The LIFE child study: a life course approach to disease and health

Associations between gestational weight gain and weight development of the offspring: Differences depending on maternal pre-pregnancy BMI

PURPOSE

Obesity rates are rising, and the gestational weight gain (GWG) of most women does not comply with current guidelines. This study assesses the association of pre-pregnancy BMI (ppBMI) and GWG with the child's weight development and investigates whether associations with GWG differ depending on ppBMI.

METHODS

Data were obtained from the cohort study LIFE Child (Germany), comprising 691 mother-child pairs. Children's weight was followed until age five. Associations between maternal ppBMI, GWG, and children's weight were evaluated using regression analyses.

RESULTS

The association between GWG and birth weight (BW) was significantly positive in normal and underweight (n/u) women (βGWG = 0.05, p < 0.01, 95% confidence interval (CI) 0.03-0.07), but not in women with overweight or obesity (o/o) (βGWG = 0.0002, p = 0.99, 95% CI -0.03 to 0.03). The risk of giving birth to an infant who was large for gestational age (LGA) increased with rising GWG in n/u women (OR = 1.6, p < 0.01, 95% CI 1.23-2.25). Women with o/o were at increased risk for a LGA baby regardless of GWG (OR = 3, p < 0.01, 95% CI 1.34-6.97). This trend persisted in the child's weight development during the first 5 years of life.

CONCLUSION

Women with o/o might increase their offspring's risk for higher weight at birth and in early childhood. In n/u women, GWG might be the more influential factor. Women should strive for normal weight before conception and should be more attentive to GWG.

Creatine kinase serum levels in children revisited: New reference intervals from a large cohort of healthy children and adolescents

BACKGROUND

Creatine Kinase (CK) has become increasingly important in pediatrics as a commonly used laboratory screening parameter for neuromuscular diseases. Recent research suggests that hyperCKemia in children is not always associated with pathology and can occur due to several reasons. Little is known of various clinical factors that may influence CK throughout child development.

OBJECTIVE

This study aimed to establish reliable age- and sex-specific reference ranges for serum CK levels in healthy infants, children, and adolescents. In addition, the effect of puberty, oral contraceptive (OC) use as well as steroid hormones on CK was examined.

MATERIALS AND METHODS

The data was collected from subjects of the longitudinal population-based "LIFE Child"-cohort between 2011 and 2016 in Leipzig, Germany. 5238 blood samples of 2707 healthy children, aged between 0.14 months and 18 years, were analyzed.

RESULTS

Serum CK levels raised during the first year of life, peaking shortly after age one (P50girls = 2.7 µkat/L, P50boys = 2.90 µkat/L). There was a pronounced difference in the 97.5th percentile between boys and girls during adolescence with its maximum at age 18 (P97.5girls = 5.74 µkat/L, P97.5boys= 14.48 µkat/L). Also, mean CK serum levels were significantly higher in boys (bboys = 0.29, pboys < 0.001). Intake of oral contraceptives (OC), extreme underweight, underweight and obesity revealed a significant inverse correlation with CK serum levels.

CONCLUSION

Age, sex, OC intake and weight status affect serum CK levels, particularly during infancy and puberty. We recommend the use of age- and sex-specific reference values for CK serum levels to assess the clinical relevance of measurements.

Epigenetic inheritance of diet-induced and sperm-borne mitochondrial RNAs

Spermatozoa harbour a complex and environment-sensitive pool of small non-coding RNAs (sncRNAs)1, which influences offspring development and adult phenotypes1-7. Whether spermatozoa in the epididymis are directly susceptible to environmental cues is not fully understood8. Here we used two distinct paradigms of preconception acute high-fat diet to dissect epididymal versus testicular contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNAs (mt-tRNAs) and their fragments (mt-tsRNAs) as sperm-borne factors. In humans, mt-tsRNAs in spermatozoa correlate with body mass index, and paternal overweight at conception doubles offspring obesity risk and compromises metabolic health. Sperm sncRNA sequencing of mice mutant for genes involved in mitochondrial function, and metabolic phenotyping of their wild-type offspring, suggest that the upregulation of mt-tsRNAs is downstream of mitochondrial dysfunction. Single-embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tRNAs at fertilization and suggested their involvement in the control of early-embryo transcription. Our study supports the importance of paternal health at conception for offspring metabolism, shows that mt-tRNAs are diet-induced and sperm-borne and demonstrates, in a physiological setting, father-to-offspring transfer of sperm mitochondrial RNAs at fertilization.

Pediatric reference intervals for serum folate and cobalamin based on a European population without exposure to folic acid fortification

The aim of the present study was to define pediatric reference intervals for serum cobalamin and folate utilizing data generated from a population not exposed to food fortified with folic acid. Folate and cobalamin results analyzed by electrochemiluminescence immunoassay (Roche Cobas) were obtained from 2375 children (2 months to 17.99 years of age). The serum samples were collected between 2011 and 2015 as part of the LIFE (Leipzig Research Centre for Civilization Diseases) Child cohort study in Germany, where folic acid fortification of food is not mandated. These results were used to generate age- and gender-specific reference intervals presented as non-parametric 2.5 and 97.5 percentiles. Because of a subsequent restandardisation of the Roche folate assay in 2016, folate values were recalculated accordingly for adaptation to results obtained using the present calibration. In both genders, folate concentrations decreased continuously with age, whereas cobalamin concentrations peaked at five years of age and then declined. Teenage females had higher concentrations of cobalamin in the age group 12-17.99 years.

Relation between socioeconomic status and maternal serum lipids to infant lipid concentrations and anthropometry in the first year of life

PURPOSE

The physical health and development of an individual are influenced by multiple parameters and shaped by internal and external factors during pregnancy. However, it is unclear whether there is an association between maternal lipid concentrations in the third trimester of pregnancy and infant serum lipids as well as anthropometric growth, and whether these factors are influenced by the socioeconomic status (SES) of the mothers.

METHODS

Between 2011 and 2021, 982 mother-child pairs were recruited in the LIFE-Child study. To investigate the influence of prenatal factors, pregnant women at the 24th and 36th week of gestation as well as children at the age of 3, 6 and 12 months were examined and serum lipids determined. Socioeconomic status (SES) was assessed using the validated Winkler Index.

RESULTS

A higher maternal BMI was associated with a significantly lower Winkler score and a higher infant weight, height, head circumference and BMI from birth up to the 4th-5th week of life. In addition, the Winkler Index correlates with maternal HDL cholesterol and ApoA1 levels. There was no relation between the delivery mode and the maternal BMI or SES. For the maternal HDL cholesterol concentration in the third trimester, an inverse relation to children's height, weight, head circumference and BMI up to the first year of life as well as the chest and abdominal circumference to an age of 3 months was found. Children born to mothers with dyslipidemia in pregnancy tended to have a worse lipid profile than those born to normolipidemic mothers.

CONCLUSION

Serum lipid concentrations and anthropometric parameters of children in the first year of life are affected by multiple factors like maternal BMI, lipid levels and SES.

