RESUMO
UNLABELLED: In this study we compared plasma contents of long-chain polyunsaturated fatty acids (LC-PUFAs) and trans fatty acids in triglycerides (TG), phospholipids (PL) and cholesterolesters (CE) in young children fed milk diets containing different amounts of linoleic (LA) and alpha-linolenic acid (ALA). Because the diets differed in vitamin A and E content, plasma concentrations of vitamin A and E were also studied. Thirty-seven 1-y-old children were randomly assigned to one of four feeding groups: (1) low-fat milk (LF) (1.0 g cow's milk fat/dL); (2) standard-fat milk (SF) (3.5 g cow's milk fat/dL); (3) partially vegetable fat milk (PVF) (3.5 g fat/dL; 50% vegetable fat from rapeseed oil, 50% milk fat); and (4) full vegetable fat milk (FVF) (3.5 g fat/dL; 100% vegetable fat from palm-, coconut- and soybean oil). We found higher amounts of plasma LA in the FVF group than in the LF and SF groups (p < 0.001) and higher amounts of ALA in the PVF group than in the SF (p < 0.001 in TGs, p < 0.05 in CEs) and LF (p < 0.01 in PLs and CEs, p < 0.05 in TGs) groups. However, amounts of plasma arachidonic acid (AA) were similar between groups as well as the amounts of docosahexaenoic acid (DHA) in CEs and PLs. Total trans FAs were lower in CEs in the PVF and FVF groups than in the SF group (p < 0.05 SF vs PVF; p < 0.01 SF vs FVF). Plasma concentrations of alpha-tocopherol were higher in the FVF group than in the other groups (p < 0.05 FVF vs SF, p < 0.01 FVF vs SF and PVF). CONCLUSION: Children consuming milk diets containing high amounts of vegetable fat present with higher plasma LA and ALA without any effects on amounts of plasma LC-PUFA. The plasma LC-PUFA status is not adversely affected by a low-fat milk diet. AHA and DHA in plasma are not affected by the diets studied, presumably because 15-mo-old children may be able to compensate for dietary influences through endogenous LC-PUFA metabolism.
Assuntos
Dieta , Gorduras na Dieta/administração & dosagem , Ácidos Graxos Insaturados/sangue , Leite , Animais , Metabolismo Energético , Ácidos Graxos Essenciais/sangue , Feminino , Humanos , Lactente , Fenômenos Fisiológicos da Nutrição do Lactente , Ácido Linoleico/análise , Masculino , Probabilidade , Estudos Prospectivos , Estatísticas não ParamétricasRESUMO
UNLABELLED: Iron intakes and iron status were evaluated in 36 young Swedish children given either iron-fortified or unfortified cow's milk. All children had good iron status and had received breast milk or iron-fortified formulae during infancy. Twenty 1-y-old children were randomized to a diet with iron-fortified milk (7.0 or 14.9 mg Fe l(-1) and 16 to a diet with unfortified milk. The iron intakes in the unfortified group at 15 and 18 mo (mean +/- SD 5.19 +/- 2.29 and 5.84 +/- 1.62 mg d(-1)) were low in relation to Nordic Nutrition Recommendations, while the intakes in the iron-fortified group (10.20 +/- 2.60 and 10.87 +/- 2.79mg d(-1)) were normal in relation to recommendations. The gain (increase) from receiving fortified diet during the study period was at most [upper limit for 95% confidence interval (CI)] 2.6 g l(-1) in blood haemoglobin, 1.9 fl in mean corpuscular volume, 2.7 micromol in serum iron and 4.5% in transferrin iron saturation, and the gain (decrease) was at most (lower limit for 95% CI) 0.29g l(-1) in serum transferrin and 0.9mg l(-1) in serum transferrin receptor (TfR). None of these differences was statistically significant. There was an almost significantly higher increase in serum ferritin (1.4 times higher relation of values at the end compared with the beginning, p = 0.06) and a significantly higher (1.2; p = 0.047) decrease in TfR/ log10 ferritin ratio in the fortified group. CONCLUSION: One-year-old children starting out with good iron status given either iron-fortified or unfortified cow's milk from 12 to 18 mo maintain sufficient iron status during this period. However, children fed unfortified cow's milk have an iron intake which is low in relation to recommendations and the quantitative development of their reserve iron in iron stores seems to be weaker than that of the fortified group. The consequences of this require further study.
