Protein Balance and Body Composition in Preterm Infants

Study Overview
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Brief Summary
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The adequacy of the quality of protein supply could influence the rate and the relative composition of weight gain in very low birth weight preterm infants. Aim of the study is to investigate protein balance according to feeding regimen and the association between human milk feeding and fat free mass content at term corrected age in a cohort of very low birth weight infants.

Detailed Description
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Nutritional management of preterm infants aims to approximate tissue growth and body composition of a foetus of same postconceptional age. The adequacy of the quality of protein supply could influence the rate and the relative composition of weight gain. Aim of the study is to investigate protein balance according to feeding regimen and the association between exclusive human milk feeding and fat free mass content at term corrected age in a cohort of very low birth weight infants. A prospective observational study. Infants are included according to inclusion criteria. Enrollment is performed at hospital discharge. Infants are divided into two groups (exclusively human milk or exclusively formula) according to own mother's milk availability. At enrollment macronutrients' intakes and protein balance are determined. Anthropometric measurements and body composition are also assessed. Nutritional composition of human milk is calculated by infrared spectroscopy (MIRIS® AB, Uppsala, Sweden). Protein balance is determined according to nitrogen balance standard method. Body composition is assessed by an air-displacement plethysmography system system (PEA POD Infant Body Composition System, COSMED SRL, Roma, Italy). At term corrected age anthropometry and body composition assessments are repeated.

Official Title
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Protein Balance and Body Composition in Preterm Infants According to Feeding Regimen

Conditions
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PreTerm Birth, Human Milk

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: gestational age ≤32 weeks birth weight < 1500 grams birth weight ≥10th percentile according to Fenton's growth chart stable clinical conditions at discharge feeding by mouth with either exclusively human milk or formula at discharge Exclusion Criteria: congenital or chromosomal abnormalities conditions that could interfere with growth such as chronic lung disease, neurological disorders, metabolic, cardiac disease and abdominal surgery, renal failure and/or sepsis (defined as a positive blood culture).

Ages Eligible for Study
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Minimum Age: 23 Weeks
Maximum Age: 32 Weeks

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Human milk fed infants<br>Infants fed fortified human milk at enrollment Any intervention is performed. Groups distinction is made according to own mother's milk availability. | |
| Preterm formula<br>Infants fed preterm formula milk at enrollment. Any intervention is performed. Groups distinction is made according to own mother's milk availability. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Protein balance | Protein balance will be determined according to nitrogen balance standard method and defined as the difference between daily nitrogen intake and daily urinary nitrogen excretion. Nitrogen intake will be measured from the amount of total protein intake (i.e. grams of nitrogen intake=grams of protein intake/6.25). Urinary urea nitrogen excretion will be considered representative of total nitrogen loss. Urinary urea will be calculated from urine specimens collected by cotton balls. | at hospital discharge (that is 35-36 post conceptional weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fat free mass content | Body composition will be assessed by an air-displacement plethysmography system (PEA POD Infant Body Composition System, COSMED SRL, Roma, Italy). The PEA POD assesses fat mass and fat-free mass by direct measurements of body mass and volume and the application of a classic densitometric model. | Term corrected age (that is 40 post conceptional weeks) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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protein accretion, body composition