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

European survey showed wide variations in diagnostic procedures and management strategies for metabolic bone disease of prematurity in 22 countries

AIM

The aim of this study was to evaluate the clinical relevance, diagnostic procedures and treatment strategies for metabolic bone disease in preterm infants across Europe.

METHODS

An e-survey was distributed by email to 545 neonatal units in 38 European countries between July and October 2021. The protocol was based on the Checklist for Reporting Results of Internet E-Surveys.

RESULTS

In total, 76 neonatal units (14%) from 22 European countries (58%) completed the e-survey. In the 12 months prior to the survey, 29% of 76 units reported at least one symptomatic case of fracture associated with metabolic bone disease of prematurity, and 18% of 76 units reported at least one case of craniofacial deformity. Most centres followed local guidelines for diagnosis (77% of 73 units) and treatment (63% of 72 units). Alkaline phosphatase was the blood marker most used for treatment indication (81% of 72 units), and phosphate supplementation was the treatment most used (82% of 71 units).

CONCLUSION

Metabolic bone disease of prematurity remains clinically relevant. Wide variations in diagnostic procedures and management strategies were observed in European neonatal units. Evidence-based consensus guidelines appear urgently needed to reduce the number of symptomatic cases.

Role of fibroblast growth factor-23 as an early marker of metabolic bone disease of prematurity

PURPOSE

Metabolic bone disease of prematurity (MBDP) remains a significant cause of morbidity in extremely premature newborns. In high-risk patients, suspected diagnosis and subsequent treatment modifications, with limitations in terms of sensitivity and specificity, rely on low phosphorus levels and/or high levels of alkaline phosphatase (ALP). We investigated the potential of fibroblast growth factor-23 (FGF23) as an early marker for MBDP when measured at 3-4 weeks of life in at-risk patients.

METHODS

A single-center prospective observational non-interventional study including preterm newborns of both sexes, with a gestational age of less than 32 weeks and/or a birth weight of less than 1500 g. In the standard biochemical screening for MBDP performed between 3 and 4 weeks of life within a nutritional profile, the determination of FGF23 was included along with other clinical and metabolic studies. The study was conducted at Marqués de Valdecilla University Hospital in Santander, Spain, from April 2020 to March 2021. Participants provided informed consent. Biochemical analyses were conducted using various platforms, and follow-up evaluations were performed at the discretion of neonatologists. Patients at high risk for MBDP received modifications in treatment accordingly. The sample was descriptively analyzed, presenting measures of central tendency and dispersion for continuous variables, and absolute numbers/percentages for categorical ones. Tests used included t-tests, Mann‒Whitney U tests, chi-square tests, logistic regressions, Pearson correlation, and ROC curve analysis (IBM SPSS Statistics version 19). Significance level: P < 0.05.

RESULTS

In the study involving 25 at-risk premature newborns, it was found that 20% (n = 5) were diagnosed with MBDP. Three of these patients (60%) were identified as high-risk based on standard biochemical evaluation at 3-4 weeks of age, while the other two patients (40%) were diagnosed in subsequent weeks. However, in all 5 patients, measurement of FGF23 levels would allow for early identification and optimization of treatment before other markers become altered. Low levels of FGF23 at 3-4 weeks, even with normal phosphorus and ALP levels, indicate the need for modifications in nutritional supplementation.

CONCLUSIONS

MBDP remains a significant concern in extremely premature newborns. Current diagnostic methods rely on limited biochemical markers. Early detection of low FGF23 levels enables timely interventions, potentially averting demineralization.

Biomarkers and Biochemical Indicators to Evaluate Bone Metabolism in Preterm Neonates

The purpose of the present study was to evaluate the concentrations of some bone turnover markers in preterm neonates with uncomplicated clinical course in the first month of life. Samples from 13 preterm neonates were collected at three different times: at birth (T0) from umbilical cord blood (UCB); and at 15 (T1) and 30 (T2) days of life from peripheral blood (PB). The concentrations of calcium (Ca), phosphate (P), total alkaline phosphatase (ALP), Collagen Type 1 Amino-terminal Propeptide (PINP), osteocalcin (OC), Collagen Type 1 Carboxyl-Terminal Telopeptide (CTX) and Leptin were assessed. A statistically significant difference for ALP concentration at birth versus T1 and T2 was found. An evident increase in the median concentrations of CTX, OC and PINP from T0 to T2 were observed. A significant difference was also found for Leptin concentration at T0 compared to T1. In preterm infants, in the absence of acute or chronic medical conditions and without risk factors for metabolic bone disease (MBD) of prematurity, there is a significant increase in bone turnover markers during the first month of life. The knowledge of the variations in these markers in the first weeks of life, integrated by the variations in the biochemical indicators of bone metabolism, could help in recognizing any conditions at risk of developing bone diseases.

Neurodevelopment Outcomes in Very-Low-Birth-Weight Infants with Metabolic Bone Disease at 2 Years of Age

Metabolic bone disease (MBD) predominantly affects preterm infants, particularly very-low-birth-weight (VLBW) infants weighing <1500 g. However, there are limited reports on MBD and neurodevelopmental outcomes. This study aimed to analyze the risk factors for MBD and understand its impact on neurodevelopmental outcomes at 2 years of corrected age. Overall, 749 VLBW infants weighing <1350 g at birth were enrolled. Exclusion criteria were major congenital abnormalities, chromosomal abnormalities, and loss of follow-up on the Bayley Scales of Infant Development, Third Edition (BSID-III) test at 24 months of corrected age. Infants were retrospectively assessed by a trained case manager using the BSID-III test at 6, 12, and 24 months old. Infants were categorized as with or without MBD according to radiographic signs. Of those enrolled, 97 VLBW infants were diagnosed with MBD, compared to 362 VLBW infants without MBD. The proportion of infants that completed three follow-ups was 86%. At the assessment at 2 years of age, infants with MBD had lower and more significant differences in motor, language, and cognitive composites. MBD is associated with poor neurodevelopmental outcomes in cognitive, motor, and language composites for VLBW infants at 24 months of corrected age.

Characterisation of parathyroid hormone concentration in extremely preterm or very low birthweight infants in routine clinical screening for metabolic bone disease: A service evaluation cohort study

AIM

To characterise parathyroid hormone (PTH) concentrations in infants at high risk for metabolic bone disease, in order to assist clinical decisions around the use of PTH for screening.

METHODS

Infants born under 28 weeks' postmenstrual age or with birthweight under 1.5 kg in a tertiary neonatal unit in the UK were included. Clinical guidance was to assess PTH concentration in the first 3 weeks after birth. Clinical information was extracted from prospective records.

RESULTS

Sixty-four infants had mean birth gestation of 26 weeks and birthweight of 882 g. Median PTH (sent on median day 18 of life) was 9.2 pmol/L (interquartile range 5.3-17 pmol/L). Sixty-seven per cent of infants had a PTH greater than 7 pmol/L. For 22% of the infants, raised PTH was not accompanied by abnormal phosphate or alkaline phosphatase. Eighty-nine per cent of infants tested were insufficient or deficient for 25-hydroxyvitamin D.

CONCLUSIONS

Universal screening highlights the high frequency of high PTH in this high-risk population, implying a need for calcium supplementation. A considerable number of infants would not be identified as showing potential signs of metabolic bone disease if the assessment excludes the use of PTH. The high level of 25-hydroxyvitamin D deficiency may be a confounder.