Assuntos
Desenvolvimento Infantil/fisiologia , Alimentos Fortificados , Ferro/administração & dosagem , Leite/química , Animais , Feminino , Ferritinas/sangue , Humanos , Lactente , Masculino , Estado Nutricional , Transferrina/análiseRESUMO
OBJECTIVE: The study was designed to investigate the prevalence of celiac disease (CD) among 2.5-year-old children in a Swedish urban population with a high incidence of CD. MATERIAL AND METHODS: Six hundred ninety apparently healthy children, born in the 12-month period of July 1992 through June 1993, were screened for immunoglobulin A (IgA) antigliadin antibodies and IgA antiendomysium antibodies, and those antibody-positive at repeated testing were further investigated with intestinal biopsy. RESULTS: Of the 690 children, 6 were both IgA antigliadin antibody- and IgA antiendomysium antibody-positive, and 7 were antiendomysium antibody-positive but antigliadin antibody-negative. Jejunal biopsy, performed in 12 cases, manifested partial or total villous atrophy in 8 cases. Thus, together with an additional child whose parents declined the offered biopsy, but whose response to a gluten-free diet confirmed the presence of CD, the prevalence of CD in the study series was 1.3% (9/690; 95% confidence interval:.4-2.2). However, independent of the study, an additional 22 cases of symptomatic, biopsy-verified CD have already been detected in the birth cohort of 3004 children. CONCLUSIONS: The prevalence of CD in our study series was high, at least 1.0%, but may be as high as 2.0% if the frequency of silent CD is as high as we have found in the remaining unscreened cohort. These findings confirm that CD is one of the most common chronic disorders.
Assuntos
Doença Celíaca/diagnóstico , Doença Celíaca/epidemiologia , Programas de Rastreamento/estatística & dados numéricos , Atrofia , Biópsia , Doença Celíaca/dietoterapia , Pré-Escolar , Feminino , Seguimentos , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Jejuno/patologia , Masculino , Programas de Rastreamento/métodos , Prevalência , Valores de Referência , Testes Sorológicos , Suécia/epidemiologiaRESUMO
BACKGROUND: Differences in fatty acid content of plasma lipid fractions and serum lipid concentrations were investigated among young children fed different milk diets composed to achieve a recommended saturated fat intake. METHODS: Thirty-eight healthy children were randomly assigned to one of four feeding groups at 12 months: 1) low-fat milk (1.0 g/dL cow's milk fat); 2) standard-fat milk (3.5 g/dL cow's milk fat); 3) partially vegetable fat milk (3.5 gtat/dL fat; 50% vegetable fat: rapeseed oil); and 4) full vegetable-fat milk (3.5 gtat/dL fat; 100% vegetable fat: palm, coconut, and soy oil). Plasma fatty acids, blood lipids, and apolipoproteins were analyzed at 15 months, and dietary intakes at 12, 15, and 18 months. RESULTS: There were significantly lower percentage contributions of saturated fatty acids in plasma triglycerides in children fed low-fat milk or milk with 50% or 100% vegetable fat than in children fed standard-fat milk. Plasma polyunsaturated fatty acid levels were significantly higher in children fed milks with vegetable fat than in children fed standard-fat milk. Plasma saturated and polyunsaturated fatty acids in triglycerides most closely reflected dietary intake. Blood lipid concentrations were lower in children fed milk with 50% vegetable fat. CONCLUSIONS: Children fed milk with 50% or 100% vegetable fat, together with high vegetable-fat and low milk-fat dairy products have lower percentages of plasma saturated fatty acids and higher percentages of polyunsaturated fatty acids than children fed standard- or low-fat milk and dairy products.
