Aldosterone cord levels in preterm newborn infants

We measured umbilical cord aldosterone concentrations in 64 premature newborn infants. The median serum aldosterone level was 74.5 ngdl^-1 (range 22-280 ng dl^-1). Of the studied perinatal factors, only gestational age and birthweight presented a significant influence on the umbilical cord aldosterone levels. Newborn infants with a gestational age of over 34 weeks and a birthweight of over 2000 g had a significantly higher aldosterone cord level than those aged 34 weeks or younger and 2000 g or less in weight.     

Urinary excretion of lactose and oligosaccharides in preterm infants fed human milk or infant formula

At present, not much is known about the absorption and metabolism of human milk (HM) oligosaccharides in term and preterm infants. We investigated the renal excretion of lactose and complex oligosaccharides in preterm infants fed HM ( n = 9, mean actual body weight 2290 g) or a cow's milk-based infant formula ( n = 9, mean actual body weight 2470 g). We found that the renal excretion of lactose in HM-fed infants was slightly lower than in formula-fed infants (14.0 ± 7.4 versus 20.4 ± 8.7 mg kg^-1 day^-1, mean ± SD). The excretion of neutral sugars deriving from oligosaccharides was similar in HM-fed and formula-fed infants (3.8 ± 2.1 versus 2.9 ± 0.9mgkg^-1 day^1-); the difference between means was not statistically significant. The separation and characterization of oligosaccharides by high-pH anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) and subsequent analysis by fast atom bombardment-mass spectrometry (FAB-MS) revealed a more complex pattern in HM-fed infants compared to the formula-fed group. Lactose-derived oligosaccharides characteristic for HM (e.g lacto- N -tetraose, and lacto- N -fucopentaoses I and II) were excreted in HM-fed but not in formula-fed infants. These results indicate that nutrition has a significant impact on the oligosaccharide composition in urine of preterm infants.     

Levels of lipoprotein(a) and plasma lipids in Spanish children aged from 4 to 18 years

Increased plasma lipoprotein(a)-Lp(a)-levels are linked to a high risk of cardiovascular disease unrelated to other lipoproteins. It seems that Lp(a) values in childhood remain unaltered up to adulthood. In a randomly chosen population of 1970 children, aged from 4 to 18 years and living in a Spanish community, the following serum parameters were studied: total cholesterol, total triglycerides, Lp(a), high-density lipoprotein cholesterol and low-density lipoprotein cholesterol. Mean Lp(a) serum values were 15.0 ± 14.7mg dl^-1. No differences were seen between either sex in the first years of childhood. Of the studied children, 15.1% presented Lp(a) concentrations above 30 mg dl^-1. A correlation between Lp(a) and total cholesterol concentrations, which disappeared when low-density lipoprotein cholesterol concentrations were corrected according to cholesterol present in Lp(a), was observed.     

Infantile colic and small intestinal function: a nutritional problem?

Approximately 25% of infants with moderate or severe colic (crying > 3 h d⁻¹) have a cow's milk-dependent colic. The author recommends a strict cow's milk-free diet for the mother (with an extra supplement of calcium) in breastfed infants and a casein-hydrolysate formula for formula-fed infants. With this dietary regimen, there will be no nutritional problems. Later in infancy a relatively high proportion of the infants will continue to show an adverse reaction to cow's milk and will also develop allergies to other foods. Several signs (e.g. increased macromolecular absorption, increased motilin levels in serum, increased breath hydrogen excretion, decreased gallbladder contractility) indicate an abnormal intestinal function in colicky infants. The nature of this abnormality is still unknown.     

Neural maturation of breastfed and formula-fed infants

Background: Human milk provides infants with a full complement of all polyunsaturated fatty acids, including docosahexaenoic acid (DHA) and arachidonic acid (AA). Formula milks only contain the precursors of DHA, AA and linoleic acid, and hence formula-fed infants must synthesize their own DHA and AA. Aim: To evaluate the effect of feeding—whether breastfeeding or formula-feeding—in early infancy upon subsequent neurodevelopment and achievement of optimum brain function. Subjects and methods: The study included 53 normal, healthy infants (30 exclusively breastfed infants and 23 exclusively formula-fed infants) at the age of 1 y (±1 mo). Each infant was subjected to a full physical and neurological examination together with neurophysiological studies including flash visual evoked potential (FVEP), brainstem auditory evoked potential (BAEP) and somatosensory evoked potential (SSEP). Results: There was significant prolongation of P ₁₀₀ wave latency of FVEP in formula-fed infants, together with significant prolongation of absolute latency of waves I, III and V of BAEP in formula-fed infants compared with breastfed infants. There was significant prolongation in inter-peak latencies between cortical and Erb's components in formula-fed infants compared with breastfed infants.

