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

Growth Plate Gene Involment and Isolated Short Stature

Purpose Short stature is a common clinical presentation, thus it is widely accepted that it is a polygenic trait. However, genome wide association and next generation sequencing studies have recently challenged this view, suggesting that many of the children classified as idiopathic short stature could instead have monogenic defects. Linear growth is determined primarily by chondrogenesis at the growth plate. This process results from chondrocyte proliferation, hypertrophy, and extracellular matrix secretion, and it is perfectly coordinated by complex networks of local paracrine and endocrine factors. Alterations in genes which control growth plate development can explain a large number of cases of isolated short stature, allowing an etiological diagnosis. Methods/Results We reviewed recent data on the genetic alterations in fundamental cellular processes, paracrine signaling, and cartilage matrix formation associated with impaired growth plate chondrogenesis. In particular we focused on growth plate gene involvement in nonsyndromic short stature. Conclusions The identification of genetic basis of growth failure will have a significant impact on the care of children affected with short stature

Sustained activation of the renin-angiotensin-aldosteron system after fetal exposure to AT1 blockers: Effects on kidney and bone in a preterm newborn

The renin-angiotensin-aldosterone system (RAAS) plays a key role in development of fetal kidney. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor type 1 (AT1) antagonists alter RAAS-signaling compromising metanephrogenesis, and vascular and tubular development. The result is a fetal "RAS blockage syndrome" that may occur not only following exposure during the second and third trimester, but also after the use of these drugs at the beginning of pregnancy. The in-utero exposure to AT1 antagonists is not confined exclusively to the risk of neonatal renal failure, but also to skull ossification defect that worsens the neonatal prognosis. We report the case of early arterial hypertension development, marked increase of plasma renin and aldosterone, severe hypocalvaria, and low bone mineralization in a female preterm infant in-utero exposed to AT1 antagonists

Monoclonal antibodies for treating osteoporosis

Osteoporosis is the most widespread skeletal disease requiring innovative therapeutic strategies for its management. The understanding of receptor activator of nuclear factor kappa-B ligand (RANKL) and sclerostin's role in bone cell biology is completely changing the therapeutic landscape. RANKL supports osteoclast formation and activity and is mainly produced by cells of osteoblastic lineage. Sclerostin, an antagonist of the Wnt pathway, has a key role in bone formation and is mainly secreted by osteocytes. High levels of RANKL and sclerostin have been detected in osteoporosis, leading to the production of antibodies able to neutralize their activity. Areas covered: In this review, the authors give an overview and discuss the literature and data on denosumab and romosozumab to treat osteoporosis. Clinical studies indicate that long-term treatment with denosumab causes a continuous increase in bone mineral density with low incidence of adverse effects. Romosozumab treatment gives increases bone formation and improves bone mineral density (BMD) though further studies are needed to better evaluate the adverse effects. Expert opinion: Denosumab and romosozumab show promise in the treatment of osteoporosis. Furthermore, their different mechanisms of action compared to existing anti-osteoporotic drugs may permit alternative strategies for osteoporosis treatment down the line

An update on the role of RANKL–RANK/osteoprotegerin and WNT-ß-catenin signaling pathways in pediatric diseases

Background: Bone remodeling is a lifelong process due to the balanced activity of osteoclasts (OCs), the bone-reabsorbing cells, and osteoblasts (OBs), and the bone-forming cells. This equilibrium is regulated by numerous cytokines, but it has been largely demonstrated that the RANK/RANKL/osteoprotegerin and Wnt/β-catenin pathways play a key role in the control of osteoclastogenesis and osteoblastogenesis, respectively. The pro-osteoblastogenic activity of the Wnt/β-catenin can be inhibited by sclerostin and Dickkopf-1 (DKK-1). RANKL, sclerostin and DKKs-1 are often up-regulated in bone diseases, and they are the target of new monoclonal antibodies. Data sources: The authors performed a systematic literature search in PubMed and EMBASE to June 2018, reviewed and selected articles, based on pre-determined selection criteria. Results: We re-evaluated the role of RANKL, osteoprotegerin, sclerostin and DKK-1 in altered bone remodeling associated with some inherited and acquired pediatric diseases, such as type 1 diabetes mellitus (T1DM), alkaptonuria (AKU), hemophilia A, osteogenesis imperfecta (OI), 21-hydroxylase deficiency (21OH-D) and Prader–Willi syndrome (PWS). To do so, we considered recent clinical studies done on pediatric patients in which the roles of RANKL-RANK/osteoprotegerin and WNT-ß-catenin signaling pathways have been investigated, and for which innovative therapies for the treatment of osteopenia/osteoporosis are being developed. Conclusions: The case studies taken into account for this review demonstrated that quite frequently both bone reabsorbing and bone deposition are impaired in pediatric diseases. Furthermore, for some of them, bone damage began in childhood but only manifested with age. The use of denosumab could represent a valid alternative therapeutic approach to improve bone health in children, although further studies need to be carried out

Can Anti-Thyroid Antibodies Influence the Outcome of Primary Chronic Immune Thrombocytopenia in Children?