Prenatal and Neonatal Bone Health: Updated Review on Early Identification of Newborns at High Risk for Osteopenia

Bone health starts with maternal health and nutrition, which influences bone mass and density already in utero. The mechanisms underlying the effect of the intrauterine environment on bone health are partly unknown but certainly include the 'foetal programming' of oxidative stress and endocrine systems, which influence later skeletal growth and development. With this narrative review, we describe the current evidence for identifying patients with risk factors for developing osteopenia, today's management of these populations, and screening and prevention programs based on gestational age, weight, and morbidity. Challenges for bone health prevention include the need for new technologies that are specific and applicable to pregnant women, the foetus, and, later, the newborn. Radiofrequency ultrasound spectrometry (REMS) has proven to be a useful tool in the assessment of bone mineral density (BMD) in pregnant women. Few studies have reported that transmission ultrasound can also be used to assess BMD in newborns. The advantages of this technology in the foetus and newborn are the absence of ionising radiation, ease of use, and, above all, the possibility of performing longitudinal studies from intrauterine to extrauterine life. The use of these technologies already in the intrauterine period could help prevent associated diseases, such as osteoporosis and osteopenia, which are characterised by a reduction in bone mass and degeneration of bone structure and lead to an increased risk of fractures in adulthood with considerable social repercussions for the related direct and indirect costs.

Diagnostic markers of metabolic bone disease of prematurity in preterm infants

Due to the higher birth rate of preterm infants and improvements in their management, metabolic bone disease of prematurity (MBDP) has a high incidence and is attracting attention. However, clear indicators for the early diagnosis of MBDP are lacking. We aimed to explore simple and feasible early warning indicators for diagnosing MBDP. Our study collected case data of premature infants from two medical centers in Chongqing from January 2020 to February 2022. According to the inclusion and exclusion criteria, data from 136 cases were collected. The correlation between 14 variables in each case and the occurrence of MBDP was analyzed. According to area under the receiver operating characteristic curve (AUROC) analysis, the best cutoff value for each variable was determined. Potential predictors were selected, and Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used to establish the association of two models with MBDP, whose results were used to develop a diagnostic nomogram. Furthermore, a model decision curve was analyzed. Four predictors were selected from 14 clinical variables by LASSO regression, and Model I was established, including the following characteristics: height (>36 cm), head circumference (≤29.49 cm), total serum calcium (Ca) (>2.13 mmol/L), and alkaline phosphatase (ALP) (>344 U/L) levels. A single predictor, the ALP level (>344 U/L), was used to establish Model II. The AUROC values of the two models were 0.959 for Model I and 0.929 for Model II. In conclusion, in this study, two diagnostic models of MBDP were developed using four combinations of predictors and ALP as a single predictor. Both models showed good sensitivity and specificity for the early diagnosis of metabolic bone disease (MBD), and an ALP level of 344 U/L was defined as a simple and effective diagnostic threshold. In future studies, using larger samples, diagnostic threshold values of ALP for premature infants of different ages should be established, and internal and external validations are needed to improve the adaptability of the current model.

Early elevated alkaline phosphatase as a surrogate biomarker of ongoing metabolic bone disease of prematurity

Very low birth weight (VLBW) neonates present a high risk of metabolic bone disease (MBD). Our main objective was to determine the easiest way to make an early diagnosis of this disease by identifying surrogate biomarkers before any radiological signs occurred. We conducted in our NICU a 6-month observational prospective study, with inclusion of all singleton VLBW neonates. We collected clinical and biological data, and nutritional intakes during hospitalization. We defined biological MBD (bMBD) as alkaline phosphatase (ALP) levels superior to 600 UI/L at day of life 30 (DOL30) and performed a case-control analysis. Nine out of 30 patients (30%) exhibited bMBD. All have extremely low birth weight and were significantly younger in gestational age (GA) and smaller at birth. There was no statistically significant difference in nutritional intake between bMBD and control groups. In the bMBD group, phosphatemia was lower since DOL3. ALP was already significantly higher at DOL15, and way beyond normal range.

CONCLUSIONS

Our results showed that even the strict respect of nutritional guidelines cannot completely prevent bMBD in high-risk patients and suggest that an early screening from DOL15, with ALP levels greater than 500 UI/L, could be sufficient for detection of upcoming MBD.

WHAT IS KNOWN

• Metabolic bone disease of prematurity (MBD) definition is not consensual, but biological changes appear earlier than radiological signs of rickets. • MBD management relies on biological evidence. Treatment is based on phosphate and/or calcium and calcitriol supplementation.

WHAT IS NEW

• Studying phosphocalcic biological assessment in very low birth weight neonates, we showed respect of nutritional guidelines could not protect from biological MBD. • Increase in alkaline phosphatase (ALP), about 500 UI/l at day of life 15, could be a biomarker of MBD with no need of X-ray evaluation and sufficient to begin a treatment to prevent osteopenia.

Early calcium and phosphorus supplementation in VLBW infants to reduce metabolic bone disease of prematurity: a quality improvement initiative

Objective

To reduce the incidence of metabolic bone disease (MBD) among very low birthweight (VLBW) infants admitted to neonatal intensive care unit from baseline of 35% by 50% over 2 years by implementing a quality improvement (QI) initiative.

Methods

A multidisciplinary QI team used evidence-based interventions and the healthcare improvement model to reduce MBD rate in VLBW infants. The specific interventions included routine enteral supplementation of calcium and phosphorus using Human Milk Fortifier (HMF) to expressed breast milk by day 14 of life (Plan/Do/Study/Act (PDSA) cycle 1), parenteral and early enteral supplementation of calcium and phosphorus (PDSA cycles 2 and 3). We included VLBW infants admitted within the study period at birth and excluded babies with congenital malformations, skeletal disorders and those who died before 2 weeks of age. Compliance with adding HMF by day 14, compliance with adding calcium and phosphorus in total parenteral nutrition (TPN) from day 1 of life and compliance with starting HMF when the baby reached 100 mL/kg/day of feeds were used as process indicators. The incidence of MBD was used as an outcome indicator during the study. The incidence of MBD was tracked using the Statistical Process Control methodology.

Results

The baseline MBD rate in 2015 was 35%. After the first PDSA cycle, 20% developed MBD (p=0.02). The same was sustained for a period of 1 year with the rate of 22%. After the second and third PDSA cycles, there was a drop in the MBD rate to 17%, and sustained for 3 months with 21%.

Conclusion

Implementation of QI initiatives decreased the MBD rate from 35% to <20%. Early parenteral calcium and phosphorus supplementation in TPN and optimising enteral supplementation with multicomponent fortifiers appear to have significant reduction in the incidence of MBD.

Relationship of caffeine regimen with osteopenia of prematurity in preterm neonates: a cohort retrospective study

BACKGROUND

Caffeine is a routinely prescribed pharmacological active compound in neonatal intensive care units (NICU) for treating apnea of prematurity (AOP), which also decreases the risk of bronchopulmonary dysplasia and cerebral palsy in neonates. Caffeine-induced excessive calcium loss can promote the development of metabolic bone disease (MBD) in preterm neonates. This study aimed to evaluate the effect of the caffeine regimen on the development of osteopenia of prematurity (OOP), using serum alkaline phosphatase (serum-ALP) concentrations as a surrogate marker at the 4^th week of life.

METHODS

This retrospective cohort study was conducted including neonates of < 32 weeks gestational age (GA) and birth weight < 1500 g, admitted to NICU from April-2017 to December-2018 and received caffeine therapy till 28 days of life for AOP. Based on serum-ALP levels, formed the high and low-ALP groups. Neonatal characteristics, caffeine regimen, risk factors for OOP, including duration of parenteral nutrition (PN), exposure to medicines associated with MBD, and intake of essential vitamins and minerals, were compared in both groups. Predictors of OOP were analyzed through logistic regression.