Assuntos
Apolipoproteínas/sangue , Laticínios , Gorduras na Dieta/administração & dosagem , Ácidos Graxos/sangue , Lipídeos/sangue , Leite , Animais , Colesterol na Dieta/administração & dosagem , Ingestão de Energia , Ácidos Graxos Insaturados/sangue , Humanos , Lactente , Lipoproteínas/sangue , Estudos Prospectivos , Triglicerídeos/sangueRESUMO
The aim of the study was to compare protein intake and metabolism between infants from two countries given similar infant formulae but different weaning foods. Healthy Swedish and Italian infants were studied between 3 and 12 mo. Infants in both populations were assigned to 1 of 3 infant formulae, containing 13, 15 or 18/20 g l(-1) of protein, given in addition to Swedish or Italian weaning foods. Protein intake from weaning foods was higher in Italian than in Swedish infants at 6 and 12 mo, whereas protein intake from formula at 6 mo and from formula/milk at 12 mo was similar in both populations. Plasma isoleucine, leucine, lysine, histidine and valine at 6 mo were lower in Italian than in Swedish infants fed formula with 13 g l(-1) of protein. All essential plasma amino acids were similar in Italian and Swedish groups at 12 mo. Serum urea was similar at 6 mo in corresponding formula groups, but was higher at 12 mo in the Italian than in the Swedish formula group. Serum albumin and growth were normal in both populations throughout infancy. In conclusion, formula with protein content of 13 g l(-1) seems to provide sufficient protein intake when combined with Swedish or Italian weaning foods during the second half of infancy, as indicated by normal serum albumin and normal growth. However, the bioavailability of protein and amino acids from weaning foods, in addition to their protein content, should be considered, as indicated by some indices of protein metabolism in the Italian infants.
Assuntos
Desenvolvimento Infantil/fisiologia , Suplementos Nutricionais/análise , Alimentos Infantis/análise , Fenômenos Fisiológicos da Nutrição do Lactente , Proteínas/administração & dosagem , Proteínas/metabolismo , Albuminas/análise , Aminoácidos/análise , Peso Corporal , Feminino , Humanos , Lactente , Itália , Masculino , Estatísticas não Paramétricas , Suécia , Ureia/análise , DesmameRESUMO
The purpose of the study was to compare fat intake and metabolism between two infant populations from Sweden and Italy given breast milk or similar infant formulas, but different weaning foods. Nutrient intake and fat metabolism were studied prospectively from 3-12 mo in 68 Swedish and 46 Italian healthy infants, breastfed or given similar infant formulas in combination with Swedish or Mediterranean weaning foods. Although nutrient intake and fat metabolism were similar at 6 mo, fat intake was lower at 12 mo in the Italian than in the Swedish formula group (p < 0.001). At 6 and 12 mo, higher dietary ratios of monounsaturated to saturated fatty acids (p < 0.01 and p < 0.001, respectively), and monounsaturated to polyunsaturated fatty acids (p < 0.05, p < 0.001) were found in the Italian than in the Swedish formula group. Total cholesterol and apolipoprotein B were lower at 6 mo (p < 0.01) in Italian breastfed infants than in Swedish ones. Lower concentrations at 6 and 12 mo of total cholesterol (p < 0.05, p < 0.05, respectively), apolipoprotein B (p < 0.05, p < 0.01) and triglycerides (p < 0.001, p < 0.01), and of apolipoprotein A1 (p < 0.01) at 12 mo, were found in the Italian formula group than in the Swedish one. In conclusion, plasma total cholesterol, apolipoprotein B and triglycerides were found to be lower in Italian infants than in Swedish infants during the second half of infancy. These findings may partly result from differences in fat compositions between Swedish and Mediterranean weaning diets and in total fat intake in late infancy. Differences in duration of breastfeeding and possibly in breast milk composition may also have influenced our results.
