Monitoring of Urinary Calcium and Phosphorus Excretion in Preterm Infants: Comparison of 2 Methods

作者：Staub Eveline^*; Wiedmer Nicolas; Staub Lukas P; Nelle Mathias; von Vigier Rodo O

来源：Journal of Pediatric Gastroenterology and Nutrition, 2014, 58(4): 404-408.

DOI：10.1097/MPG.0000000000000244

• preterm infant
• dietary supplement
• phosphorus
• metabolic bone disease
• calcium

Objectives:
Premature babies require supplementation with calcium (Ca) and phosphorus (P) to prevent metabolic bone disease of prematurity. To guide mineral supplementation, 2 methods of monitoring urinary excretion of Ca and P are used: urinary Ca or P concentration and Ca/creatinine (Crea) or P/Crea ratios. We compare these 2 methods in regards to their agreement on the need for mineral supplementation.
Methods:
Retrospective chart review of 230 premature babies with birth weight <1500 g, undergoing screening of urinary spot samples from day 21 of life and fortnightly thereafter. Hypothetical cutoff values for urine Ca or P concentration (1 mmol/L) and urine Ca/Crea ratio (0.5 mol/mol) or P/Crea ratio (4 mol/mol) were applied to the sample results. The agreement on whether to supplement the respective minerals based on the results with the 2 methods was compared. Multivariate general linear models sought to identify patient characteristics to predict discordant results.
Results:
A total of 24.8% of cases did not agree on the indication for Ca supplementation, and 8.8% for P. Total daily Ca intake was the only patient characteristic associated with discordant results.
Conclusions:
With the intention to supplement the respective mineral, comparison of urinary mineral concentration with mineral/Crea ratio is moderate for Ca and good for P. The results do not allow identifying superiority of either method on the decision as to which babies require Ca and/or P supplements.

• 出版日期2014-4