Parent-perceived recurrent pain in children: associations with maternal pain, depressiveness, socioeconomic status, and children's behavioural difficulties

Objectives

The current study aimed to examine the potential transgenerational associations between maternal pain and depressiveness and childhood pain, and to explore the associations between the children's difficulties and recurrent pain (defined as pain occurring at least once a month in the previous 6 month) in healthy children aged 3-13 years.

Methods

We collected Data between 2015 and 2019 as part of the LIFE Child study in Germany and investigated associations of maternal pain and depressiveness, child age, sex, pubertal stage, emotional difficulties, conduct difficulties, hyperactivity/inattention, peer group difficulties, and prosocial skills, and family socioeconomic status with the frequency of parent-perceived headache, backache, and stomachache in a sample of 1,850 children (4,819 documented visits) using logistic and ordinal regression analyses.

Results

Overall, 10.4%, 24.4%, and 45.2% of parents reported their children had recurrent backache, headache, and stomachache, respectively, with 5.5% of children were reported to experience all three types of pain simultaneously. Higher age, female sex, puberty, emotional difficulties, low family socioeconomic status, as well as higher maternal impairment due to pain and maternal depressiveness were significantly associated with more frequent pain.

Conclusions

Our study suggests that maternal pain, maternal depressiveness, and lower family socioeconomic status as well as child's emotional difficulties are significantly associated with a higher frequency of recurrent pain in children perceived by their parents.

Early child development and its determinants: Findings from a large cohort of healthy children growing up in a low-risk environment

BACKGROUND

Despite numerous studies on early child development, there is still much to be discovered about the significance of possible risk factors. This study examines cognitive, motor, and language development of healthy children growing up in a low-risk environment and how various individual and environmental factors are associated with it. The study also considers whether the importance of particular parameters changes depending on child age.

METHODS

Within the framework of the LIFE Child study in Leipzig, Germany, 481 children participated in a total of 832 visits between 1 and 36 months of age. Developmental status was assessed using the Third Edition of the Bayley Scales of Infant and Toddler Development. Linear regression analyses were applied to examine the associations between child development and sex, gestational age, birth weight, birth mode, overweight, height, and parental education.

RESULTS

Mean Bayley composite scores for cognitive, language, and motor development were close to the standard value of 100. Poorer developmental outcomes were significantly associated with lower gestational age, vacuum cup/forceps birth, being overweight, small height, and lower parental education, although some of the associations became insignificant after applying multivariate models. While the association between gestational age and language development became weaker with advancing age, our interaction models found disparities related to parental education to become more apparent in older children across all three domains of early child development.

CONCLUSIONS

Several factors were identified to be associated with early child development. As children grow older, obstetric parameters, for example, gestational age, might become less relevant compared with sociodemographic factors, for example, parental education.

Family structure, socioeconomic status, and mental health in childhood

The changing landscape of family structures over the last decades has led to a growing need to investigate its impact on children's well-being. This study examined differences in mental health among children from different family compositions and how these differences may be affected by familial socioeconomic status (SES). Data were collected within the LIFE Child study. Participants included 2828 children aged 3-17 years raised in traditional families, stepfamilies, or single-parent families. Mental health was measured using the Strengths and Difficulties Questionnaire (SDQ (behavioral strengths and difficulties)) and the KIDSCREEN-27 questionnaire (quality of life). Linear regression analyses were applied to examine associations between family structure, SES, and mental health outcomes. Children from single-parent families exhibited worse mental health outcomes than those from traditional families across all domains of the SDQ and the KIDSCREEN-27. Children from stepfamilies showed significantly higher Total Difficulties scores (B = 1.29 and 1.42), with 3- to 10-year-olds displaying higher scores in the Hyperactivity & Inattention (B = 0.61) and Peer Relationship Problems (B = 0.36) subscales, and 11- to 17-year-olds showing higher Conduct Problems (B = 0.31), Emotional Symptoms (B = 0.58), and a worse Parent Relationship scores (B = - 1.82) than children from traditional families (all p < 0.05). After controlling for SES, several associations between family structure and mental health lost significance, while others persisted, particularly among older children. To promote mental health in non-traditional families, interventions should address socioeconomic disparities while also investigating factors contributing to the direct impact of family structure on mental well-being.Trial registration The LIFE Child study is registered on clinicaltrials.gov (No. NCT02550236).

Bone turnover in lactating and nonlactating women

PURPOSE

During lactation, bone turnover increases, reflecting the mobilization of Calcium from maternal skeletal stores and resulting in bone loss. However, mechanisms are not yet fully understood, and previous studies have been comparatively small. We aim to assess bone metabolism during lactation by comparing bone-metabolism-related-parameters between large cohorts of lactating and nonlactating women.

METHODS

In a retrospective cohort study, we recruited 779 postpartum women and 742 healthy, nonpregnant, nonlactating controls. Postpartum women were examined 3 and 6 months after delivery and retrospectively assigned to either the exclusively breastfeeding (exc-bf) group if they had exclusively breastfed or the nonexclusively breastfeeding (nonexc-bf) group if they had not exclusively breastfed up to the respective visit. Serum levels of PTH, Estradiol, total Calcium, Phosphate, and bone turnover markers (ßCTX, P1NP, Osteocalcin) were compared between the groups.

RESULTS

Bone turnover markers were significantly increased in exc-bf and nonexc-bf women compared with the controls (all ps < .001). ßCTX was approximately twice as high in exc-bf women than in the controls. PTH levels were marginally higher in exc-bf (p < .001) and nonexc-bf women (p = .003) compared with the controls (6 months). Estradiol was suppressed in exc-bf women compared with the controls (p < .001, 3 months).

CONCLUSION

Exc-bf and even nonexc-bf states are characterized by an increase in bone formation and resorption markers. The PTH data distribution of exc-bf, nonexc-bf, and control groups in the underpart of the reference range suggest that lactational bone loss is relatively independent of PTH.

Body image and behavioural and emotional difficulties in German children and adolescents

BACKGROUND

Behavioural and emotional difficulties might play an important role in the development of body image disturbances, which represent serious risk factors for eating disorders or depression. The present study provides a detailed overview on body image disturbances and several behavioural and emotional difficulties (differences between gender, age, and weight status) and their inter-relations in German children and adolescents.

METHODS

Data on body image disturbances, assessed through a Figure Rating Scale, and on behavioural and emotional difficulties, assessed through Goodman's Strengths and Difficulties Questionnaire (SDQ), were available for 5255 observations of 1982 German children and adolescents aged 8 to 18 years from the LIFE Child study, based in Leipzig, Germany. Associations were investigated using multiple logistic regression. Each association was checked for interaction with gender, age, and weight status.

RESULTS

Boys reported more behavioural difficulties than girls, while girls reported more emotional difficulties. Gender, age and weight status were related to behavioural and emotional difficulties as well as body image disturbances. Individuals with fewer difficulties were more satisfied with their own body. Children and adolescents who desired to be larger showed more prosocial behaviour problems, conduct and emotional problems and more signs of hyperactivity. Those, who desired to be thinner showed more problems in all SDQ-subscales. A more accurate body size perception was associated with fewer behavioural and emotional difficulties. Children and adolescents who overestimated their body size showed more prosocial behaviour and emotional problems. Underestimation one's body size was associated with more signs of hyperactivity.

