Levels In Healthy Children Research Articles

High altitude impact on serum bicarbonate in healthy Mexican children: concerning the overdiagnosis of renal tubular acidosis

BackgroundAltitude influences bicarbonate levels, it is a variable that is hardly considered in diagnosing Renal Tubular Acidosis (RTA), so it should be a factor to consider when diagnosing this pathology, especially at 2250 mts over the sea level as it is the case of Mexico City. RTA is most often misdiagnosed. Regarding of this, the present study established reference limits for bicarbonate levels in healthy children without pathologies associated with alterations in the acid-base balance in Mexico City and it´s metropolitan area.MethodsA total of 267 healthy pediatric patients were included, within normal estimated glomerular filtration rate (eGFR), and without any associated pathology of any alteration in the acid-base balance.ResultsCompared to older children, children younger than two years of age showed statistically higher levels of calcemia and cystatin C. On the other hand, this same group showed lower values of creatininemia, pCO2, and HCO3-. Percentile 50 of bicarbonate in children under two years of age were 19.9 mEq/L and 21.9 mEq/L in those over that age. A correlation was identified between HCO3- levels and pCO2 (r = 0.68; p < 0.001).ConclusionsIn the study population, an effect of altitude on blood levels of pCO2 and HCO3- was observed.

Hypertension in children and adolescents: perspectives in Japan.

Hypertension in children and adolescents is associated with increased risk of hypertension and cardiovascular disease (CVD) in adulthood. Therefore, preventing hypertension among children and adolescents is an important public health objective worldwide. Although the importance of hypertension in children and adolescents has increasingly been recognized, the field of research is relatively new and evidence for etiologies, prevention and treatment is sparse. This review mainly summarizes the content regarding hypertension in children and adolescents published in Hypertension Research in 2023/24. Highlights include the following: The prevalence of hypertension was higher in female than male Japanese junior high school students (13.7% vs. 4.7%), but there was no significant gender difference among Japanese senior high school students (7.4% vs. 5.4%). Hematological parameters, including red blood cell counts, hemoglobin counts, hematocrit and iron levels, were positively associated with blood pressure (BP) levels in healthy children and adolescents. Higher-risk longitudinal BP trajectories in early life were associated with increased risk of target organ damage (TOD) and higher combined TOD load in midlife. BP phenotypes (e.g., masked hypertension, white-coat hypertension) assessed using office and 24-h ambulatory BP monitoring were not highly reproducible in children. The salt check sheet was a useful tool for evaluating the approximate dietary salt intake in Japanese children and adolescents. It is recommended that healthcare providers screen for hypertension in children and adolescents and recognize the importance of early intervention for those with elevated BP levels. Beginning in childhood, continuous education on hypertension and proper dietary salt intake are key to reducing the risk of hypertension and decreasing the burden of CVD in adulthood.

Association of Whole Blood Amino Acid and Acylcarnitine Metabolome with Anthropometry and IGF-I Serum Levels in Healthy Children and Adolescents in Germany.

Physiological changes of blood amino acids and acylcarnitines during healthy child development are poorly studied. The LIFE (Leipziger Forschungszentrum für Zivilisationserkrankungen) Child study offers a platform with a large cohort of healthy children to investigate these dynamics. We aimed to assess the intra-person variability of 28 blood metabolites and their associations with anthropometric parameters related to growth and excess body fat. Concentrations of 22 amino acids (AA), 5 acylcarnitines (AC) and free carnitine of 2213 children aged between 3 months and 19 years were analyzed using liquid chromatography/tandem mass spectrometry. Values were transformed into standard deviation scores (SDS) to account for sex- and age-related variations. The stability of metabolites was assessed through the coefficient of determination. Associations with parameters for body composition and insulin-like growth factor-I (IGF-I) SDS were determined by the Pearson correlation and linear regression. Our research revealed substantial within-person variation in metabolite concentrations during childhood and adolescence. Most metabolites showed a positive correlation with body composition parameters, with a notable influence of sex, pubertal status and weight group. Glycine exhibited negative associations with parameters of body fat distribution, especially in normal weight girls, overweight/obese boys and during puberty. Blood AA and AC measurements may contribute to elucidating pathogenesis pathways of adiposity-related comorbidities, but the specific timings and conditions of development during childhood and adolescence need to be taken into consideration.