RESULTS

From the total of 268 participants, 52 (19%) developed OOP, mostly female (61.5%). In the high ALP group, the serum-ALP levels were significantly higher than in the low-ALP group (725.0 ± 143.8 vs 273.6 ± 55.0 units/L, p < 0.001). The high-ALP group received significantly (p < 0.001) higher daily and cumulative caffeine doses and were associated with a higher likelihood of developing OOP in this study cohort [cumulative dose (mg) (AOR = 1.082 95% CI 1.011 to 1.157) and daily dose (mg/kg/day) (AOR = 2.892 95% CI 1.392 to 6.007)]. Smaller GA was found directly related to OOP. Among the other medical risk factors, phosphorus intake was significantly low in the high-ALP group. No, significant relationship between duration of PN and use of steroids and diuretics, and intake of vitamins and minerals were identified.

CONCLUSION

The daily and cumulative doses of caffeine and smaller GA are associated with the development of OOP in this study cohort. Clinical randomized control studies are needed to validate the outcomes and determine the range of safest and most effective caffeine doses for treating AOP in preterm neonates.

Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper

OBJECTIVES

Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations.

STUDY DESIGN

We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies.

RESULTS

We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations.

CONCLUSION

This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.

Determination of serum alkaline phosphatase reference in healthy children aged 1-18 years

BACKGROUND

The growth and development of children affect biochemical variables. This population-based study was designed to evaluate the reference interval for alkaline phosphatase (ALP) routinely measured in the clinical laboratory.

METHODS

For this examination, 873 cases were selected among the healthy children and adolescents aged 1-18 years who referred to the endocrinology clinic of Amirkola Children's Hospital for growth evaluation. After overnight fasting, early morning blood samples were obtained to measure the ALP level and other biochemical parameters using an automatic biochemical analyzer. Subjects were categorized by age, sex, and body mass index (BMI) values. The age groups were categorized as follows: 1-4 years, 5-8 years, 9-13 years, and 14-18 years.

RESULTS

There was a significant difference among the age and sex categories; on the contrary, there was no meaningful variation between the two groups categorized by BMI. The reference range for ALP was 474.14-517.71 U/L for children aged 1-4 years, 273.47-871.44 U/L for 5-8 years, 215.04-893.69 U/L for 9-13 years, and 228.9-739.22 U/L for 14-18 years. Also, significant positive correlation was found between ALP with length (P=0.000, r=0.134), weight (=0.04, r=0.073), phosphorus (P) (P=0.001, r=0.122), and alanine aminotransferase (SGPT) (P=0.000, r=0.142) respectively.

CONCLUSION

This project's data established a reference interval for ALP in healthy children and adolescents, which will prepare a basis for diagnosis and monitoring liver- or bone-related disorders.

Vitamin D and bone minerals in neonates

Osteopenia and rickets remain a problem for high-risk infants, especially preterm infants <1500 g birthweight (very low birth weight, VLBW). The primary cause of osteopenia in VLBW infants is a low intake of calcium and phosphorus compared to requirements for the rapidly growing skeleton. Human milk is a relatively low mineral containing substance and cannot meet the bone mineral needs of very low birth weight infants. As such, most VLBW infants need additional bone minerals and in many neonatal care units these are provided as part of human milk fortificants or specialized infant formulas. In some nurseries, these are given to all infants < 1800-2000 g birthweight. Management of full-term infants who are small for gestational age at birth is less clear, but in general bone mineral content is associated more with body size than gestational age and supplementation is often provided to these infants. Although all infants, including preterm ones need a source of vitamin D, the benefits of providing high doses of vitamin D to healthy preterm neonates is unproven. Some evidence indicates that most calcium absorption is non-vitamin D dependent in the first weeks of life in both preterm and term infants. However, after achieving full feeds in the preterm infant, it is prudent to provide vitamin D at amounts comparable to that used in full-term infants. Higher doses increase serum 25-hydroxyvitamin D levels more rapidly, but evidence is inconclusive as to the relative benefits vs possible risks of higher doses. In healthy full-term infants, although vitamin D provision via supplement drops to the breastfed infant, high dose maternal supplementation to the lactating mother or infant formula is generally recommended, the current evidence only strongly supports its use in identified at-risk infants.

Bone Mineralization and Calcium Phosphorus Metabolism

The accretion of adequate mineral content is essential for normal bone mineralization [...].

Metabolic bone disease of prematurity-National survey of current neonatal and paediatric endocrine approaches

AIM

This study aimed to identify current trends in the management of metabolic bone disease of prematurity (MBDP) in the United Kingdom.

METHODS

A nationwide electronic survey was disseminated to all neonatal networks across the United Kingdom, as well as to paediatric endocrinologists for comparison. Weighted averages were used to compare relative importance placed on screening and diagnostic investigations (1 = not important, 5 = essential).

RESULTS

Sixty-nine individuals responded from 53 neonatal units. Greatest emphasis was placed on levels of serum phosphate and alkaline phosphatase for screening (weighted average 4.5 and 4.6, respectively), diagnosis (weighted average 4.1 and 4.5, respectively) and monitoring (93% and 97% of neonatal responders, respectively) of MBDP by neonatologists. Although similar results were obtained for endocrinologists, significantly greater emphasis was placed on plasma parathyroid hormone (PTH) level for screening, diagnosis and monitoring (p < 0.001 for each). Phosphate supplementation was reported almost universally by neonatal responders (99%), but was significantly less for endocrine responders (62%) for the treatment of MBDP (p < 0.001).

CONCLUSION

There is an under-utilisation of plasma PTH as a screening, diagnostic and monitoring investigation to guide appropriate supplementation for MBDP by neonatologists.

Update on Calcium and Phosphorus Requirements of Preterm Infants and Recommendations for Enteral Mineral Intake

Background: With current Ca and P recommendations for enteral nutrition, preterm infants, especially VLBW, fail to achieve a bone mineral content (BMC) equivalent to term infants. During the first 3 years, most notably in light at term equivalent age (<−2 Z score) VLBW infants’ BMC does not catch up. In adults born preterm with VLBW or SGA, lower adult bone mass, lower peak bone mass, and higher frequency of osteopenia/osteoporosis have been found, implying an increased risk for future bone fractures. The aim of the present narrative review was to provide recommendation for enteral mineral intake for improving bone mineral accretion. Methods: Current preterm infant mineral recommendations together with fetal and preterm infant physiology of mineral accretion were reviewed to provide recommendations for improving bone mineral accretion. Results: Current Ca and P recommendations systematically underestimate the needs, especially for Ca. Conclusion: Higher enteral fortifier/formula mineral content or individual supplementation is required. Higher general mineral intake (especially Ca) will most likely improve bone mineralization in preterm infants and possibly the long-term bone health. However, the nephrocalcinosis risk may increase in infants with high Ca absorption. Therefore, individual additional enteral Ca and/or P supplementations are recommended to improve current fortifier/formula mineral intake.

Evaluation of radiologic evidence of metabolic bone disease in very low birth weight infants at fourth week of life

AIM

The aim of this study is to determine the incidence of metabolic bone disease (MBD) and assess the risk factors for development radiologic evidence of MBD.

METHODS

Preterm infants with gestational age ≤32 weeks and birth weight ≤1500 g were included in this prospective study. Metabolic bone disease was defined as hypophosphatemia (phosphorus levels <4 mg/dl), ALP levels >450 U/L, or radiologic findings of MBD at four weeks of age.

RESULTS

The study included 254 infants (gestational age: 29 (27-30) weeks, birth weight: 1130 g (960-1300)). Metabolic bone disease was diagnosed in 96 patients (37%); 48 infants had only radiologic evidence of MBD, 24 infants had only biochemical diagnosis of MBD, and 24 infants had both radiologic evidence of MBD and biochemical diagnosis of MBD.

CONCLUSIONS

Our results showed that radiologic evidence of MBD existed in some infants with normal biochemical results. That finding may guide further development of screening programs for MBD.