Assuntos
Aleitamento Materno , Gorduras na Dieta/administração & dosagem , Alimentos Infantis , Lipídeos/sangue , Desmame , Fatores Etários , Apolipoproteínas/sangue , Colesterol/sangue , Interpretação Estatística de Dados , Ingestão de Energia , Humanos , Lactente , Itália , Estudos Prospectivos , Suécia , Triglicerídeos/sangueRESUMO
BACKGROUND: Milk is the major source of protein and saturated fats in the diet after infancy. In the present study, the effects of different fat and protein quantity as well as fat quality in milk and dairy products on nutrient intake and growth in young children were determined. METHODS: Thirty-eight healthy children were randomly assigned to one of four feeding groups at 12 months of age: 1) Low-fat milk (1.0 g fat/dl, 3.3 g protein/dl); 2) standard-fat milk (3.5 g fat/dl, 3.3 g protein/dl); 3) partially vegetable fat and protein-reduced milk (3.5 g fat/dl, 50% vegetable; 2.2 g protein/dl); and 4) full-vegetable-fat milk (3.5 g fat/dl, 100% vegetable; 3.0 g protein/dl). Nutrient intake and growth were measured at 12, 15, and 18 months. RESULTS: The protein intake was significantly reduced with the protein-reduced milks. The intake of saturated fat was significantly lower with low-fat milk (11% of energy) or milks containing vegetable fat (13%) than in standard-fat milk (19.6%). However, the total fat intake was below 30% of energy in low-fat milk, whereas the total fat intake remained more than 30% in the other groups. Energy intake and growth were similar in all groups. CONCLUSIONS: A modified milk with reduced protein content for young children results in protein intakes closer to recommendations. A modified milk with either 50% or 100% vegetable fat and dairy products with low milk fat and high vegetable fat content results in intakes of total and saturated fats closer to international recommendations, compared with standard or low-fat milk and dairy products.
Assuntos
Laticínios , Gorduras na Dieta/administração & dosagem , Alimentos Infantis , Leite , Animais , Antropometria , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Feminino , Humanos , Lactente , MasculinoRESUMO
OBJECTIVE: This study was conducted to investigate the prevalence of celiac disease (CD) in children and adolescents at diagnosis of insulin-dependent diabetes mellitus (IDDM) before insulin treatment was started. MATERIAL AND METHODS: At diagnosis of IDDM, and before treatment was started, 115 children and adolescents were screened for IgA- antiendomysium (EMA) and IgA-antigliadin antibodies (AGA). Those found to be EMA-positive and/or AGA-positive were investigated further with intestinal biopsy. RESULTS: Of the 115 patients, 2 had known CD at diagnosis of IDDM; of the remainder of patients, 6% (7/113) were found to be EMA-positive and 9% (10/113) were found to have AGA levels above normal. Of the 6 patients who underwent biopsy, 5 manifested villous atrophy. In addition, 2 patients with high EMA and AGA antibody titers refused biopsy, and 4 patients with low EMA and/or AGA titers were found to have normal titers at control before biopsy decision. CONCLUSION: Because the prevalence of CD at diagnosis of IDDM would seem to be 6% to 8%, screening for CD seems to be justified among patients with newly diagnosed IDDM.