Sirtuin 1 serum concentration in healthy children - dependence on sex, age, stage of puberty, body weight and diet.

Sirtuin 1 (SIRT1) is known to be involved in sensing cellular energy levels and regulating energy metabolism. This study aimed to evaluate fasting serum SIRT1 levels in healthy children, and to analyse the influence of age, sex, puberty, body weight, height, and diet on its concentration. 47 healthy children aged 4-14 with weight and height within normal range and no chronic disease were included into the study. Fasting serum SIRT1 concentrations were estimated by Enzyme Linked Immunosorbent Assay (ELISA). Results showed that serum SIRT1 concentrations in healthy children did not differ with respect to sex, age, height, weight and puberty. Whereas, it appeared that a higher frequency of fruits, vegetables and dairy products consumption was associated with an increase in serum SIRT1 levels. Studying SIRT1 in the context of children's health may have implications for a broader understanding of growth processes, pubertal development, metabolic disorders and nutrition.

Distribution of blood lead and cadmium levels in healthy children aged 0 to 18 years and analysis of related influencing factors in Henan, China: data findings from 2017 to 2022

BackgroundThere is still a lack of data on blood lead levels (BLLs) and blood lead levels (BLLs) in healthy children of all ages from 0 to 18 years in China. This study was performed to analyze the BLLs and BCLs in healthy children aged 0-18 years from 2017 to 2022 in urban and rural areas of Henan Province, Central China, as well as their relationships with socio-demographic variables and certain relevant exposure factors. To provide a basis for evaluating public health policy development and exposure risk management.MethodsThis was an observational study containing data from 17 prefecture-level cities in Henan, China. Blood Pb and Cd levels were determined using a triple quadrupole inductively coupled plasma mass spectrometer equipped with an autosampler. We first calculated the concentrations of Pb and Cd elements in participants of different genders, ages and years, and then created visual graphs depicting the distribution of each element in terms of gender, age and year (2017-2022). The rates between different groups were compared using the Chi-square test or Fisher exact test (if applicable). The means were compared by one-way ANOVA, medians were compared with the Kruskal-Wallis rank-sum test. Generalized linear models (GLM) were performed to estimate the effects of various factors on blood Pb and Cd concentrations in children.ResultsWe recruited a total of 25,920 children (16,142 boys and 9,778 girls) aged 0.01 to 18.00 years (2.58 (1.00,6.25)). The median of BLLs was 23.48µg/L, around 9.39% of studied children had elevated BLLs. The median of BCLs was 0.66µg/L, around 1.84% of studied children had elevated BCLs. The median blood Pb concentration was higher in boys (23.90µg/L) than in girls (22.75µg/L) (P<0.001). The median blood Pb concentration was highest in the 3-7 years group (24.51µg/L) and the median blood Cd concentration was highest in the 1-3 years group (0.66µg/L) among all age groups. Both BLLs and BCLs were substantially higher in children in 2020-2022 compared to 2017-2019. Rural children had lower BLLs and higher BCLs. The results of the generalized linear model showed that children in households using Oil, coal, pellet or other wood as a fuel for heating, children with higher frequency of exposure to tobacco smoke and beverage intake had significantly increased chances of elevated BLLs and BCLs.ConclusionsPb and Cd exposure of children in this area is relatively low, but associated risk factors continue to exist in vulnerable populations. This study is the first big data analysis of Pb and Cd in children in Henan, China, and provides baseline information for future research.

Influence of growth and metabolic markers on hs-troponin T and NT-proBNP levels in healthy children.