Modified Serum ALP Values and Timing of Apparition of Knee Epiphyseal Ossification Centers in Preterm Infants with Cholestasis and Risk of Concomitant Metabolic Bone Disease of Prematurity

The usefulness of serum alkaline phosphatase (ALP) and phosphorous in screening and monitoring of metabolic bone disease of prematurity (MBDP) still has some limitations, especially in preterm infants with concomitant conditions such as cholestasis. We aimed to assess a modification of serum ALP (M-ALP) as a biomarker for MBDP in preterm infants, and the use of ultrasound monitoring for the apparition of knee ossification centers as marker of bone mineralization. Biochemical and clinical registers were taken from 94 preterm newborns <32 weeks. A significant correlation existed between serum ALP and direct bilirubin (DB), expressed by the regression equation: M-ALP (IU/L) = 302.1 + 96.9 (DB (mg/dL)). The ratio ALP/M-ALP > 1 was demonstrated to be more specific (87.5%) in the diagnosis of MBDP than the cut-off value of serum ALP > 500 IU/L (62.5%). ALP/M-ALP > 1 showed 100% sensitivity and specificity for the diagnosis of MBDP, and a good correlation with specific bone ALP (B-ALP). Patients with the knee nucleus by post-menstrual week 37 had lower B-ALP compared to patients with no nucleus, and no patients with MBDP presented the nucleus by the 40th week. In the absence of reliable specific B-ALP, reinterpreting serum ALP values by M-ALP plus monitoring of knee ossification centers contribute to better management of MBDP in preterm infants with cholestasis.

Metabolic Bone Disease of Prematurity: Risk Factors and Associated Short-Term Outcomes

Despite the importance of early recognition of metabolic bone disease (MBD) of prematurity, there is still significant variability in screening practices across institutions. We conducted an observational study of infants born at ≤32 weeks of gestation with a birth weight of ≤1500 g (n = 218) to identify clinical factors associated with biochemical indicators of MBD. Bone mineral status was assessed by measuring alkaline phosphatase and phosphate levels between weeks 3 and 5 of life. Two comparisons were performed after classifying infants as either MBD (cases) or non-MBD (controls), and as either high or low risk for MBD, as determined based on the results of MBD screening. In total, 27 infants (12.3%) were classified as cases and 96 (44%) as high-risk. Compared with controls, MBD infants had a significantly lower gestational age and birth weight, and a longer duration of parenteral nutrition and hospital stay. Respiratory outcomes were significantly poorer in high- versus low-risk infants. Multivariate logistic regression showed that birth weight was the only independent risk factor for MBD (odds ratio [OR]/100 g, 0.811; confidence interval [CI95%], 0.656-0.992; p = 0.045) and that birth weight (OR/100 g, 0.853; CI95%, 0.731-0.991; p = 0.039) and red blood cell transfusion (OR, 2.661; CI95%, 1.308-5.467; p = 0.007) were independent risk factors for high risk of MBD. Our findings provide evidence of risk factors for MBD that could help clinicians to individualize perinatal management. The association of red blood cell transfusion with MBD is a novel finding that may be related to iron overload and that merits further study.

Metabolic Bone Disease in Premature Neonates: An Unmet Challenge

Metabolic bone disease (MBD) is an important cause of morbidity in premature, very low birth weight (VLBW) and sick infants and, if left undiagnosed, may lead to structural deformities and spontaneous fractures. MBD is defined as impaired bone mineralization in a neonate with lower than expected bone mineral levels in either a fetus or a neonate of comparable gestational age and/or weight, coupled with biochemical abnormalities with or without accompanying radiological manifestations. MBD has been reported to occur in 16% to 40% of extremely low birth weight neonates and presents by 6-16 weeks after birth. Insufficient calcium and phosphorous stores during the phase of accelerated growth predispose to MBD in neonates along with the use of some medications such as caffeine or steroids, prolonged parenteral nutrition and chronic immobilization. Enhanced physical activity in preterm infants facilitates bone mineralization and weight gain. Biochemical abnormalities tend to worsen significantly, as the severity of disease progresses. These abnormalities may include hypocalcemia, hypophosphatemia, hyperphosphatasia and secondary hyperparathyroidism. In addition, urinary phosphate wasting and hypovitaminosis D can be additional complications. Conversely, biochemical abnormalities may not be accompanied by rachitic changes. Newer diagnostic modalities include non-invasive bone densitometry by quantitative ultrasound over the mid-tibial shaft. The management of MBD includes adequate calcium, phosphorous and vitamin D supplementation, along with optimum nutrition and physical activity. Similarly, preventive strategies for MBD should target nutritional enhancement in combination with enhanced physical activity. MBD usually results in preventable morbidity in preterm and VLBW neonates. Treatment consists of optimum nutritional supplementation and enhanced physical activity.

Hypophosphatemia as an Early Metabolic Bone Disease Marker in Extremely Low-Birth-Weight Infants After Prolonged Parenteral Nutrition Exposure

BACKGROUND

Early metabolic bone disease (MBD) detection is important in preterm infants to decrease long-term consequence. We aim to explore the early MBD biochemical marker in extremely low-birth-weight (ELBW) infants.

METHODS

Retrospective cohort study of 95 preterm infants born in a tertiary care-level neonatal intensive care unit between January 2015 and June 2018, with birth weight <1000 g. Thirty-five infants were "nothing by mouth" for >14 days and categorized as the high-risk group; the remaining 60 were categorized as the control group. Mineral intake in the first 14 days and the trend of serum calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels were compared in both groups.

RESULTS

The Ca and P supplementation in the first 2 weeks of life were inadequate in both groups. Compared with the control group, significantly lower serum P (mg/dL) levels were noted in the high-risk group on weeks 2 (3.65 ± 1.2 vs 4.67 ± 1.45; P < .001), 4 (3.21 ± 0.95 vs 5.83 ± 1.18; P < .0001), and 6 (3.94 ± 1.1 vs 6.22 ± 0.78; P <.0001). There was no significant difference in the serum Ca level, and significantly higher ALP (U/L) levels were found up until 2 months of life in the high-risk group (458.36 ± 189.02 vs 335.7 ± 111.51; P < .014).

CONCLUSION

Hypophosphatemia developed as early as 2 weeks old in high-risk preterm infants because of inadequate supplementation. Neither the serum Ca or ALP levels were affected. Thus, the routine monitoring of serum P level should be started 2 weeks after birth for early MBD detection in extremely ELBW infants.

Effect on metabolic bone disease markers in the neonatal intensive care unit with implementation of a practice guideline

OBJECTIVES

To determine the effect of implementing a 2015 policy for the screening, prevention, and management of metabolic bone disease for very low birth weight (VLBW) infants in two Level IV NICUs.

STUDY DESIGN

Retrospective cohort study of VLBW infants in the 2 years prior to (2013-2014) and after (2016-2017) policy implementation.

RESULTS

We identified 316 VLBW infants in 2013-2014 and 292 in 2016-2017 who met study criteria. After policy implementation, vitamin D supplementation began earlier (20.1 ± 15.5 days vs 30.2 ± 20.1 days, p < 0.0005), the percentage of infants with alkaline phosphatase obtained increased (89.7% vs 76.3%, p < 0.0005), while the percentage of infants with alkaline phosphatase >800 IU/L (11.7 vs 4.5%, p = 0.0001) and phosphorous <4 mg/dL (14.2% vs 7.9%, p = 0.014) fell significantly.

CONCLUSIONS

After policy implementation, vitamin D supplementation began significantly earlier and the rate of detecting abnormal biochemical markers of metabolic bone disease decreased significantly.

