1
|
Wilson BM, Ko FC, Moran MM, Adra A, Rasmussen MB, Thymann T, Sangild PT, Sumner DR. Skeletal consequences of preterm birth in pigs as a model for preterm infants. J Bone Miner Res 2024; 39:791-803. [PMID: 38655758 DOI: 10.1093/jbmr/zjae064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 03/18/2024] [Accepted: 04/22/2024] [Indexed: 04/26/2024]
Abstract
Preterm birth affects about 10% of all live births with many resultant health challenges, including metabolic bone disease of prematurity (MBDP), which is characterized by elevated alkaline phosphatase, suppressed phosphate, and deficient skeletal development. Because of the lack of an animal model, very little is known about bone structure, strength, and quality after preterm birth. This study investigated the utility of a pig model to replicate clinical features of preterm birth, including MBDP, and sought to determine if early postnatal administration of IGF-1 was an effective treatment. Preterm pigs, born by caesarean section at 90% gestation, were reared in intensive care facilities (respiratory, thermoregulatory, and nutritional support) and compared with sow-reared term pigs born vaginally. Preterm pigs were systemically treated with vehicle or IGF-1 (recombinant human IGF-1/BP-3, 2.25 mg/kg/d). Tissues were collected at postnatal days 1, 5, and 19 (the normal weaning period in pigs). Most bone-related outcomes were affected by preterm birth throughout the study period, whereas IGF-1 supplementation had almost no effect. By day 19, alkaline phosphatase was elevated, phosphate and calcium were reduced, and the bone resorption marker C-terminal crosslinks of type I collagen was elevated in preterm pigs compared to term pigs. Preterm pigs also had decrements in femoral cortical cross-sectional properties, consistent with reduced whole-bone strength. Thus, the preterm pig model replicates many features of preterm bone development in infants, including features of MBDP, and allows for direct interrogation of skeletal tissues, enhancing the field's ability to examine underlying mechanisms.
Collapse
Affiliation(s)
- Brittany M Wilson
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, 60612, United States
| | - Frank C Ko
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, 60612, United States
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, United States
| | - Meghan M Moran
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, 60612, United States
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, United States
| | - Amal Adra
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, 60612, United States
| | - Martin B Rasmussen
- Comparative Pediatrics and Nutrition, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, DK-1958, Denmark
| | - Thomas Thymann
- Comparative Pediatrics and Nutrition, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, DK-1958, Denmark
| | - Per T Sangild
- Comparative Pediatrics and Nutrition, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, DK-1958, Denmark
- Department of Neonatology, Rigshospitalet, Copenhagen, DK-2100, Denmark
- Department of Pediatrics, Odense University Hospital, Odense, DK-5000, Denmark
- Faculty of Theology, University of Copenhagen, Copenhagen, DK-2300, Denmark
| | - Dale Rick Sumner
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, 60612, United States
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, United States
| |
Collapse
|
2
|
Saif SA, Maghoula M, Babiker A, Abanmi M, Nichol F, Al Enazi M, Guevarra E, Sehlie F, Al Shaalan H, Mughal Z. A Multidisciplinary and a Comprehensive Approach to Reducing Fragility Fractures in Preterm Infants. Curr Pediatr Rev 2024; 20:434-443. [PMID: 36545738 DOI: 10.2174/1573396319666221221122013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 11/14/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
With advances in neonatal care, bone fractures prior to discharge from the hospital in preterm infants receiving contemporary neonatal care, are rare. Nevertheless, such fractures do occur in very low birth weight and extremely low birth weight infants who go on to develop metabolic bone disease of prematurity (MBDP), with or without secondary hyperparathyroidism. MBDP is a multifactorial disorder arising from the disruption of bone mass accrual due to premature birth, postnatal immobilisation, and loss of placental oestrogen resulting in bone loss, inadequate provision of bone minerals from enteral and parenteral nutrition, and medications that leach out bone minerals from the skeleton. All of these factors lead to skeletal demineralisation and a decrease in bone strength and an increased risk of fractures of the long bones and ribs. Secondary hyperparathyroidism resulting from phosphate supplements, or enteral/parenteral feeds with a calcium-tophosphate ratio of < 1.3:1.0 leads to subperiosteal bone resorption, cortical thinning, and further skeletal weakening. Such fractures may occur from routine handling and procedures such as cannulation. Most fractures are asymptomatic and often come to light incidentally on radiographs performed for other indications. In 2015, we instituted a comprehensive and multidisciplinary Neonatal Bone Health Programme (NBHP), the purpose of which was to reduce fragility fractures in highrisk neonates, by optimising enteral and parenteral nutrition, including maintaining calcium-tophosphate ratio ≥1.3:1, milligram to milligram, biochemical monitoring of MBDP, safe-handling of at-risk neonates, without compromising passive physiotherapy and skin-to-skin contact with parents. The at-risk infants in the programme had radiographs of the torso and limbs at 4 weeks and after 8 weeks from enrolment into the program or before discharge. Following the introduction of the NBHP, the bone fracture incidence reduced from 12.5% to zero over an 18-month period.
Collapse
Affiliation(s)
- Saif Al Saif
- Neonatal Department, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- Department of Pediatrics,, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Mohammad Maghoula
- Neonatal Department, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Amir Babiker
- Department of Pediatrics,, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- Division of Pediatric Endocrinology, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Mashael Abanmi
- Department of Physiotherapy, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Fiona Nichol
- Department of Occupational Therapy, King Abdulaziz Medical City, Riyadh, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Modhi Al Enazi
- Neonatal Department, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Elenor Guevarra
- Department of Dieticians, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Faisal Sehlie
- Pharmacy Department, King Abdulaziz Medical City, Riyadh, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Hesham Al Shaalan
- Department of Pediatric Radiology, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Zulf Mughal
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK
- Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK
| |
Collapse
|
3
|
Torró-Ferrero G, Fernández-Rego FJ, Agüera-Arenas JJ, Gomez-Conesa A. Effect of physiotherapy on the promotion of bone mineralization in preterm infants: a randomized controlled trial. Sci Rep 2022; 12:11680. [PMID: 35804078 PMCID: PMC9270394 DOI: 10.1038/s41598-022-15810-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/29/2022] [Indexed: 11/21/2022] Open
Abstract
Preterm infants have a low level of bone mineralization compared to those born at term. The purpose of the present study was to investigate the effect of reflex locomotion therapy (RLT) on bone mineralization and growth in preterm infants and compare its effect to other physiotherapy procedures. Forty-six preterm infants born at 29–34 weeks were randomized into three groups: one group received RLT (n = 17); the other group received passive movements with gentle joint compression (n = 14); and the control group received massages (n = 15). All the treatments were performed at the neonatal unit for one month. The main outcome measure was bone mineralization, which was measured using the tibial speed of sound (Tibial-SOS). All the groups were similar in terms of gestational age (31.8 ± 1.18), birth weight (1,583.41 ± 311.9), and Tibia-SOS (1,604.7 ± 27.9) at the beginning of the intervention. At the end of the study, significant differences were found among the groups in the Tibial-SOS [F(4,86) = 2.77, p = 0.049, ηp2 = 0.114] in terms of the benefit to the RLT group. In conclusion, RLT has been effective at improving Tibial-SOS levels and has been more effective than other physical therapy modalities; therefore, it could be considered an effective physiotherapeutic modality for the prevention and treatment of osteopenia from prematurity.
