Feeding iron-fortified premature formula during initial hospitalization to infants less than 1800 grams birth weight.

OBJECTIVE: A randomized, double-blind study was conducted comparing high-iron content (15 mg/L) with low-iron content (3 mg/L) premature formula given during initial hospitalization to infants with birth weights less than 1800 g to determine the influence of these differing intakes on the iron nutritional status during the first 4 months of life. A third group of similar infants received human milk mixed with an equal volume of liquid fortifier resulting in an iron content of approximately 1.7 mg/L. PATIENTS AND METHODS: Mean birth weight, gestational age, age at study entry, volume of blood removed for studies, and volume of red cells transfused were not different among the three groups. After hospitalization both formula-fed groups were given a cow milk formula with an iron content of 12 mg/L, and breast-fed infants were given an iron-containing multivitamin with a resulting iron intake of 10 mg/d. Infants were observed to 8 weeks after discharge. RESULTS: There were no differences in serum iron, ferritin, transferrin, transferrin saturation, hemoglobin, hematocrit, or reticulocyte count among the three groups at study entry, although mean corpuscular hemoglobin and mean corpuscular volume were lower in infants in the low-iron formula group. Mean plasma ferritin was significantly lower in infants receiving low-iron content premature formula at the time of hospital discharge compared with the other two groups. The incidence of anemia (hemoglobin < 9.0 g/dL) and low transferrin saturation (< 24%) was also greater in the low-iron content formula group. Eight weeks after discharge, the incidence of low plasma ferritin (< 19 ng/mL) remained greater in infants receiving low-iron content formula than in the other two groups. No adverse effects of iron intake were observed. Growth was not different among the three groups. CONCLUSIONS: These data indicate that preterm infants with < 1800 g birth weight receiving premature infant formula benefit from formula given during initial hospitalization containing 15 mg/L iron compared with that containing 3 mg/L.

Frontal brain asymmetry and immune function.

The relation between brain activity and the immune system was evaluated by assessing immune responses in 20 healthy women who manifested extreme differences in the asymmetry of frontal cortex activation. One group showed extreme and stable left frontal activation; the other group showed extreme and stable right frontal activation. As predicted, women with extreme right frontal activation had significantly lower levels of natural killer cell activity (at effector:target cell ratios of 33:1 and 11:1) than did left frontally activated individuals. This difference did not extend to two other immune measures, lymphocyte proliferation and T-cell subsets. However, higher immunoglobulin levels of the M class were observed in the right frontal group. In this study, the immune patterns could not be accounted for by plasma cortisol levels, anxiety- and depression-related symptomatology, or recent health histories. These findings support the hypothesis that there is a specific association between frontal brain asymmetry and certain immune responses.

Individual differences in anterior brain asymmetry and fundamental dimensions of emotion.

This research assessed whether individual differences in anterior brain asymmetry are linked to differences in basic dimensions of emotion. In each of 2 experimental sessions, separated by 3 weeks, resting electroencephalogram (EEG) activity was recorded from female adults during 8 60-s baselines. Mean alpha power asymmetry across both sessions was extracted in mid-frontal and anterior temporal sites. Across both regions, groups demonstrating stable and extreme relative left anterior activation reported increased generalized positive affect (PA) and decreased generalized negative affect (NA) compared with groups demonstrating stable and extreme relative right anterior activation. Additional correlational analyses revealed robust relations between anterior asymmetry and PA and NA, particularly among subjects who demonstrated stable patterns of EEG activation over time. Anterior asymmetry was unrelated to individual differences in generalized reactivity.

Feeding of premature infant formula after hospital discharge of infants weighing less than 1800 grams at birth.

A randomized, double-blind study was conducted to determine whether continued feeding of premature infant formula after hospital discharge improve biochemical measures of bone mineral or protein status and anthropometrics during the first 8 and 12 weeks, respectively, after initial hospital discharge. Forty-three subjects were randomized to receive either a 20 kcal/ounce standard cow's milk-based formula with iron or a 20 kcal/ounce premature infant formula with iron for 8 weeks after hospital discharge. Sixteen exclusively breast-fed infants (mother's own milk) who received a multivitamin supplement with iron were compared with infants in both formula groups. There were no differences among the three groups in gender, birth weight, gestational age, or weight and age at the time of study entry. Alkaline phosphatase values were lower in infants receiving premature infant formula than in those receiving standard formula 8 weeks after discharge. Phosphorus values were lower and alkaline phosphatase values higher in the human milk-fed group than in both formula groups 8 weeks after discharge despite supplementation with calcium, phosphorus, and vitamin D before and during the study. At 8 weeks after discharge, human milk-fed infants also had lower transferrin levels than infants fed formulas. Infants in both formula groups grew similarly in weight, whereas the infants fed human milk weighed less throughout the study. The group fed premature infant formula had greater mean length and head circumference than the standard formula or human milk-fed groups. These data indicate that premature infants weighing < 1800 gm at birth may benefit from the continuation of premature infant formula during the first 8 weeks after initial hospital discharge.

Calcium and phosphorus supplementation after initial hospital discharge in breast-fed infants of less than 1800 grams birth weight.