Conclusion: We can conclude that VEP, BAEP and SSEP are more mature in breastfed infants relative to formula-fed infants at 1 y of age, and thus breast milk helps earlier development and maturation of some aspects of the nervous system than milk formulas.     

α-Lactalbumin-enriched low-protein infant formulas: a comparison to breast milk feeding

Tryptophan (TRP) is the limiting amino acid in low-protein infant formulas. This is mainly due to lower α-lactalbumin (αLA) content in cow's milk whey as compared with human milk protein. To study the effect of αLA-enrichment on the TRP supply, cross-over studies were carried out in 20 healthy infants up to 3 months of age. In this study, two protein-reduced (1.3%) infant formulas (moderate TRP content of 1.88% and higher TRP content of 2.10%) were alternately fed over a 2 week period in two groups of infants. Serum TRP levels of the formula-fed infants with the higher TRP content did not differ significantly from an exclusively breastfed control group of 11 infants (10.5 ±4.8 versus 10.9±4.7mgl^-1, p = 0.841), whereas levels of the formula-fed infants with the moderate TRP content were significantly lower (7.4 ± 3.9, p = 0.038). The supplementation of αLA resulting in a higher TRP supply to low-protein diets is a further step towards the production of infant formulas more closely adapted to human breast milk.     

Leptin levels in breast-fed and formula-fed infants

Aim: Leptin, a hormone that regulates food intake and energy metabolism, is present in breast milk and thus may be involved in body composition differences between breastfed and formula-fed infants. The aim of this study was to evaluate whether diet and gender affect plasma leptin concentration in breastfed and formula-fed infants during the first months of life. Methods: Anthropometric and bioelectrical impedance measurements [total body water (TBW) calculated with the Fjeld equation] were made and venous blood plasma samples were analysed for leptin concentration in healthy, exclusively breastfed or formula-fed Italian infants in the first year of life. Infants were subdivided in two ways: three groups (periods) in relation to age, and five groups in relation to weight. Results: The average serum concentration of leptin was 7.35 ng ml -1 . Serum leptin values were higher in breastfed than in formula-fed infants. Breastfed infants in group 1 had a statistically higher serum leptin concentration (2500-3749 g). There were no significant differences in anthropometric measurements, body mass index or skinfold thickness between breastfed and formula-fed infants. In the periods I and II, breastfed infants had a significantly higher TBW than formula-fed infants. Males had a significantly higher TBW than females in periods I and II. Breastfed infants in group 2 (3750-4999 g) had a significantly higher TBW than formula-fed infants.

Conclusion: The data on TBW, weight and skinfold thickness suggest that the higher leptin concentration observed in breastfed infants in the first months of life may be due not only to adipose tissue production but also to human milk.     

Vitamin K status of lactating mothers and their infants

Vitamin K deficiency remains a world-wide problem in the newborn. Vitamin K traverses the placenta from mother to infant very poorly and is present only in very low concentrations in human milk. Thus, it is not surprising that the newborn infant has undetectable vitamin K serum levels with abnormal amounts of the coagulation proteins and undercarboxylated prothrombin. Hemorrhagic disease of the newborn, secondary to vitamin K deficiency, remains largely a disease of breastfed infants. Lactating mothers easily achieve the recommended dietary allowance for vitamin K (1 μg kg⁻¹ d⁻¹) and the breast milk concentration is readily increased by increasing maternal vitamin K intake. Breastfed infants do not receive the recommended vitamin K intake via human milk. To prevent vitamin K deficiency in the newborn, intramuscular or oral vitamin K prophylaxis is necessary.     

Plasma lipids and apolipoproteins in breastfed and formula-fed Swedish infants

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.     

Ghrelin, leptin and the neurometabolic axis of breastfed and formula-fed infants

The possible long-term effects of prolonged breastfeeding in preventing obesity have led to the reconsideration of different growth curves of breastfed and formula-fed infants in the light of haematochemical markers. Leptin, ghrelin, insulin-like growth factors and other compounds may not only represent mediators involved in the metabolism of fat tissues, but may also potentially be able to explain the complex relationships between the gastrointestinal tract and the hypothalamic regulation of the sense of hunger and satiety.