Immune thrombocytopenia (ITP) is an acquired immune mediated disorder characterized by isolated thrombocytopenia. Pediatric ITP patients can develop autoantibodies such as anti-thyroglobulin (TG) and anti-thyroperoxidase (TPO), even in absence of clinical signs of autoimmune disease. Objective; The purpose of this article is to provide a review about: 1) the prevalence of positivity of anti-thyroid antibodies (TPO and TG) in pediatric patients with chronic ITP; 2) the role of autoimmune thyroiditis on the outcome of chronic ITP

Congenital hypothyroidism after newborn screening program reorganization in the Apulia region

Background Congenital hypothyroidism (CH) is the most frequent congenital endocrine disorder. The purpose of the present study was to evaluate the incidence and etiological classification of CH in Apulia in a three-year period according to the reorganization of the regional screening program in a single central laboratory, as well as to analyze the growth characteristics and the associated risk factors of the CH newborns diagnosed during the study period. Methods Data derived from the reorganization of the newborn screening program for CH in a single central laboratory that collects dried blood spot (DBS) from 27 Maternity Hospitals are analyzed over a three-year period. Birth weight and length, daily dose of L-T4 at specific key points (3, 6, 12 and 18 months, 2, 2.5 and 3 years) were also obtained from medical records of the CH newborns during the study period and calculated as standard deviation score (SDS). Results The screening program diagnosed 90 newborns with confirmed CH (incidence 1:990; recall rate: 3.6%). In detail, 75.6% newborns had an eutopic thyroid, and 24.4% had thyroid dysgenesis; 33 out of the 90 newborns (36.6%) had one or more risk factors. Among these, the multiple pregnancies are the most important because they tripled the risk of CH. At diagnosis, TSH levels were different between patients with dysgenesis and those with an eutopic thyroid (p = 0.005). Treatment was started at a mean of 18.5 +/- 12.8 days of life. The mean starting dose of levothyroxine (L-T4) was 11.38 +/- 2.46 mu g/kg/day. Conclusions The results of these study show an increase of CH cases in newborns with an eutopic thyroid compared to the traditional classification. The centralization of the screening program allows a closer cooperation between laboratory and clinical centers and facilitates the implementation of appropriate diagnostic evaluations and timely initiation of treatment, with positive effects on the management of the condition

Sex Hormone-Binding Globulin (SHBG) Reduction: The Alarm Bell for the Risk of Non-Alcoholic Fatty Liver Disease in Adolescents with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) represents an endocrine condition affecting 5–18% of adolescents, frequently in association with obesity, metabolic alterations, and liver dysfunction. In this study, we aimed to evaluate the prevalence and risk factors for developing non-alcoholic fatty liver disease (NAFLD) in a cohort of PCOS adolescents. Thirty-two girls were assessed for anthropometric and biochemical markers: total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), glucose, insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma glutamyl transpeptidase (γGT). In addition, LH, FSH, 17β-Estradiol (E2), prolactin, testosterone (T), free testosterone, delta 4-androstenedione (D4 A), dehydroepiandrosterone sulfate (DHEAS) and sex hormone binding protein (SHBG) were also evaluated. All subjects underwent liver ultrasound to detect NAFLD. Our data demonstrated that PCOS adolescents complicated with NAFLD accounted for 37.5%, and those with obesity and lower SHBG were more predisposed to developing NAFLD. Moreover, SHBG showed a negative correlation with several parameters such as blood pressure, body mass index, waist circumference, insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR). Our results demonstrated that the assessment of SHBG may allow the identification of PCOS adolescents at risk for developing NAFLD and metabolic alterations

Different Variation of Intra-familial Body Mass Index subjected to Covid-19 Lockdown

Background and aims: Coronavirus disease 2019 (COVID-19) lockdown has represented an inedited model of increased metabolic risk in all age groups, due to negative changes in dietary habits, physical activity, lifestyle. These effects have been generally explored at a population level in distinct age groups. Potential intra-familial, specific effects in adults and children sharing the same socio-economic, cultural level and living habits have been scarcely explored. We aimed to characterize changes of anthropometric indices in parents and in their children during COVID-19 lockdown. Methods: A cohort of 149 couple parent/children were prospectively enrolled. By a validated questionnaire we explored changes of body mass index (BMI) and individual lifestyle during a 2-month lockdown (May- July 2020). Results: BMI increased in 70.5% of parents and in 67.8% of their children, with a Δ-BMI of 1.44+0.09 kg/ m 2 and 0.36+0.02 Kg/m 2 , respectively. BMI increments, however, were only significant in adults and did not correlate in the couple parents/children. Most adults (80.5%) and children (71.4%) did not perform regular physical activity during the lockdown. Direct correlations between dietary changes and BMI variations became evident in children, mainly in terms of a decreased consumption of fresh fruit, pulses, fish, and an increased consumption of cereals, carbohydrates, dairy products, olive oil. In normal weight, overweight and obese children, but not in adults, the increase in sleep hours increased with BMI. Conclusions: Despite marked lifestyle changes imposed by the COVID-19 lockdown, BMI variations in parents were independent from those observed in their children, pointing to different outcomes in response to the same external, critical event. Thus, primary prevention measures aimed at maintaining a healthy lifestyle require different approaches according to age