早产儿出生后早期的钙磷代谢

Early postnatal calcium and phosphorus metabolism in preterm infants.

作者信息

Christmann Viola, de Grauw Anne M, Visser Reina, Matthijsse René P, van Goudoever Johannes B, van Heijst Arno F J

机构信息

*Department of Paediatrics, Subdivision of Neonatology, Radboud University Medical Centre, Nijmegen †Department of Paediatrics, Leiden University Medical Centre, Leiden ‡Department of Paediatrics, Medisch Spectrum Twente, Enschede §Department of Paediatrics, VU University Medical Centre, Amsterdam, The Netherlands.

出版信息

J Pediatr Gastroenterol Nutr. 2014 Apr;58(4):398-403. doi: 10.1097/MPG.0000000000000251.

DOI:10.1097/MPG.0000000000000251

PMID:24253367

Abstract

OBJECTIVES

Bone mineralisation in preterm infants is related to the supply of calcium (Ca) and phosphorus (P). We increased the amount of minerals in parenteral nutrition (PN) for preterm infants and evaluated postnatal Ca and P metabolism in relation to mineral and vitamin D (vitD) intake.

METHODS

Preterm infants, included on their first day of life, received standard PN, providing a maximum Ca/P intake of 3/1.92 mmol · kg(-1) · day(-1) on day 3. Ca/P content of formula was 2.5/1.6 mmol/dL, and fortified human milk was 2.4/1.95 mmol/dL. PN supplied 80 IU · kg(-1) · day(-1) vitD. Formula and fortified human milk contained 200 IU/dL of vitD. During a 5-week period, serum concentrations and urinary excretion of Ca/P were registered and related to the intake of minerals and vitD.

RESULTS

During 12 months, 79 infants (mean gestational age 29.8 ± 2.2 weeks, mean birth weight 1248 ± 371 g) were included. The recommended intake for minerals was achieved by day 5 and for vitD by 4 weeks. Infants developed hypercalcaemia, hypercalciuria, and hypophosphataemia during the first postnatal week, leading to the additional P supplementation in 49 infants. The renal tubular reabsorption of P was >95% until day 9 but decreased <70% after the second week. Alkaline phosphatase was normal at birth, increased to a maximum of 450 IU/L by day 14, and remained above the normal range for the remaining period.

CONCLUSIONS

Parenteral intake of P appeared to be too low, leading to mineral imbalances in the early postnatal period, and vitD intake was also below recommendations.

摘要

目的

早产儿的骨矿化与钙（Ca）和磷（P）的供应有关。我们增加了早产儿肠外营养（PN）中的矿物质含量，并评估了出生后钙和磷的代谢与矿物质和维生素D（vitD）摄入量的关系。

方法

从出生第一天起纳入早产儿，给予标准PN，在第3天提供的最大钙/磷摄入量为3/1.92 mmol·kg⁻¹·天⁻¹。配方奶的钙/磷含量为2.5/1.6 mmol/dL，强化母乳为2.4/1.95 mmol/dL。PN提供80 IU·kg⁻¹·天⁻¹的vitD。配方奶和强化母乳含有200 IU/dL的vitD。在5周期间，记录钙/磷的血清浓度和尿排泄量，并与矿物质和vitD的摄入量相关联。

结果

在12个月期间，纳入了79名婴儿（平均胎龄29.8±2.2周，平均出生体重1248±371 g）。矿物质的推荐摄入量在第5天达到，vitD的推荐摄入量在4周时达到。婴儿在出生后的第一周出现高钙血症、高钙尿症和低磷血症，导致49名婴儿额外补充磷。直到第9天，磷的肾小管重吸收>95%，但在第二周后降至<70%。碱性磷酸酶在出生时正常，到第14天最高升至450 IU/L，并在剩余时间内保持在正常范围以上。