Assuntos
Autoanticorpos/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Gliadina/imunologia , Imunoglobulina A/imunologia , Fibras Musculares Esqueléticas/imunologia , Adolescente , Doença Celíaca/imunologia , Criança , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Seguimentos , Gliadina/sangue , Humanos , Imunoglobulina A/sangue , Lactente , Masculino , Prevalência , Estudos Retrospectivos , Estudos Soroepidemiológicos , Suécia/epidemiologiaRESUMO
This study was carried out to compare plasma lipid pattern in breastfed and formula-fed infants and the effects of exchanging breast milk for formula and of introducing weaning foods. Healthy infants, exclusively breastfed at least until 3 mo, were at this age randomly assigned to infant formulas with similar fat composition. Formula was gradually introduced when breastfeeding was discontinued. One group continued to breastfeed beyond 6 mo of age. All infants received the same weaning foods and were studied between 3 and 12 mo of age. Decreased plasma concentrations of total and low-density lipoprotein cholesterol (TC, LDL-C), apolipoprotein B (apo B) and A1 (p < 0.001), and of high-density lipoprotein cholesterol (p < 0.05) were found when breast milk was exchanged for formula before 6 mo. At this age plasma TC, LDL-C and apo B were lower in formula-fed than in breastfed infants (p < 0.001). These plasma lipids then increased (p < 0.01) when the intake of formula decreased and that of weaning foods increased. However, plasma TC and/or LDL-C remained lower at 12 mo in formula-fed than in breastfed infants (p < 0.05). Our results indicate that the plasma lipid profile of infants is highly responsive to the dietary nutrient intake, as indicated by the decrease in plasma lipids and apolipoproteins when breast milk was exchanged for formula and by the increase in these concentrations when the intake of weaning foods gradually increased.
Assuntos
Apolipoproteínas/sangue , Aleitamento Materno , Fenômenos Fisiológicos da Nutrição do Lactente , Lipídeos/sangue , Apolipoproteínas B/sangue , LDL-Colesterol/sangue , Humanos , Lactente , Leite Humano/química , SuéciaRESUMO
BACKGROUND: The serum transferrin receptor (TfR) concentration in adults is suggested to provide a sensitive measure of iron depletion and together with the serum ferritin concentration to indicate the entire range of iron status, from iron deficiency to iron overload. However, little is known about TfR concentrations in children. OBJECTIVE: Our objective was to compare serum TfR and ferritin concentrations and their ratios in children and adults and look for correlations between TfR concentrations and other measures of iron status. DESIGN: Our study groups were healthy 1-y-old infants (n = 36), 11-12-y-old prepubertal boys (n = 35), and 20-39-y-old men (n = 40). RESULTS: TfR concentrations were higher in infants (x; 95% reference interval: 7.8 mg/L; 4.5, 11.1) than in prepubertal boys (7.0 mg/L; 4.7, 9.2) and higher in prepubertal boys than in men (5.8 mg/L; 3.1, 8.5). Geometric mean TfR-ferritin ratios were higher in infants (316; 95% reference interval: 94, 1059) than in prepubertal boys (219; 78, 614) and higher in prepubertal boys than in men (72; 23, 223). By multiple linear regression analysis, the best predictors of TfR concentration were serum iron (P = 0.004) and log serum ferritin (P < 0.0001), both being inverse correlations (R2 = 0.32). Mean corpuscular volume, blood hemoglobin, transferrin iron saturation, transferrin, and even age seemed to not have an influence on the TfR concentration and erythropoiesis was not a determinant of TfR concentration. CONCLUSIONS: Low serum ferritin and iron concentrations, even within the normal physiologic range, result in high TfR concentrations. The lower the iron stores, the stronger the influence of ferritin on TfR. A high TfR concentration in children, especially in infants, is a response to physiologically low iron stores. Age-specific reference concentrations for TfR are needed.
