Healthy Low Birth Weight Infants Research Articles

Effects of iron supplementation on serum hepcidin and serum erythropoietin in low-birth-weight infants

The iron-regulatory hormone hepcidin has not been studied in infants, who experience large physiologic changes in iron status. The objective was to study hepcidin and erythropoietin and their correlation with iron status in iron-replete and iron-deficient low-birth-weight (LBW) infants-a group at particular risk of iron deficiency (ID). We randomly assigned 285 otherwise healthy LBW infants to receive, from 6 wk to 6 mo of age, 3 doses of iron supplements: 0 (placebo), 1, or 2 mg/kg daily. Hepcidin, erythropoietin, hemoglobin, and variables of iron status were analyzed. Serum hepcidin did not change over time in the placebo group, despite a rapid decrease in serum ferritin. In iron-supplemented infants, hepcidin increased significantly, reaching a mean (±SD) concentration of 19.2 ± 2.5 ng/mL in the 2-mg/kg group compared with 13.0 ± 2.6 ng/mL in the placebo group at age 6 mo (P < 0.001). The difference was even larger between iron-deficient and iron-replete infants. Hepcidin was independently positively correlated with ferritin at all ages and was negatively correlated with the transferrin receptor concentration at age 6 wk and with transferrin at age 6 mo. Erythropoietin was initially similar between groups but decreased significantly in iron-supplemented infants. In addition to being negatively correlated with hemoglobin, it was also independently negatively correlated with indicators of iron status. Hepcidin is closely associated with iron status and may be a useful indicator of iron stores and ID in infants. Erythropoietin is negatively correlated with iron status, which suggests a feedback mechanism that needs further study. This trial is registered at clinicaltrials.gov as NCT00558454.

Effects of Iron Supplementation on Serum Hepcidin in Low Birth Weight Infants

Background and aims: The iron regulatory hormone hepcidin has not been studied in infants, who experience large physiological changes in iron status. The objective was to study hepcidin and its correlation to iron status in iron-replete and iron-deficient low birth weight (LBW) infants, a group at particular risk of iron deficiency (ID).Methods: We randomized 285 healthy LBW infants to receive three different levels of iron supplements; 0 (Placebo), 1, or 2 mg/kg/day, from 6 weeks to 6 months of age. Hepcidin, Hb, and six variables of iron status were analyzed.Result: Serum hepcidin did not change over time in the placebo group, despite a rapid decrease in serum ferritin. In iron supplemented infants, hepcidin increased significantly, reaching a mean (SD) concentration of 19.2 (2.5) ng/mL in the 2 mg/kg/day-group vs 13.0 (2.6) ng/mL in the placebo group at 6 months (p < .001). Figure [Hepcidin responce to iron supplements] The difference was even larger between iron-deficient infants and iron-replete infants at 6 mo (7.0 (2.9) ng/mL vs 21.6 (2.4) ng/mL). Hepcidin was independently correlated to ferritin and transferrin receptor concentration at 6 wk, ferritin alone at 12 wk, and to ferritin, transferrin, and Hb at 6 mo.Conclusions: Hepcidin is closely associated with iron status and may be a useful indicator of iron stores in infants, possibly less age dependent than ferritin.

Perinatal hip assessment in very low birth weight infants

Fifty healthy low birth weight infants (less than 1500 g) without risk factors for congenital hip dysplasia (CHD) were examined by ultrasonography (100 hips) at 40 weeks corrected age and controlled at 3 months postnatal age. Sonographic assessment was performed using the classification of Graf. A physiological delay of hip maturation was observed in 10% of the patients (type IIa). At follow-up all of them had normal hip morphology without any pathological finding. Our results suggest that prematurity alone should not be considered a risk factor for CHD.

Assessment of neonatal jaundice in low birth weight infants comparing transcutaneous, capillary and arterial bilirubin levels

Total serum bilirubin level was assessed in a group of jaundiced low birth weight infants using three different methods. Transcutaneous bilirubinometry was compared with conventional capillary and arterial methods to investigate the over-or underestimation of neonatal jaundice. Sampling site did not influence bilirubin levels. Capillary and arterial results showed a linear correlation (r = 0.9) suggesting no influence of environmental light on peripheral bilirubin isomerization. Similar results were obtained comparing both serum levels with transcutaneous values (r = 0.7). We conclude that treatment decisions may be made on the basis of one of the three mentioned methods in healthy low birth weight infants with neonatal jaundice.