Conclusion: Diet-related differences in the circulating levels of mediators implicated in energy metabolism during infancy might explain anthropometric and behavioural differences between breastfed and formula-fed infants with potential long-term consequences.     

Serum bilirubin levels at 72 hours by selected characteristics in breastfed and formula-fed term infants delivered by cesarean section

The present multicenter study analysed the relative impact of maternal and infant factors on serum bilirubin levels at 72 +/- 12 h in exclusively breastfed vs formula-fed term infants. End-tidal carbon monoxide levels corrected for ambient air (ETCOc), an index of bilirubin production, were measured in exclusively breastfed (B = 66) or formula-fed (F = 210) term infants at 2-8 h of age. Inclusion criteria included cesarean section to ensure a 3 d hospitalization, birthweight > or = 2,500 g, gestational age >37 wk and absence of any illness. The ETCOc for B infants and F infants did not differ significantly (1.3 +/- 0.7 ppm vs 1.3 +/- 0.8 ppm). The serum bilirubin level at 72 +/- 12 h was significantly higher in B infants than in F infants (8.5 +/- 3.4mg dl(-1) vs 6.7 +/- 3.4mg dl(-1) p < 0.001), as was the percentage weight loss from birthweight. Serum bilirubin levels were significantly higher in infants who were male, who did not have meconium-stained amniotic fluid, and in those whose mothers were insulin-dependent diabetics or hypertensive. There was no difference between groups in the need for phototherapy or exchange transfusion. CONCLUSION: Although higher bilirubin levels were observed in group B at 72 +/- 12 h compared with group F, this finding was not of clinical or therapeutic consequence in this study. The lack of difference in ETCOc between the groups may be a factor of the timing of ETCOc measurement in this study, or may suggest that early increased bilirubin production is not a significant contributor to jaundice observed in exclusively breastfed infants. Key words: bilirubin, breastfeeding, jaundice     

Protein Intake during Weaning

ABSTRACT. Metabolic responses to different feeding regimens during the weaning period have not previously been studied. In this study 30 healthy infants aged 4–6 months were divided into three feeding regimens with 10 infants in each. The regimens were: Human milk (HM-group), formula F₁ with 1.9g protein/100 ml (F₁-group) or formula F² with 2.7 g protein/100 ml (F₂-group). All infants received the same supplementary food and were fed ad libitum. Concentrations of serum urea were significantly higher ( p <0.001) in the formula groups as compared to the breast-fed infants throughout the entire study period. Serum albumin concentrations were within normal limits in the breast-fed infants indicating adequate protein nutritional status. There were no differences in the concentrations of creatinine and total nitrogen in urine between the artificially fed and the breast-fed infants at the beginning of the study (4 months), but at 6 months these concentrations were significantly higher in the formula-fed infants ( p <0.001). The results suggest that formulas now in common use during weaning provide amounts of protein which produce metabolic manifestations implying excessive protein intakes.     

Decreased ferritin levels, despite iron supplementation, during erythropoietin therapy in anaemia of prematurity

Erythropoietin (rHuEPO) therapy has been shown to be beneficial in preventing and treating anaemia of prematurity and to decrease the need for blood transfusions. There is, however, only scanty data on the effect of rHuEPO therapy on iron metabolism. We studied 29 preterm infants (age 34 ± 14 days) who were randomly assigned to receive either rHuEPO 900 U kg^-1 week^-1 with 6 mg kg^-1 day^-1 of iron for 4 weeks ( n= 15) or no therapy. The following parameters were evaluated and compared between and within groups at the beginning, during and at the end of the study: Haematocrit (SI), reticulocytes (10⁹μgl^-1), serum ferritin (μg1^-1) and iron (μmol 1^-1). The results were as follows. At the baseline, erythropoietin levels were similar in both groups: 7.2 ± 5.6 versus 6.2 ± 3.2 mU ml^-1 (NS). In the treated infants the haematocrit remained stable during the study and was significantly higher than in the control group by the end of the study: 0.34 ± 0.03 versus 0.28 ± 0.05 ( p = O.001). rHuEPO therapy increased the reticulocyte count from 130 ± 70 to 430 ± 200 ( p = 0.0002). However, rHuEPO therapy depleted both serum ferritin and it-on levels from 321 ± 191 to 76 ± 58 $uMgl^-1 ( p = 0.04) and from 18 ± 5 to 13 ± 4 μmoll^-1 ( p = 0.03), respectively. We conclude that rHuEPO therapy prevented anaemia and its sequelae; however, serum ferritin and iron levels were depleted. We suggest that the effect of rHuEPO may be further increased by higher iron supplementation.     

