTI
SGAI
39.2k 1.0 3391k113
34.4k0.8 1988+101
39.2+ 1.2 2164+53
100k13
100+10
97_+13 10
100+9
95+7 105k7 12
~
Gestational age (weeks) Birth weight (g) Weight change (%) 0-3 days 3-7 days Number of infants
~
II
Infants suffering any kind of pathology and those showing formula intolerance were excluded. The data were evaluated from the following groups of infants: 10 healthy full-term; 1 1 preterm with birth weight adequate for gestational age; and 12 full-term, small-for-gestational-age.
Diets
All infants were fed exclusively on formulas following the ESPGAN recommendations (12, 13). Full-term infants were fed on formula 1 and preterm and SGA infants on formula 2. The composition of the formulas is given in Table 2.
Low-birth-weight-infanl lipoproteins
ACTA PEDIATR 8 I ( 1992)
Tuble 2. Main composition of the formulas. Values are given per 100 kcal.
Formula Component Proteins (g) (caseinlwhey proteins) Lipids (g) (milk fatlvegetable fat) Carbohydrates (9) (dextrinmaltose/lactose) Minerals and vitamins Humidity (g)
1
2
2.4 40160 5.1
2.9 40160 5.4 25/75 9.9 54/46 0.6 0.6
50/50
11.1 25/75 0.5 0.6
Sample collection Blood samples were taken at delivery, and on postnatal days 3 and 7 immediately before feeding. Blood was collected in tubes containing EDTA (1 mg/ml) and centrifuged, and the resulting plasma was kept at - 20°C until analysis.
775
electrophoresis according to Maguire et a]. (17). Apo AI was determined with specific antibodies by the Sebia Hydragel electro-immune-diffusion kit (France). Statistical analysis
Comparisons between groups were made by a two-way analysis of the variance and by the multiple a posteriori comparison tests of Tukey and Student-NewmanKeuls, both methods using the BMDP statistics software package (UCLA, CA, USA). A value of p