Pulmonary mechanics and energetics of normal, non‐ventilated low birthweight infants

Pulmonary mechanics and energetics were determined in 33 healthy low birthweight infants (less than 1,500 g, 28-34 weeks gestation) who had never received ventilatory support. Tidal volume, dynamic pulmonary compliance, pulmonary resistance, pressure-volume relationships, and tidal flow-volume measurements were obtained by pneumotachography and the esophageal balloon technique. Standardized data collection and software data analysis by least mean squares technique yielded data at 0.5, 1, 2, and 4 weeks postnatally, as a function of gestational age (less than 30, 30-32, and greater than 32 weeks gestation). Relatively stable values were obtained for tidal volume and minute ventilation (normalized for body weight); these were associated with values of peak-to-peak esophageal pressure significantly (P less than 0.001) increasing from 4.4 +/- 0.3 SEM cmH2O at 0.5 weeks to 8.1 +/- 0.8 SEM cmH2O at 4 weeks of age. Dynamic pulmonary compliance ranged from 2.0 to 2.4 mL/cmH2O in the first 4 weeks of life. When normalized for weight, compliance decreased with age, which may suggest a slower pulmonary maturation as compared to increase of body weight. Mean pulmonary resistance decreased from 62.9 cmH2O/L/s at less than 30 weeks gestation to 32.5 cmH2O/L/s at greater than 32 weeks gestation, 0.5 weeks postnatally. Pulmonary resistance peaked at 2 weeks postnatally (P less than 0.05), at all gestational ages, then decreased. Changes in pulmonary mechanics resulted in increasing resistive work of breathing. Our findings suggest a postnatal retardation of pulmonary and airway growth, relative to gestation maturation. These data can provide an objective base of comparison for data in sick, low birthweight neonates.

IMPORTANCE OF FORMULA Ca/Pi RATIO ON CALCIUM BALANCE IN THE LOW BIRTHWEIGHT INFANTS DURING THE FIRST THREE DAYS OF LIFE

Twenty four healthy low birthweight infants were placed into three groups according to the formula fed. Group 1(10 infants) received a formula with a Ca/Pi ratio of 2.4 .Group 2 (9 infants) a Ca/Pi ratio of 1.6 and Croup 2s the same formula as Group 2 but supplemented with calcium lactate giving off a Ca/Pi ratio of 4.2 . All ratios were obtained after 78 determinations of formula feedings. Pi content in Group 1 formula was significantly lower (p < 0.01) than in Group 2 and 2s. No differences (F) were detected in the neonatal status. Calcium retention (mg/Kg/d) was significantly higher (p < 0.05) in Group 1 than in Group 2 (50.8±15.9 versus 39.3±12.8) but lower than in Group 2s (107.7±25.6 ; p < 0.001).Magnesium retention was 5.6±2.3; 4.6±1.8 and 5.6±2.1 respectively with no significant differences. Pi retention was significantly higher (p < 0.01) in Group 2 (39.2±5.2) than in both Group 1 (31.4±5.6) and Group 2s (31.9±3.6). Calcium retention correlates (r = 0.79 p < 0.001) with the real Ca/Pi ratio. Hypocalcemia appeared only in two infants from Group 2. According to these data, higher Ca/Pi ratios increase calcium and decrease Pi retention.

A Study of the Development of Somatosensory Evoked Potential in Developing Brain. I. On Healthy Low Birth Weight Infants

A Study of the Development of Somatosensory Evoked Potential in Developing Brain. I. On Healthy Low Birth Weight Infants

Time course of gamma glutamyl transpeptidase in the serum of low birth weight infants

The time course of gamma-glutamyl transpeptidase (GGTP) was traced during a number of weeks after birth in 31 apparently healthy low birth weight infants. Also glutamic-pyruvic transaminase (GPT), 5'-nucleotidase (5 'ND) and alkaline phosphatase (AP) were determined in most of the same samples. In many of the prematures, but not in all, the GGTP showed a transient elevation, reaching maximal levels up to 150 I.U. Most values of GPT and 5'ND, however, were within the normal range, whereas for AP rather large variations were found. No age dependency could be established for the appearance of the GGTP maximum; neither the period of its occurrence nor its height showed a correlation to birth weight and to the degree of prematurity. The significance of transient GGTP activity in prematures is discussed. The results of our investigations suggest that in such infants increased values of GGTP have to be interpreted very carefully. Other enzyme and chemical parameters have to be considered simultaneously in order to establish cholestatic liver disease.