CONCLUSION

The current findings highlight the importance of raising the awareness about the association between behavioural and emotional difficulties and body image disturbances in children and adolescents to prevent negative outcomes.

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

Background and objectives

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).

Material and methods

Serum values, medical history and anthropometric data provided by 2522 children aged 0.25-18 years were collected and analyzed as per study protocol.

Results

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.

Conclusion

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.

Sex hormones associated with temporomandibular pain on palpation in male adolescents-Results of the epidemiologic LIFE child study

OBJECTIVE

This study aimed to investigate whether the sex steroid precursor hormone dehydroepiandrosterone sulphate (DHEA-S), sex hormone-binding globulin (SHBG) and testosterone (TT) are associated with temporomandibular (TM) pain on palpation in male adolescents.

METHODS

Out of the LIFE Child study dataset containing 1022 children and adolescents aged 10-18 years (496 males, 48.5%), we used a subsample of 273 male adolescents (mean age: 13.8 ± 2.3 years) in advanced pubertal development (PD) to analyse the association between hormones and TM pain. The Tanner scale was applied to describe the stage of PD. Pain on palpation of the temporalis and masseter muscles and the TM joints (palpation pain) was assessed using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum levels of sex hormones (DHEA-S, SHBG and TT) were determined using standardised laboratory analyses. Free TT was estimated from the ratio between TT and SHBG (free androgen index[FAI]). We calculated the risk of perceived positive palpation pain for male participants as a function of hormone levels (DHEA-S, FAI) taking into account age and body mass index (BMI).

RESULTS

Among more developed (Tanner stage 4-5) male adolescents, 22.7% (n = 62) reported palpation pain in the TM region. In these participants, FAI levels were approximately half that of individuals without such pain (p < .01). DHEA-S levels were about 30% lower in the pain group (p < .01). In multivariable regression analyses, the odds ratio (OR) for pain on palpation decreased to 0.75 (95% confidence interval [CI]: 0.57-0.98) per 10 units of FAI level compared to those without pain, after controlling for the effects of age and adjusted BMI. We observed the same effect for this subgroup per unit of DHEA-S serum level (OR = 0.71; 95% CI: 0.53-0.94).

CONCLUSION

At subclinical lower levels of serum free TT and DHEA-S, male adolescents are more likely to report pain on standardised palpation of the masticatory muscles and/or TM joints. This finding supports the hypothesis that sex hormones may influence pain reporting.

Novel Three-Dimensional Body Scan Anthropometry versus MR-Pelvimetry for Vaginal Breech Delivery Assessment

In this prospective, monocentric study, we investigated the potency of a novel three-dimensional (3D) body scanner for external pelvic assessment in birth planning for intended vaginal breech delivery. Between April 2021 and June 2022, 73 singleton pregnancies with intended vaginal birth from breech presentation (>36.0 weeks of gestation) were measured using a pelvimeter by Martin, a three-dimensional body scanner, and MR-pelvimetry. Measures were related to vaginal birth and intrapartum cesarean section. A total of 26 outer pelvic dimensions and 7 inner pelvic measurements were determined. The rate of successful vaginal breech delivery was 56.9%. The AUC (area under the curve) of the obstetric conjugate (OC) measured by MRI for predicting the primary outcome was 0.62 (OR 0.63; p = 0.22), adjusted for neonatal birth weight 0.66 (OR 0.60; p = 0.19). Of the 22 measured 3D body scanner values, the ratio of waist girth to maternal height showed the best prediction (AUC = 0.71; OR 1.27; p = 0.015). The best predictive pelvimeter value was the distantia spinarum with an AUC of 0.65 (OR = 0.80). The 3D body scanner technique is at least equal to predict successful vaginal breech delivery compared to MRI diagnostics. Further large-scale, prospective studies are needed to verify these results.

Tracking of serum lipids in healthy children on a year-to-year basis

OBJECTIVES

To assess the stability of lipid profiles throughout childhood and evaluate their onset and dynamic.

MATERIALS AND METHODS

Lipid markers were longitudinally measured in more than 1300 healthy children from the LIFE Child study (Germany) and categorized into normal, at-risk, or adverse. Year-to-year intra-person persistence of the categories during follow-ups was examined and Pearson's correlation coefficient was calculated.

RESULTS

We found strong positive correlations for TC, LDL-C and ApoB (r > 0.75, p < 0.001) from the age of four years. Correlations were lowest during the first two years of life. Most children with normal levels also had normal levels the following year. Children with at-risk levels showed a tendency towards normal levels at the follow-up visit. Adverse levels of TC, LDL-C, ApoB (all ages), and HDL-C (from age 15) persisted in more than half of the affected children. Age-dependent patterns of stability were most pronounced and similar for TC, LDL-C, and ApoB.

CONCLUSIONS

Normal levels of serum lipids show high stability and adverse levels stabilized in early childhood for TC, LDL, and ApoB. At-risk and adverse levels of TC, LDL-C or ApoB may warrant further or repeated diagnostic measurements with regards to preventing CVD in the long run.

Beyond dirty teeth: Integrating dental calculus studies with osteoarchaeological parameters

The study of ancient human dental calculus (mineralized dental plaque, also known as tartar) is becoming increasingly important in osteoarchaeology, human palaeoecology and environmental archaeology. Microremains of different origin (e.g. starch granules, pollen, phytoliths, feather barbules) as well as biomolecules and chemical compounds retrieved from its mineral matrix may represent an important link between past humans and their physical, biological and social environment, but they are rarely fully linked to the evidence from skeletal remains. This paper critically reviews the lines of evidence retrieved from dental calculus in relation to osteoarchaeological parameters, employing macroscopic, microscopic and biomolecular approaches, assessing synergy potential and limitations. The scope of this paper is also to contribute to the building of a much needed theoretical framework in this emerging subfield.

Active school transport in an urban environment:prevalence and perceived barriers

BACKGROUND

Active school transport (AST) can increase children's and adolescents' physical activity. The proportion of children and adolescents who engage in AST has declined internationally in recent decades. This study examines the prevalence, correlates, and perceived barriers to AST in the city of Leipzig, Germany.

METHODS

The study sample includes 1070 participants, 364 children and 706 adolescents, aged between 6 and 18 years, as well as their parents. The parents as well as adolescents age 10 and above completed questionnaires concerning sociodemographic variables, means of transport/AST and perceived barriers to AST. The distance between home and school was calculated as the network distance from the home to school address using the Dijkstra algorithm. Based on these data, logistic models were fitted in a two-step variable selection process, using AST as the dependent variable.

RESULTS

Approximately half of the children (59%) and adolescents (51%) engaged in AST. The prevalence of AST exhibited a negative correlation with age (Odds Ratio (OR) = 0.94, 95% confidence interval (CI) = 0.9-0.99, p = 0.015) and did not significantly differ by gender (children: OR_girls = 1.5, CI = 0.95-2.25, p = 0.075, adolescents: OR_girls = 1.01, CI = 0.75-1.37, p = 0.924). A high socioeconomic status was positively correlated to AST on the morning trip (OR = 1.7, CI 1.3-2.21, p < 0.01) but negatively on the afternoon trip (OR = 0.7, CI = 0.53-0.9, p < 0.01) in the summer. Common barriers for children (from their parents' perspective) and for adolescents (from their own and their parents' perspective) were distance and a heavy load to carry. The parents of adolescents did not perceive any other specific barriers as a serious impediment. Further significant barriers perceived by the younger children's parents were adults giving a lift on the way to other errands, no other children to walk or cycle with, and too much traffic. Too much traffic was also a significant barrier for adolescents, as were taking too much time and bad weather conditions.

