RESUMO
OBJECTIVES: We studied the left ventricular systolic and diastolic function in preterm infants during the first month of life in comparison with the respective patterns in term neonates. STUDY DESIGN: Serial 2-dimensional/M-mode and Doppler transmitral flow velocity measurements were performed in 20 preterm (gestational age, 32 to 36 weeks) and 25 term infants between days 2 and 5 after birth and at age 1 month. RESULTS: After birth, the early velocity, early integral, early filling fraction, early and atrial velocity ratios, and early and atrial integral ratios were lower in the preterm than in the term infants (P <.01). During the first 4 weeks of life, these values, the atrial velocity, and the atrial integral increased gradually, whereas the atrial filling fraction, diastolic filling time, and deceleration time of early diastolic filling decreased slightly with postnatal age (P <.01) in the preterm infants. At age 1 month their diastolic function reached the level of term infants with the exception of early and atrial integral ratios and atrial filling fraction. The measures of systolic performance were within normal range, but midwall fractional shortening at 2 to 5 days (P <.05), and fractional shortening area (P <.05), as well as midwall fractional shortening (P <.01) at 1 month of age, were slightly inferior in the preterm than in the term infants. During the first month the left ventricular mass and left ventricular mass/body surface area ratio increased more markedly in the preterm than term infants, significantly in both groups (P <.05). CONCLUSIONS: The preterm diastolic patterns represent a transition between the patterns of the fetus and those of term neonates. These changes reflect an improvement in the left ventricular diastolic function, more markedly in relaxation than in compliance. The postnatal increase in the transmitral measures and left ventricular mass suggest marked myocardial adaptation to the extrauterine environment in the preterm infant already during the first month.
Assuntos
Diástole/fisiologia , Recém-Nascido Prematuro/fisiologia , Sístole/fisiologia , Função Ventricular Esquerda/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Desenvolvimento Infantil/fisiologia , Ecocardiografia Doppler , Feminino , Seguimentos , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Volume Sistólico/fisiologiaRESUMO
OBJECTIVE: To investigate cholesterol-lowering efficacy and safety of plant stanol ester margarine in healthy 6-year-old children already consuming a low-saturated-fat, low-cholesterol diet. STUDY DESIGN: Eighty-one intervention children from the STRIP project, a randomized prospective trial aimed at reducing exposure of young children to the known environmental atherosclerosis risk factors, were recruited to this double-blind crossover study at 6 years of age. In randomized order the families were advised to replace daily 20 g of the child's dietary fat intake with plant stanol ester margarine or control margarine for 3 months. The washout period lasted 6 weeks. Statistical analysis was performed according to intention-to-treat principle with analysis of variance for crossover design. RESULTS: The mean daily plant stanol ester margarine consumption was 18.2 g (1.5 g plant stanol). The well-tolerated plant stanol ester margarine reduced serum total and low-density lipoprotein cholesterol concentrations by 5.4% and 7.5%, respectively (P =.0001 for both). The serum high-density lipoprotein cholesterol and triglyceride concentrations and alpha-tocopherol to low-density lipoprotein cholesterol ratio remained unchanged. The serum beta-carotene to low-density lipoprotein cholesterol ratio decreased by 19% (P =.003). CONCLUSION: Plant stanol ester margarine significantly diminishes serum total and low-density lipoprotein cholesterol concentration without adverse clinical effects in healthy children who already consume a low-saturated-fat, low-cholesterol diet but decreases the serum beta-carotene to low-density lipoprotein cholesterol ratio.
Assuntos
Colesterol/sangue , Hipolipemiantes/administração & dosagem , Lipoproteínas LDL/sangue , Margarina , Sitosteroides/administração & dosagem , Criança , Pré-Escolar , Estudos Cross-Over , Gorduras na Dieta/administração & dosagem , Método Duplo-Cego , Finlândia , Humanos , Hipolipemiantes/efeitos adversos , Lactente , Lipoproteínas LDL/efeitos dos fármacos , Margarina/efeitos adversos , Estudos Prospectivos , Valores de Referência , Sitosteroides/efeitos adversos , Fatores de TempoRESUMO
OBJECTIVE: To determine the influence of gender, apolipoprotein E phenotypes, and diet on the interindividual variances in serum lipid and lipoprotein concentrations in children at 7 and 13 months of age. STUDY DESIGN: Prospective randomized intervention trial. Half of 1062 families with 7-month-old infants received dietary and lifestyle counseling aimed at partially replacing saturated fat with mono- and polyunsaturated fat and reducing exposure to other known atherosclerosis risk factors. This study comprises all trial children who at 8 months of age received, in addition to solid food, only breast milk or only formula (N = 553). Forward stepwise multiple regression analysis was used in the evaluation of the contributions of gender, apolipoprotein E phenotype, and diet. RESULTS: Apolipoprotein E phenotypes, gender, and milk type provided independent information concerning serum lipid values at 7 and 13 months of age (three-way ANOVA, p < 0.01). At 7 months, milk type was the most significant predictor of total, non-high-density lipoprotein and high-density lipoprotein cholesterol and apolipoprotein B and A1 concentrations. At 13 months when the effects of gender (5%) and apolipoprotein E type (5%) were excluded, diet predicted only 2% of the variance in serum cholesterol concentration. The apolipoprotein E type predicted 8% of the variance in non-high-density lipoprotein cholesterol concentration and 7% of the variance in apolipoprotein B concentration (p < 0.001), together explaining only 3% of the variance in serum high-density lipoprotein cholesterol and apolipoprotein A1 concentrations. CONCLUSIONS: At 7 months of age diet is an important predictor of serum lipid and lipoprotein concentrations. At the age of 13 months the apolipoprotein E phenotype significantly predicts the concentrations of serum non-high-density lipoprotein cholesterol and apolipoprotein B. However, at both ages apolipoprotein E phenotype, gender, and diet together explain only from 1.4% to 15.5% of the variance in serum lipids and apolipoproteins, suggesting that other, presumably genetic, factors are major determinants.