The impact of intrauterine and extrauterine weight gain in premature infants on later body composition

Effects of higher protein formula with improved fat blend on growth, feeding tolerance and nutritional biomarkers in preterm infants: A double-blind, randomized, controlled clinical trial

BACKGROUND

Preterm formulas containing greater protein:energy ratio are beneficial for non-breastfed infants, since protein is critical for promoting catch-up growth and synthesis of lean body mass. Additionally, formulas containing enriched sn-2 palmitate (sn-2) and reduced medium chain triglycerides (MCTs) may support better feeding tolerance and nutrient utilization.

METHODS

The objective of this randomized, controlled, double-blinded clinical trial is to evaluate growth, feeding tolerance and nutritional biomarkers of preterm infants with birth weight ≤2000g and gestational age ≤33wks from one neonatal unit in Vietnam receiving experimental formula (EF, n = 80) containing higher protein level of 3.4 g/100 kcal and improved fat blend with enriched sn-2 and modified level of MCTs or isocaloric control formula (CF, n = 80) containing protein level of 2.9 g/100 kcal and standard fat blend. The differences in weight gain (g/d; primary endpoint) from day 1 (D1) of full enteral feeding (FEF) until D21 between groups was evaluated for non-inferiority (margin = -2.5  g/d) and superiority (margin = 0  g/d).

RESULTS

Mean weight gain was 3.09  g/d greater in EF than CF; the lower limit of 95% CI (0.31  g/d) exceeded both non-inferiority and superiority margins. There was no significant difference in length-for-age and head circumference-for-age z-score. By D79, the mean change in weight-for-age z-scores from D1 in EF group (+0.76 SDs) surpassed the criteria for catch-up growth (+0.67 SDs). Infants in the EF group (vs. CF) tended to have softer stools (EF = 3.2 ± 0.59 vs. CF = 3.4 ± 0.58; P = 0.07) based on 5-point scale (1 = watery, 5 = hard). Difference in blood urea nitrogen and biomarkers for bone mineral status (i.e., plasma phosphorus, alkaline phosphatase and urinary calcium/phosphorus ratio) between EF and CF on FEF Day 21 reached statistical significance (P < 0.05) but all mean values stayed within normal clinical ranges for both groups.

CONCLUSION

Preterm formula with greater protein:energy ratio and new fat blend is safe, nutritionally suitable, well-tolerated, and improves catch-up weight gain of preterm infants. Clinical trial registry identifier is NCT03055052 (ClinicalTrials.gov).

Bone density and body composition in small for gestational age children with adequate catch up growth: A preliminary retrospective case control study

BACKGROUND

Fetal growth patterns and birth weight (BW) have been associated with bone mineral density (BMD) and content (BMC) throughout infancy and childhood up to early adulthood. We hypothesized that in small for gestational age (SGA) children, compensatory infant catch-up growth to normal height centiles counteracts the adverse consequences of low BW on bone accrual.

AIM

To evaluate BMD and BMC of SGA children born at term who experienced a normal catch-up growth as compared to children born appropriate for gestational age (AGA).

PATIENTS

We recruited 53 SGA (26 females) and 60 AGA children (27 females), aged 6 to 18 years, matched for sex and body mass index (BMI). Fat mass (FM); Free fat mass (FFM); Lumbar spine and Total body less head (TBLH) BMD; BMC and BMD standard deviation scores corrected for body size (BMAD, BMAD z-score and TBLH BMD/Height) and TBLH BMC for FFM (TBLHBMC/FFM) were derived from Dual Energy X-ray absorptiometry (DXA) scans.

RESULTS

SGA and AGA children did not differ in any auxological, body composition and bone parameters appropriately adjusted for height and FFM. BMI, FM and, remarkably, FFM were significantly correlated with bone mass parameters in both groups while no correlation was found between FM and FFM with the BW SDS in the univariate analysis.

CONCLUSION

Our preliminary data demonstrate that SGA children born at term who recover from their growth deficiency through catch-up growth achieve bone mass and body composition not different from children born AGA.

Early weight gain trajectories and body composition in infancy in infants born very preterm

BACKGROUND

Concerns are raised about the influence of rapid growth on excessive fat mass (FM) gain in early life and later cardiometabolic health of infants born preterm.

OBJECTIVES

To study the association between postnatal weight gain trajectories and body composition in infancy in infants born very preterm.

METHODS

In infants born <30 weeks gestation, we evaluated associations between weight Z-score trajectories for three consecutive timeframes (NICU stay, level-II hospital stay and at home) and body composition, measured at 2 and 6 months corrected age by air-displacement plethysmography.

RESULTS

Of 120 infants included, median gestational age at birth was 27⁺⁵ (interquartile range 26⁺¹ ;28⁺⁵ ) and birth weight 1015 g (801;1250). The majority of infants did not make up for their initial loss of weight Z-score, but growth and later body composition were within term reference values. Weight gain during NICU stay was not associated with fat mass (absolute, %FM or FM index) in infancy. Weight gain during NICU and level II hospital stay was weakly associated with higher absolute lean mass (LM), but not after adjustment for length (LM index). Weight gain in the level-II hospital was positively associated with fat mass parameters at 2 months but not at 6 months. Strongest associations were found between weight gain at home and body composition (at both time points), especially fat mass.

CONCLUSIONS

Weight gain in different timeframes after preterm birth is associated with distinct parameters of body composition in infancy, with weight gain at home being most strongly related to fat mass.

Developmental Programming of Body Composition: Update on Evidence and Mechanisms

PURPOSE OF REVIEW

A growing body of epidemiological and experimental data indicate that nutritional or environmental stressors during early development can induce long-term adaptations that increase risk of obesity, diabetes, cardiovascular disease, and other chronic conditions-a phenomenon termed "developmental programming." A common phenotype in humans and animal models is altered body composition, with reduced muscle and bone mass, and increased fat mass. In this review, we summarize the recent literature linking prenatal factors to future body composition and explore contributing mechanisms.

RECENT FINDINGS

Many prenatal exposures, including intrauterine growth restriction, extremes of birth weight, maternal obesity, and maternal diabetes, are associated with increased fat mass, reduced muscle mass, and decreased bone density, with effects reported throughout infancy and childhood, and persisting into middle age. Mechanisms and mediators include maternal diet, breastmilk composition, metabolites, appetite regulation, genetic and epigenetic influences, stem cell commitment and function, and mitochondrial metabolism. Differences in body composition are a common phenotype following disruptions to the prenatal environment, and may contribute to developmental programming of obesity and diabetes risk.