CONCLUSIONS

Future interventions promoting AST in an urban environment should be guided by the identified perceived barriers.

TRIAL REGISTRATION

LIFE Child has been retrospectively registered with ClinicalTrials.gov (NCT02550236).

Pharmacoepidemiological Analysis of Oral Contraceptive Use in Adolescents in a German Longitudinal Cohort Study

To assess the use of oral contraceptives (OC) in adolescents, using data from a longitudinal, population-based pediatric cohort study (LIFE Child). We also investigated associations between OC use and socioeconomic status (SES), and associations between OC use and potential adverse drug reactions such as effects on blood pressure. We included 609 female participants of the LIFE Child cohort, aged ≥13 to <21 years, who visited the study center between 2012 and 2019. Data collection compromised drug use in the past 14 days, SES, and anthropometric data such as blood pressure. An analysis of covariance was used to detect potential associations between participants' blood pressure and OC. Multivariate binary logistic regression was used to obtain odds ratios (aOR) adjusted for age and 95% confidence intervals (95% CI). The prevalence of OC use was 25.8%. OC intake was less common in participants with a high SES (aOR 0.30, 95% CI 0.15, 0.62). The mean age at OC initiation did not change between 2012 and 2019. We observed an increased use of second-generation OC (2013: 17.9%, 2019: 48.5%; p = 0.013) and a decreased use of fourth-generation OC (2013: 71.8%, 2019: 45.5%; p = 0.027). We found a higher systolic (mean: 111.74 mmHg, p < 0.001) and diastolic (69.15 mmHg, p = 0.004) blood pressure in OC users compared to non-users (systolic: 108.60 mmHg; diastolic: 67.24 mmHg). Every fourth adolescent took an OC. The share of second-generation OC increased during the study period. OC intake was associated with low SES. OC users had a slightly higher blood pressure than non-users.

Mental health in children and adolescents with overweight or obesity

BACKGROUND

Overweight and obesity represent huge concerns for children's physical and mental well-being. This study examined the relationship between body mass index (BMI) and health-related quality of life (HRQoL), somatoform complaints, and behavioral problems in children and adolescents. Additionally, the influence of sex, age, and socioeconomic status (SES) on these associations was considered.

METHODS

In total, we studied 2350 participants between the ages of 4 and 18 years (1213 4- to 10-years-old (child sample) and 1137 11-to 18-year-olds (adolescent sample)). To assess HRQoL, somatoform complaints, and behavioral difficulties, we applied the KIDSCREEN-27, a short form of the Giessen Complaints Questionnaire, and the Strengths and Difficulties Questionnaire (SDQ). The BMI was transformed to BMI standard deviation scores (BMI-SDS), according to German gender- and age-specific reference data. Associations were investigated using linear regression analyses. Each association was checked for interaction with sex, age, and SES.

RESULTS

Regarding HRQoL, we found worsening scores in physical well-being and psychological well-being with increasing BMI-SDS. Somatoform complaints were not significantly associated with BMI-SDS. Conduct problems, peer relationship problems, and emotional problems (the latter only in the adolescent sample) were positively associated with BMI-SDS. While we did not observe any significant interactions with sex, we found some significant interactions with age and/or SES.

CONCLUSION

Our findings highlight the importance of mental difficulties in children and adolescents with higher BMI and, consequently, underline the relevance of including psychological interventions in the treatment of overweight or obesity.

Associations between Stressful Life Events and Increased Physical and Psychological Health Risks in Adolescents: A Longitudinal Study

Stressful life events (SLEs) are understood as risk factors for mental and physical health problems, particularly in the vulnerable period of adolescence. Using a longitudinal approach, this study investigated associations between SLE and several negative health outcomes in adolescents. Moderating effects of sociodemographic factors were considered. We analyzed the data of a healthy adolescent sample from the LIFE Child study in Leipzig, Germany (n = 2024, aged 10-18 years). SLEs were measured by a questionnaire, addressing SLEs in the family and the social environment domain. Health-related quality of life (HrQoL), behavioral difficulties and BMI were compared before and after an SLE had occurred. Moderator effects of socioeconomic status (SES), age, and sex were investigated using linear regression models. All considered health parameters had, on average, deteriorated after the occurrence of an SLE in the social environment. Differences in HrQoL before and after an SLE were significantly stronger in girls. Higher SES functioned as a slight protective factor against decreased well-being after an SLE. The findings suggest that SLEs function as risk factors for mental and physical health disadvantages in adolescents. Prevention programs should seek to support adolescents in all age and SES groups affected by SLEs, with a specific focus on girls.

The relationship between myopia and near work, time outdoors and socioeconomic status in children and adolescents

Background

To investigate environmental and social risk factors for myopia in children and adolescents in Germany.

Methods

1437 children aged between 3 and 18 inclusive were examined as part of the LIFE Child study based in Leipzig, Germany. Information about leisure time activities and social status was ascertained by parents and children in a questionnaire. Refractive status was attained by measuring noncycloplegic autorefraction. Myopia was defined as spherical equivalent (SE) ≤ − 0.75 D. Risk factors were identified using multiple logistic regression analysis.

Results

In multiple logistic regression analysis, myopia was significantly associated with less frequent outdoor activity (“once a week” vs. “twice a week or more”: odds ratio (OR) 4.35, 95% confidence interval (CI) 1.89–9.98, p<0.01) and longer near work sessions (1–2 h vs. < 1 h: OR 1.83, CI 1.10–3.04, p=0.02; > 3 h vs. < 1 h: OR 3.71, CI 1.43–9.61, p<0.01) after adjustment for age, sex and socioeconomic status (SES). Duration of outdoor activity, near work frequency and SES showed no significant association with myopia (p > 0.05). Children with a lower SES were involved in longer periods of outdoor and near work activities but on fewer occasions over the course of the week, although this connection was not significant.

Conclusion

Myopia is associated with environmental factors. The present findings suggest that daily exposure to sunlight and a restriction of long-duration near work activities might protect against pathological eye growth. Prevention strategies should be implemented for children at all ages.

Associations between sociodemographic and behavioural parameters and child development depending on age and sex: a cross-sectional analysis

OBJECTIVES

To explore environmental and individual factors that are associated with child development and to investigate whether the strength of these associations differs according to the age of the children.

DESIGN

Cross-sectional study.

SETTING

This study was part of the LIFE Child study, a large cohort study conducted in Leipzig, Germany.

PARTICIPANTS

778 children aged between 0.5 and 6 years (48.6% girls, mean age=2.67 years).