As part of the LIFE Child study, we previously described the associations between N-terminal-pro-hormone brain natriuretic peptide (NT-proBNP) and hs-troponin T (hs-TnT) levels and an individual's sex, age and pubertal status, as well as with body mass index (BMI) and serum lipid levels. For NT-proBNP, we found inverse associations with advancing puberty, increasing BMI and serum lipid levels. These findings led us to further question the putative influences of the developing individual's metabolic and growth status as represented by levels of insulin-like growth factor-1 (IGF-1) and IGF-1-binding protein-3 (IGF-BP3) as well as hemoglobin A1c (HbA1c) and Cystatin C (CysC). Serum values, medical history and anthropometric data provided by 2522 children aged 0.25-18 years were collected and analyzed as per study protocol. A strong negative association between NT-proBNP values and IGF-1, IGF-BP3 and HbA1c levels was identified. For IGF-BP3, this interaction was modulated by sex and age, for HbA1c only by age. For hs-TnT, a positive association was found with IGF-BP3, IGF-1 and CysC. The association between hs-TnT and IGF-1 was sex dependent. The association between CysC and hs-TnT was stronger in girls, but the interaction with age was only seen in boys. Between hs-TnT and HbA1c, the association was significantly negative and modulated by age. Based on our large pediatric cohort, we could identify age- and sex-dependent interactions between the metabolic status represented by IGF-1, IGF-BP3, CysC and HbA1c levels and the cardiac markers NT-proBNP and hs-TnT.

Relationship between vitamin D sufficiency and interferon-γ levels in children with chronic lung diseases

Introduction. The role and mechanism of the effect of vitamin D on the course of chronic lung diseases in children are not yet fully understood. In particular, there are not enough studies on the effect of vitamin D status on the production of interferon-γ (IFN-γ) in children with cystic fibrosis and bronchial asthma.Aim. To analyse the changes in IFN-γ levels in children with cystic fibrosis and bronchial asthma according to the serum 25(OH)D level before and during cholecalciferol supplementation.Materials and methods. A total of 114 children (aged from 3 months to 18 years old) were examined, including 51 (44.7%) children with bronchial asthma, 34 (29.8%) children with cystic fibrosis, and 29 (25.5%) children of the control group. If hypovitaminosis D was diagnosed, the children received a three-month cholecalciferol course at doses in accordance with the recommendations of the national consensus - Cystic Fibrosis: Definition, Diagnostic Criteria, Therapy and the national program - Vitamin D Deficiency in Children and Adolescents of the Russian Federation: Current Approaches to Management. The 25(OH)D and IFN-γ levels were twice determined in all children.Results. Median 25(OH)D levels in patients with cystic fibrosis and bronchial asthma did not reach the level of healthy children either before or after supplementation with cholecalciferol drugs at the recommended doses. Vitamin D intake resulted in a decrease in IFN-γ levels in healthy children from 3.07 [2.29; 4.81] pg/ml to 2.18 [1.74; 3.45] pg/ml (p &lt; 0.05), whereas such changes were not detected in the paediatric patients with cystic fibrosis and bronchial asthma in the general population. However, after supplementation with cholecalciferol, the IFN-γ level was significantly higher in patients with cystic fibrosis and bronchial asthma - 2.86 [2.13; 3.86] pg/ml and 3.11 [0.89; 5.0] pg/ml, respectively, than in healthy children - 2.18 [1.74; 3.45] pg/ml (p &lt; 0.05). A statistically significant decrease in IFN-γ level was observed in girls with cystic fibrosis and in healthy girls after supplementation with cholecalciferol, whereas no significant changes in IFN-γ levels were detected in the groups of boys.Conclusion. Modulation of IFN-γ levels appears to be one of the mechanisms of immunotropic effect of vitamin D on the course of chronic inflammation of infectious (cystic fibrosis) and allergic (bronchial asthma) etiology in children.

Nonlinear main components of the cytokine profile in children with community-acquired pneumonia