Collapse
Affiliation(s)
- Galaad Torró-Ferrero
- International School of Doctorate of the University of Murcia (EIDUM), University of Murcia, Murcia, Spain.
| | | | - Juan José Agüera-Arenas
- Neonatal Intensive Care Unit, Clinic Hospital University Virgen de La Arrixaca, Murcia, Spain
| | - Antonia Gomez-Conesa
- Research Group Research Methods and Evaluation in Social Sciences, Mare Nostrum Campus of International Excellence, University of Murcia, Murcia, Spain
| |
Collapse
|
4
|
Torró-Ferrero G, Fernández-Rego FJ, Jiménez-Liria MR, Agüera-Arenas JJ, Piñero-Peñalver J, Sánchez-Joya MDM, Fernández-Berenguer MJ, Rodríguez-Pérez M, Gomez-Conesa A. Effect of physical therapy on bone remodelling in preterm infants: a multicenter randomized controlled clinical trial. BMC Pediatr 2022; 22:362. [PMID: 35739544 PMCID: PMC9229521 DOI: 10.1186/s12887-022-03402-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Background Preterm infants have a low level of bone mineralization compared to those born at term, since 80% of calcium incorporation occurs at the end of pregnancy. The purpose of the present study was to investigate the effect of reflex locomotion therapy on bone modeling and growth in preterm infants and to compare its effect with those of other Physiotherapy modalities. Methods A multicentre randomized controlled clinical trial was conducted (02/2016 – 07/2020). 106 preterm infants born at the Virgen de la Arrixaca University Clinical Hospital, the General University Hospital of Elche and the Torrecárdenas University Hospital of Almería, between 26 and 34 weeks with hemodynamic stability, complete enteral nutrition and without any metabolic, congenital, genetic, neurological or respiratory disorders were evaluated for inclusion. Infants were randomly assigned to three groups: one group received reflex locomotion therapy (EGrlt); another group received passive mobilizations with gentle joint compression (EGpmc); and the control group received massage (CG). All treatments were carried out in the neonatal units lasting one month. The main outcome measure was bone formation and resorption measured with bone biomarkers. A mixed ANOVA was used to compare the results of bone biomarkers, and anthropometric measurements. Results Infants were randomized to EGrlt (n = 38), EGpmc (n = 32), and CG (n = 36). All groups were similar in terms of gender (p = 0.891 female 47.2%), gestational age (M = 30.753, SD = 1.878, p = 0.39) and birth weight (M = 1413.45, SD = 347.36, p = 0.157). At the end of the study, significant differences were found between the groups in their interaction in bone formation, measured with osteocalcin [F (2,35) = 4.92, p = 0.013, ηp2 = 0.043], in benefit of the EGrlt. Conclusions Reflex locomotion therapy has been effective in improving bone formation, more so than other Physiotherapy modalities. Therefore, reflex locomotion therapy could be considered one of the most effective physiotherapeutic modalities for the prevention and treatment of osteopenia of prematurity. Trial registrstion Trial retrospectively registered at ClinicalTrials.gov. First posted on 22/04/2020. Registration number: NCT04356807. Supplementary Information The online version contains supplementary material available at 10.1186/s12887-022-03402-2.
Collapse
Affiliation(s)
- Galaad Torró-Ferrero
- International School of Doctorate of the University of Murcia (EIDUM), University of Murcia, 30100, Murcia, Spain.
| | - Francisco Javier Fernández-Rego
- Department of Physical Therapy, Faculty of Medicine University of Murcia, Espinardo, 30100, Murcia, Spain.,Early Intervention Center of Lorca City Council, Lorca, 30800, Murcia, Spain
| | | | | | - Jessica Piñero-Peñalver
- Department of Developmental and Educational Psychology, University of Murcia, Murcia, Spain.,Faculty of Psicology, University of Murcia, Espinardo, 30100, Murcia, Spain
| | | | | | | | - Antonia Gomez-Conesa
- Research Group Research Methods and Evaluation in Social Sciences. Mare Nostrum Campus of International Excellence, University of Murcia, Murcia, Spain
| |
Collapse
|
5
|
Torró-Ferrero G, Fernández-Rego FJ, Gómez-Conesa A. Physical Therapy to Prevent Osteopenia in Preterm Infants: A Systematic Review. CHILDREN (BASEL, SWITZERLAND) 2021; 8:664. [PMID: 34438555 PMCID: PMC8391284 DOI: 10.3390/children8080664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/16/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND During the last trimester of pregnancy, about 80% of the infant's calcium is incorporated, and for this reason, preterm infants have less bone mineralization compared to those born at term. The aim of the present systematic review was to identify, evaluate and summarize the studies that deal with the effect of physiotherapy modalities in the prevention and treatment of osteopenia in preterm infants. METHODS A comprehensive search (09/2019-02/2021) using PubMed, Web of Science, SCOPUS, ProQuest, SciELO, Latindex, ScienceDirect, PEDro and ClinicalTrials.gov was carried out. The following data were extracted: The number of participants, characteristics of the participants, design, characteristics of the intervention, outcome measures, time of evaluation and results. A non-quantitative synthesis of the extracted data was performed. The methodological quality and risk of bias were assessed using a PEDro scale and ROB-2 scale, respectively. RESULTS A total of 16 studies were analyzed, presenting a methodological quality that ranged from 3 to 8 points, and all showed some concerns regarding their risk of bias. Almost all studies (15/16) used passive mobilizations with joint pressure to prevent osteopenia, but they differed in the intensity and frequency of application. CONCLUSIONS A daily exercise program of passive mobilizations with joint pressure, improves bone mineralization in preterm infants admitted to neonatal units.
Collapse
Affiliation(s)
- Galaad Torró-Ferrero
- International School of Doctorate of the Univesity of Murcia (EIDUM), University of Murcia, 30100 Murcia, Spain
| | | | - Antonia Gómez-Conesa
- Research Group Research Methods and Evaluation in Social Sciences, Mare Nostrum Campus of International Excellence, University of Murcia, 30100 Murcia, Spain;
| |
Collapse
|
6
|
Rosendahl K, Lundestad A, Bjørlykke JA, Lein RK, Angenete O, Augdal TA, Müller LSO, Jaramillo D. Revisiting the radiographic assessment of osteoporosis-Osteopenia in children 0-2 years of age. A systematic review. PLoS One 2020; 15:e0241635. [PMID: 33137162 PMCID: PMC7605664 DOI: 10.1371/journal.pone.0241635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 10/18/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Imaging for osteoporosis has two major aims, first, to identify the presence of low bone mass (osteopenia), and second, to quantify bone mass using semiquantitative (conventional radiography) or quantitative (densitometry) methods. In young children, densitometry is hampered by the lack of reference values, and high-quality radiographs still play a role although the evaluation of osteopenia as a marker for osteoporosis is subjective and based on personal experience. Medical experts questioned in court over child abuse, often refer to the literature and state that 20-40% loss of bone mass is warranted before osteopenia becomes evident on radiographs. In our systematic review, we aimed at identifying evidence underpinning this statement. A secondary outcome was identifying normal references for cortical thickness of the skeleton in infants born term, < 2 years of age. METHODS We undertook systematic searches in Medline, Embase and Svemed+, covering 1946-2020. Unpublished material was searched in Clinical trials and International Clinical Trials Registry Platform (ICTRP). Both relevant subject headings and free text words were used for the following concepts: osteoporosis or osteopenia, radiography, children up to 6 years. RESULTS A total 5592 publications were identified, of which none met the inclusion criteria for the primary outcome; the degree of bone loss warranted before osteopenia becomes visible radiographically. As for the secondary outcome, 21 studies were identified. None of the studies was true population based and none covered the pre-defined age range from 0-2 years. However, four studies of which three having a crossectional and one a longitudinal design, included newborns while one study included children 0-2 years. CONCLUSIONS Despite an extensive literature search, we did not find any studies supporting the assumption that a 20-40% bone loss is required before osteopenia becomes visible on radiographs. Reference values for cortical thickness were sparse. Further studies addressing this important topic are warranted.