OUTCOME MEASURES

The outcomes were cognitive development, language development, body and hand motor skills, social-emotional development, and tracing skills, measured with a standardised development test. We analysed the associations between development and gestational age, socioeconomic status (SES), sex, behavioural difficulties, siblings, sleep duration, breastfeeding duration and overweight/obesity. We also tested for interactions between these variables and child age or sex.

RESULTS

Higher gestational age (b ranging between 0.12 and 0.26) and higher SES (b ranging between 0.08 and 0.21) were associated with better outcomes in almost all developmental domains (all p<0.019). Children with older siblings had improved body and hand motor skills compared with children without older siblings (both b=0.55, all p<0.029). Boys had poorer scores than girls in body and hand motor skills and tracing (b=-0.45, -0.68 and -1.5, all p<0.019). Children with behavioural difficulties had significantly poorer outcomes in most developmental domains. Some of the associations with SES and sex were stronger in older than in younger children. Associations between gestational age and motor development were weaker in older children. We did not find significant associations between child development and sleep duration, breastfeeding duration or overweight/obesity.

CONCLUSION

Some factors had a protective, others an adverse effect on development of children under 6 years of age. The effect of SES and sex increased, while the effect of gestational age decreased with age.

TRIAL REGISTRATION NUMBER

NCT02550236.

The Influence of Coordinative Skills on the Oral Health of Children and Adolescents in Permanent Dentition

Removing dental plaque by using a toothbrush is the most important measure for oral hygiene. The aim of the present study was to estimate the impact of the coordination skills of children and adolescents on their oral health (plaque level, DMF/T: decayed, missing, filled teeth). Within a prospective cohort study, 996 children (10 to 18 years) were examined. The results of three coordination tests from the Motorik Modul (MoMo) were included to evaluate the coordination skills. Other parameters taken into account were age, sex, orthodontic treatment and socioeconomic status (SES). Univariate and various multivariate analyses were performed to evaluate relationships. Better results in precision coordination tests were significantly related to a better oral hygiene (backward balancing: logistic regression OR 0.86, 95%CI: 0.73−0.99, p = 0.051, proportional odds model OR 0.86, 95%CI: 0.75−0.99, p = 0.037; one-leg-stand: logistic regression OR 0.78, 95%CI: 0.63−0.96, p = 0.018, proportional odds model OR 0.77, 95%CI: 0.64−0.92, p = 0.003). Higher scores on one-leg-stand were significantly related to a lower caries prevalence (logistic regression OR 0.81, 95%CI: 0.66−0.99, p = 0.037; Poisson regression exp(ß) 0.82, 95%CI: 0.74−0.91, p < 0.001). Coordination test under a time constraint (jumping side-to-side) showed no significant relation. Oral hygiene was poorer in younger children, boys and low SES. Caries prevalence increased with low SES and increasing age. The present results suggest that oral health is influenced by coordinative skills.

Association between hair cortisol concentration and behavioral difficulties in children and adolescents

This study aimed to assess associations between behavioral difficulties and an objectively measurable indicator for long-term stress (hair cortisol) in children and adolescents. We expected increased hair cortisol levels in participants with more externalizing (conduct problems, hyperactivity/inattention) or internalizing (peer relationship problems, emotional problems) behavioral difficulties. Behavioral difficulties were assessed using the parent version of the Strengths and Difficulties Questionnaire (SDQ). Hair cortisol concentration (HCC), measured via liquid chromatography mass spectrometry (LC-MS3), was used as stress marker. A 1 cm strand of hair was cut off from the occipital or parietal cranium closest to the scalp. The study sample comprised 1321 children and adolescents aged between 3 and 17 years participating in the LIFE Child cohort study (Leipzig, Germany). To assess associations, we applied multiple linear regression analyses. Only a few associations met expectations, others contradicted our hypotheses. No association reached statistical significance. The present findings may suggest that behavioral difficulties gathered by SDQ are not associated with stress measured through HCC.

Having siblings promotes a more healthy weight status—Whereas only children are at greater risk for higher BMI in later childhood

Background

Birth order and having at least one sibling are known to be associated with an increased risk for development of overweight. However, there are no studies assessing pre- and postnatal factors for developing overweight within families. Therefore, the present study aimed to analyse the association of the mother’s weight gain during pregnancy, prepregnancy BMI, mother’s age at birth, breastfeeding, age gap between siblings, and physical activity together with sibling-related characteristics on the development of overweight in children and adolescents.

Methods

Data were obtained from the longitudinal LIFE Child cohort. The study sample included n = 1932 children, stratified into first-born (n = 578), second-born (n = 608), third-or-later-born single-born siblings (n = 162), only children (n = 526), and twin children (n = 58). Children with chronic or syndromic diseases, born prematurely or from mothers with gestational diabetes were excluded. Data were adjusted for multiple children per family using mixed models. Pregnancy weight gain, prepregnancy BMI and mother’s age were considered prenatal co-variates. Postnatal factors included the duration of breastfeeding and the children’s physical activity level.

Results

Particularly until the onset of puberty, the BMI-SDS differed between single-born siblings, only children and twins, and increased with birth order. Compared to children with siblings, only children exhibited a strong increase in BMI-SDS starting at age nine. A higher age gap between siblings was associated with a higher BMI-SDS in second- and third-or-later-born children. Single-born siblings had the highest rate and duration of breastfeeding. Physical activity was highest in twins and third-or-later-born children and lowest in only children. In a multivariate model, being an only child showed a highly significant association with BMI-SDS.

Conclusion

The present study demonstrated that siblings had a lower BMI-SDS than only children did. For single-born siblings, the association between birth order and increased BMI-SDS seemed to persist only up to 11 years of age.

The Influence of Steroid Hormones on Tooth Wear in Children and in Adolescents

(1) Background: From a young age, boys are more often affected by tooth wear than girls. This suggests an influence of the male sex hormone (testosterone) on the aetiology of tooth wear. The aim of the present study was to investigate the incidence of tooth wear in relation to steroid hormone levels in children. (2) Methods: 1022 test persons aged between 10 and 18 (491 male, 531 female) from the LIFE Child study underwent medical and dental examination. Tooth wear was measured through clinical inspection. Blood samples were taken to determine hormone levels (testosterone, SHBG). The level of free testosterone was calculated from the ratio of testosterone to SHBG. Using multivariable methods, the incidence of tooth wear was analyzed as a function of hormone levels, while controlling for confounders such as age, sex, social status, and orthodontic treatment. (3) Results: The incidence of tooth wear increased with age in both sexes. Boys showed significantly more often attrition facets than girls (17.5% vs. 13.2%, p < 0.001). Subjects with tooth wear showed significantly higher free testosterone levels than those without (males: p < 0.001, females: p < 0.05). After controlling for confounding variables, the risk of tooth wear increased by approximately 30.0% with each year of life (odds ratio [OR]boys = 1.29, 95% confidence interval [CI] = 1.04−1.56; [OR]girls = 1.32, 95% CI = 1.08−1.61). In addition, the risk of tooth wear increased by 6.0% per free testosterone scale score only in boys (OR = 1.06, 95% CI = 1.01−1.12). (4) Conclusions: Tooth wear is common in children and in adolescents, and it increases steadily with age in both sexes. The stronger increase and the higher prevalence among male adolescents can be explained by the additional effect of free testosterone.

