High frequencies of elevated alkaline phosphatase activity and rickets exist in extremely low birth weight infants despite current nutritional support

Shannon M Mitchell, Stefanie P Rogers, Penni D Hicks, Keli M Hawthorne, Bruce R Parker, Steven A Abrams, Shannon M Mitchell, Stefanie P Rogers, Penni D Hicks, Keli M Hawthorne, Bruce R Parker, Steven A Abrams

Abstract

Background: Osteopenia and rickets are common among extremely low birth weight infants (ELBW, <1000 g birth weight) despite current practices of vitamin and mineral supplementation. Few data are available evaluating the usual course of markers of mineral status in this population. Our objectives in this study were to determine the relationship between birth weight (BW) and peak serum alkaline phosphatase activity (P-APA) in ELBW infants and evaluate our experience with the diagnosis of rickets in these infants.

Methods: We evaluated all ELBW infants admitted to Texas Children's Hospital NICU in 2006 and 2007. Of 211 admissions, we excluded 98 patients who were admitted at >30 days of age or did not survive/stay for >6 weeks. Bone radiographs obtained in 32 infants were reviewed by a radiologist masked to laboratory values.

Results: In this cohort of 113 infants, P-APA was found to have a significant inverse relationship with BW, gestational age and serum phosphorus. In paired comparisons, P-APA of infants <600 g (957 +/- 346 IU/L, n = 20) and infants 600-800 g (808 +/- 323 IU/L, n = 43) were both significantly higher than P-APA of infants 800-1000 g (615 +/- 252 IU/L, n = 50), p < 0.01. Thirty-two patients had radiographic evaluation for evidence of rickets, based on P-APA greater than 800 IU/L, parenteral nutrition greater than 3 to 4 weeks, or clinical suspicion. Of these, 18 showed radiologic rickets and 14 showed osteopenia without rickets. Infants with BW <600 g were more likely to have radiologic rickets (10/20 infants) compared to those with BW 600-800 g (6/43 infants) and BW 800-1000 g (2/50 infants), p < 0.01 for each. P-APA was not significantly higher in infants with radiologic rickets (1078 +/- 356 IU/L) compared to those without radiologic evidence of rickets (943 +/- 346, p = 0.18).

Conclusion: Elevation of P-APA >600 IU/L was very common in ELBW infants. BW was significantly inversely related to both P-APA and radiologic rickets. No single value of P-APA was related to radiological findings of rickets. Given the very high risk of osteopenia and rickets among ELBW infants, we recommend consideration of early screening and early mineral supplementation, especially among infants <600 g BW.

Figures

Figure 1
Figure 1
Average peak alkaline phosphatase according to birth weight.
Figure 2
Figure 2
Flow diagram to guide radiographic evaluation for rickets.

References

    1. Koo WW, Sherman R, Succop P, Krug-Wispe S, Tsang RC, Steichen JJ, Crawford AH, Oestreich AE. Fractures and rickets in very low birth weight infants: conservative management and outcome. J Pediatr Orthop. 1989;9:326–330.
    1. Glasgow JF, Thomas PS. Rachitic respiratory distress in small preterm infants. Arch Dis Child. 1977;52:268–273. doi: 10.1136/adc.52.4.268.
    1. Fewtrell MS, Cole TJ, Bishop NJ, Lucas A. Neonatal factors predicting childhood height in preterm infants: evidence for a persisting effect of early metabolic bone disease? J Pediatr. 2000;137:668–673. doi: 10.1067/mpd.2000.108953.
    1. Lucas A, Brooke OG, Baker BA, Bishop N, Morley R. High alkaline phosphatase activity and growth in preterm neonates. Arch Dis Child. 1989;64:902–909. doi: 10.1136/adc.64.7_Spec_No.902.
    1. So KW, Ng PC. Treatment and prevention of neonatal osteopenia. Current Paediatrics. 2005;15:106–113. doi: 10.1016/j.cupe.2004.12.011.
    1. Koo WW. Parenteral nutrition-related bone disease. J Parenteral Enteral Nutr. 1992;16:386–394. doi: 10.1177/0148607192016004386.
    1. Aiken CG, Sherwood RA, Lenney W. Role of plasma phosphate measurements in detecting rickets of prematurity and in monitoring treatment. Ann Clin Biochem. 1993;30:469–475.
    1. Kovar I, Mayne P, Barltrop D. Plasma alkaline phosphatase activity: a screening test for rickets in preterm neonates. Lancet. 1982;1:308–310. doi: 10.1016/S0140-6736(82)91569-0.
    1. Koo WW, Gupta JM, Nayanar VV, Wilkinson M, Posen S. Skeletal changes in preterm infants. Arch Dis Child. 1982;57:447–452. doi: 10.1136/adc.57.6.447.
    1. Faerk J, Peitersen B, Petersen S, Michaelsen KF. Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate. Arch Dis Child Fetal Neonatal Ed. 2002;87:133–136. doi: 10.1136/fn.87.2.F133.
    1. Harrison CM, Johnson K, McKechnie E. Osteopenia of prematurity: a national survey and review of practice. Acta Paediatr. 2008;4:407–413. doi: 10.1111/j.1651-2227.2007.00721.x.
    1. Guglielmi G, Muscarella S, Leone A, Peh WC. Imaging of metabolic bone diseases. Radiol Clin North Am. 2008;46:735–754. doi: 10.1016/j.rcl.2008.04.010.
    1. Namgung R, Tsang RC. Bone in the pregnant mother and newborn at birth. Clin Chim Acta. 2003;333:1–11. doi: 10.1016/S0009-8981(02)00025-6.
    1. Hokuto I, Ikeda K, Tokieda K, Mori K, Sueoka K. An ultra premature baby of 290 g birth weight needed more than 500 mg/kg of calcium and phosphorus daily. Eur J Pediatr. 2001;160:450–451. doi: 10.1007/s004310100761.
    1. Backström MC, Kouri T, Kuusela AL, Sievänen H, Koivisto AM, Ikonen RS, Mäki M. Bone isoenzyme of serum alkaline phosphatase and serum inorganic phosphate in metabolic bone disease of prematurity. Acta Paediatr. 2000;89:867–873. doi: 10.1080/080352500750043792.
    1. Glass EJ, Hume R, Hendry GM, Strange RC, Forfar JO. Plasma alkaline phosphatase activity in rickets of prematurity. Arch Dis Child. 1982;57:373–376. doi: 10.1136/adc.57.5.373.
    1. Lucas A, Brooke OG, Baker BA, Bishop N, Morley R. High alkaline phosphatase activity and growth in preterm neonates. Arch Dis Child. 1989;64:902–909. doi: 10.1136/adc.64.7_Spec_No.902.
    1. Litmanovitz I, Dolfin T, Regev R, Arnon S, Friedland O, Shainkin-Kestenbaum R, Lis M, Eliakim A. Bone turnover markers and bone strength during the first weeks of life in very low birth weight premature infants. J Perinat Med. 2004;32:58–61. doi: 10.1515/JPM.2004.010.

Source: PubMed

Szponzorok és közreműködők

Egészségi állapot

Kábítószer-beavatkozások

3
Iratkozz fel