Persistent elevation of fibroblast growth factor 23 concentrations in healthy appropriate-for-gestational-age preterm
Insights
Most preterm infants achieved adequate vitamin D levels, but fibroblast growth factor 23 (FGF23) remained high. Further research is needed to understand the clinical implications of elevated FGF23 in premature infants.
Area of Science:
- Neonatal medicine
- Pediatric endocrinology
- Nutritional science
Background:
- Premature infants require careful monitoring of vitamin D and mineral metabolism.
- Understanding the dynamics of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), and fibroblast growth factor 23 (FGF23) is crucial for preterm infant health.
Purpose of the Study:
- To investigate the temporal changes in 25(OH)D, its epimer, PTH, FGF23, and minerals in healthy, appropriate-for-gestational-age preterm infants.
- To assess vitamin D sufficiency and mineral balance during early neonatal life.
Main Methods:
- A prospective study involving 11 preterm infants (28-32 weeks gestational age) monitored at 1, 3, 5 weeks, and term.
- Measurements included plasma and urine calcium, phosphorus, creatinine, PTH, C-terminal and intact FGF23 (iFGF23), and 25(OH)D via liquid chromatography-tandem mass spectrometry.
- Regression analyses were employed to evaluate the data.
Main Results:
- All infants achieved normal standard chemistries; none were vitamin D deficient.
- 58% reached 25(OH)D concentrations ≥50 nmol/L with a median intake of 540 IU/day.
- Elevated concentrations of 25(OH)D C-3 epimer, intact FGF23 (double adult norms), and C-terminal FGF23 (ten times adult norms) were observed, while phosphorus tubular resorption remained normal (88%±8%).
Conclusions:
- The majority of preterm infants achieved satisfactory 25(OH)D3 levels.
- The clinical significance of persistently elevated FGF23 levels in this cohort remains undetermined.
Objective:
To explore the temporal evolution of 25-hydroxyvitamin D [25(OH)D], its epimer, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and minerals in healthy appropriate-for-gestational-age preterms.
Patients:
A prospective study was undertaken in infants born at 28-32 weeks with monitoring at 1, 3, 5 weeks and term.
Methods:
Morning plasma and urine calcium; phosphorus; creatinine; PTH, C-terminal and intact FGF23 (iFGF23) and liquid chromatography-tandem mass spectrometry measurements of 25(OH)D were undertaken. Analyses included regression models.
Results:
Some 11 infants (5 males) were recruited at a median gestational age of 31.2 weeks (interquartile range: 28.1-31.8). Standard chemistries were normal. No infant was vitamin D deficient; 58% achieved 50 nmol/L with a median intake of 540 IU/day. High concentrations of C-3 epimer were detected. iFGF23 and C-terminal concentrations were persistently elevated (double and ten times adult norms, respectively). Tubular resorption of phosphorus was normal (88%±8%).
Conclusions:
Most infants achieved acceptable 25(OH)D3 concentrations. The biologic significance of the elevated FGF23 is unclear.