Cytokines are the key mediators which control and regulate immune and inflammatory responses via complex networks and serve as biomarkers of many diseases. Quantitative determination of cytokines is helpful in assessing immune status and adjusting therapy for various inflammatory diseases, such as sepsis and pneumonia. Since community-acquired pneumonia remains a common cause of childhood morbidity and mortality. At the present stage, prognosis of the disease severity in children is an urgent problem. The aim of our study was to identify associations between cytokine levels in healthy children and in children with community-acquired pneumonia (CAP), depending on the age of patients and severity of the pathological process. The work was carried out at the Department of Microbiology, Virology and Immunology, Department of Propaedeutics of Childhood Diseases and Pediatrics, and at the Research Institute of Immunology at the South Ural State Medical University. The study included 117 children aged 1 to 18 years with radiologically confirmed diagnosis of CAP, either severe or mild degree. The comparison group was composed from 28 healthy children who did not have community-acquired pneumonia, as well as other signs of acute respiratory viral infection at the time of examination, being observed for any chronic disorders. The levels of IL-1β, IFNγ, IL-6, IL-4, IL-10, IL-2, TNFα, IFNλ2 (IL-28A), IFNλ3 (IL-28B), IL-8, MCP-1, IL-17AF, GM-CSF were determined in blood serum by means of ELISA test systems (a “sandwich” technique with peroxidase as an indicator enzyme). For statistical analysis, a multidimensional method was used, i.e., non-linear analysis of the principal components using the CATPCA algorithm. Among the children with CAP, our study revealed a consistent increase of IL-1ß, IL-4, IL-10, IL-2, TNFα, IFNλ2 (IL-28A), IFNλ3 (IL-28B), IL-8, MCP-1, IL-17AF, GM-CSF in blood serum. The highest correlation with severity was shown for IFNλ2 (IL-28A), IFNλ3 (IL-28B) and MCP-1, which may be considered additional biomarkers of the CAP severity. There was also a significant variability of the cytokine profile in healthy children and its significant skewing in pneumonia, especially in severe cases.

The associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents: a prospective cohort study.

Uncontrolled pediatric hypertension may increase the risk of hypertension in adulthood. Several studies have reported an association between hematological parameters and blood pressure (BP) levels. However, epidemiologic evidence of this association in children and adolescents remains scarce. This study aims to explore the associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents. This longitudinal study was conducted with 1368 participants aged 6-8 years from baseline visit to follow-up visit. Compared with participants from the normal blood pressure (BP) group, participants from the elevated BP group had significantly higher baseline red blood cell (RBC) counts, hemoglobin (Hb) counts and hematocrit (Hct) levels (all P < 0.001). A multilevel linear mixed model was conducted to analyze the relationship between hematological parameters and BP levels. The results suggested that SBP, DBP and MAP increased significantly with a quartile increase of levels of hematological parameters (all P < 0.05). Furthermore, a multilevel mixed logistic regression model was used to analyze the risk of per interquartile range increase in hematological parameters on the incidence of prehypertension and hypertension. The risk of prehypertension and hypertension incidence increased by (1.34 (95%CIs: 1.20, 1.50)), (1.38 (95%CIs: 1.24,1.54)), (1.33 (95%CIs: 1.19,1.50)), (1.14 (95%CIs: 1.03,1.26)) fold with a one-quartile increase in levels of RBC, Hb, Hct and Fe, respectively (all P < 0.05). This longitudinal study showed that hematological parameters were positively associated with BP levels in healthy children and adolescents, which excluded the effect of antihypertensive drugs on BP levels that often appeared in adults.

The effect of immunomodulatory therapy with recombinant human interferon alpha-2β on blood cytokine levels in children with recurrent episodes of acute obstructive bronchitis.

The high incidence of children with recurrent episodes of acute obstructive bronchitis is a widespread problem. Correct identification of children at risk of developing bronchial asthma at school age may improve treatment and prevention approaches to this pathology, but the ability to identify these children remains limited. The purpose of the study was to determine the effectiveness of recombinant interferon alpha-2β in children with recurrent episodes of acute obstructive bronchitis in the course of treatment based on the assessment of cytokine profile. The study examined 59 children of the main group with recurrent episodes of acute obstructive bronchitis and 30 children of the comparison group who suffered from acute bronchitis, aged 2-8 years, who were in the hospital. The results of laboratory studies were compared with the data of 30 healthy children. In children with recurrent episodes of acute obstructive bronchitis, the content of serum interferon-γ and interleukin-4 was significantly reduced compared to healthy children, after treatment with recombinant human interferon alpha-2β, the content of interferon-γ and interleukin-4 in children significantly increased. The content of interleukin-1β in children with recurrent episodes of acute obstructive bronchitis was significantly higher than in healthy children, after immunomodulatory therapy with recombinant interferon alpha-2β, interleukin-4 normalized to its level in healthy children. It was found that children with recurrent episodes of acute obstructive bronchitis have an imbalance of cytokines, the effectiveness of recombinant human interferon alpha-2β therapy, which normalized the levels of the studied cytokines in the serum.