This study evaluated whether calcium and phosphorus supplementation after initial hospital discharge was advisable in infants of < 1800 gm birth weight who were being breast fed. Twenty-seven infants (15 without any illness affecting nutritional intake and 12 with medical illness) received breast milk plus a liquid human milk fortifier mixed 1:1 and 400 IU vitamin D daily during initial hospitalization. At discharge, 12 infants (6 without and 6 with previous illness) were randomly assigned to receive calcium and phosphorus supplementation, and 15 infants (9 without illness and 6 with previous illness) received no mineral supplementation. A third group of seven healthy infants received a formula for premature infants during initial hospitalization and a standard cow's milk formula (20 calories per ounce) after discharge. The mean plasma calcium, phosphorus, and alkaline phosphatase levels did not differ among the three groups at study entry. Eight weeks after discharge, eight infants (four without illness and four with illness) had hypophosphatemia < 4.5 mg/dl. All were breast fed, and seven of eight had not received posthospitalization calcium and phosphorus supplementation. The incidence of hypophosphatemia in infants with or without illness was significantly greater in infants who did not receive supplementation (p = 0.038). These data indicate that calcium, phosphorus, and vitamin D supplementation may be necessary in approximately 50% of breast-fed infants of < 1800 gm birth weight after hospital discharge. It is recommended that serum calcium, phosphorus, and alkaline phosphatase be measured 4 to 8 weeks after discharge to identify those infants who require supplementation.

Frontal brain asymmetry and emotional reactivity: a biological substrate of affective style.

Individuals differ dramatically in the quality and intensity of their response to affectively evocative stimuli. On the basis of prior theory and research, we hypothesized that these individual differences are related to variation in activation of the left and right frontal brain regions. We recorded baseline brain electrical activity from subjects on two occasions 3 weeks apart. Immediately following the second recording, subjects were exposed to brief positive and negative emotional film clips. For subjects whose frontal asymmetry was stable across the 3-week period, greater left frontal activation was associated with reports of more intense positive affect in response to the positive films, whereas greater right frontal activation was associated with more intense reports of negative affect in response to the negative film clips. The methodological and theoretical implications of these data are discussed.

Psychometric properties of resting anterior EEG asymmetry: temporal stability and internal consistency.

We examined whether resting anterior electroencephalographic (EEG) asymmetry in the alpha frequency band has psychometric properties that would be expected of a measure assessing individual differences. In each of two experimental sessions, separated by three weeks, resting EEG in midfrontal and anterior temporal sites was recorded from 85 female adults during eight 60-s baselines. Resting alpha asymmetry demonstrated acceptable test-retest stability and excellent internal consistency reliability. Analyses including other frequency bands indicated that degree of stability varied somewhat as a function of band and region. In addition, asymmetry was less stable than absolute power. Discussion focuses on the implications of the present findings for the measurement and conceptualization of resting anterior asymmetry.

Hypophosphatemia in breast-fed low-birth-weight infants following initial hospital discharge.

The present study evaluated 12 infants with birth weights less than 2000 g who received human milk plus a multivitamin supplement and 20 similar infants who received standard cow's milk formula for 16 weeks from the time of initial hospital discharge. Examination at birth, at hospital discharge (study entry), at 4 and 16 weeks after hospitalization, and at 52 weeks of age revealed no intergroup differences in body weight, length, and head circumference. Hypophosphatemia (plasma phosphorus concentration less than or equal to 1.45 mmol/L) developed in 6 infants fed human milk (5 infants at 4 weeks and 1 infant at 16 weeks of study). Mean vitamin D intakes, but not calcium and phosphorus intakes, were significantly lower during hospitalization in human milk-fed infants with hypophosphatemia (44 [25, SD] IU/d) compared with those without hypophosphatemia (322 [180] IU/d). These data indicate that human milk-fed, low-birth-weight infants are at risk for hypophosphatemia following initial hospital discharge. Plasma calcium, phosphorus, and alkaline phosphatase concentrations at hospital discharge may not predict the infants at risk. Vitamin D supplementation early in the infants' hospital course may prevent hypophosphatemia.

Visual acuity, erythrocyte fatty acid composition, and growth in term infants fed formulas with long chain polyunsaturated fatty acids for one year. Ross Pediatric Lipid Study.

The CNS and the retina are enriched in long chain polyunsaturated (LCP) fatty acids, specifically docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6), which are present in human milk but not in most infant formulas. In the present study of 134 formula-fed and 63 breast-fed infants, we prospectively evaluated whether providing a source of DHA and AA or DHA alone in formula would increase red blood cell (RBC) phospholipid levels of these fatty acids, enhance visual function, or affect growth during the first year. Healthy term infants < 7 d old were randomized to be fed formulas containing linoleic acid (approximately 10% kcal) and alpha-linolenic acid (approximately 1% kcal) plus (1) no added LCP fatty acids (control formula), (2) DHA (0.12 wt% fatty acids) and AA (0.43 wt%) from egg yolk phospholipid (AA + DHA formula), or (3) DHA (0.2 wt%) from fish oil (DHA formula). A breast-fed group was studied concurrently and permitted formula supplementation after 3 mo. Visual acuity was measured using both the acuity card procedure and a visual evoked potential method at 2, 4, 6, 9, and 12 mo. Infants fed the control formula had 10-40% lower RBC levels of DHA and AA than infants in the breast-fed group. Infants fed the AA + DHA formula had levels of both LCP within approximately 10% of the values for infants in the breast-fed group, and infants fed the DHA formula had 25-55% higher DHA levels and 15-40% lower AA levels. There were no differences in growth or in visual function during this 12-mo feeding study.