Arsenic exposure from drinking water and endothelial dysfunction in Bangladeshi adolescents

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide, with ∼80% of CVD-related deaths occurring in low- and middle-income countries. Growing evidence suggests that chronic arsenic exposure may contribute to CVD through its effect on endothelial function in adults. However, few studies have examined the influence of arsenic exposure on cardiovascular health in children and adolescents. To examine arsenic's relation to preclinical markers of endothelial dysfunction, we enrolled 200 adolescent children (ages 15-19 years; median 17) of adult participants in the Health Effects of Arsenic Longitudinal Study (HEALS), in Araihazar, Bangladesh. Participants' arsenic exposure was determined by recall of lifetime well usage for drinking water. As part of HEALS, wells were color-coded to indicate arsenic level (<10 μg/L, 10-50 μg/L, >50 μg/L). Endothelial function was measured by recording fingertip arterial pulsatile volume change and reactive hyperemia index (RHI) score, an independent CVD risk factor, was calculated from these measurements. In linear regression models adjusted for participant's sex, age, education, maternal education, land ownership and body weight, individuals who reported always drinking water from wells with >50 μg/L arsenic had a 11.75% lower level of RHI (95% CI: -21.26, -1.09, p = 0.03), as compared to participants who drank exclusively from wells with ≤50 μg/L arsenic. Sex-stratified analyses suggest that these associations were stronger in female participants. As compared to individuals who drank exclusively from wells with ≤50 μg/L arsenic, the use of wells with >50 μg/L arsenic was associated with 14.36% lower RHI (95% CI: -25.69, -1.29, p = 0.03) in females, as compared to 5.35% lower RHI (95% CI: -22.28, 15.37, p = 0.58) in males for the same comparison. Our results suggest that chronic arsenic exposure may be related to endothelial dysfunction in adolescents, especially among females. Further work is needed to confirm these findings and examine whether these changes may increase risk of later adverse cardiovascular health events.

Associations between problematic smartphone use and behavioural difficulties, quality of life, and school performance among children and adolescents

BACKGROUND

European studies on determinants and factors associated with problematic smartphone use (PSU) in children and adolescents are still sparse. This study reports the current amount of PSU symptoms and the presence of (clinically relevant) PSU in German children and adolescents. We also investigated associations between socio-demographic factors, different smartphone usage patterns, and daily smartphone usage time and the amount of PSU symptoms in this group. In addition, associations of PSU symptoms and high smartphone usage times (> 2 h/day) with behavioural problems, quality of life (QoL), and school performance were investigated.

METHODS

Within the framework of the LIFE Child study, 564 children and adolescents aged 10-18 years provided information on PSU symptoms (using the Smartphone Addiction Proneness Scale), daily smartphone usage time, smartphone activities, behavioural strengths and difficulties (using the Strengths and Difficulties Questionnaire), QoL (using the KIDSCREEN-27), and school performance. Multiple regression analyses were applied to assess associations.

RESULTS

In the present sample, PSU was present in 13 children (2.3%). Older age, female gender, high daily smartphone usage time of > 2 h, and intensive smartphone use for social networking, gaming, or watching video clips were significantly associated with more PSU symptoms. Children and adolescents reporting more PSU symptoms also showed lower QoL, more behavioural difficulties, and poorer school performance, independently of age, gender, socio-economic status, and daily smartphone usage time. In contrast, daily smartphone usage time per se showed only weak or non-significant associations with these aspects of health and behaviour.

CONCLUSION

Intensive smartphone use for entertainment may increase the risk of developing PSU symptoms. Furthermore, the results indicate that PSU symptoms (more than long smartphone usage times per se) are associated with more behavioural difficulties and poorer QoL.

Association of Oral Health Conditions in Adolescents with Social Factors and Obesity

This study aimed to investigate associations between psychosocial factors, obesity, and oral health in a study population of 10- to 18-year-old adolescents who participated in the LIFE Child study. Psychosocial information (socioeconomic status (SES) based on parents’ education, occupation and household income, Strengths and Difficulties Questionnaire (SDQ), health-related quality of life) and physical activity behavior were obtained. Nutritional status was classified based on age- and sex-adjusted body mass index into underweight, overweight, normal weight and obese. Clinical dental examinations were performed and scored with respect to caries experience (CE), oral hygiene (OH), and periodontal status (periodontal health score: PERIO-S). Age-adjusted regression analysis under the assumption of a double Poisson distribution was performed with and without adjusting for SES (α = 5%). A total of 1158 study participants (590 girls, 568 boys; mean age 13.2 ± 2.3 years) were included (17.2% were classified as obese). CE was 20% higher for moderate and 60% higher for low SES compared to high SES (p < 0.05). PERIO-S was 10% higher for moderate and 30% higher for low compared to high SES (p < 0.05). Poor OH was associated with higher CE (Ratio R = 2.3, p < 0.0001) and PERIO-S (R = 3.1, p < 0.0001). Physical activity in a sports club was associated with lower CE-S and PERIO-S (R = 0.85, p < 0.001). Obesity was associated with increased CE (R = 1.3, p < 0.001) compared to normal weight. For low but not high SES, more reported difficulties were associated with higher CE. In conclusion, low SES, poor OH, and obesity are associated with unfavorable oral health conditions, whereas physical activity and high SES are potentially protective.

Substance use in childhood and adolescence and its associations with quality of life and behavioral strengths and difficulties

BACKGROUND

Substance use in childhood and adolescence continues to be a current health concern. The aims of the present study were to identify trends in the use of alcohol, cigarettes, and cannabis in children and adolescents in the last 10 years and to assess associations between substance use and quality of life and behavioral strengths and difficulties.

METHODS

Substance use was examined in 1829 9- to 18-year-old German children and adolescents participating in the LIFE Child cohort study between 2011 and 2020. Quality of life was investigated using the KIDSCREEN-27 questionnaire. The Strength and Difficulties Questionnaire was used to assess behavioral strengths and difficulties. Associations were assessed using linear regression analyses. All effects were adjusted for age, gender, and family socio-economic status.

RESULTS

38.44% of participants reported drinking alcohol at least sometimes. Smoking (6.23%) and the use of cannabis (3.94%) were less frequent. While we observed no significant changes in smoking between 2011 and 2021, the consumption of cannabis and the frequent consumption of alcohol has increased in this time period. Cigarette and cannabis use were associated with additional symptoms of hyperactivity/inattention and reduced prosocial behavior. For all three substances, usage was associated with more conduct problems. We also found significant associations between substance use and a lower quality of life in the areas of physical wellbeing, psychological wellbeing, parent relation and autonomy, and school environment. One noteworthy finding was that cigarette consumption and frequent alcohol use were associated with higher quality of life in terms of social support/peer group relations. Some significant interactions between substance use and child age indicated that associations between substance use and quality of life or behavioral difficulties were stronger in younger than in older children.

CONCLUSIONS

The results show that quality of life and behavioral difficulties are associated with substance use and should be considered when developing or implementing preventive measures to counter substance use. Furthermore, the findings indicate that substance use can be accompanied by improved peer relations. Therefore, the influence of peers, especially of peers who use these substances, should not be underestimated.