Selenium status of preterm infants: the effect of postnatal age and method of feeding

Indicators of selenium (Se) status were measured in a longitudinal study of 63 preterm and 46 term infants. Se levels in both groups were similar in the first few days of life. Preterm infants fed parenteral nutrition (PN) for several weeks developed very low plasma Se levels (<10/μg/l). In those receiving either breast milk or formula in conjunction with PN, plasma Se also declined over the first 6 weeks. In the breastfed term infants plasma levels increased by 50%, but there was no increase in the term formula-fed group. In healthy preterm infants who received mainly breast milk, plasma Se concentrations remained constant at newborn levels and were below those of breastfed term infants at 6 weeks. Erythrocyte GSHPx activity did not reflect plasma Se or Se intake. In conclusion, the type of feeding, and hence Se intake, influenced plasma Se concentration in preterm infants. Provision of enteral feeding in conjunction with PN was unable to prevent a decline in plasma Se and at 6 weeks levels were well below those of the reference breastfed term infants.     

Plasma total homocysteine increases from day 20 to 40 in breastfed but not formula-fed low-birthweight infants

Homocysteine is an intermediate in the folate cycle and methionine metabolism. This study investigated whether formula-fed infants have different plasma total homocysteine to their breastfed counterparts, and during what period any difference developed. Plasma total homocysteine was determined in 53 formula-fed and 15 breastfed healthy low-birthweight babies (< or = 2500 g) around days 10, 20 and 40. Total homocysteine was also measured in human milk. Mean +/- SD plasma total homocysteine levels (micromol l(-1)) at days 10, 20 and 40 were 6.4 +/- 2.6, 6.7 +/- 2.4 and 9.1 +/- 2.4 (breastfed), and 7.5 +/- 3.2, 7.3 +/- 2.1 and 7.4 +/- 1.6 (formula-fed). Homocysteine of breastfed babies at day 40 was higher than that of breastfed babies at day 20 (p < 0.0001), and that of formula-fed counterparts at day 40 (p = 0.002). Homocysteine correlated negatively with formula (day 10) and breast milk (day 40) volume intakes. Median (range) homocysteine in 12 mature human milk samples was 0.30 (not detectable to 0.7) micromol l(-1). Conclusion: Increasing plasma total homocysteine in breastfed babies to higher levels compared with formula-fed babies may be caused by a gradually developing suboptimal B-vitamin status in lactating women.     

Serum levels of CD14 in neonatal sepsis by Gram-positive and Gram-negative bacteria

The purpose of this study is to measure soluble CD14 (sCD14) levels in sera from newborn with sepsis, to compare it with other markers, and to study its evolution in Gram-negative and Gram-positive sepsis. Forty normal newborns were included (26 were full term and 14 were preterm infants), 20 babies had a positive blood culture (11 Gram-positive and 9 Gram-negative) and 16 cases were suspected of having sepsis based on clinical and laboratory findings, but a negative blood culture. Interleukin-6 (IL-6), sCD14, and tumour necrosis factor-α (TNFα) were measured by enzyme immunoassay, and fibronectin (FN) and C-reactive protein (CRP) by radial immunodiffusion. Neonates with a positive blood culture had increased levels of sCD14(3.20 ± 1.26μgml^-1, p < 0.001), CRP(69 ± 46 μgml^-1, p < 0.001)and IL-6 (134 ± 150 pg ml^-1, p < 0.001), and decreased values of FN (12.3 ± 6.6 mg ml^-1, p < 0.001). TNFα levels were also high (160 ± 37 pg ml^-1), but this increase was not statistically significant. Newborn infants suspected of having sepsis but a negative blood culture had similar but milder abnormalities. Soluble CD 14 levels correlated with CRP values; however, there was no correlation between sCD 14, TNFα and IL-6. Neonates with sepsis by Gram-positive bacteria had lower sCD14 levels than patients with Gram-negative sepsis (2.63 ± 1.2 versus 4.04 ± 1.0μgml^-1, p < 0.05). In conclusion, the sCD14 level is increased in newborn infants with sepsis, and this is higher in infections by Gram-negative bacteria, suggesting a different contribution of monocyte and macrophage cells. In contrast, IL-6, TNFα, CRP and FN values are similar in infections by Gram-positive and Gram-negative bacteria.     