Comparison of Oxidative Stress Levels in Healthy Children and Children with Allergic Rhinitis.

Background/aim: Allergic rhinitis (AR) is characterized by chronic inflammation of the nasal mucosa. Under the influence of exogenous factors - allergens, reactive oxygen species (ROS) are released during cellular metabolism. They induce a series of pathological changes in the mucosa. Oxidative stress is а result of an imbalance between the production of ROS and the ability to neutralize them. The aim of this study is to compare the levels of oxidative stress between healthy children and children with allergic rhinitis. Material and methods: A total number of 60 children were included (30 healthy children and 30 children with AR). The oxidative stress index was determined by using the FRAS 5 (Free Radical Analytical System) Bravo system. Demographic characteristics, medical history, children's living conditions and eating habits were obtained from the questionnaire. Anthropometric measurements and the absolute number of eosinophils in the peripheral smear were performed on each child. Results: This study showed high oxidative stress index and a significantly higher value of the absolute number of eosinophils in the peripheral smear in children with AR in comparison to healthy children (p<0.05). The group of children with AR had more atopic characteristics and was more exposed to passive smoking than healthy children. Conclusion: Compared to healthy children, children with AR have a high index of oxidative stress, despite of the very high mean value of the concentration of water-soluble antioxidants in serum (PAT test) in the group of children with AR.

Soluble receptor for advanced glycation end-products (sRAGE) in childhood obesity: association with gene expression of RAGE and cardiometabolic markers.

Introduction: advanced glycation end-products (AGEs) interact with the receptor for AGEs (RAGE). Full-length RAGE is associated with intracellular signal transduction, and soluble-RAGE (sRAGE) lacks the transmembrane and cytoplasmic domains, acting as a competitive inhibitor of AGEs-RAGE binding. sRAGE levels in healthy children are associated with cell surface expression of RAGE. However, the expression of RAGE has not been explored in childhood obesity. Objective: the study aim was to evaluate the sRAGE levels and the gene expression of RAGE in children and its association with cardiometabolic markers. Methods: this is a cross-sectional study with 6-11-year children, 20 with overweight and 20 with obesity. Anthropometric measurements included waist circumference (cm) (WC), neck circumference (NC), weight (kg), fat mass (%), trunk fat (kg), muscular mass (kg), height (cm), and body mass index (BMI) (kg/m2). Blood samples following an overnight fast were collected to measure glucose (mg/dl) and lipid profile with colorimetric methods. sRAGE was determined in serum using the enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription (RT-qPCR) was performed to analyze RAGE transcripts in peripheral blood mononuclear cells isolated by Ficoll®-Hypaque. Results: we found higher RAGE (p = 0.0315) and lower sRAGE (p = 0.0305) levels in the obesity group. sRAGE level showed a negative correlation with RAGE (r = -0.35) and BMI (r = -0.24), and positive with HDL-cholesterol (r = 0.29). Regression analysis suggests that HDL-C and RAGE levels are predictors of sRAGE levels. Conclusions: expression of RAGE is associated with lower sRAGE levels in childhood obesity. Moreover, obese children show higher cardiometabolic risk markers, and a positively associated with sRAGE.

Vitamin B12 levels in children and adolescents on plant-based diets: a systematic review and meta-analysis.

