Related Experiment Video
Updated: Mar 25, 2026
Establishment of a Simple and Effective Rat Model for Intraoperative Parathyroid Gland Imaging
Published on: August 17, 2022
Screening for secondary hyperparathyroidism in preterm infants
Yuri Dowa1, Masahiko Kawai2, Hoshinori Kanazawa2
1Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan. doway@gcmc.pref.gunma.jp.
Insights
Serum alkaline phosphatase (ALP) effectively screens for hyperparathyroidism in preterm infants. Combined with tubular reabsorption of phosphate (%TRP), it accurately indicates elevated parathyroid hormone (PTH).
Area of Science:
- Neonatal Medicine
- Pediatric Endocrinology
- Biochemistry
Background:
- Osteopathy of prematurity is primarily caused by phosphate deficiency, with secondary hyperparathyroidism from calcium or vitamin D deficiency also contributing.
- Elevated parathyroid hormone (PTH) exacerbates osteopathy by mobilizing bone minerals.
- Identifying reliable markers for hyperparathyroidism screening in preterm infants is crucial.
Purpose of the Study:
- To evaluate serum and urinary biochemical markers for screening and diagnosing hyperparathyroidism in preterm infants.
- To assess the efficacy of intact parathyroid hormone (iPTH) and other biomarkers.
Main Methods:
- Serum and urinary samples were collected from 95 preterm infants.
- Biomarkers including serum intact PTH (iPTH), serum alkaline phosphatase (ALP), and percent tubular reabsorption rate of phosphate (%TRP) were measured.
- Statistical analysis, including receiver operating characteristic (ROC) curves, was used to determine marker performance.
Main Results:
- Fourteen infants (14.7%) exhibited elevated iPTH (>65 pg/mL).
- Serum ALP (cut-off >1300 IU/L) demonstrated good sensitivity (78.6%) and specificity (86.4%) for detecting elevated iPTH.
- %TRP (cut-off ≤93%) showed lower individual performance, but combined with serum ALP, specificity increased to 93.8%.
Conclusions:
- Serum ALP measurement is an effective screening tool for hyperparathyroidism in preterm infants.
- The combined assessment of serum ALP and %TRP provides a reliable indicator of elevated iPTH.
- These markers aid in the early detection and management of metabolic bone disease in premature neonates.
Background:
The major cause of osteopathy of prematurity is dietary phosphate deficiency, but secondary hyperparathyroidism caused by calcium deficiency or vitamin D deficiency is also important. Because parathyroid hormone (PTH) mobilizes calcium and phosphate from the bone, hyperparathyroidism worsens osteopathy of prematurity. In order to identify useful markers to screen for and diagnose hyperparathyroidism in preterm infants, we measured serum and urinary biochemical markers.
Methods:
Several biomarkers, including serum intact PTH (iPTH), were measured in urine and serum samples obtained from 95 preterm infants, and the relationship between serum iPTH and the other parameters was analyzed.
Results:
Mean gestation was 33.2 ± 2.9 weeks, and mean birthweight was 1705 ± 402 g. Samples were collected around postnatal day 17.3 ± 7.4. Fourteen infants (14.7%) had iPTH >65 pg/mL. Cut-offs for serum alkaline phosphatase (ALP) and percent tubular reabsorption rate of phosphate (%TRP) were fixed at 1300 IU/L and 93%, respectively using receiver operating characteristic curves with iPTH cut-off of 65 pg/mL. Serum ALP was proven to be a good marker: ALP had a sensitivity of 78.6% and a specificity of 86.4%, while %TRP itself was not: %TRP had a sensitivity of 64.3% and a specificity of 58.0%. Combined measurement of serum ALP (>1300 IU/L) and %TRP (≤93%), however, had a specificity of 93.8% for detecting elevated iPTH.
Conclusion:
Measurement of serum ALP (>1300 IU/L) is considered as an effective screening method to detect hyperparathyroidism. In addition, combined assessment of ALP(>1300 IU/L) and %TRP(≤93%) is a good indicator of elevated iPTH in preterm infants.