Socioeconomic Status Is Related to Pubertal Development in a German Cohort

INTRODUCTION

Current health literature suggests that there has been a decline in the age of pubertal onset and that pubertal onset/duration of puberty may, besides weight status, be influenced by socioeconomic context.

OBJECTIVE

The goal of this study was to determine whether pubertal onset/duration and puberty-triggering hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH) vary according to socioeconomic status (SES). Moreover, we aimed to propose cutoff values of serum LH and FSH for predicting gonadarche in boys.

METHODS

2,657 apparently healthy children and adolescents between 5.5 and 18 years from the area of Leipzig were recruited from the LIFE Child study. Age at pubertal onset/end of puberty was given in 738/573 children, respectively. Anthropometric parameters of puberty, blood measurements of LH and FSH, and questionnaires assessing SES were evaluated.

RESULTS

Lower SES was associated with earlier thelarche and longer duration of puberty in overweight/obese girls, whereas age of menarche was not affected. In boys with low SES, a trend versus earlier puberty onset can be seen. Lower SES was significantly associated with boys' age at mutation. No significant differences in boys' and girls' serum levels of LH and FSH during puberty according to SES were observed. Serum LH levels of 0.56 IU/L and serum FSH levels of 1.74 IU/L showed the best prediction of gonadarche in boys.

CONCLUSION

Puberty onset/duration and boys' age at mutation is affected by SES. The proposed cutoff levels for serum LH and FSH could provide a serological tool to determine gonadarche in boys.

Reference centiles based on year-to-year changes for a longitudinal evaluation of motor performance in children and adolescents

Objectives

The aim was to evaluate the longitudinal course of motor skills development in children with a view to improve the understanding of intra-individual variance. Previous publications have been based on cross-sectional data or analyzed longitudinal studies in a cross-sectional manner.

Design

Longitudinal. Year-to-year change.

Methods

The present study is based on motor function data collected in the LIFE Child study (Germany). The participants (6 to 17 years) completed parts of the motor tests according to the standard of the German Motor Performance Test 6–18 (DMT). For a total of 1653 participants, 4616 motor tests with an annual interval in the period 2011 to 2019 were included in the evaluation.

Results

We were able to produce gender and age-specific change centiles for the test items standing long jump, jumping sideways, push-ups, stand and reach and balancing walking backwards. Each set of centiles revealed a range of variability in motor development in children and adolescents, with distinct progressive patterns in the different test items and different genders. The supplied tables offer an indication of expected year-to-year change for each test item depending on age and gender. Depending on the test item and the mean age, a deterioration in test results after a one-year interval was observed, despite cross-sectional centiles showing an upward trend.

Conclusion

We present a user-friendly tool as a way to assess individual dynamic changes in motor development of children and adolescents. In combination with the well-known cross-sectional centiles as baseline, this can be helpful for the scientific evaluation of motor skills tests and can also be used in school settings.

Medicine and supplement use in infants, children, and adolescents depends on sex, age, and socioeconomic status: results of a German longitudinal population-based cohort study (LIFE Child)

Children and adolescents are exposed to medicines and supplements, but only a few studies have evaluated the actual intake in routine care. Thus, we performed a pharmacoepidemiological evaluation of a longitudinal population-based pediatric cohort study (LIFE Child) conducted at the University Hospital of Leipzig between 2014 and 2019. We analyzed all visits of the participants of the LIFE Child cohort between 1 January 2014 and 31 December 2019. Participants were asked to bring their medicines and supplements to their appointments at the study center. If they had not brought the preparations with them, attempts were made to obtain the relevant information during a telephone call after the visit to the study center. Furthermore, the participants and their parents were interviewed on medicine and supplement use and on sociodemographic and socioeconomic data during their visit to the study center. Associations of medicine and supplement use with age, sex, and socioeconomic status were analyzed using multivariate binary logistic regressions to obtain adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). Furthermore, the number of the respective visit was included as possible confounder in the multivariate model. We included 3602 participants who visited the study center 11,906 times. The intake of 9759 medicines and supplements was recorded. Based on the evaluation of all study visits, 49% of the children and adolescents took at least one medicine or supplement. Self-medication accounted for 28% of the medicines and supplements. The prevalence of overall intake increased from 45% in 2014 to 53% in 2019 (aOR 2.63, 95% CI 2.23, 3.09). The prevalence was the highest (77%) in children aged 0- < 3 years, owing mainly to vitamin D. The prevalence of medicine use was higher in females (40%; aOR 1.18, 95% CI 1.10, 1.28) than in males (35%), owing mainly to the intake of ibuprofen and hormonal contraceptives in adolescent females. A high socioeconomic status was a predictor of lower medicine (aOR 0.80, 95% CI 0.68, 0.95) and higher supplement (aOR 1.47, 95% CI 1.09, 1.98) use.

CONCLUSION

Half of all children and adolescents took at least one medicine or supplement. The intake varied depending on age and sex. Furthermore, high socioeconomic status was associated with a decreased probability of medicine intake.

WHAT IS KNOWN

• Half of all children and adolescents in Germany are exposed to medicines and supplements. • Data on the actual intake are scarce as most studies focus on prescribed medicines.

WHAT IS NEW

• The prevalence of medicine/supplement use rose from 2014 (45%) to 2019 (53%). The prevalence was age-dependent: it was the highest in children aged < 3 years, and the lowest in children aged 6-< 9 years. Females took medicines more frequently than males. • High socioeconomic status was associated with lower medicine and higher supplement use. Self-medication accounted for 28% of all preparations.

Cystatin C relates to metabolism in healthy, pubertal adolescents

INTRODUCTION

The cystatin C (CysC) serum level is a marker of glomerular filtration rate and depends on age, gender, and pubertal stage. We hypothesize that CysC might overall reflect energy homeostasis and be regulated by components of the endocrine system and metabolites in pubertal adolescents.

METHODS

Serum CysC levels and further possible effector parameters in 5355 fasting, morning venous blood samples from 2035 healthy participants of the LIFE Child cohort study (age 8 to 18 years) were analyzed. Recruitment started in 2011, with probands followed up once a year. Linear univariate and stepwise multivariate regression analyses were performed.

RESULTS

Annual growth rate, serum levels of thyroid hormones, parathyroid hormone, insulin-like growth factor 1, hemoglobin A1c (HbA1c), uric acid, and alkaline phosphatase show relevant and significant associations with CysC serum concentrations (p <0.001). Furthermore, male probands' CysC correlated with the body mass index and testosterone among other sexual hormones. Multivariate analyses revealed that uric acid and HbA1c are associated variables of CysC independent from gender (p <0.001). In males, alkaline phosphatase (p <0.001) is additionally significantly associated with CysC. Thyroid hormones show significant correlations only in multivariate analyses in females (p <0.001).

CONCLUSIONS

The described associations strongly suggest an impact of children's metabolism on CysC serum levels. These alterations need to be considered in kidney diagnostics using CysC in adolescents. Additionally, further studies are needed on CysC in children.