The popularity of plant-based diets, characterized by a partial or complete exclusion of animal products, has increased significantly over the last 10 years. The exclusion of animal products removes the most common sources of vitamin B12, which can lead to vitamin B12 deficiency and result in irreversible damage, such as growth stunting. This aim of this systematic review and meta-analysis was to qualitatively evaluate all studies on this subject and to quantify the potential difference in vitamin B12 levels in healthy children and adolescents aged 5 to 18 years. PubMed and Embase databases were searched for relevant studies investigating vitamin B12 levels in healthy children and adolescents aged 5 to 18 years on plant-based diets. Studies were assessed qualitatively with the AXIS tool and quantitatively with Stata 16.0 software. Overall, children and adolescents on plant-based diets had a significantly lower vitamin B12 level than omnivorous children and adolescents (-97 pmol/L; 95%CI, -187 to -7; I2 = 98.5%), a difference that remained statistically significant after adjusting for methodological confounders. After subgroup analyses, this effect was not statistically significant for children and adolescents on vegetarian diets but remained significant in children and adolescents on vegan or macrobiotic diets. Moreover, total vitamin B12 intake nullified the mean difference in vitamin B12 levels. Despite high heterogeneity across studies, these results indicate that children and adolescents on plant-based diets, especially those on vegan and macrobiotic diets, may be at risk of developing vitamin B12 deficiency.

The human cathelicidin hCAP ‐18 in serum of children with haemato‐oncological diseases

SummaryThe human cathelicidin hCAP‐18 (pro‐LL‐37) is the pro‐protein of the antimicrobial peptide LL‐37. hCAP‐18 can be produced by many different cell types; bone marrow neutrophil precursors are the main source of hCAP‐18 in the circulation. Neutrophil count is used as a marker for myelopoiesis but does not always reflect neutrophil production in the bone marrow, and thus additional markers are needed. In this study, we established the reference interval of serum hCAP‐18 level in healthy children and compared serum hCAP‐18 levels between different diagnostic groups of children with haemato‐oncological diseases, at diagnosis. We found that children with diseases that impair myelopoiesis, such as acute leukaemia, aplastic anaemia, or myelodysplastic syndrome, presented with low hCAP‐18 levels, whereas patients with non‐haematological malignancies displayed serum hCAP‐18 levels in the same range as healthy children. Children with chronic myeloid leukaemia presented with high circulating levels of hCAP‐18, probably reflecting the high number of all differentiation stages of myeloid cells. We suggest that analysis of serum hCAP‐18 provides additional information regarding myelopoiesis in children with haemato‐oncological diseases, which may have future implications in assessment of myelopoiesis in clinical management.

Admission Circulating Cell-Free DNA Levels as a Prognostic Factor in Pediatric Burns.

Background Burn injuries in children are a major physical and psychological trauma, often a severe condition with long-term consequences. Current methods of assessing the extent of burn injuries on admission are inaccurate. Circulating cell-free DNA (cfDNA) is a potential marker of tissue damage that may be useful in burn care. Objective To explore the use of cfDNA admission levels as a prognostic marker of pediatric burn severity and outcome. Methods cfDNA levels of 38 pediatric burn patients (otherwise healthy) and 12 matched pediatric controls (minor elective surgery patients) admitted to our center were quantified by a direct fluorometric assay. Results We found significantly higher admission cfDNA levels in the patient group (median 724 ng/ml, range 44-4405), compared to the control group (median 423 ng/ml, range 206-970, Mann–Whitney, P = 0.03) and a significant difference between cfDNA levels of partial-thickness burns (median 590 ng/ml, range 44-2909) and full-thickness burns (median 2394 ng/ml, range 528-4405, Mann–Whitney, P = 0.01). We also found significant correlations between cfDNA levels and hospitalization duration (Spearman, R = 0.42, P < 0.01) and undergoing surgical procedures (Spearman, R = 0.40, P < 0.01). PICU admission did not correlate to cfDNA levels (Spearman, R = 0.14, P = NS). Discussion. Admission cfDNA levels may be a valuable objective tool for assessing the severity of pediatric burn injuries on admission, including correlations with the length of hospitalization and surgical burden. Conclusion Admission cfDNA levels may be a promising novel pediatric burn assessment method. Further investigation of cfDNA levels in healthy children standardized to age and larger cohorts are needed to establish cfDNA as a valuable prognostic factor for pediatric burn injury.