Collapse
Affiliation(s)
- Karen Rosendahl
- Faculty of Health Sciences, Department of Clinical Medicine, UiT the Arctic University of Norway, Tromsø, Norway
- Section of Paediatric Radiology, University Hospital of North Norway, Tromsø, Norway
- * E-mail:
| | | | - John Asle Bjørlykke
- Section of Paediatric Radiology, Haukeland University Hospital, Bergen, Norway
| | | | - Oskar Angenete
- Department of Radiology and Nuclear Medicine, St Olav Hospital, Trondheim, Norway
- Department of Circulation and Medical imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thomas Angell Augdal
- Faculty of Health Sciences, Department of Clinical Medicine, UiT the Arctic University of Norway, Tromsø, Norway
- Section of Paediatric Radiology, University Hospital of North Norway, Tromsø, Norway
| | | | - Diego Jaramillo
- Columbia University Medical Center, New York, New York, United States of America
| |
Collapse
|
7
|
Dokos C, Tsakalidis C, Manaridou K, Koliakos G. Acetylcholinesterase activity and bone biochemical markers in premature and full-term neonates. J Pediatr Endocrinol Metab 2018; 31:1363-1366. [PMID: 30427781 DOI: 10.1515/jpem-2018-0426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/15/2018] [Indexed: 01/17/2023]
Abstract
Background Almost 30% of the premature infants have low body weight and bone mineral density due to prematurity. There is no consensus of screening premature neonates for metabolic bone disease; therefore, it is important to investigate the use of bone biochemical parameters. Latest studies involved the activity of acetylcholinesterase as a mediator in bone remodeling. It is hypothesized that there is a possible correlation of bone biochemical biomarkers and acetylcholinesterase (AChE) activity in premature infants. Methods We studied 50 neonates (26 preterm with gestational age <32 weeks, 24 full-term). Clinical data (sex, gestational week) and anthropometric parameters (body weight) were recorded. We directly measured the bone biochemical markers in serum such as alkaline phosphatase (ALP), calcium (Ca), phosphorus (P), magnesium (Mg) and parathyroid hormone (PTH). In addition, we measured the AChE activity. Results ALP and parathyroid hormone levels were higher, but Ca, P and AChE were lower in premature neonates group compared with full-term ones. There is a significant positive correlation of gestational age with body weight, Ca and AChE. A significant negative correlation was observed for ALP and PTH with gestational age. Conclusions We found a gestational age-related increase of AChE activity. There were significant relationships between AChE activity with P and PTH.
Collapse
Affiliation(s)
- Charalampos Dokos
- 2nd Neonatal Clinic, Papageorgiou University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece, Phone: +4917661465941
| | - Christos Tsakalidis
- 2nd Neonatal Clinic, Papageorgiou University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Kyriakoula Manaridou
- 2nd Neonatal Clinic, Papageorgiou University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Department of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - George Koliakos
- Department of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
8
|
Dokos C, Tsakalidis C, Manaridou K, Karayianni P, Kyrkos I, Roussos I. Clinical-laboratory findings of bone metabolism in healthy premature and full-term neonates: preliminary results. CLINICAL CASES IN MINERAL AND BONE METABOLISM : THE OFFICIAL JOURNAL OF THE ITALIAN SOCIETY OF OSTEOPOROSIS, MINERAL METABOLISM, AND SKELETAL DISEASES 2017; 14:167-172. [PMID: 29263727 PMCID: PMC5726203 DOI: 10.11138/ccmbm/2017.14.1.167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Premature infants are a major risk group for bone metabolic disorders. The purpose of this study is to clarify certain aspects of bone metabolism in healthy preterm and full-term neonates. Forty neonates (20 preterm and 20 full-term) were the material of the study. For each neonate demographic data (gender, gestational week) and anthropometric data (body weight) were recorded. Blood samples were collected and biochemical markers of bone metabolism (serum ALP, Ca, P, Mg) were immediately estimated. According to the results there is a statistically significant difference in average ALP of preterm neonates compared to full term neonates. Slightly higher values of Ca, P, Mg occurred in premature neonates while there was a statistically significant difference in the weeks of gestation and body weights between the two groups. It is typical in premature neonates the decrease in levels of ALP by the weeks of gestation and the stable levels of Ca. Gestational week seems to positively affect P and Mg levels in preterm neonates. Conclusively from our study's results arises that the week of gestation and not so much the body weight influence the alterations of bone biochemical biomarkers in healthy premature newborns. It seems that very premature neonates have high levels of serum ALP in decompensation of lower levels of Mg and P from all the newborns in this study. Therefore in very premature neonates, it is recommended to estimate serum ALP, Mg and P for assessment of bone turnover.
Collapse
Affiliation(s)
- Charalampos Dokos
- 2 Neonatal Clinic, Papageorgiou University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Christos Tsakalidis
- 2 Neonatal Clinic, Papageorgiou University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Kyriakoula Manaridou
- 2 Neonatal Clinic, Papageorgiou University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Paraskevi Karayianni
- 2 Neonatal Clinic, Papageorgiou University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Ioannis Kyrkos
- 3 Orthopaedic Clinic, Papageorgiou University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Israel Roussos
- 2 Pediatric Clinic, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
9
|
The Clinical and Biochemical Predictors of Bone Mass in Preterm Infants. PLoS One 2016; 11:e0165727. [PMID: 27806112 PMCID: PMC5091911 DOI: 10.1371/journal.pone.0165727] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/17/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Metabolic bone disease of prematurity still occurs in preterm infants, although a significant improvement in neonatal care has been observed in recent decades. Dual-energy X-ray absorptiometry (DXA) is the precise technique for assessing bone mineral content (BMC) in preterm infants, but is not widely available. AIM To investigate the clinical and biochemical parameters, including bone metabolism markers as potential predictors of BMC, in preterm infants up to 3 months corrected age (CA). MATERIALS AND METHODS Ca-P homeostasis, iPTH, 25-hydroxyvitamin D, osteocalcin, N-terminal propeptide, cross-linked C-telopeptide and amino-terminal pro C-type natriuretic peptide and the DXA scans were prospectively performed in 184 preterm infants (≤ 34 weeks' gestation) between term age and 3 mo CA. Lower bone mass was defined as BMC below or equal to respective median value for the whole study group, rounded to the nearest whole number. RESULTS The appropriate quality DXA scans were available for 160 infants (87%) examined at term and for 130 (71%) tested at 3 mo CA. Higher iPTH level was the only independent predictor of lower BMC at term, whereas lower BMC at 3 mo CA was associated both with lower urinary phosphate excretion and higher serum osteocalcin level. ROC analysis showed that iPTH >43.6 pg/mL provided 40% sensitivity and 88% specificity in identification of preterm infants with lower BMC at term. In turn, urinary phosphate excretion (TRP>97% or UP/Cr ≤0.74 mg/mg) and serum osteocalcin >172 ng/mL provided 40% sensitivity and 93% specificity in identification of infants with decreased BMC at 3 mo CA. CONCLUSION Serum iPTH might to be a simple predictor of reduced BMC in preterm infants at term age, but urinary phosphate excretion and serum osteocalcin might predict reduced BMC at 3 mo CA. These results represent a promising diagnostic tool based on simple, widely available biochemical measurements for bone mass assessment in preterm infants.
Collapse
|
10
|
Fatani T, Binjab A, Weiler H, Sharma A, Rodd C. Persistent elevation of fibroblast growth factor 23 concentrations in healthy appropriate-for-gestational-age preterm infants. J Pediatr Endocrinol Metab 2015; 28:825-32. [PMID: 25968436 DOI: 10.1515/jpem-2014-0186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 12/08/2014] [Indexed: 11/15/2022]
Abstract
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.
