Increased nutritional supplementation in preterm infants does not affect bone health, growth
Infants born preterm or small for gestational age who received increased supplemental nutrition during the first week of life achieved a “catch-up” height and weight by age 6 months that was comparable to similar infants who did not receive increased parenteral nutrition, with a normal growth trajectory persisting during 10 years of follow-up, according to findings published in Bone.
“Achieving growth and development comparable to healthy, term-born infants has been a challenge for the treatment of preterm-born infants for many decades,” Viola Christmann, MD, of the department of pediatrics at Radboud University Medical Center in Nijmegen, the Netherlands, and colleagues wrote. “As the survival of very low birth weight infants has increased significantly during the last years, it is important to evaluate their long-term outcomes, especially since the recommendations and policies with regard to nutritional intake have been changed to improve postnatal growth.”
In an observational, follow-up study, Christmann and colleagues analyzed data from infants with a birth weight of 3.3 lb or less, born at or before 32 weeks’ gestation in 2004 (n = 63) and in 2005 (n = 66), who participated in a prospective study evaluating changes in the composition of parenteral nutrition. The 2005 birth cohort received a higher intake of calcium (3 mmol/kg per day), phosphate (1.92 mmol/kg per day) and protein with parenteral nutrition compared with the 2004 cohort. Researchers assessed length and body weight data collected during standard follow-up visits for 5 years, with data from 52 children born in 2004 and 54 children born in 2005 available from the 5-year follow-up visit. Researchers also analyzed height and weight data collected from 32 children born in 2004 and 30 children born in 2005 at age 9 to 10 years, and DXA measurements from 31 and 29 children born in 2004 and 2005, respectively. Researchers evaluated long-term growth trajectories for each cohort separately born appropriate and small for gestational age, stratified by sex, and used linear regression analysis to examine the effect of nutritional intake on growth and bone mineralization.
Both the 2004 and 2005 cohorts achieved a catch-up length within the first 6 months, with an improvement in standard deviation (SD) scores up to the normal range for the reference population, according to researchers. Children in the 2005 cohort who received supplemental nutrition had “slightly improved” length vs. the 2004 cohort until age 2 years, the researchers noted, with a more pronounced difference observed for girls born appropriate for gestational age at age 5 years. BMI also increased steadily during the first 6 months for both cohorts, with no between-cohort differences or differences between appropriate for gestational age vs. small for gestational age infants.
Bone mineral content and bone mineral density were within the normal range and not different between the cohorts.
For the total group, researchers observed evidence that birth weight was associated with length, with a 1-g increase associated with a 0.001 SD score increase in length (95% CI, 0.0002-0.002). For boys and girls, researchers found no link between length at age 9 to 10 years and nutritional intake in the first 14 days of life. Additionally, there was no association between mean, whole body and lumbar spine BMD and BMD SD score and nutritional intake as a preterm or very low birth weight infant, according to researchers.
“In contrast to our hypothesis, the significant different nutritional intake did not lead to a higher bone mass,” the researchers wrote. “The results from the linear regression showed no effect of mineral intake on bone mineralization, neither for boys nor for girls. The nutritional increment of calcium, phosphate in combination with more protein may not have been adequate for bone development.” – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.