Effect of High Protein and High Energy Intakes and Physical Activity on Growth and Body Composition of Extremely Low Birth Weight Infants: a Randomised Controlled Trial.

Brief Summary

Detailed Description

Increasing protein and energy intake above the anabolic capacity of a given individual may result in increased lipogenesis and excessive fat deposition. Adults with reduced mobility or with neuromuscular conditions will develop excessive fat deposition if they receive normal to high protein and energy intakes. Excessive fat deposition have been demonstrated in preterm infants receiving high energy intakes. Given that physical activity in preterms is often reduced for the prematurity itself, the associated sickness and the numerous medications, the investigators speculate that physical stimulation may have a beneficial effect on protein accretion and on lean mass accretion. The investigators further hypothesize that today's recommended daily intakes of proteins and energy cannot be fully incorporated into lean body mass without a concomitant physical activity. In spite of the fact that this notion is well accepted in adult physiology and in the elderly, it has never been tested in preterm infants. This factorial randomised controlled trial will evaluate the effect of increasing amino acid intake (by 1 g/kg/d) and energy intake (by 20 kcal/kg/d) during parenteral nutrition and also of increasing protein intake and energy intake by an extra 1 g/kg/d during enteral nutrition, with and without the stimulation of the infant's physical activity, on growth of extremely low birth weight infants. The investigators aim at demonstrating that increasing energy and protein intake above the standard of care intakes will result in better growth only in association with adequate physical activity, in particular in relation to body composition and lean mass accretion.

Primary Outcomes

Secondary Outcomes

• Lean body mass estimate using deuterium dilution(36 weeks postmenstrual age (+-1d ))
• Skinfold thickness(32 weeks postmenstrual age(+-1d ), 34 weeks postmenstrual age(+-1d ), 36 weeks postmenstrual age(+-1d ), 40 weeks postmenstrual age(+-1d ), between 22 and 24 months (2 years correct age))
• Weight(birth, daily up to 36 weeks postmenstrual age; 40weeks postmenstrual age (+-1d ), between 22 and 24 months (2 years correct age))
• Total body length(birth, weekly until 36 weeks postmenstrual age; 40weeks postmenstrual age (+-1d ), between 22 and 24 months (2 years correct age))
• Head circumference(birth, weekly up to 36 weeks postmenstrual age; 40weeks postmenstrual age (+-1d ), between 22 and 24 months (2 years correct age))
• Bayley III Motor Score (PDI)(between 22 and 24 months (2 years correct age))
• Bone ultrasound (1)(32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Bone ultrasound (2)(32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Safety (haematology)(At least daily during the first week of life, weekly up to 30 weeks postmenstrual age (when applicable), 30 weeks postmenstrual age (+-1d ), 32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Bone mineralisation(6 weeks of age, 32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Muscle ultrasound(32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age(+-1d ), 36 weeks postmenstrual age(+-1d ), 40 weeks postmenstrual age(+-1d ))
• Adipose tissue ultrasound(32 weeks postmenstrual age(+-1d ), 34 weeks postmenstrual age(+-1d ), 36 weeks postmenstrual age(+-1d ), 40 weeks postmenstrual age(+-1d ))
• Tibial length(birth, 32 weeks postmenstrual age(+-1d ), 34 weeks postmenstrual age(+-1d ), 36 weeks postmenstrual age(+-1d ), 40 weeks postmenstrual age(+-1d ), between 22 and 24 months (2 years correct age))
• Weight gain (BW recovery-36W PMA)(birth weight recovery up to 36 weeks postmenstrual age)
• Bayley III Language Score(between 22 and 24 months (2 years correct age))
• Morbidity(Hospital stay, on average 36 weeks postmenstrual age)
• Brain MRI(40 weeks postmenstrual age (+-1d ))
• Bayley III Cognitive Score (MDI)(between 22 and 24 months (2 years correct age))
• Measurement of physical activity(32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ), 40 weeks postmenstrual age (+-1d) if still hospitalized)
• Safety (metabolic tolerance)(At least daily during the first week of life, weekly up to 30 weeks postmenstrual age (when applicable), 30 weeks postmenstrual age (+-1d ), 32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Safety (gas-analysis)(At least daily during the first week of life, weekly up to 30 weeks postmenstrual age (when applicable), 30 weeks postmenstrual age (+-1d ), 32 weeks postmenstrual age (+-1d ), 34 weeks postmenstrual age (+-1d ), 36 weeks postmenstrual age (+-1d ))
• Mortality(hospital stay, on average 36 weeks postmenstrual age)