Collapse
|
11
|
do Prado MRMC, Oliveira FDCC, Assis KF, Ribeiro SAV, do Prado Junior PP, Sant'Ana LFDR, Priore SE, Franceschini SDCC. [Prevalence of vitamin D deficiency and associated factors in women and newborns in the immediate postpartum period]. REVISTA PAULISTA DE PEDIATRIA 2015; 33:287-94. [PMID: 26100593 PMCID: PMC4620955 DOI: 10.1016/j.rpped.2015.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/12/2015] [Accepted: 01/18/2015] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To assess the prevalence of vitamin D deficiency and its associated factors in women and their newborns in the postpartum period. METHODS This cross-sectional study evaluated vitamin D deficiency/insufficiency in 226 women and their newborns in Viçosa (Minas Gerais, BR) between December 2011 and November 2012. Cord blood and venous maternal blood were collected to evaluate the following biochemical parameters: vitamin D, alkaline phosphatase, calcium, phosphorus and parathyroid hormone. Poisson regression analysis, with a confidence interval of 95% was applied to assess vitamin D deficiency and its associated factors. Multiple linear regression analysis was performed to identify factors associated with 25(OH)D deficiency in the newborns and women from the study. The criteria for variable inclusion in the multiple linear regression model was the association with the dependent variable in the simple linear regression analysis, considering p<0.20. Significance level was α<5%. RESULTS From 226 women included, 200 (88.5%) were 20 to 44 years old; the median age was 28 years. Deficient/insufficient levels of vitamin D were found in 192 (85%) women and in 182 (80.5%) neonates. The maternal 25(OH)D and alkaline phosphatase levels were independently associated with vitamin D deficiency in infants. CONCLUSIONS This study identified a high prevalence of vitamin D deficiency and insufficiency in women and newborns and the association between maternal nutritional status of vitamin D and their infants' vitamin D status.
Collapse
|
12
|
Altuncu E, Akman I, Yurdakul Z, Ozdoğan T, Solakoğlu M, Selim N, Bilgen H, Ozek E, Bereket A. Quantitative ultrasound and biochemical parameters for the assessment of osteopenia in preterm infants. J Matern Fetal Neonatal Med 2009; 20:401-5. [PMID: 17674245 DOI: 10.1080/14767050701287418] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Our study aimed to evaluate the feasibility of quantitative ultrasound (QUS) evaluation in osteopenia of prematurity and to compare the results to biochemical parameters. METHODS QUS assessment of bone was performed at the end of the first postnatal week and at term-corrected age (CA) in premature infants (N = 30) and within the first week in full-term infants (N = 25). On the same day of measurement of QUS, the serum calcium, phosphorus (inorganic), and alkaline phosphatase (ALP) activity were measured in the preterm infants. RESULTS The median of tibia z score at term-CA in premature infants was significantly lower compared to that of first postnatal week (-1 and 0.4, respectively; p < 0.0001) and it was also lower than that of term-matched controls (0.0; p = 0.001). Preterm infants at term-CA had lower weights and lengths in comparison to term infants. The median ALP value was 585 IU/L at the first postnatal week and 703 IU/L at term-CA in preterm infants (p = 0.003). The median tibia z score of infants with ALP >or=900 IU/L was significantly lower than that of the infants with ALP <900 IU/L (-1.4 vs. 0.1; p = 0.001). An inverse correlation was found between ALP levels and tibia z score at term-CA in preterm infants (rho = -0.61, p = 0.01). CONCLUSIONS Bone density of preterm infants at term-CA was lower than that at first postnatal week. Serum ALP levels increased during the first postnatal weeks. The tibia z scores were correlated to serum ALP levels. QUS is a good screening tool for the detection of osteopenia.
Collapse
Affiliation(s)
- Emel Altuncu
- Department of Pediatrics, Divisions of Neonatology and Endocrinology, School of Medicine, Marmara University, Istanbul, Turkey.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Effects of motor physical therapy on bone mineralization in premature infants: a randomized controlled study. J Perinatol 2008; 28:624-31. [PMID: 18633420 DOI: 10.1038/jp.2008.60] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To study the effect of physical therapy on bone mineralization, weight gain and growth in preterm infants. METHOD After fulfilling the inclusion criteria, preterm infants were matched for gestational age and birth weight and then randomly assigned to the physiotherapy group (PG, n=15) and control group (CG, n=14). The PG received motor physical therapy for 15 min daily, 5 times per week until hospital discharge. Bone mineralization was measured by total body dual energy X-ray beam absorptiometry (DEXA) at the onset and end of the study. Statistical analysis was realized by ANCOVA and linear correlation tests. RESULT The physical therapy group (PG) presented greater body weight gain per day (27.4+/-2.4 vs 21.01+/-4.4 g, P<0.001) and length (1.3+/-0.3 vs 0.8+/-0.2 cm week(-1), P<0.001) than did the control group (CG). Body composition values verified by DEXA were greater for the PG. The mean gain in bone mineral content (BMC) (mg) was greater in the PG (434+/-247.5 vs -8.9+/-11.4, P<0.001), as was the mean bone mineral density (BMD) gain (mg cm(-2)) (8.4+/-5.6 vs -3.1+/-5.5, P<0.001). The gain in bone area (BA,cm(2)) was 10.3+/-5 in the PG vs 1.5 +/-2 in the CG (P<0.001). The gain in lean mass (LM) (g) in the PG was also greater than in the CG (271.1+/-21.4 vs 109.1+/-1.0, P<0.009). The fat mass (g) was similar between the groups (P=0.432). CONCLUSION These results showed that physiotherapy in preterm infants produced greater gains in growth, body weight, BMC, BMD, BA and LM.
Collapse
|
14
|
Abstract
Premature infants are more vulnerable to bone fractures than term infants for numerous reasons, directly or indirectly related to prematurity. Although the reported incidence of fractures in this vulnerable population is somewhat inconsistent, the increased risk is clear. Metabolic disorders, genetic disease, accidental trauma, and non-accidental injury can all account for fractures in premature infants, so that determining the etiology is of importance. This increased risk does not appear to continue into childhood. Thus, most of these fractures would be found in children <3 years of age, often within the first year of life. Unfortunately, this is the same age group in which the majority of non-accidental injury (NAI) cases, frequently presenting with fractures, are seen. Further confounding the diagnosis is the possibility of previously undiagnosed fractures from trauma during delivery, and fractures due to bone weakening by metabolic diseases. A multi-dimensional approach using a combination of diagnostic procedures is necessary to properly identify the location of the fractures, the bone structure and characteristics, and the history with regards to family situation and medical treatment. This paper reviews the potential factors related to fractures in premature infants and the differential diagnoses of child abuse fractures.
Collapse
Affiliation(s)
- David M Carroll
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada
| | | | | |
Collapse
|
15
|
Abstract
Bone disease of prematurity is a complication of preterm birth. This article reviews the aetiology, treatment and prevention of bone disease of prematurity. Provision of adequate nutrition including energy, protein, and minerals is required for both treatment and prevention. Screening for bone disease is controversial. While further research is required quantitative ultrasound appears to be a promising tool for screening and monitoring response to therapy. Further research is needed before recommending physical activity to prevent bone disease of prematurity.