Assuntos
Receptores da Transferrina/sangue , Adulto , Fatores Etários , Criança , Índices de Eritrócitos , Eritropoese , Feminino , Ferritinas/sangue , Hemoglobinas/metabolismo , Humanos , Lactente , Ferro/sangue , Masculino , Análise de RegressãoRESUMO
BACKGROUND: The metabolic response to different protein intakes from breast milk and/or formulas varying in protein concentrations, in combination with supplementary foods, has not been studied in infants who are in the second half of infancy. METHODS: Healthy infants, exclusively breast-fed until 3 months old, were randomly assigned to one of three groups, F13, F15, or F18, and were given formulas with 13, 15, or 18 g/l of protein, respectively. Infants breast-fed (B) and mixed-fed (M) (breast milk and formula) at 6 months formed the fourth and fifth groups. All infants received the same supplementary foods and were studied from ages 3 to 12 months. RESULTS: The concentrations of albumin, prealbumin, and transferrin were similar in all groups. At 6 months, serum and urine urea concentrations were lower in B and M, compared with urea levels in the formula-fed groups of infants. At 12 months, urine urea was lower in B + M than it was in F18. At 6 months, plasma concentrations of phenylalanine, tyrosine, and methionine were higher in all formula-fed groups; and those of valine. isoleucine, and threonine were higher in F18 and F15 than they were in B and M. Plasma concentrations of methionine, valine, and threonine were higher in F18 than in F13. At 12 months, plasma levels of tyrosine, methionine, valine, isoleucine, and leucine were higher in F18 than they were in B + M. CONCLUSION: Many indexes of protein metabolism were similar in groups F13, B, and M, particularly at 6 months. In contrast, the provision of a formula with 18 g/l of protein resulted in a different metabolic pattern, which could indicate unnecessarily high protein intakes.
Assuntos
Aminoácidos/metabolismo , Proteínas Alimentares/administração & dosagem , Alimentos Infantis , Leite Humano , Proteínas/metabolismo , Envelhecimento/metabolismo , Aminoácidos de Cadeia Ramificada/sangue , Aminoácidos Essenciais/sangue , Creatinina/sangue , Humanos , Lactente , Pré-Albumina/metabolismo , Albumina Sérica/metabolismo , Transferrina/metabolismo , Ureia/sangue , Ureia/urinaRESUMO
BACKGROUND: Results on growth and nutrient intake in infants in the second half of infancy fed human milk or formulas with varying protein concentrations in combination with supplementary foods have not previously been reported. METHODS: Seventy-one healthy infants were studied from 3 to 12 months of age. They were exclusively breast-fed until 3 months and were then randomly assigned to one of three feeding groups, F13, F15, or F18, indicating formulas with 13, 15 or 18 g/l of protein, respectively. Formula was gradually introduced when breast-feeding was terminated. Infants fed breast milk only were included in the breast-fed group, and those with breast milk and formula were included in the mixed-fed group. The same supplementary foods were provided to all infants. RESULTS: There were no differences in growth between the feeding groups. Total protein intake exceeded minimum recommendations in all groups at all ages and was higher at 6 months in F18 than in F13 (2.3 vs. 1.9 g/kg per day; p < 0.01), whereas formula protein intake was higher at all ages in F18 compared with F13. Intake of protein from supplementary foods increased, but that from formula decreased between 6 and 12 months in all groups. CONCLUSIONS: Intake of breast milk or infant formula with 13 g/l of protein along with high-protein supplementary foods provided enough protein with no adverse effect on growth. Infants fed formulas with higher protein concentrations had similar growth, despite higher intakes of formula protein.
Assuntos
Proteínas Alimentares/administração & dosagem , Crescimento , Alimentos Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Leite Humano , Antropometria , Estatura , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Método Duplo-Cego , Ingestão de Alimentos , Ingestão de Energia , Humanos , Lactente , Estudos Prospectivos , Aumento de PesoRESUMO
Good nutrition is essential during the critical period of infancy to promote the child's optimal growth and development. Proteins in human milk are discussed. Protein requirement and recommended dietary intake of healthy term infants during the first 6 months are reviewed. Recommendations for protein content in infant starting formulas and weaning are also discussed.
