Infant formula paper smells like salami, retracted

semperinatolcoverSeminars in Perinatology has retracted a 2002 paper by a group of authors in France and Belgium who’d used a previously published article (their own) as a template for the benighted work.

The article, “Nitrogen utilization and bone mineralization in very low birth weight infants fed partially hydrolyzed preterm formula,” by Jean-Charles Picaud and colleagues, appeared in December 2002. But it was based largely on this May 2001 paper in the Journal of Pediatric Gastroenterology and Nutrition, titled “Nutritional Efficacy of Preterm Formula With a Partially Hydrolyzed Protein Source: A Randomized Pilot Study.”

According to the retraction notice:

This article has been retracted at the request of the Editors-in-Chief.

In this article, the authors have replicated large portions of their prior paper published in J. Pediatr. Gastroenterol. Nutr., 32 (2001) 555–561, http://dx.doi.org/10.1097/00005176-200105000-00012.

When submitting a paper for publication the authors are required to present work that is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. The scientific community takes a strong view on this matter and apologies are offered to readers of the journal for the inconvenience.

The abstracts of the two papers look pretty similar — not surprising given that the bone mineral density analysis was an obvious extension of the initial analysis, which looked at calcium absorption.

From the earlier article, which has been cited 18 times, according to Thomson Scientific’s Web of Knowledge:

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.

And from the retracted paper, which has been cited twice:

Partially hydrolyzed formulas have been proposed for term and preterm infants, but decreased nitrogen and calcium intestinal absorption rates, together with plasma amino acid imbalances have been reported in preterm infants. We evaluated a new formula with modified nitrogen and calcium sources (glycerophosphate). During their second week of life, 16 preterm infants were randomly assigned to 1 of 2 groups: 9 were fed the new partially hydrolyzed formula and 7 a conventional formula. A nutrient balance was performed at the end of the first month of life. Amino acid concentrations and whole-body mineralization were measured at the end of study period (theoretical term). Birth weight and gestational age (mean +/- SD) were similar in the 2 groups (28.9 +/- 7.0 wks and 1,183 +/- 242 g v 27.7 +/- 1.0 wks and 1,139 +/- 162 g). Median nitrogen absorption rate (85% v 89%; P = .03) was lower in infants fed the new formula than in those fed the conventional one. After correction for difference in nitrogen intake, there was no significant difference in N retained between the 2 groups (P = .11). Plasma amino acid concentrations were also similar in the 2 groups. At theoretical term, median bone mineral content was not significantly different between the 2 groups (50 g/kg v 55 g/kg; P = .17) and it was close to the reference values obtained in term neonates just after birth. As long as nitrogen content is 10% higher in protein hydrolyzed formula than in entire protein formula, appropriate nitrogen retention, plasma amino acid profile can be achieved with the new partially hydrolyzed formula. In both groups, bone mineralization at theoretical term was close to the mineralization observed term neonates just after birth.

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