Collapse
Affiliation(s)
- M Sharp
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women and Princess Margaret Hospital for Children, Subiaco, Western Australia, Australia.
| |
Collapse
|
16
|
Mercy J, Dillon B, Morris J, Emmerson AJ, Mughal MZ. Relationship of tibial speed of sound and lower limb length to nutrient intake in preterm infants. Arch Dis Child Fetal Neonatal Ed 2007; 92:F381-5. [PMID: 17369280 PMCID: PMC2675363 DOI: 10.1136/adc.2006.105742] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Metabolic bone disease of prematurity is characterised by impaired postnatal mineralisation of the rapidly growing infant skeleton. OBJECTIVE To longitudinally evaluate postnatal changes in tibial speed of sound (tSOS; which reflects cortical thickness and bone mineral density) and lower limb length (LLL; a measure of tibial growth) in very low birthweight preterm infants receiving contemporary neonatal care. METHODS tSOS and LLL were measured using a quantitative ultrasound device and an electronic neonatal knemometer, respectively, in the same limb, weekly, for a median period of four weeks (3-16 weeks) in 84 preterm infants (median gestation 26.8 weeks (range 23-35.2 weeks) and median birth weight 869.5 g (range 418-1481 g)). RESULTS Initial tSOS and LLL were correlated with gestation (r = 0.42, p<0.001; r = 0.76, p<0.001, respectively) and birth weight (r = 0.23, p = 0.038; r = 0.93, p<0.001, respectively). Postnatally, tSOS decreased (r = -0.15, p = 0.011) whereas LLL increased (r = 0.96, p<0.001) with age. The rate of postnatal change in LLL, but not in tSOS, was positively influenced by intake of calcium (p = 0.03), phosphorus (p = 0.01) and vitamin D (p = 0.03). CONCLUSIONS The postnatal decline in tSOS, which is probably due to cortical thinning secondary to endocortical bone loss, and increase in LLL provide new insight into the development of long bones in preterm infants.
Collapse
Affiliation(s)
- J Mercy
- Department of Paediatric Medicine, St Mary's Hospital for Women & Children, Hathersage Road, Manchester M13 0JH, England.
| | | | | | | | | |
Collapse
|
17
|
|
18
|
Rigo J, Pieltain C, Salle B, Senterre J. Enteral calcium, phosphate and vitamin D requirements and bone mineralization in preterm infants. Acta Paediatr 2007; 96:969-74. [PMID: 17577338 DOI: 10.1111/j.1651-2227.2007.00336.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
UNLABELLED With major advances in life-support measures, nutrition has become one of the most debated issues in the care of very low birth-weight (VLBW) infants. Current nutritional recommendations are based on healthy premature infants and designed to provide postnatal nutrient retention during the 'stable-growing' period equivalent to the intrauterine gain of a normal foetus. However, this reference is still a matter of discussion, especially in the field of the mineral requirements. After birth, there are dramatic physiological changes in bone metabolism resulting from various factors: disruption in maternal mineral supply, stimulation of calciotropic hormone secretion, change in hormonal environment and relative reduction in mechanical stress. These events stimulate the remodelling process leading to an increase in endosteal bone resorption and a decrease in bone density. In preterm infants, these adaptation processes modify the mineral requirement, since, by itself, the increased remodelling provides a part of the mineral requirement necessary for postnatal bone growth and turnover. The care of newly born premature infants should not necessarily aim to achieve intrauterine calcium accretion rates. CONCLUSION Considering that a calcium retention level ranging from 60 to 90 mg/kg/day assures appropriate mineralization, and decreases the risk of fracture and diminishes the clinical symptoms of osteopenia, an intake of 100 to 160 mg/kg/day of highly bioavailable calcium salts, 60 to 90 mg/kg/day of phosphorus and 800 to 1000 IU of vitamin D per day is recommended.
Collapse
Affiliation(s)
- Jacques Rigo
- Pediatrics and Neonatal Department, University of Liege CHR Citadelle, Liège, Belgium.
| | | | | | | |
Collapse
|
19
|
Abstract
For a number of reasons there is a need to explore reliable non-invasive methods for assessing bone health in neonates and young infants. Epidemiological studies suggest that early events in life may predispose the adult to degenerative diseases such as osteoporosis. Preterm infants have an increased risk of low bone mass because of limited bone mass accretion in utero and a greater need for bone nutrients. Despite improvements in neonatal care fractures still occur. The diagnosis of osteopaenia of prematurity remains difficult as there is no screening test which is both sensitive and specific. Biochemical indices are non-diagnostic, and plain X-rays in the absence of fractures are poor at diagnosing bone disease. Although dual energy X-ray absorptiometry is increasingly used to assess bone mineral status in newborn infants, the size and immobility of the scanner, the length of time to perform the scan and use of ionising radiation make it unsuitable for routine use in the setting of the fragile very low birth weight infant. Quantitative ultrasound (QUS) was first developed in 1984, as a non-ionising, portable and low cost method of assessing bone health. The measurements obtained from QUS are thought to be related not only to the mineral density of the bone but also to reflect parameters of bone quality and strength. Preliminary studies suggest that this technique may be a useful method of assessing changes in bone health in preterm infants, but the data need to be interpreted carefully. This review will concentrate on the methodology of QUS and the studies that have already been performed in neonates.
Collapse
Affiliation(s)
- H McDevitt
- Bone and Endocrine Research Group, Royal Hospital for Sick Children, Glasgow, UK
| | | |
Collapse
|
20
|
Tomlinson C, McDevitt H, Ahmed SF, White MP. Longitudinal changes in bone health as assessed by the speed of sound in very low birth weight preterm infants. J Pediatr 2006; 148:450-5. [PMID: 16647403 DOI: 10.1016/j.jpeds.2005.12.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 10/07/2005] [Accepted: 12/06/2005] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess longitudinal changes in speed of sound (SOS) in very low birth weight (VLBW) infants and investigate the relationship with markers of osteopathy of prematurity (OP) and clinical illness. STUDY DESIGN Twenty-five infants were recruited. Eighteen infants, median gestation 27 weeks (range 24-32), median birth weight 957 g (range 625-1500 g), had serial scans. SOS was measured at both tibiae weekly until 35 to 37 weeks corrected gestational age (CGA). RESULTS Initial median SOS standard deviation score (SDS) (Z) score was -0.07 (range-1.3-1.3). SOS correlated with gestation (r, 0.8, P<.005), and birth weight (r, 0.67, P<.005.) SOS fell from a median of 2923 m/s (2672-3107) at birth to 2802 m/s (2502-2991) at 35 to 37 weeks CGA (P<.05). This fall was greater in the 24- to 27-week gestation cohort with a median reduction of 2.2 SDS (1.6, 4.0) compared with 1.3 SDS (0.8-2.2) in those>28 weeks (P<.05). There was a negative correlation between SOS, at the end of the study, peak serum alkaline phosphatase (ALP) (r, 0.6, P<.05), CRIB (Clinical Risk Index for Babies)/CRIB II scores (both r, 0.6, P<.05), and duration of total parenteral nutrition (TPN) (r, 0.58, P<.05.) CONCLUSIONS Although tibial SOS was within the expected range at birth, there was a subsequent failure to gain SOS, and this was most marked in infants of a lower gestation.
Collapse
MESH Headings
- Alkaline Phosphatase/blood
- Analysis of Variance
- Biomarkers
- Bone Development
- Bone Diseases, Metabolic/diagnosis
- Bone Diseases, Metabolic/diagnostic imaging
- Bone Diseases, Metabolic/epidemiology
- Child Development
- Female
- Humans
- Infant, Newborn
- Infant, Premature
- Infant, Premature, Diseases/diagnosis
- Infant, Premature, Diseases/diagnostic imaging
- Infant, Premature, Diseases/epidemiology
- Infant, Very Low Birth Weight
- Longitudinal Studies
- Male
- Severity of Illness Index
- Ultrasonography
Collapse
Affiliation(s)
- C Tomlinson
- Neonatal Unit, Princess Royal Maternity Hospital, Glasgow, UK
| | | | | | | |
Collapse
|
21
|
Nakano K, Iwamatsu T, Wang CM, Tarasima M, Nakayama T, Sasaki K, Tachikawa E, Noda N, Mizoguchi E, Osawa M. High bone turnover of type I collagen depends on fetal growth. Bone 2006; 38:249-56. [PMID: 16214433 DOI: 10.1016/j.bone.2005.07.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 07/19/2005] [Accepted: 07/28/2005] [Indexed: 11/26/2022]
Abstract
The bone metabolic processes of proliferation and differentiation in preterm and term newborns have yet to be fully elucidated. Seventy-four umbilical cord blood samples were collected from preterm and term newborns delivered at 27 to 42 gestational weeks (GWs). Carboxy-terminal propeptide of type I procollagen (PICP), pyridinoline cross-linked telopeptide domain of type I collagen (ICTP), alkaline phosphatase (ALP), and bone-specific alkaline phosphatase (BAP) were measured. Calcitonin (CT), estrogen (E2), intact parathyroid hormone, and insulin-like growth factor-I (IGF-I) were also examined in 20 or 23 randomly selected samples. We conducted cross-sectional regression analyses for bone metabolic markers, fetal growth markers including GWs, birth weight (BW), height (BH) and head circumference (HC), and bone related hormones. PICP and ICTP activities were very high, but decreased significantly with fetal growth based on GWs, BW, BH, and HC changes (GWs, BW, and BH to both PICP and ICTP, P < 0.0001; HC to ICTP, P < 0.0001; HC to PICP, P < 0.05), while BAP and ALP did not change significantly. E2 and CT both showed a significant positive correlation with Ca (P < 0.05), but neither hormone had any apparent correlation with PICP, ALP, BAP, or ICTP. These results suggest very active bone formation and resorption of type I collagen to be dependent on fetal growth and that fetal osteoblasts dominate the proliferation phase of development rather than the maturation phase. However, factors contributing to high bone turnover in the fetus remain to be elucidated.