How Vitamin D Levels of Children Changed During COVID-19 Pandemic: A Comparison of Pre-pandemic and Pandemic Periods

Objective:The synthesis of vitamin D is related to sun exposure, thus the restrictions during the Coronavirus disease-2019 (COVID-19) pandemic may have affected the levels of vitamin D in all age groups. The aim of this study was to evaluate vitamin D levels of healthy children and adolescents during the first year of the pandemic.Methods:The study group included healthy children and adolescents who were admitted for general check-ups and evaluated with 25(OH)D levels. Then, it was divided into two groups: Group 1 “pre-pandemic”, and Group 2 “pandemic”. Vitamin D levels were recorded from the hospital database and were compared according to age groups, gender, and the season, retrospectively.Results:The study group [mean age=90.29±59.45 median age=79 interquartile range (IQR): 102 months, male/female: 1409/1624] included 3033 children and adolescents (Group 1/Group 2 n=1864/1169). Although the mean 25(OH)D levels among preschool children did not differ between groups, the vitamin D levels of school-aged children and adolescents were significantly lower in the pandemic period than in the pre-pandemic period [Group 1 median=16.50 (IQR: 10.5) vs Group 2 median=15.9 (IQR: 11.3) in 6-12 age group (p=0.026); Group 1 median=13.30 (IQR: 10.2) vs Group 2 median=11.20 (IQR: 9.7) in 12-18 age group (p=0.003)]. Moreover, the 25(OH)D levels of adolescents showed seasonal variance with lower levels in winter, and unexpectedly, in summer.Conclusion:Pandemic-related restrictions have caused significant decreases in vitamin D levels of school-aged children and adolescents. We suggest that children and adolescents should be given vitamin D supplementation in order to maintain sufficient levels of vitamin D during the pandemic.

Carbon dioxide rises beyond acceptable safety levels in children under nose and mouth covering: Results of an experimental measurement study in healthy children

Nose and mouth covering (NMC) has been made compulsory for children in many countries during the Covid-19 pandemic. We wanted to determine the average CO2 levels in inhaled air with NMC in children between age 6 and 17. We used short term measurements under surgical masks and FFP2 masks according to European norm EN 149, compared to baseline in an experimental, intra-individually controlled study over 25 min. CO2 content was measured every 15 s using an automated dual-wavelength infrared CO2 measurement device (G100, Geotech, Leamington Spa, UK) over 25 min in a short-term experimental setting, with children seated. After baseline measurement children were provided with two types of commonly worn NMC: surgical masks and FFP2--masks in randomized sequence for 3 min each. We kept ambient CO2-levels below 1000 parts per million (ppm) through frequent ventilation. We measured breathing frequency and pulse as potential physiological moderator variables. Forty-five children, 25 boys, 20 girls, with a mean age of 10.7 years (standard deviation 2.6) were measured. We measured 13,100 ppm (SD 380) under surgical mask and 13,900 ppm (SD 370) under FFP2 mask in inhaled air. A linear model with age as a covariate showed a highly significant effect of the condition (p < 1*10−9). We measured 2,700 ppm (SD 100) CO2 at pre-baseline and 2,800 ppm (SD 100) at post-baseline, a non-significant small difference. Appropriate contrasts revealed that the change was due to the masks only and the difference between the two types of masks was small and not significant. Wearing of NMC (surgical masks or FFP2- -masks) raises CO2 content in inhaled air quickly to a very high level in healthy children in a seated resting position that might be hazardous to children's health.

Pediatric Continuous Reference Intervals of Serum Insulin-like Growth Factor 1 Levels in a Healthy Chinese Children Population – Based on PRINCE Study