Coronary risk factors in Turkish school children—report of a pilot study

In 432 school children aged 7–15 years we investigated the following parameters: body mass index, blood pressure, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. Only 2.8% of children were considered to be obese. Of the children, 3.5% had systolic, 4.9% had diastolic and 3.9% had both blood pressures higher than the acceptable age- and sex-stratified values. The mean total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels were 3.37, 1.93 and 1.33 mmol1^-1 respectively. In 31 (7.1%) of the children, total cholesterol levels were found to be above the risk cut-off level of 4.4 mmol l^-1; in 39 (9%) of the children, low-density lipoprotein cholesterol levels were elevated above an acceptable upper limit of 2.84 mmol1^-1. Significantly reduced high-density lipoprotein cholesterol values were observed in 8.8%. Mean total cholesterol and low-density lipoprotein cholesterol values were elevated significantly in hypertensive cases, while high-density lipoprotein cholesterol levels showed no difference. Sensitivity and the positive predictive value for selected total cholesterol cut-off points for determining elevated low-density lipoprotein cholesterol were 67% and 54%, respectively. These levels of risk are considerably lower than those found in studies in Western countries.     

Infant feeding and early neonatal jaundice

The feeding patterns and third day serum bilirubin levels were evaluated in 30 newborn infants receiving formula feeds in the neonatal special care unit and in 30 breastfed babies. Initiation of milk feeds were delayed in breast-fed babies and the frequency of feeding was significantly lower than in the formula-fed infants. Supplementary water was given only in the breast-fed group. Serum bilirubin levels were significantly higher in breast-fed infants (9·74±3·17 ml/dl) than those on formula (6·59±3·50 mg/dl), t=3·69, p<0·001). There appeared to be no influence of supplementation with water.     

High and low dose initial thyroxine therapy for congenital hypothyroidism

Objective : To assess factors influencing thyroxine (T₄ levels 1 month after initiating replacement therapy for congenital primary hypothyroidism.
Methodology : A retrospective review of 41 children with congenital hypothyroidism who received either high or low dose initial T₄ therapy. Thyroid scintiscan was performed, and T₄ levels determined before starting treatment and after 1 month.
Results : T₄ levels at 1 month were correlated ( r ²=0.38, P <0.001) with the pretreatment T₄ level ( r = 0.48), as well as with the T₄ dose ( r = 0.46). Suboptimal treated T₄ levels (<130nmol/L) were seen with greater frequency in infants with thyroid agenesis (7/11) rather than ectopia (7/28, P <0.03), despite receiving similar doses of thyroxine. Infants with suboptimal treated T₄ levels had lower pretreatment T₄ levels than those with optimal levels (21±7 vs 48±34nmol/L, P <0.02). Biochemical hyperthyroidism (T₄ >216nmol/L) occurred in six patients: four of six had ectopia.
Conclusions : These data suggest that infants with little residual thyroid function should receive higher initial T₄ doses than those with significant ectopia.     

Effects of early postnatal dexamethasone therapy on calcium homeostasis and bone growth in preterm infants with respiratory distress syndrome

The effects of dexamethasone therapy on calcium homeostasis and bone growth were evaluated in 49 infants (24 placebo and 25 dexamethasone) who participated in a double-blind trial of early dexamethasone therapy for the prevention of chronic lung disease. Dexamethasone (0.25 mg kg^-1 b.i.d. on d 1–7; 0.12 mg kg^-1 b.i.d. on d 8-14; 0.05mg kg^-1 b.i.d. on d 15-21; 0.02mg kg^-1 b.i.d. on d 22-28) or saline placebo was given i.v. Serum calcium (Ca), phosphorus (P) and parathyroid hormone (PTH), and the corresponding urinary excretion of calcium (FE_Ca) and phosphorus (FE_P) were measured on d 2, 3, 7, 10, 14, 21 and 28 after starting the study. Radiographic evaluations of bone growth were also evaluated. Infants in the dexamethasone group had significantly higher PTH on d 2 ( p < 0:01), 7 and 14 ( p < 0:05) than infants in the placebo group. The dexamethasone-treated infants also had significantly higher FE_P on d 2,7 and 14 ( p < 0:05) and lower FE_Ca on d 7 and 14 ( p < 0:05) than control infants. There was no significant difference between the groups in bone growth during the study. It was concluded that early dexamethasone therapy causes a transient elevation in PTH without apparent change in bone growth. The long-term effect remains to be evaluated further.