Collapse
Affiliation(s)
- Kazutoshi Nakano
- Department of Pediatrics, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
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. [PMID: 15008388 DOI: 10.1515/jpm.2004.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To determine the association between changes in bone turnover markers and bone strength of very low birth weight infants during the first eight postnatal weeks. STUDY DESIGN Twelve very low birth weight premature infants [mean gestational age: 28.4 +/- 0.6 weeks, mean birth weight: 1131 +/- 62 grams] participated in the study. Bone strength was evaluated weekly by quantitative ultrasound measurements of tibial bone speed of sound (SOS, Sunlight Omnisense). Bone specific alkaline phosphatase (BSAP), a marker of bone formation, and carboxy terminal cross-links telopeptide of type-I collagen (ICTP), a marker of bone resorption, were collected at the ages of one, four and eight weeks. RESULTS BSAP increased significantly (from 119.9 +/- 16.2 U/L to 132.1 +/- 11.9 U/L and 152.1 +/- 15.7 U/L at one, four and eight weeks of life, respectively, p<0.05). ICTP decreased significantly during the study period (from 122.3 +/- 8.7 ng/ml to 96.0 +/- 4.8 ng/ml and 92.3 +/- 5.4 ng/ml at one, four and eight weeks of life, respectively; p<0.05). There was a significant decrease in bone SOS (from 2886 +/- 29 m/sec to 2792 +/- 30 m/sec and 2753 +/- 30 m/sec at birth, four weeks and eight weeks of life, respectively; p<0.02). There was no correlation between the levels of bone markers and bone SOS. CONCLUSION In VLBW premature infants, there is a significant decrease in bone strength concomitant with biochemical evidence for new bone formation (increase in BSAP and a decrease in ICTP) during the first eight postnatal weeks. Changes in the biochemical markers could not predict the changes in bone strength.
Collapse
Affiliation(s)
- Ita Litmanovitz
- Department of Neonatology, Meir General Hospital, Sapir Medical Center, Kfar Saba, Israel.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Blanaru JL, Kohut JR, Fitzpatrick-Wong SC, Weiler HA. Dose response of bone mass to dietary arachidonic acid in piglets fed cow milk-based formula. Am J Clin Nutr 2004; 79:139-47. [PMID: 14684410 DOI: 10.1093/ajcn/79.1.139] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The addition of arachidonic acid (AA) and docosahexaenoic acid (DHA) to infant formula was recently approved in North America. In piglets, dietary AA is linked to elevations in bone mass. OBJECTIVE The objective was to investigate the effects of varied amounts of dietary AA on bone modeling and bone mass with the use of the piglet model for infant nutrition. DESIGN Male piglets (n = 32) were randomly assigned to receive 1 of 4 formulas supplemented with AA (0.30%, 0.45%, 0.60%, or 0.75% of fat) plus DHA (0.1% of fat) from days 5 to 20 of life. Measurements included biomarkers of bone modeling, fatty acid status, and whole-body and femur bone mineral content; bone area was measured by dual-energy X-ray absorptiometry. Differences among groups were detected with two-factor analysis of variance. Regression analyses were used to determine factors responsible for bone mineral content after dietary AA was accounted for. RESULTS Proportions of AA in plasma, liver, and adipose were modified by the dietary treatments, but bone modeling was not affected. Liver AA was positively related to plasma insulin-like growth factor 1 and calcitriol and urinary N-telopeptide. Whole-body bone mineral content was elevated in the piglets fed 0.60% and 0.75% AA and was best predicted by dietary AA and bone resorption. CONCLUSIONS This study confirms that dietary AA alters bone mass and clarifies the best amount of AA to add to the diet of pigs born at term. Because the amount of dietary DHA was held constant, whether other amounts of DHA are related to bone mass requires investigation.
Collapse
Affiliation(s)
- Janice L Blanaru
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Canada
| | | | | | | |
Collapse
|
24
|
Abstract
Rickets, once thought vanquished, is reappearing. In some less developed countries it hardly went away. This seminar reviews the effects of genes, stage of development, and environment on clinical expression of the disease. Rickets can be secondary to disorders of the gut, pancreas, liver, kidney, or metabolism; however, it is mostly due to nutrient deficiency and we concentrate on this form. Although calcium deficiency contributes in communities where little cows' milk is consumed, deficiency of vitamin D is the main cause. There are three major problems: the promotion of exclusive breastfeeding for long periods without vitamin D supplementation, particularly for babies whose mothers are vitamin D deficient; reduced opportunities for production of the vitamin in the skin because of female modesty and fear of skin cancer; and the high prevalence of rickets in immigrant groups in more temperate regions. A safety net of extra dietary vitamin D should be re-emphasised, not only for children but also for pregnant women. The reason why many immigrant children in temperate zones have vitamin D deficiency is unclear. We speculate that in addition to differences in genetic factors, sun exposure, and skin pigmentation, iron deficiency may affect vitamin D handling in the skin or gut or its intermediary metabolism.
Collapse
Affiliation(s)
- Brian Wharton
- MRC Childhood Nutrition Research Centre, Institute of Child Health, WC1N 1EH, London, UK.
| | | |
Collapse
|
25
|
Abstract
Temporary brittle bone disease (TBBD) is a recently described phenotype of multiple, unexplained fractures in the first year of life and predominantly in the first 6 months of life. There is usually no other injury such as bruising, subdural hematomas, retinal hemorrhages, or other internal organ injury. The susceptibility to fracture is transient, and there are no other radiographic or biochemical abnormalities noted in the standard evaluation that might suggest an underlying cause. The child abuse and pediatric radiology communities have, for the most part, been unwilling to accept this as a real condition, for they believe it is a ruse for child abuse. This review describes the experience of the author in evaluating infants with multiple unexplained fractures and the hypothesis that has emerged for explaining TBBD. The hypothesis is a prenatal application of the mechanostat/bone loading theory of bone formation and states that TBBD is caused by fetal immobilization which leads to fetal bone unloading and transient, relative osteopenia. Such susceptible infants can fracture with routine handling and present with a pattern of fractures that is similar to that which has been thought to be highly specific for child abuse. The review presents: (a) the evidence that indicates that normal fetal movement is important for normal fetal bone strength, (b) a critique of the radiologic approach in the diagnosis of child abuse in infants with multiple unexplained fractures, (c) observations that would indicate that child abuse is unlikely in infants with TBBD, and (d) new approaches to the infant with multiple unexplained fractures that would assist in accurate diagnosis.