Screening for Metabolic Bone Disease of prematurity

Metabolic bone disease (MBD) of prematurity remains a significant comorbid condition in preterm, low birth weight infants. As the majority of in utero calcium (Ca) and phosphorus (Phos) accretion occurs during the third trimester, many of these children have inadequate mineral stores and are at risk for deficiencies of Ca and Phos. While fortification of formula has allowed for increased mineral delivery to premature infants, intestinal immaturity prevents optimal absorption. This is compounded by immobilization, delayed establishment of enteral feeds, long term parenteral nutrition and medications that may alter mineral levels. Over time, biochemical changes occur and accompany MBD, with poor bone mineralization during this period increasing the risk for complications such as osteopenia, rickets and fractures. Screening is largely based on risk factors, but despite the 2013 AAP Consensus Statement, there remains significant variation in screening practices across institutions. A combination of laboratory and radiologic testing is often used to diagnose and manage MBD of prematurity, but there exists a lack of consensus on which screening tests and thresholds to use. This is in part related to a lack of normative data and clinical trials for preterm infants, and a result, a lack of evidence-based guidelines on the diagnosis and timing of potential treatment. Biochemical markers, such as serum Phos, alkaline phosphatase (ALP) and parathyroid hormone (PTH), have shown some benefit in the diagnosis of MBD in some studies, but have not always been reproducible. Radiographs may identify different degrees of skeletal changes, but these changes may not be detected until later in MBD development. Other modalities, such as DXA and ultrasound, have also been used, but these may be limited by lack of standards in preterm infants or lack of availability in some centers. Further research, more specifically clinical trials, are needed to determine which combination of tests can detect MBD at its earliest, in order to promote early treatment and prevent short- and long-term complications of MBD.

Association of Protein and Vitamin D Intake With Biochemical Markers in Premature Osteopenic Infants: A Case-Control Study

Osteopenia in preterm infants (OP) remains an important challenge and is largely dependent on nutritional post-natal intake of factors influencing bone mineralization. We conducted a prospective case-control study to evaluate the importance of protein and vitamin D intake in OP among neonates with birth weight <1,250 g. Simultaneous serum parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium (Ca), phosphorus (P), vitamin D and protein levels were measured during the first six post-natal weeks. At 6 weeks of age, OP was evaluated using wrist radiographs. Comparisons were analyzed using multivariate linear regression, receiver operating characteristic curves, χ2 and Wilcoxon Rank Sum. Of the 26 premature infants enrolled, 13 developed radiographic OP. Daily protein intake (coef = -0.40, p = 0.001) and vitamin D concentrations (21 ± 5.7 ng/ml) were significantly lower in the OP group compared to non-OP subjects. ALP concentration exceeding 619 IU/L, sensitivity of 76.9% and specificity of 75%, was predictive of OP at 6 weeks post-natally. PTH levels were higher at 6 weeks in OP subjects (193 ± 102.5 pg/ml, p < 0.001) compared to non-OP subjects. The findings in this study support the role of vitamin D and protein intake in the development of OP in VLBW infants and inform future practice and research on best practices for OP management.

Human milk-derived fortifier versus bovine milk-derived fortifier for prevention of mortality and morbidity in preterm neonates

BACKGROUND

Preterm infants who are fed breast milk in comparison to infant formula have decreased morbidity such as necrotizing enterocolitis. Multi-nutrient fortifiers used to increase the nutritional content of the breast milk are commonly derived from bovine milk. Human milk-derived multi-nutrient fortifier is now available, but it is not clear if it improves outcomes in preterm infants fed with breast milk.

OBJECTIVES

To determine whether the fortification of breast milk feeds with human milk-derived fortifier in preterm infants reduces mortality, morbidity, and promotes growth and development compared to bovine milk-derived fortifier.

SEARCH METHODS

We searched the following databases for relevant trials in September 2018. Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 9), electronic journal reference databases including MEDLINE (1980 to 20 September 2018), PREMEDLINE, Embase (1974 to 20 September 2018), CINAHL (1982 to 20 September 2018), biological abstracts in the database BIOSIS and conference abstracts from 'Proceedings First' (from 1992 to 2011). We also included the following clinical trials registries for ongoing or recently completed trials: ClinicalTrials.gov (ClinicalTrials.gov), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; www.whoint/ictrp/search/en/) and the ISRCTN Registry (www.isrctn.com/), and abstracts of conferences: proceedings of Pediatric Academic Societies (American Pediatric Society, Society for Pediatric Research and European Society for Paediatric Research) from 1990 in the 'Pediatric Research' journal and 'Abstracts online' (2000 to 2017).

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials that compared preterm infants fed breast milk fortified with human milk-derived fortifier versus those fed with breast milk fortified with bovine milk-derived fortifier.

DATA COLLECTION AND ANALYSIS

The data were collected using the standard methods of Cochrane Neonatal. Two authors evaluated trial quality of the studies and extracted data. We reported dichotomous data using risk ratios (RRs), risk differences (RDs), number needed to treat (NNT) where applicable, and continuous data using mean differences (MDs). We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

One randomized trial with 127 infants met the eligibility criteria and had low risk of bias. Human milk-based fortifier did not decrease the risk of necrotizing enterocolitis in exclusively breast milk-fed preterm infants (RR 0.95, 95% CI 0.2 to 4.54; 1 study, 125 infants, low certainty of evidence). Human milk-derived fortifiers did not improve growth, decrease feeding intolerance, late-onset sepsis, or death.

AUTHORS' CONCLUSIONS

There is insufficient evidence evaluating human milk-derived fortifier with bovine milk-derived fortifier in exclusively breast milk-fed preterm infants. Low-certainty evidence from one study suggests that in exclusively breast milk-fed preterm infants human milk-derived fortifiers in comparison with bovine milk-derived fortifier may not change the risk of necrotizing enterocolitis, mortality, feeding intolerance, infection, or improve growth. Well-designed randomized controlled trials are needed to evaluate short-term and long-term outcomes.

Metabolic bone disease of prematurity: causes, recognition, prevention, treatment and long-term consequences

Metabolic bone disease of prematurity (MBDP) is characterised by skeletal demineralisation, and in severe cases it can result in fragility fractures of long bones and ribs during routine handling. MBDP arises from prenatal and postnatal factors. Infants who are born preterm are deprived of fetal mineral accumulation, 80% of which occurs in the third trimester. Postnatally, it is difficult to maintain a comparable intake of minerals, and medications, such as corticosteroids and diuretic therapy, lead to bone resorption. With improvements in neonatal care and nutrition, the incidence of MBDP in preterm infants appears to have decreased, although the recent practice of administering phosphate supplements alone will result in secondary hyperparathyroidism and associated bone loss, worsening MBDP. Postnatal immobilisation and loss of placental supply of oestrogen also contribute to skeletal demineralisation. There is no single diagnostic or screening test for MBDP, with pitfalls existing for most radiological and biochemical investigations. By reviewing the pathophysiology of calcium and phosphate homeostasis, one can establish that plasma parathyroid hormone is important in determining the aetiology of MBDP - primarily calcipaenia or phosphopaenia. This will then direct treatment with the appropriate supplements while considering optimal physiological calcium to phosphate ratios.

Do Maternal Vitamin D Levels Influence Vitamin D Levels in Preterm Neonates?

Objective

To determine the prevalence of Vitamin D (VitD) deficiency/insufficiency in mothers of preterm neonates less than or equal to 32 weeks of gestation and determine if the current level of VitD supplementation used for preterm neonates is appropriate.

Design

Prospective study from 10^th May 2015 to 1^st November 2016.

Setting

Neonatal Intensive Care Unit at the Canberra Hospital.

Patients

Mothers and their preterm neonates born less than or equal to 32 weeks gestation.

Interventions

Maternal VitD levels were obtained within 3-4 days following delivery. Neonatal VitD levels were obtained in the first 3-4 days of life, at 3-4 weeks of age, and at 6-8 weeks of age. Demographic data and data on VitD intake from parenteral nutrition, enteral feeds, and vitamin supplementation agents were collected.