Assuntos
Alimentos Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Leite Humano , Proteínas , Humanos , Lactente , Recém-Nascido , Necessidades Nutricionais , Valor NutritivoRESUMO
Preprandial plasma and urine amino acid concentrations were measured in 28 growing, very low birth weight, appropriate-for-gestational-age infants randomly assigned to either protein-unenriched (n = 14) or human milk protein-enriched (n = 14) human milk. The two groups of infants had similar birth weights (900 to 1500 g) and gestational ages (26 to 32 weeks). The study was initiated at a mean age of 19 days when the infants tolerated full feeding volumes and lasted for a mean time of 28 days. Mean protein intake values were 2.1 +/- 0.3 and 3.6 +/- 0.3 g/kg per day (mean +/- SD) and weight gain values were 26.6 +/- 7.4 and 35.1 +/- 3.6 g/day in the protein-unenriched and the protein-enriched groups of infants, respectively. Human milk protein enrichment resulted in significantly increased concentrations of all plasma amino acids except serine, taurine, and histidine. Most urine amino acid concentrations correlated with protein intake and with the plasma concentrations, suggesting that the effects of protein quality and quantity can be evaluated by measuring urinary amino acid concentrations alone, thereby making such studies less invasive. Infants fed protein-unenriched human milk had growth rates below the estimated intrauterine rate as well as low plasma and urine amino acid concentrations, indicating suboptimal protein intake levels. When the plasma concentrations of the essential amino acids in the protein-enriched infants from the present study were compared with concentrations found in the literature in fetal and umbilical cord plasma, both were found to be much higher.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aminoácidos/sangue , Recém-Nascido de Baixo Peso/sangue , Proteínas do Leite/metabolismo , Leite Humano/metabolismo , Aminoácidos/urina , Alimentos Fortificados/análise , Humanos , Recém-Nascido de Baixo Peso/crescimento & desenvolvimento , Recém-Nascido de Baixo Peso/urina , Recém-Nascido , Leite Humano/químicaRESUMO
Concentrations of 11 plasma proteins were measured in 28 healthy, growing, very low birth weight, appropriate-for-gestational-age infants fed varying levels of human milk protein intake (range 1.7 to 3.9 g/kg per day). Significant positive correlations were found between mean protein intake and concentrations of 7 of the plasma proteins studied (transthyretin, retinol-binding protein, and transferrin: P less than .001; vitamin D-binding protein and apolipoprotein B: P less than .01; albumin and apolipoprotein A I: P less than .05). A weak negative correlation with mean protein intake was seen for the plasma level of orosomucoid, whereas no significant correlations were found for the plasma concentrations of fibronectin and alpha 1-antichymotrypsin. Protein intake, not energy intake, constituted the main contribution to the changes in the concentrations of transthyretin, retinol-binding protein, and transferrin. The levels of plasma transthyretin and transferrin were also strongly correlated with weight and length growth of the infants during the study as well as with other indicators of protein nutritional status such as preprandial concentrations of plasma amino acids and serum and urine urea. These data indicate that of the 11 plasma proteins studied, transthyretin, transferrin, and retinol-binding protein are the most suitable to evaluate protein nutritional status in very low birth weight infants.
Assuntos
Proteínas Sanguíneas/análise , Proteínas Alimentares/metabolismo , Recém-Nascido de Baixo Peso/sangue , Estado Nutricional , Ingestão de Energia , Humanos , Recém-Nascido de Baixo Peso/crescimento & desenvolvimento , Recém-Nascido , Leite Humano/química , Leite Humano/metabolismo , Pré-Albumina/análise , Proteínas de Ligação ao Retinol/análise , Proteínas Plasmáticas de Ligação ao Retinol , Transferrina/análiseRESUMO
Urea concentrations in serum and urine were measured in 28 growing, very low birth weight, appropriate-for-gestational age infants fed varying human milk protein intakes (range 1.7 to 3.9 g/kg/day). We found a high correlation between serum urea values at the end of the study and mean protein intake (rs = 0.85, p less than 0.001) and between urinary urea concentrations in eight-hour urine collections and protein intake (rs = 0.81, p less than 0.001). All serum and urine urea values were below 1.6 and 18 mmol/l, respectively, at protein intakes less than 3 g/kg/day. Higher protein intakes caused higher serum and urinary urea concentrations. We also found a strong correlation between the individual serum and urinary urea values at the end of the study (rs = 0.90, p less than 0.001). The presented data are consistent with the growth data previously reported and indicate that inadequate or excessive protein intakes can be detected by measurement of urea concentrations in serum and/or urine. If urine urea samples alone can be used for estimating optimal protein intake, painful blood sampling procedures could be obviated.