Collapse
|
26
|
Abstract
The bone disease of preterm birth has traditionally been explained by a decrease in bone formation from insufficient availability of calcium and phosphorus. However, there is emerging evidence that there is increased bone resorption in the bone disease of preterm birth, an observation that indicates some other explanation for this condition. The biomechanical model of postnatal bone formation states that, through a regulatory feedback system in the bone called the mechanostat, bone is able to respond to increased bone loading by increasing bone strength and to decreased bone loading by decreasing bone strength. It is suggested that this increased bone resorption in the markedly preterm infant compared with the term infant is secondary to decreased bone loading. Application of this model to the fetus and preterm infant suggests that intrauterine bone loading of the fetus from movement and kicking against the uterus is critical for normal fetal bone formation. The associated muscle growth from this activity also contributes to bone loading. The markedly preterm infant is deprived of much of this critical time period of intrauterine bone accretion, and bone formation occurs in the less favorable extrauterine environment, where there is significantly less bone loading.
Collapse
Affiliation(s)
- Marvin E Miller
- Department of Pediatrics, Wright State University School of Medicine, Dayton, OH 45404, U.S.A.
| |
Collapse
|
27
|
Weiler HA, Fitzpatrick-Wong SC. Modulation of essential (n-6):(n-3) fatty acid ratios alters fatty acid status but not bone mass in piglets. J Nutr 2002; 132:2667-72. [PMID: 12221227 DOI: 10.1093/jn/132.9.2667] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dietary (n-6) and (n-3) fatty acids have been implicated as important regulators of bone metabolism. The main objective of this research was to define the response of whole-body growth, fatty acid status and bone mass to a reduced dietary (n-6):(n-3) fatty acid ratio. A secondary objective was to determine whether there is an amount of fat x fatty acid ratio interaction for these outcomes. Piglets (n = 32) were randomized to 1 of 4 diets: group 1: [30 g fat/L + (n-6):(n-3) ratio 4.5:1]; group 2: [30 g fat/L + (n-6):(n-3) ratio 9.0:1]; group 3: [60 g fat/L + (n-6):(n-3) ratio 4.5:1]; and group 4: [60 g fat/L + (n-6):(n-3) ratio 9.0:1]. After 21 d, outcomes assessed included growth, fatty acid status and bone mass and metabolism. Growth and bone mass did not differ among the four groups nor did arachidonic acid (AA as g/100 g fatty acids) in plasma, adipose and brain. Piglets fed diets 1 and 3 with the lower (n-6):(n-3) ratio had lower liver AA (P < 0.001). Those fed diets 1 and 2 containing 30 g fat/L had lower docosahexaenoic acid (DHA as g/100 g fatty acids) in liver (P < 0.001), plasma (P = 0.019) and adipose tissue (P = 0.045). However, piglets fed diets 1 and 3 had higher (P < 0.001) brain DHA than those fed diets with a higher (n-6):(n-3) ratio. Higher plasma DHA was associated with less bone resorption (r = -0.44, P = 0.01). Therefore, elevation of dietary (n-3) fatty acids supports growth and fatty acid status while not compromising bone mass. The results may be of relevance to the nutritional management of preterm infants whose DHA status is often too low and bone resorption too high.
Collapse
Affiliation(s)
- Hope A Weiler
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada.
| | | |
Collapse
|
28
|
Ng PC, Lam CWK, Wong GWK, Lee CH, Cheng PS, Fok TF, Chan IHS, Wong E, Cheung K, Lee SY. Changes in markers of bone metabolism during dexamethasone treatment for chronic lung disease in preterm infants. Arch Dis Child Fetal Neonatal Ed 2002; 86:F49-54. [PMID: 11815549 PMCID: PMC1721351 DOI: 10.1136/fn.86.1.f49] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To characterise the change in serum and urinary bone markers in the early postnatal period, and to assess the effect of systemic corticosteroid on bone metabolism in preterm infants. METHODS Bone formation was quantified by measurement of serum concentrations of bone specific alkaline phosphatase (BALP) and osteocalcin. Bone resorption was measured by monitoring creatinine adjusted urinary deoxypyridinoline (Dpd) concentration. Blood and urinary samples were collected from corticosteroid treated infants (n = 19) immediately before the start (T(d-pre)), three weeks after the start (T(d-end)), and two (T(d-post2)) and four weeks (T(d-post4)) after the end of the dexamethasone course. Untreated patients (n = 30) had specimens taken at week 3 (T(wk-3)), 6 (T(wk-6)), 8 (T(wk-8)), and 10 (T(wk-10)) of postnatal age. RESULTS Serum concentrations of BALP and osteocalcin at T(d-end) were significantly lower than pretreatment levels and the levels at the corresponding time point (T(wk-6)) of the non-treatment group. In contrast, urinary Dpd concentration at T(d-end) was not significantly decreased compared with the pretreatment level. However, it was significantly lower than the urinary Dpd concentration at T(wk-6) of the non-treatment group. The rate of increase in lower leg length was significantly higher in the non-treatment group between weeks 3 and 6 than in the corresponding period during dexamethasone treatment in the corticosteroid group. CONCLUSION Systemic corticosteroid causes appreciable suppression of serum BALP and osteocalcin and, to a lesser extent, urinary Dpd. The results suggest that corticosteroid inhibits bone growth mainly by decreasing bone formation.
Collapse
Affiliation(s)
- P C Ng
- Department of Paediatrics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
A large number of molecular, cellular, and epidemiologic factors have been implicated in the regulation of bone development. A major unsolved problem is how to integrate these disparate findings into a concept that explains the development of bone as an organ. Often events on the organ level are simply presented as the cumulative effect of all factors that individually are known to influence bone development. In such a cumulative model it must be assumed that each bone cell carries the construction plan of the entire skeletal anatomy in its genes. This scenario is implausible, because it would require an astronomical amount of positional information. We therefore propose a functional model of bone development, which is based on Frost's mechanostat theory. In this model the genome only provides positional information for the basic outline of the skeleton as a cartilaginous template. Thereafter, bone cell action is coordinated by the mechanical requirements of the bone. When mechanical challenges exceed an acceptable level (the mechanostat set point), bone tissue is added at the location where it is mechanically necessary. The main mechanical challenges during growth result from increases in bone length and in muscle force. Hormones, nutrition, and environmental factors exert an effect on bone either directly by modifying the mechanostat system or indirectly by influencing longitudinal bone growth or muscle force. Predictions based on this model are in accordance with observations on prenatal, early postnatal, and pubertal bone development. We propose that future studies on bone development should address topics that can be derived from the mechanostat model.
Collapse
Affiliation(s)
- F Rauch
- Children's Hospital, University of Cologne, 50924 Cologne, Germany.
| | | |
Collapse
|
30
|
Weiler HA. Dietary supplementation of arachidonic acid is associated with higher whole body weight and bone mineral density in growing pigs. Pediatr Res 2000; 47:692-7. [PMID: 10813598 DOI: 10.1203/00006450-200005000-00022] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Essential fatty acids are fundamental to normal growth and development, but North American formulas do not contain arachidonic (AA) and docosahexaenoic acid (DHA). The main objective of the present study was to determine whether addition of AA and DHA to formula elevates growth and bone mineralization in piglets. A secondary objective was to establish whether liver fatty acid composition is related to that of bone. Twelve 10-d-old male piglets were randomized to receive either a standard formula with an n-6:n-3 fatty acid ratio of 4.9:1.0 or the same formula made with an equal amount of fat but containing AA (0.5% wt/wt total fat) and DHA (0.1% wt/wt total fat) for 14 d. Piglets in the supplemented group had significantly (p < 0.05) higher weight and greater bone mineral density of the whole body, lumbar spine, and femur. No differences were observed in whole body length, calcium absorption, or biochemical markers of bone metabolism. Feeding AA resulted in lower linoleic acid (p < 0.05) and higher (p < 0.05) AA in liver total lipid (% wt/wt) and bone FFA (% wt/wt) but no change to DHA. Liver AA (% wt/wt total lipid) was positively related (p < 0.05) to growth, free AA (% wt/wt) in bone, bone mineral content, bone mineral density, and urinary prostaglandin E2 but negatively related (p < 0.05) to free linoleic acid in bone. Inverse relationships were observed when liver linoleic acid was substituted for liver AA as the independent variable. These data indicate that feeding AA is associated with elevated weight and higher whole body and regional bone mineral density.