Results

70 neonates were enrolled into the study. Median gestation was 29 (27-30) weeks and median birth weight 1197 (971.2-1512.5) grams. Median maternal VitD level was 54.5 (36-70.7) nmol/L, median neonatal Vit D level at birth was 57 (42-70) nmol/L. Median Vit D level at 3 weeks and 6 weeks were 63.5 nmol/L (53-80.2) nmol/L and 103 (71.5-144) nmol/L respectively. 22/55 (40%) mothers were VitD deficient/insufficient. 25/70 (36%) neonates were VitD deficient/insufficient at birth. Of those neonates who were VitD deficient/insufficient at birth 5/25(10%) were deficient/insufficient at 6 weeks. The median intake of VitD at 6 weeks was 826.5 (577.5-939.5) IU/day.

Conclusions

VitD deficiency/insufficiency in mothers of preterm neonates and in preterm neonates at birth is common. Routine screening of maternal VitD and their preterm neonates along with individualized supplementation regimens in mothers and preterm infants may optimize VitD status and reduce risk of ongoing VitD deficiency/insufficiency.

Metabolic Bone Disease of Prematurity: Diagnosis and Management

Metabolic Bone Disease (MBD) of prematurity is a multifactorial disorder commonly observed in very low birth weight (VLBW, <1,500 g) newborns, with a greater incidence in those extremely low birth weight (ELBW, <1,000 g). MBD is characterized by biochemical and radiological findings related to bone demineralization. Several antenatal and postnatal risk factors have been associated to MBD of prematurity, although the main pathogenetic mechanism is represented by the reduced placental transfer of calcium and phosphate related to preterm birth. The diagnosis of MBD of prematurity requires the assessment of several biochemical markers, radiological, and ultrasonographic findings. However, the best approach is the prevention of the symptomatic disease, based on the screening of subjects exposed to the risks of developing MBD. Regarding the subjects who need to be screened, there is a substantial agreement on the potential risk factors for MBD. On the contrary, different recommendations exist on the diagnosis, management and treatment of this disorder of bone metabolism. This review was aimed at: (1) identifying the subjects at risk for MBD of prematurity; (2) indicating the biochemical findings to take in consideration for the prevention of MBD of prematurity; (3) suggesting practical recommendations on nutritional intake and supplementation in these subjects. We searched for papers which report the current recommendations for biochemical assessment of MBD of prematurity and for its prevention and treatment. The majority of the authors suggest that MBD of prematurity is a disease which tends to normalize overtime, thus it is not mandatory to mimic the rate of mineral fetal accretion through parenteral or enteral supplementation. The optimization of total parenteral nutrition (TPN) and the early achievement of a full enteral feeding are important goals for the prevention and management of MBD of prematurity.

Acetylcholinesterase activity and bone biochemical markers in premature and full-term neonates

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.

Alkaline Phosphatase Activity of Staphylococcus aureus Grown in Biofilm and Suspension Cultures

Staphylococcus aureus is known for its resistance to antibiotic treatment as well as the ability to form biofilms. Biofilm formation has been seen in S. aureus infections, yet, the mechanism of biofilm formation is not completely understood. Many molecules, such as DNA and polysaccharides, have been identified in the biofilm microenvironment, but little is known about the enzymes involved in the process. In this paper, alkaline phosphatase (ALP) activity was investigated in S. aureus grown either in biofilm or suspension cultures, achieved using DNase I. A significant increase of ALP activity was observed in S. aureus biofilm culture compared to its suspension counterpart. Treatment of sodium orthovanadate, an ALP inhibitor, significantly decreased biofilm formation. Its inhibition was on par with DNase I treatment at specific doses. Thus, ALP may play an important role in the biofilm formation. Likewise, ALP inhibition may be a novel target for anti-biofilm therapeutics.

Standardized slow enteral feeding protocol reduces necrotizing enterocolitis in micropremies

BACKGROUND

Compared to early enteral feeds, delayed introduction and slow enteral feeding advancement to reduce necrotizing enterocolitis (NEC) is not well studied in micropremies (<750g birth weight).

METHODS

Pre-post case control study. Micropremies who followed a standardized slow enteral feeding (SSEF) protocol (September 2009 to March 2015) were compared with a similar group of historical controls (PreSSEF, January 2003 to July 2009). Enteral feeding withheld for first 10-14 days and advanced at <10 ml/kg/day in the SSEF group.

RESULTS

Ninety-two infants in the SSEF group were compared with 129 PreSSEF group. Birth weight and gestational age in SSEF and PreSSEF were similar. Breast milk initiation rate was higher in SSEF (87.0 vs. 72.0%, p = 0.01) compared to PreSSEF, but were similar at full enteral feeds. Compared with PreSSEF, feeding initiation day, full enteral feeding day, parenteral nutrition days, and total central line days were longer in SSEF. There was significant reduction in NEC (1.1 vs. 16.2%, p < 0.01), surgical NEC (0.0 vs. 7.8%, p < 0.01) and NEC/death (7.6 vs. 29.5%, p < 0.01), in SSEF compared to PreSSEF. SSEF, compared to PreSSEF, had more cholestasis (41.8 vs 28.8%, p = 0.04), higher peak serum alkaline phosphatase (638 vs. 534 IU/dL, p < 0.01), but similar rates of late-onset sepsis (39.1 vs 43.4%, p = 0.53). In infants who survived to discharge, SSEF had higher discharge weight, lower extra-uterine growth restriction, and similar length of stay, compared to PreSSEF.

CONCLUSIONS

A SSEF protocol significantly reduces the incidence of NEC and combined NEC/death in micropremies.

Mineral Homeostasis and Effects on Bone Mineralization in the Preterm Neonate

Most bone formation and mineralization occurs late in gestation. Accretion of adequate minerals is a key element of this process and is often interrupted through preterm birth. In utero, mineral transport is accomplished via active transport across the placenta and does not require fetal hormone input. Postnatal mineral homeostasis requires a balance of actions of parathyroid hormone, calcitonin, and vitamin D on target organs. Preterm birth, asphyxia, acidosis, and prolonged parenteral nutrition increase the risk of mineral imbalance and metabolic bone disease (MBD). Aggressive postnatal nutrition is key to preventing and treating MBD in preterm infants.

Incidence of metabolic bone disease in preterm infants of birth weight <1250 g and in those suffering from bronchopulmonary dysplasia

BACKGROUND & AIMS

Preterm infants are exposed to a higher risk of developing Metabolic Bone Disease (MBD) with an increased bone fragility, a higher fracture risk and a long-term reduced linear growth and childhood height. Monitoring bone growth has become mandatory in neonatology. Several risk factors have been identified among the population of extremely low birth weight infants, but we still do not know which is the real incidence of MBD since its evaluation is not routinely performed worldwide. The aim of this study was to evaluate the incidence of MBD in preterm infants and in those suffering from bronchopulmonary dysplasia (BPD).

METHODS

Prospective evaluation of patients who developed BPD (BPD group) versus infants who did not develop it (no-BPD group). We examined, in preterms <1.250 g, the metacarpus bone transmission time (mc-BTT) at birth, 21 days and 36 weeks of gestational age (GA) together with biochemical markers of bone status.

RESULTS

We included 135 patients, 55 with BPD. BPD patients received less total proteins in the first two weeks and less energy in the first month of life (p = 0.007 and p < 0.001 respectively). BPD patients had a worse growth velocity at two weeks of age (12.36 ± 7.86 vs 16.59 ± 7.05 g/kg/day, p = 0.001). At 21 days, BPD patients had lower phosphatemia (1.65 ± 0.031 mmol/L vs 1.85 ± 0.034 mmol/L, p = 0.007) and higher alkaline phosphatase levels (411.62 ± 135.31 IU/l vs 338.98 ± 102.20 IU/l, p = 0.005). BPD patients had significantly worse mc-BTT at 36 weeks GA (0.45 ± 0.06 vs 0.50 ± 0.08 μsec, p < 0.001) and a higher incidence of MBD (60% vs 34%; p = 0.012).