ObjectivesWe aimed to establish age- and sex-dependent reference intervals for insulin-like growth factor 1 (IGF-1) based on the measurements of healthy Chinese children from the pediatric reference intervals in China study and to investigate whether body mass index (BMI) and height affect IGF-1 levels. MethodsA total of 3753 individuals with eligible blood specimens resampled from the pediatric reference intervals in China population were enrolled as reference individuals. IGF-1 levels were measured using a chemiluminescent immunoassay kit. The lower limit and upper limit values of the reference individuals were calculated by defining the 2.5th and 97.5th percentiles. The skewness-median-coefficient of variation method was used to calculate the standard deviation score (SDS) of serum IGF-1, and cubic spline curves were applied to depict a smoothed curve for each age- and sex-specific stratification of the L, M, and S parameters. ResultsSerum IGF-1 levels increased with age from the age of 1 year, peaking at around the age of 13 years in girls and 15 years in boys and then began to decline (both P <.001). Before 14 years, IGF-1 levels were higher in girls than in boys at the same age, and the difference was statistically significant (P < .05), but there was no significant difference in the IGF-1 levels between girls and boys aged 14 to 16 and 18 years. The Spearman correlation coefficients of height SDS, weight SDS, and BMI SDS with IGF-1 SDS were 0.29, 0.33, and 0.20, respectively (P < .001). ConclusionThis study established age- and sex-specific normative IGF-1 data for Chinese children and adolescents between the ages of 1 and 19 years. The BMI and height SDS had no effect on IGF-1 levels in healthy children.

Cerebrospinal Fluid Histamine Levels in Healthy Children and Potential Implication for SIDS: Observational Study in a French Tertiary Care Hospital.

ObjectiveA defect of the waking systems could constitute a factor of vulnerability for sudden infant death syndrome (SIDS). A decrease in orexin levels, which promotes wakefulness and activates histaminergic neurons (another hypothalamic wake-promoting system) has already been demonstrated between 2 and 6 months. This work aims to study the levels of histamine (HA), tele-methylhistamine (t-MeHA), its direct metabolite, and t-MeHA/HA ratio in the cerebrospinal fluid (CSF) of healthy children, to evaluate the maturation of the histaminergic system and its possible involvement in SIDS.MethodsSeventy Eight French children between 0 and 20 years (48.7% boys) were included, all of whom had a clinical indication for lumbar puncture, but subsequently found to be normal. Measurements of HA and t-MeHA in CSF were performed by reverse phase liquid chromatography coupled to mass spectrometry detection. Statistical analyses were performed using Spearman correlations and Non-parametric pairwise ranking tests.ResultsA negative correlation was found between age and CSF HA (r = −0.44, p < 10−4) and t-MeHA (r = −0.70, p < 10−4) levels. In pairwise comparisons, no difference in CSF HA and t-MeHA levels was observed between youngest age groups (i.e., 0–2 mo vs. 3–6 mo), but CSF HA and t-MeHA levels were significantly lower in older children (i.e., >6 mo vs. 0–6 mo). The CSF HA decrease with age was only observed in boys, who also presented global lower CSF HA levels than girls.ConclusionCSF HA and t-MeHA levels decrease with age in boys, and global levels are lower in boys than in girls. These results reveal changes in histaminergic transmission and metabolism during maturation. Whether lower CSF histamine values in boys compared to girls could contribute to their higher risk of SIDS warrants further research.

Effect of treadmill exercise stress testing on troponin levels in children and adolescents.

Chest pain is a common complaint among paediatric patients and cardiac troponin (cTn) level is often part of the initial emergency department evaluation. It is well known that after intense endurance exercise cTn levels can be elevated in patients with otherwise healthy hearts, however the effect shorter duration exercise has on cTn levels in this population is not known. Determine the behaviour of cTn levels in healthy children and adolescent patients after short burst, high-intensity aerobic exercise. Patients without haemodynamically significant heart disease referred for a treadmill exercise stress test (EST) were recruited over a 6-month period. cTn levels were measured prior to exercise and 4 hours after exercise. Thirteen patients enrolled. Indications for EST were exertional syncope (six), chest pain (four), and long QT syndrome (three). The median exercise time was 12.9 (9.9-13.7) minutes with an average endurance at the fiftieth percentile for age and maximum heart rate rose to an average of 92 (74-98)% of the predicted peak for age. cTn levels prior to exercise were undetectable in all patients. There was no cTn rise in any patient after exercise. There were no ischaemic changes or arrhythmias on exercise electrocardiograms. Serum cTn levels do not rise significantly in healthy children after short duration, high-intensity aerobic exercise. Physicians evaluating paediatric patients with an elevated cTn level after less than prolonged strenuous activity likely cannot attribute this lab value solely to exercise and may need to undertake further cardiac investigation.