Collapse
Affiliation(s)
- H A Weiler
- Department of Foods and Nutrition, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
31
|
Rigo J, De Curtis M, Pieltain C, Picaud JC, Salle BL, Senterre J. Bone mineral metabolism in the micropremie. Clin Perinatol 2000; 27:147-70. [PMID: 10690569 DOI: 10.1016/s0095-5108(05)70011-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Environmental factors, nutritional supplies, hormonal status, diseases, and treatments appear to affect postnatal skeletal growth and mineralization in VLBW infants. Compared with their term counterparts, ELBW infants are at risk of postnatal growth deficiency and osteopenia at the time of hospital discharge. From recent data, DXA is becoming one of the reference techniques to evaluate mineral status, whole-body composition, and effects of dietary manipulations on weight gain composition and mineral accretion in preterm infants. Weight gain and length increases need to be evaluated carefully during the first weeks of life, in the intensive care unit and out of it, in the step down unit. Nutritional survey is required to improve the nutritional supply and to maximize linear growth. As the critical epoch of growth extends, during the first weeks or months after discharge, follow-up and nutritional support need to be provided during the first years to promote early catch-up growth and mineralization. Further studies need to determine precisely the most optimal feeding regimen during this period but also need to evaluate the long-term implications of such a policy on stature, peak bone mass, and general health at adulthood.
Collapse
Affiliation(s)
- J Rigo
- Department of Pediatrics, University of Liège, CHR Citadelle, Belgium.
| | | | | | | | | | | |
Collapse
|
32
|
Ward WE, Atkinson SA, Donovan SM, Paes B. Bone metabolism and circulating IGF-I and IGFBPs in dexamethasone-treated preterm infants. Early Hum Dev 1999; 56:127-41. [PMID: 10636592 DOI: 10.1016/s0378-3782(99)00039-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM To characterize the ontogeny of circulating IGF-I, the IGF binding proteins (IGFBPs) and biochemical markers of bone turnover in dexamethasone (DEX)-treated preterm infants with chronic lung disease. METHODS Plasma and urine samples from 17 infants were obtained prior to DEX, after 9-12 days of DEX and 10 days after the completion of DEX to assess plasma IGF-I, IGFBPs, osteocalcin and urinary N-telopeptide. Nutrient intakes and growth were monitored from birth until term corrected age at which time body composition was evaluated by dual energy X-ray absorptiometry. RESULTS Although nutrient intakes did not differ during or after DEX, weight gain (115 vs. 174 g/week) and length gain (0.7 vs. 1.0 cm/week) were higher after DEX treatment. Plasma IGF-I, IGFBP-3 and osteocalcin increased over time. N-telopeptide was the only biochemical parameter which appeared to be suppressed during DEX (1342 nM bone collagen equivalents/mM creatinine vs. 2486 (pre-DEX) and 2292 (post-DEX)). At term corrected age, bone mineral content was lower in dexamethasone-treated infants compared to preterm and term reference infants. CONCLUSION Changes in circulating IGFBP-2 and IGFBP-3 paralleled the changes reported in non-steroid-treated infants; however, it remains uncertain whether the natural rise in IGF-I was suppressed by DEX treatment. Assessment of these circulating components provided limited insight into the mechanisms by which DEX alters growth and bone turnover.
Collapse
Affiliation(s)
- W E Ward
- Department of Pediatrics, Children's Hospital, Hamilton Health Sciences Corporation, McMaster University, Ontario, Canada
| | | | | | | |
Collapse
|
33
|
Tsukahara H, Watanabe Y, Hirano S, Tsubokura H, Kimura K, Mayumi M. Assessment of bone turnover in term and preterm newborns at birth: measurement of urinary collagen crosslink excretion. Early Hum Dev 1999; 53:185-91. [PMID: 10088987 DOI: 10.1016/s0378-3782(98)00076-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We measured urinary excretion of collagen crosslinks, pyridinoline and deoxypyridinoline, in term and preterm newborns at birth and evaluated the developmental changes in bone turnover. Collagen crosslink excretion in newborns was more than 10 times higher than reported adult values and several times higher than those of older children. The values were significantly higher in preterm newborns than in term newborns. In addition, a significant and inverse correlation was found between urinary collagen crosslinks and gestational age in preterm newborns. Excretion of crosslinks during this period did not correlate with beta2-microglobulin, suggesting that the excretion was not directly influenced by renal function in newborns. We conclude that bone turnover assessed by measurement of collagen crosslink excretion is high at birth and that preterm newborns have higher bone turnover than term newborns.
Collapse
Affiliation(s)
- H Tsukahara
- Department of Pediatrics, Faculty of Medicine, Fukui Medical University, Japan
| | | | | | | | | | | |
Collapse
|
34
|
Tsukahara H, Miura M, Hori C, Hiraoka M, Nosaka K, Hata K, Konishi Y, Sudo M. Urinary excretion of pyridinium cross-links of collagen in infancy. Metabolism 1996; 45:510-4. [PMID: 8609840 DOI: 10.1016/s0026-0495(96)90228-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This cross-sectional study evaluated urinary excretion of pyridinium cross-links of collagen, specific markers of ongoing bone resorption, in infants aged 1 week to 7 months and examined the relationship between urinary cross-links and individual renal function. Spot urines from a total of 100 infants were analyzed. The collagen cross-links, pyridinoline (Pyd) and deoxypyridinoline (D-Pyd), were assayed by fluorescence detection after high-performance liquid chromatography (HPLC). Beta2-Microglobulin (beta2M), an index of renal tubular function, was determined by radioimmunoassay. In healthy term infants, urinary collagen cross-links were several times higher than the reported data for older children, with peak values seen at 1 month of age. Excretion of Pyd and D-Pyd was also markedly elevated in 1-month-old preterm infants, despite poor somatic growth. Such high excretion of collagen cross-links probably reflects the state of accelerated bone turnover in infancy. The postnatal change in the cross-links was different from that in urinary beta2M, and the values obtained did not correlate with beta2M in either term or preterm infants. These results indicate that cross-link excretion is not influenced directly by individual renal function.
Collapse
Affiliation(s)
- H Tsukahara
- Department of Pediatrics, Fukui Medical School, Japan
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
The nature and pathophysiology of the bone loss which occurs in term and especially preterm neonates are poorly understood, and it is unclear whether this neonatal osteopenia results from impaired bone formation or increased bone resorption. This study compared the static bone histomorphometry of preterm and term babies, employing iliac crest bone biopsy specimens obtained postmortem. All the babies died within the first 6 days of life and none had any clinical, biochemical or radiologic evidence of metabolic bone disease. The trabecular bone volume, as well as static parameters of bone formation (OV/TV, OV/BV, OS/BS, OB.S/BS) did not differ significantly in preterm and term babies. Although time-spaced tetracycline labelling could not be employed in the present study, evidence of rickets was not apparent. Parameters of bone resorption in preterm babies were, however, significantly higher (p = 0.01) than those of term babies, suggesting that increased bone resorption and not impaired formation, underlies the development of osteopenia in the preterm neonate.
Collapse
Affiliation(s)
- N Beyers
- Department of Paediatrics, University of Stellenbosch, Tygerberg, South Africa
| | | | | | | | | | | |
Collapse
|