CONCLUSIONS

BPD infants are a special subset of patients among preterms who receive, in the first month of life, a lower energy intake than patients without BPD. BPD patients have a suboptimal bone growth and a higher incidence of MBD. Monitoring growth, bone status and optimizing nutritional intakes need to be further improved in preterm infants with BPD.

Rickets

Rickets is a bone disease associated with abnormal serum calcium and phosphate levels. The clinical presentation is heterogeneous and depends on the age of onset and pathogenesis but includes bowing deformities of the legs, short stature and widening of joints. The disorder can be caused by nutritional deficiencies or genetic defects. Mutations in genes encoding proteins involved in vitamin D metabolism or action, fibroblast growth factor 23 (FGF23) production or degradation, renal phosphate handling or bone mineralization have been identified. The prevalence of nutritional rickets has substantially declined compared with the prevalence 200 years ago, but the condition has been re-emerging even in some well-resourced countries; prematurely born infants or breastfed infants who have dark skin types are particularly at risk. Diagnosis is usually established by medical history, physical examination, biochemical tests and radiography. Prevention is possible only for nutritional rickets and includes supplementation or food fortification with calcium and vitamin D either alone or in combination with sunlight exposure. Treatment of typical nutritional rickets includes calcium and/or vitamin D supplementation, although instances infrequently occur in which phosphate repletion may be necessary. Management of heritable types of rickets associated with defects in vitamin D metabolism or activation involves the administration of vitamin D metabolites. Oral phosphate supplementation is usually indicated for FGF23-independent phosphopenic rickets, whereas the conventional treatment of FGF23-dependent types of rickets includes a combination of phosphate and activated vitamin D; an anti-FGF23 antibody has shown promising results and is under further study.

Metabolic bone disease in preterm infants: Relationship between radiologic grading in the wrist and serum biochemical markers

PURPOSE

To assess the relationship between radiographic findings of metabolic bone disease (MBD) and serum biochemical markers in preterm infants.

MATERIALS AND METHODS

A total of 159 preterm infants were included in this study. Two readers reviewed the wrist radiography for grading according to MBD severity. We recorded the levels of alkaline phosphatase (ALP) and phosphorous (P) immediately after birth, on the same day of the first wrist radiography (ALP-s, P-s), the highest/lowest ALP/P levels before the first wrist radiography (ALP-hb/P-lb) and during follow-up (ALP-h/P-l). For analysis, the patients were first subdivided into 4 groups according to MBD severity, and were then divided into 2 groups according to MBD presence or absence.

RESULTS

Of the 159 patients, 94, 39, 19, and 7 infants were classified into grades 0,1, 2, and 3. Analysis according to severity showed that ALP-s, ALP-hb, and ALP-h differed between grades 0-1 and 2-3 (all P<0.001); P-lb differed between grades 0 and 2 (P=0.001); and P-l differed between grades 0 and 2 or 3 (P<0.001 or P=0.001). Moreover, ALP-s, ALP-hb, ALP-h, P-s, P-lb, and P-l differed according to the presence or absence of MBD (P<0.001). ALP-h showed the largest area under the curve value (0.752, 95% confidence interval=0.676-0.828, P<0.001). The optimal cut-off value of ALP-h was 473.5U/L. The sensitivity and specificity were 81.5% and 47.9%. ALP-h was measured at 6.9±5.3 weeks after birth.

CONCLUSION

Taking the wrist radiography with reference to an ALP level measured at around 6.9 weeks after birth could be helpful for screening of MBD in preterm infants, unless a fracture is clinically suspected.

Bone Mineral Density According to Dual Energy X-ray Absorptiometry is Associated with Serial Serum Alkaline Phosphatase Level in Extremely Low Birth Weight Infants at Discharge

BACKGROUND

To examine bone mineral density in extremely low birth weight infants at discharge and investigate whether serial measurements of serum alkaline phosphatase (ALP) and phosphate can predict bone mineralization.

METHODS

The individuals were 70 preterm infants. Serum calcium, phosphate, and ALP were measured at weekly intervals during admission in extremely low birth weight infants (mean gestational age, 25.3±2.1 weeks; birth weight, 812.8±141.1 g). Bone mineral apparent density (BMAD) of the lumbar spine was prospectively evaluated by dual energy X-ray absorptiometry at discharge (n=70).

RESULTS

BMAD was classified as poor (< 25^th percentile) at < 0.014 g/cm³, fair (25^th-75^th percentile) at < 0.014-0.021 g/cm³, and good (> 75^th percentile) at > 0.021 g/cm³, based on the distribution of BMAD values in infants with noncomplicated courses of prematurity (n=43). In a further multivariate analysis, the number of total parenteral nutrition days, phosphate at 2 postnatal weeks and 3 postnatal weeks, and ALP at 4 postnatal weeks and 5 postnatal weeks had an impact on bone mineral density at the lumbar spine, independent of gestational age and body weight. Peak ALP activities exceeding 650 IU/L revealed low bone mineral density with 80% sensitivity and 64% specificity (AUC, 0.70; p=0.005).

CONCLUSION

Serial measurements of serum ALP and phosphate are associated with decreased bone mineralization by dual energy X-ray absorptiometry at discharge in extremely low birth weight infants.

Neonatal Parenteral Nutrition Containing Calcium Chloride and Sodium Phosphate

Objective. The authors’ objectives were to determine mineral as well as Al intakes for ≤1000 g birth weight (ELBW) infants supported with parenteral nutrition (PN) solutions containing calcium chloride (CaCl) and sodium phosphate (NaPhos). Study design. This study was a prospective cohort study of 32 ELBW infants. Nutrient and Al intakes were recorded based on actual fluid intakes and concentrations of nutrients and Al in PN solutions. Growth velocities and peak alkaline phosphatase (AP) levels during the hospital stay were recorded. Result. Mean (±standard deviation) weight, length, and head circumference gains and AP were 13.7 ± 1.8 g/kg/d, 1.0 ± 0.2 cm/wk, 0.7 ± 0.1 cm/wk, and 636 ± 227 U/L, respectively. Al intake was 0.27 ± 0.07 µmol/kg/d (7.2 ± 1.8 µg/kg/d) in infants receiving PN with low Al content. This study documented average parenteral Ca and P intakes of 1.15 to 1.20 and 1.19 to 1.29 mmol/kg/d, (46-48 and 37-40 mg/kg/d), respectively, with PN fluid intakes of 90 to 100 mL/kg/d. Conclusion. AP and growth in ELBW infants receiving PN solutions containing CaCl are comparable to those reported in the literature for ELBW infants. Ca and P intakes approaching those reported for preterm infants receiving PN containing calcium gluconate can be provided with PN solutions containing CaCl. Fluid restriction is a significant factor limiting mineral intakes. Al intake can be limited to near FDA recommended intakes in PN solutions containing CaCl.

Clinical-laboratory findings of bone metabolism in healthy premature and full-term neonates: preliminary results

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.

Bone fracture in severe small-for-gestational-age, extremely low birth weight infants: A single-center analysis

INTRODUCTION

Bone fracture is a complication of extremely low birth weight infants (ELBWIs). This study aimed to analyze risk factors for bone fracture in a population of severe small-for-gestational-age (SGA) ELBWIs.

METHODS

We retrospectively studied data from ELBWIs with a birth weight <1000g and <-2 standard deviations (SDs) born at the National Center for Child Health and Development, Japan, from 2013 to 2015. Infants were divided into fracture and control groups. Serum calcium (Ca) and phosphorus (P) levels, perinatal factors, and previously reported risk factors were analyzed.