Assuntos
Recém-Nascido de Baixo Peso/metabolismo , Proteínas do Leite/metabolismo , Ureia/análise , Humanos , Recém-Nascido de Baixo Peso/sangue , Recém-Nascido de Baixo Peso/urina , Recém-Nascido , Proteínas do Leite/administração & dosagem , Leite Humano/metabolismo , Ureia/sangue , Ureia/urinaRESUMO
The effects of different protein intakes on wt gain, insulin secretion, and plasma concentrations of amino acids have been evaluated in a prospective study involving 30 normal term infants. The infants were studied from 4.0 to 6.0 mo of age. Ten infants were breast-fed (BF), the others were randomly divided into two groups of 10 infants. One group was fed a formula containing 1.3 g protein/100 mL (F 1.3), the other a formula with 1.8 g protein/100 mL (F 1.8). The formulas were isocaloric (72 kcal/100 mL), and the fat concentrations were 3.5 g/100 mL (F 1.3) and 3.2 g/100 mL (F 1.8). All infants received the same supplementary foods. The urinary C-peptide excretion in the infants fed the F 1.8-formula was 4.4 +/- 2.1 nmol/mmol creatinine or 19.4 +/- 12.9 nmol/m2, significantly higher than that in the infants fed the F 1.3-formula (2.6 +/- 1.5 and 7.9 +/- 5.1) or the BF infants (1.7 +/- 1.4 and 6.3 +/- 6.0). Gain in wt was 18.0 +/- 4.3, 19.9 +/- 3.9, 22.8 +/- 1.6 g/kg/wk and corresponded to protein intakes of 1.3 +/- 0.2, 1.9 +/- 0.3, and 2.6 +/- 0.2 g/kg/d, in the BF, F 1.3, and F 1.8 groups, respectively. Gain in length was 6.7 +/- 1.8 (BF-group), 6.2 +/- 2.5 (F 1.3-group), and 7.6 +/- 2.2 (F 1.8-group) mm/m/wk. Wt gain correlated with urinary C-peptide excretion at 6.0 mo (r = 0.51, p less than 0.01) and with protein intake (r = 0.43, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aminoácidos/sangue , Proteínas Alimentares/administração & dosagem , Crescimento , Insulina/metabolismo , Peso Corporal , Peptídeo C/urina , Feminino , Humanos , Lactente , Secreção de Insulina , Masculino , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
A total of 20 healthy term infants between 4 and 6 months of age were randomly assigned to either a low protein formula (F1.3) containing 1.3 g protein/100 ml or a high protein formula (F1.8) containing 1.8 g protein/100 ml. Both formulas were isocaloric (72 kcal/100 ml) and had a whey-casein ratio of 50:50. Ten control infants were breast-fed (BF). The mean protein intakes (including supplementary foods) were 1.9 +/- 0.3, 2.6 +/- 0.2, and 1.3 +/- 0.2 g/kg/day, respectively. The mean concentrations of serum urea were 2.8 +/- 0.6 (F1.3), 4.1 +/- 0.6 (F1.8), and 2.2 +/- 0.8 mmol/liter (BF) at 6 months (F1.3 versus BF, NS, F1.8 versus BF, p less than 0.001). The urine excretion of nitrogen was similar in the F1.3 and BF groups being 81 and 78 mg/kg/day. In the F1.8-group nitrogen excretion was higher, 138 mg/kg/day. Plasma concentrations of albumin, prealbumin, and transferrin were normal and similar in the groups. Weight gain was significantly higher in the F1.8 group, 22.8 +/- 1.7 g/kg/wk when compared to the F1.3 and BF groups, 19.9 +/- 3.9 and 18.0 +/- 4.3 (p less than 0.01), respectively. These data indicate that a decreased protein-intake from formula during weaning results in many indices of protein metabolism and growth more similar to those found in BF infants than when conventional follow-up formulas are used.