Bone Mineral Density, Body Composition, and Metabolic Health of Very Low Birth Weight Infants Fed in Hospital Following Current Macronutrient Recommendations during the First 3 Years of Life

Abstract

The present study longitudinally evaluated growth, bone mineral density, body composition, and metabolic health outcome in very low birth weight (VLBW) infants whose in-hospital target nutrient intake was within recent recommendations. From six months to three years, bone mineral density (dual-energy X-ray absorptiometry, DXA), body composition, and metabolic health outcome were compared with a reference group of term infants. The aim was to test whether in-hospital achieved weight gain until 36 weeks of gestation (light or appropriate for term equivalent age; LTEA or ATEA) predicts later growth, bone mineral density (BMD), abdominal obesity, or metabolic health outcomes such as insulin resistance, relative to term infants, during the first three years of life. Target in-hospital energy and protein intake was not achieved. Growth in weight, length and head circumference, mid arm circumference, adiposity, fat free mass (FFM), and bone mineralization in VLBW infants was less than those in term infants and influenced by nutritional status at discharge. Preterm infants had poorer motor and cognitive outcomes. Post-discharge body composition patterns indicate FFM proportional to height but lower fat mass index in LTEA preterm infants than term infants, with no evidence of increased truncal fat in preterm infants. The hypothesis of early BMD catch-up in VLBW infants after discharge was not supported by the present data. The clinical significance of these findings is unclear. The data may suggest a reduced obesity risk but an increased osteoporosis risk. Since postnatal growth restriction may have permanent negative health effects, LTEA VLBW infants would especially appear to benefit from targeted preventive interventions. Further follow-up of the infants is required.

Update on Calcium and Phosphorus Requirements of Preterm Infants and Recommendations for Enteral Mineral Intake

“…However, given the average weight gain of 21 g/kg/day in this study, the achieved average mineral accretion rate was far below fetal mineral accretion (see Section 3.2.2 .). On average, at term equivalent age and at 3 months of corrected age preterm infants still fail to achieve term infant whole-body bone mineral content (BMC) [ 28 , 29 , 32 ].…”

“…However, it is unclear which level of mineralization must be achieved in preterm infants for prevention of long-term bone mineral deficits. Previous data have shown that there is some degree of bone mineral catch-up in VLBW infants post discharge within the first three years of life [ 32 ]. Further studies need to show which degree of reduced bone mineral content may be tolerated at discharge compared to term infants.…”

“…At 6 months of age, in a previous study, a similar BMC has been found in preterm infants as in a previous group of full term infants [ 28 ] and a catch-up of BMD in preterm infants within the first year of life has been hypothesized [ 30 ] and shown in a recent pilot study in which infants received extra mineral intake upon discharge until deemed appropriate [ 31 ]. In contrast, recent meticulously performed longitudinal data showed lower BMC, lower BMD and lower BMC/length 2 in VLBW preterm infants throughout the first 3 years of life [ 32 ]. Particularly light for term equivalent age VLBW infants appear to be at highest risk.…”

Die Frühgeborenenosteopenie – Pathophysiologie und Diagnostik

“…In der aktuellsten Longitudinaluntersuchung aus dem Jahr 2021 an 94 ehemaligen Frühgeborenen mit einem Geburtsgewicht von im Mittel ca. 1100 g und einem Gestationsalter von durchschnittlich 29 SSW wurde eine der Kontrollgruppe entsprechende Knochenmineralisation, gemessen mittels DXA-Knochendichtemessung im Alter von 3 Jahren, nicht erreicht [11]. Auch neuere Untersuchungen an Erwachsenen weisen auf eine verminderte Knochenmineralisation sowie ein erhöhtes Osteoporoserisiko hin [1].…”

Bone Mineralization and Calcium Phosphorus Metabolism

“…The authors concluded that the dual approach, combining M-ALP measures with the ultrasound monitoring of ossification centers favors the optimization of MBD treatments. In one important additional study [9], Mihatsch et al hypothesized that VLBW infants who were appropriate weight for their term-equivalent age (ATEA; defined by an SD weight score > −2 at 36 weeks according to Alexander growth charts, n = 39) have higher growth rates, lean body mass and fat mass, skeletal mineral deposition, and neurodevelopmental scores throughout the first three years of life than light for TEA (LTEA), defined by a weight standard deviation (SD) score of less than −2 SD at 36 weeks of gestation (n = 55). Growth, bone mineral density, body composition, and metabolic health outcome was evaluated in a prospective cohort of 94 very low birthweight infants whose in-hospital target macronutrient intake was within the recent European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) recommendations.…”