RESULTS

Of 25 cases of severe SGA ELBWIs, 5 cases of bone fracture were identified. Gestational age was 27.7±2.2, 29.1±2.6weeks (mean difference [MD] -1.4, 95% confidence interval [CI]: -4.0, -1.2, p=0.280), birth weight (BW) 448±105, 673±216g (MD -225, 95% CI: -433, -17, p=0.036) and BW-SD -4.1±0.1, -3.4±0.8 (MD -0.8, 95% CI: -1.5, -0.02, p=0.045) in the fracture and control groups, respectively. Minimums of serum Ca and P were 6.6±1.4, 8.1±0.8mg/dl (MD -1.5, 95% CI: -2.5, -0.6), p=0.003) and 2.3±0.6, 3.5±1.1mg/dl (MD -1.2, 95% CI: -2.2, -0.1, p=0.027) in the fracture and control groups, respectively.

CONCLUSION

Lower BW and BW-SD were possible risk factors for bone fracture. Hypocalcemia and hypophosphatemia may also contribute to the condition.

When Is Parenteral Nutrition Appropriate?

Parenteral nutrition (PN) represents one of the most notable achievements of modern medicine, serving as a therapeutic modality for all age groups across the healthcare continuum. PN offers a life-sustaining option when intestinal failure prevents adequate oral or enteral nutrition. However, providing nutrients by vein is an expensive form of nutrition support, and serious adverse events can occur. In an effort to provide clinical guidance regarding PN therapy, the Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) convened a task force to develop consensus recommendations regarding appropriate PN use. The recommendations contained in this document aim to delineate appropriate PN use and promote clinical benefits while minimizing the risks associated with the therapy. These consensus recommendations build on previous ASPEN clinical guidelines and consensus recommendations for PN safety. They are intended to guide evidence-based decisions regarding appropriate PN use for organizations and individual professionals, including physicians, nurses, dietitians, pharmacists, and other clinicians involved in providing PN. They not only support decisions related to initiating and managing PN but also serve as a guide for developing quality monitoring tools for PN and for identifying areas for further research. Finally, the recommendations contained within the document are also designed to inform decisions made by additional stakeholders, such as policy makers and third-party payers, by providing current perspectives regarding the use of PN in a variety of healthcare settings.

The Clinical and Biochemical Predictors of Bone Mass in Preterm Infants

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.

Screening for secondary hyperparathyroidism in preterm infants

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.

Serial serum alkaline phosphatase as an early biomarker for osteopenia of prematurity

Metabolic bone disease of prematurity is a condition characterized by reduction in bone mineral content (osteopenia). It is a problem faced by very low birth weight (VLBW) infants because of lack of fetal mineralization during the last trimester. Our aim was to assess serum alkaline phosphatase (ALP) level as an early biomarker for osteopenia in premature infants and to estimate an optimal cutoff value of serum ALP at which osteopenia is detected radiologically in premature newborns.This prospective study was conducted on a cohort of 120 newborn infants of both sex of ≤34 weeks' gestational age and <1500 g birth weight. Two blood samples, from each infant on at least 2 consecutive weeks, were reported for calcium, phosphorus, and ALP. Evidence of osteopenia was evaluated radiologically by performing wrist/knee x-ray.Sixteen infants (13.3%) had evidence of osteopenia in x-ray, whereas 104 infants (86.7%) were nonosteopenic and all the osteopenic infants were <1000-g birth weight. Birth weight and gestational age were significantly inversely related to serum ALP levels. Both samples showed statistically significantly higher mean ALP level in osteopenic than nonosteopenics (P < 0.001, and P < 0.001 respectively). There was no constant value of serum ALP related to radiologic evidence of osteopenia. However, the optimal cutoff value of serum ALP at which osteopenia is detected is 500 IU/L with 100% sensitivity and 80.77% specificity.High levels of ALP can be considered a reliable biomarker to predict the status of bone mineralization and the need for radiological evaluation in premature infants particularly those <1000-g birth weight and <32 weeks' gestation.

Effects of parenteral phosphorus dose restriction in preterm infants

BACKGROUND

In response to a national shortage of parenteral phosphorus solutions (2013), a hospital-wide phosphorus dose restriction strategies was implemented which included judicious use of phosphorus in preterm infants <1250 g birth weight and no parenteral phosphorus in preterm infants >1250 g birth weight unless they have a critically low phosphorus level.

OBJECTIVE

To study the effect of parenteral phosphorus dose restriction in preterm infants admitted to the neonatal intensive care unit.

METHODS

Preterm infants (≤35 weeks birth gestation and ≤2500 g birth weight) who received parenteral nutrition, survived >1 week and had no major congenital anomalies were studied. Clinical and laboratory data in the first 4 weeks of life of infants admitted during the parenteral phosphorus shortage (cases) were compared to infants who were admitted 6 months prior to the shortage (controls).

RESULTS

Twenty consecutive cases were compared to 40 consecutive controls. Cases had lower serum phosphorus levels, higher serum alkaline phosphatase levels, and need for greater inotropic support compared to controls. These differences were significant only in preterm infants with birth weight >1250 g, the group who received more parenteral phosphorus dose restriction while they were similar in preterm infants with birth weight <1250 g.

CONCLUSION

The modest effects of phosphorus dose restriction may become more clinically important if shortage is prolonged or severe or if it involves extreme preterm infants.

Bone status in preterm infant: influences of different nutritional regimens and possible markers of bone disease

OBJECTIVE

The objective of this study was to evaluate possible influences of parenteral nutrition on growth and bone development in preterms and to search for markers of bone status.

STUDY DESIGN

Metacarpus bone transmission time (mc-BTT) was performed at birth, 21 days and 36 weeks of gestational age (GA) in preterms, receiving two different nutritional regimens, together with biochemical analysis.

RESULT

A total of 234 patients were studied. Newborns with aggressive nutrition had significantly better growth rate and higher values of mc-BTT until discharge. Mc-BTT at day 21 correlates positively with nutritional intakes and phosphatemia; lower limb length positively correlated with mc-BTT (P<0.01). Newborns with low energy intake in the first week of life (<70 kcal kg(-1) per day) and low serum phosphate level (<1.4 mmol l(-1)) at 21 days had lower mc-BTT at 36 weeks of GA (P<0.01).

CONCLUSION

Aggressive parenteral intakes in preterms improve growth and bone status in the short-medium term, suggesting that early nutrition could influence bone development.

[Vitamin D deficiency in childhood: an opportunity for prevention]

The prevalence of vitamin D deficiency in the pediatric population has increased in recent years and continues to be underdiagnosed and undertreated. According to data from the "ENSANUT 2006" (National Health and Nutrition Survey), the prevalence of vitamin D deficiency in Mexico was 16% in children aged 2-12 years. Vitamin D plays a critical role in the formation and bone homeostasis and consequently on growth. Its deficiency is clearly associated with diseases such as rickets and osteomalacia, and it has been linked to other diseases such as obesity, metabolic syndrome, diabetes, cancer, respiratory infections and immune system disease. Specific risk groups have been described in the medical literature for vitamin D deficiency in which supplementation may offer a benefit. Currently, there is still controversy in defining the serum levels of proficiency and dose supplementation. In Mexico, the daily suggested intake of vitamin D is 5.6μg (224 IU), which is significantly lower than the recommendations in the U.S. and Europe (i.e., between 400 and 1000 IU/day). An increase in vitamin D deficiency has been reported in recent years. There is no consensus regarding the sufficiency levels of vitamin D. Cut-off values vary from 20 to 30ng/ml. Therefore, the objective of this review was to provide an overview of the problem in the pediatric population and to describe the groups at risk, as well as to analyze the current recommendations for vitamin D supplementation. Vitamin D deficiency was considered rare in Mexico according to the National Institute of Medical Science and Nutrition Salvador Zubirán. Lack of evidence did not help to establish the international recommended daily intake. Currently, vitamin D deficiency must be recognized as a health problem, worthy of attention and action. We suggest that prospective studies are carried out in our country where the relationship between serum vitamin D deficiency and poor bone mineralization will be established.