Daily clinical markers in metabolic bone disease of prematurity.

BACKGROUND: Monitoring the condition of infants' bone metabolism timely and providing tailor-made appropriate supplementation are important to prevent severe metabolic bone disease of prematurity. This study aimed to clarify the characteristics of daily clinical markers in infants with hyperparathyroidism under management based on the clinical guidelines. METHODS: A single-center, retrospective study was performed at Kyoto University Hospital. Infants born at ≤37 weeks of gestation with a birth weight 100 pg/mL). RESULTS: One hundred ninety-four infants (366 data points) were analyzed. Most infants with iPTH concentrations >100 pg/mL had serum calcium concentrations 100 pg/mL had Ur Ca/Cre 100 pg/mL) under management based on the clinical guidelines. The cutoff values using the Youden index of serum calcium and phosphorus concentrations, Ur Ca/Cre, and %TRP were 9.8 mg/dL, 6.5 mg/dL, 0.67, and 94%, respectively. Most infants with hyperparathyroidism had serum calcium concentrations <9.8 mg/dL and/or serum phosphorus concentrations <6.5 mg/dL. Most infants with hyperparathyroidism had Ur Ca/Cre <0.67 and/or %TRP < 94%. In preterm infants, iPTH can be elevated, even when daily clinical indicators are within the normal range in children or adults.