title: Calcium and phosphor intake in preterm infants: sensitivity and specifity of 6-hour urine samples to detect deficiency.
abstract: Aim of the present study was to test whether six-hour (6 h) urine specimens predict the 24-hour (24 h) mineral homeostasis in individual infants born preterm. Urinary Calcium (Ca) and Phosphate (P) concentrations were studied in 60 stable infants; gestational age 34 (25-42) weeks. In 58 infants four 6 h urine specimens and in 2 infants all spot urine specimens obtained within 24 h were analyzed. In 39 infants born preterm coefficients of variation were 0.42 (SD 0.26) and 0.41 (SD 0.26) for Ca and P measurements in the four 6 h urine specimens obtained within 24 h, respectively, The mineral homeostasis of the infants was defined as Ca or P surplus homeostasis if the 24 h urinary concentrations were ≥1 mmol/l. The sensitivity, specificity, and PPV of a 6 h urinary specimen to predict Ca deficiency homeostasis (24 h urinary Ca <1 mmol/l) were 0.93 (0.77-0.98; 95%CI), 0.72 (0.43-0.90) and 0.90 (0.74-0.96). The sensitivity, specificity and PPV for urinary P were 0.8 (0.38-0.96), 0.97 (0.85-0.995), and 0.8 (0.38-0.96). In conclusion, in infants born preterm on regular 3 or 4 h feedings, 6 h urine sampling is sufficiently precise for prediction of Ca and P mineral deficiency homeostasis (PPV 0.92 and 0.83). However, measurements at regular intervals (twice weekly) are recommended not to miss any infant in mineral deficiency homeostasis.
authors.affiliation: Kinderklinik, Diakonieklinikum Schwäbisch Hall, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Mihatsch
authors.forename: A
authors.initials: A
authors.lastname: Trotter
authors.forename: F
authors.initials: F
authors.lastname: Pohlandt
mesh_terms: D001724:Birth Weight; D001851:Bone Diseases, Metabolic / Q000175:diagnosis / Q000517:prevention & control / Q000652:urine; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000652:urine*; D002940:Circadian Rhythm / Q000502:physiology; D004750:Enteral Nutrition; D005260:Female; D005865:Gestational Age; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006996:Hypocalcemia / Q000175:diagnosis* / Q000517:prevention & control / Q000652:urine*; D017674:Hypophosphatemia / Q000175:diagnosis* / Q000517:prevention & control / Q000652:urine*; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000517:prevention & control / Q000652:urine*; D007363:Intensive Care Units, Neonatal; D008297:Male; D009751:Nutritional Requirements; D010710:Phosphates / Q000008:administration & dosage* / Q000652:urine; D011237:Predictive Value of Tests
chemical_list: D002136:Calcium, Dietary; D010710:Phosphates