Software and scan acquisition technique-related discrepancies in bone mineral assessment using dual-energy X-ray absorptiometry in neonates.

AIM: In adults, whole-body mineralization assessment by dual-energy X-ray absorptiometry can be affected by the densitometer and/or the software used. As there are no published data on neonates, the aim of this study was to evaluate the magnitude of such effects in growing preterm infants. METHODS: We analysed the absorptiometry results obtained from 44 preterm infants scanned at discharge and again 6 wk later using densitometers from the same manufacturer equipped with "Pediatric" (Group A, n = 24) or with "Infant" (Group B, n = 20) packages. Results of bone mineral content assessment were compared using an unpaired t-test and a linear regression analysis. RESULTS: At the time of the first absorptiometry (body weight = 2119 +/- 144 g, n = 44), the bone mineral content was three times lower in Group A (10 +/- 3 g) than in Group B (29 +/- 4 g) (p < 0.001). Subsequently, on the second absorptiometry (body weight = 4037 +/- 236 g, n = 44) such significant differences in bone mineral content (A: 65 +/- 19 g, B: 66 +/- 9 g, p = 0.85) were no longer in evidence. The differences in bone mineral content were related to differences in analysis algorithms between the two programs, which can lead to an overestimation of bone mineral content accretion when two successive measurements are made using the "Pediatric"package. CONCLUSION: Considering that significant differences in bone mineral assessment may depend upon which program is used, data previously collected in low birthweight infants using the "Pediatric" package should be analysed with caution. Data obtained using the "Pediatric" and "Infant" packages are not directly comparable. Careful validation studies of future densitometers and programs are required before their use in clinical paediatric studies.

Nutritional efficacy of preterm formula with a partially hydrolyzed protein source: a randomized pilot study.

BACKGROUND: Decreased nitrogen levels, calcium intestinal absorption rates, and plasma amino acid imbalances were reported for preterm infants who were fed partially hydrolyzed preterm formulas. In this pilot study, we evaluated a new formula with modified nitrogen and calcium sources. METHODS: During their second week of life, 16 preterm infants were randomly assigned to one of two groups: 9 were fed the new partially hydrolyzed formula and 7 were fed a conventional formula. Nutrient balance was performed at the end of the first month of life. Amino acid concentrations and anthropometric parameters were measured at theoretical term. RESULTS: Birth weight and gestational age (mean +/- SD) were similar in the two groups (28.9 +/- 7.0 weeks and 1183 +/- 242 g vs. 27.7 +/- 1.0 weeks and 1139 +/- 162 g). Median nitrogen absorption rates (85% vs. 89%; P = 0.03) and biological values (59% vs. 69%; P = 0.13) were lower for infants who were fed the new formula than for those fed the conventional formula. After correction for difference in nitrogen intake, there was no significant difference in nitrogen retained between the two groups (P = 0.11). Plasma amino acid concentrations were also similar in the two groups. Median calcium absorption tended to be higher in the new-formula group than in the conventional-formula group (54% vs. 45%, P = 0.19). At theoretical term, infants fed the conventional formula were heavier than infants fed the new formula (3559 +/- 362 g vs. 3193 +/- 384 g, P = 0.04). CONCLUSIONS: Because nitrogen content is 10% higher in hydrolyzed-protein formula than in entire-protein formula, appropriate nitrogen retention, plasma amino acid profile, and mineral use can be achieved with the new partially hydrolyzed formula. Further studies with larger groups are needed to evaluate the effect on growth.

The use of low-EPA fish oil for long-chain polyunsaturated fatty acid supplementation of preterm infants.

Because docosahexaenoic acid (DHA) may be an essential nutrient for the visual and early cognitive development of preterm infants, DHA enrichment of preterm formulas has been recommended. This randomized trial was designed to study the n-6 and n-3 fatty acid status of healthy preterm infants fed a formula enriched with a low eicosapentaenoic-fish oil until 4 mo corrected age compared with that of infants fed a standard formula. A reference group of breast-fed infants was studied concurrently. The fatty acid content of red blood cell (RBC) phospholipid was assessed at enrollment, hospital discharge, expected term, and 3 and 6 mo postterm. The DHA content of RBC phospholipid was higher in infants fed the enriched versus the standard formula at hospital discharge, expected term, and 3 and 6 mo postterm. However, compared with infants fed the standard formula, infants fed the enriched formula had also higher RBC phospholipid eicosapentaenoic content (0.69 +/- 0.15% versus 0.25 +/- 0.12%, p < 0.001), and lower RBC phospholipid arachidonic acid content (15.1 +/- 0.93% versus 18.8 +/- 0.89%; p < 0.001). We conclude that supplementing preterm infants with low-eicosapentaenoic fish oil is effective in improving DHA status, but results in worsening of n-6 fatty acid status. We speculate that preterm infants may require a dietary supply of arachidonic acid as well as DHA if the same fatty acid status as that of breast-fed infants is to be achieved.

Erythrocyte fatty acid composition in term infants fed human milk or a formula enriched with a low eicosapentanoic acid fish oil for 4 months.

UNLABELLED: When term infants are fed standard formula that does not contain long-chain polyunsaturated fatty acids (LC-PUFA), they still show lower levels of docosahexaenoic acid (DHA) in red blood cell (RBC) phospholipids by several weeks or months postnatally. This study was designed in order to evaluate a potential alternative for supplementing term infant formulas with DHA by adding a high-DHA/low-eicosapentanoic acid fish oil to levels similar to that in human milk (0.3%). A total of 37 term infants were included in the study at 3 days of life. DHA concentrations remained stable between inclusion and 4 months of life at around 8% of the RBC phospholipids in the LC-PUFA enriched formula-fed group whereas it decreased significantly in the standard formula-fed group. In the human milk-fed group, RBC DHA concentrations at 4 months of age were significantly lower than that at birth and were significantly correlated with the duration of breast feeding (r = 0.85; P = 0.0002). A significant decrease of arachidonic acid between inclusion and 4 months of age was observed in the enriched formula-fed group and reached a mean value at 4 months, which was significantly lower than that observed in the human milk or standard formula-fed groups (P<0.0001). CONCLUSION: Supplementing term formulas with a high-docosahexaenoic acid/low-eicosapentanoic acid fish oil up to 4 months of age is efficient in improving docosahexaenoic acid status, however it increases the risk of impaired n-6 fatty acid status.

Vitamin A and E supplementation in breast-fed newborns.

BACKGROUND: Vitamins A and E are two potent antioxidant nutrients that play a significant role in immune function. In contrast to the numerous studies of vitamin A and E status in children, adolescents, and adults, information on term infants, particularly breast-fed infants, is scarce. The goals of the present investigation were to examine the vitamins A and E nutritional status of term breast-fed infants at birth and to assess retinol and tocopherol plasma levels during a 3-month supplementation trial. METHODS: The study was a prospective, blinded comparison of a supplementation protocol with a placebo in a group of consecutively recruited term newborns. The supplemented group received 3000 IU vitamin A and 5 IU vitamin E orally. The placebo group received a solution of similar viscosity and organoleptic characteristics. Vitamin A and E were separated by reverse-phase high-performance liquid chromatography on a C18 Spectrasyl column and quantified by ultraviolet spectrophotometry. RESULTS: Vitamin A and E levels steadily increased with age in both groups of infants. However, levels at 3 months were higher in the supplemented than in the control group. CONCLUSION: The data show that supplementation with 3000 IU vitamin A and 5 IU vitamin E for 3 months increases circulating vitamin levels in newborn term babies compared with those in nonsupplemented infants.