Pediatric percentiles for transient elastography measurements - effects of age, sex, weight status and pubertal stage

BACKGROUND AND AIMS

Transient Elastography is a non-invasive, cost-efficient, non-ionizing, observer-independent and reliable method to detect liver fibrosis using Liver Stiffness Measurement (LSM) and the degree of fat accumulation in the liver using Controlled Attenuation Parameter (CAP). This study aims to derive reference values for both measures from healthy children and adolescents. Further, we aim to assess the potential influence of age, sex, puberty, and BMI-SDS on CAP and LSM.

METHODS

Within the LIFE Child study, amongst others, anthropometric data and pubertal status were assessed. Transient Elastography (TE) was performed using the FibroScan^® device in a population-based cohort at 982 study visits of 482 healthy children aged between 10 and 18 years. Percentiles for LSM and CAP were estimated, and the effects of age, sex, puberty and weight status were assessed through hierarchical regression models.

RESULTS

There was a strong age dependency for LSM with higher values for older children, most pronounced in the upper percentiles in boys. Contrarily, CAP was relatively stable across the age span without considerable difference between boys and girls. We found a significant positive correlation between BMI-SDS and both CAP and LSM for BMI-SDS >1.28. For BMI-SDS < 1.28, the association was also positive but reached statistical significance only for CAP. Further, the association between BMI-SDS and CAP was significantly stronger in younger than in older children. There was no association between pubertal status and CAP. For LSM, we found that children with a high BMI-SDS but not children with normal weight had significantly higher LSM values in Tanner stage 4.

CONCLUSIONS

Age, sex, pubertal status and weight status should be considered when interpreting LSM and CAP in pediatric patients to facilitate and improve early detection of abnormal liver function, which is associated with common pathologies, such as NAFLD.

Associations of media use and early childhood development: cross-sectional findings from the LIFE Child study

BACKGROUND

Excessive media usage affects children's health. This study investigated associations between children's and mother's media use, parent-child interactions, and early-childhood development outcomes.

METHODS

Two hundred and ninety-six healthy 2-5-year-old preschoolers (52.4% male, mean age = 3.5 years) and 224 mothers from the LIFE Child cohort study were analyzed. Screen times and parent-child interactions were assessed using standardized parental questionnaires. Developmental skills were investigated using the standardized development test ET 6-6-R.

RESULTS

High screen times in children (>1 h/day) were significantly associated with lower percentile ranks in cognition (b = -10.96, p < 0.01), language (b = -12.88, p < 0.01), and social-emotional skills (b = -7.80, p = 0.05). High screen times in mothers (>5 h/day) were significantly associated with high media use by children (OR = 3.86, p < 0.01). Higher parent-child interaction scores were significantly associated with better body motor (b = 0.41, p = 0.05), cognition (b = 0.57, p < 0.01), language (b = 0.48, p = 0.02), and social-emotional outcomes (b = 0.80, p < 0.01) in children.

CONCLUSIONS

Public health strategies should seek to educate caregivers as competent mediators for their children's media habits, with focus on the need for children to have frequent parent-child interactions.

IMPACT

High media usage in children is related to poorer cognition, language, and social-emotional skills. More frequent parent-child interactions are associated with better body motor, cognition, language, and social-emotional skills in children. High level of media use in mothers is not directly related to children's development outcomes but is directly related to high media usage of children. Public health strategies should seek to raise media awareness and management in both parents and children.

Age-Dependent Reference Values for hs-Troponin T and NT-proBNP and Determining Factors in a Cohort of Healthy Children (The LIFE Child Study)

This study aimed to provide reliable pediatric reference values for N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitive Troponin T (hsTnT) obtained from a population of well children and investigate for associations with sex, pubertal status, body mass index (BMI), and serum lipid levels. We analyzed hsTnT and NT-proBNP values obtained from 4826 samples provided by 2522 children aged 0.25-18 years participating in a prospective longitudinal population-based cohort study, "LIFE child" in Leipzig, Germany (Poulain et al., Eur J Epidemiol 32:145-158, 2017). NT-proBNP values decreased throughout childhood from values over 400 ng/L at 3 months to 138 ng/L in females and 65 ng/L in males by 18 years of age. Values dropped rapidly with advancing pubertal stage. We found a strong association between lower NT-proBNP values and higher BMI or elevated serum lipids, the latter effect being more pronounced in males. For hsTnT levels, approximately half of the measurements were below the detection limit. However, 76% of those aged 3 months and 21% of those aged 6 months had values exceeding the adult cut-off limit. Females had slightly higher levels in the first 2 years of life but this was reversed during puberty. In males, there was an upward trend from pubertal stage 2 onward. We identified a positive association between hsTnT and BMI but a negative association with low-density lipoprotein (LDL) cholesterol and triglyceride levels in boys but not in girls. Based on a large number of healthy children, we have established reliable reference values for NT-proBNP and hsTnT for use in everyday clinical practice. We have also identified important associations between certain metabolic and cardiac markers.Clinical Trial Registration ClinicalTrial.gov (NCT02550236).

Composition and Culture of Eating (CoCu) pregnancy: a new short questionnaire to evaluate diet composition and culture of eating during pregnancy

OBJECTIVE

The project aimed to validate a short questionnaire (CoCu pregnancy - Composition and Culture of Eating during pregnancy) and to investigate associations with age and socio-economic status (SES).

DESIGN

The questionnaire was developed according to the validated CoCu for children and adolescents containing a diet composition (fourteen items) and a culture of eating part (six items). A Nutritional Health Score (NHS) was calculated based on diet composition (-120 and +120, with higher scores indicating healthier diets). The validity was assessed by comparing answers in CoCu pregnancy with a FFQ. In a subsample (n 97), we assessed the percentage of having chosen the same (or adjacent) response categories in the 24th and 36th week of pregnancy (wp).

SETTING

Data were collected within the LIFE Child study in Leipzig, Germany.

PARTICIPANTS

We evaluated 430 questionnaires of pregnant women (24th wp).

RESULTS

The results indicated a healthy diet in the present sample (NHS at 24th wp = 49·74 (95 % CI 47·27, 52·22)). The analyses revealed significant positive correlations between CoCu and FFQ (rho ranging from 0·32 to 0·61). For each food item, >90 % of women had chosen the same (50-60 %) or adjacent response categories in the 24th and 36th wp. The analysis revealed associations of the NHS with age (β = 0·11, P = 0·027), SES (β = 0·21, P < 0·001), snacking (β = -0·24, P < 0·001) and media use (β = -0·18, P < 0·001).

CONCLUSIONS

The questionnaire represents a useful tool for surveying the diets during pregnancy for research and clinical practice.

Concentrations of oligosaccharides in human milk and child growth

BACKGROUND

The relationship between human milk oligosaccharides (HMO) and child growth has been investigated only insufficiently with ambiguous results. Therefore, this study examines potential influencing factors of HMO concentrations and how HMO are associated with child growth parameters.

METHODS

Milk samples from the German LIFE Child cohort of healthy children were analyzed for 9 HMO. Putative associations with maternal and child cofactors and child height, head circumference and BMI between 3 months and 7 years of age were examined. Secretor status, defined as the presence of 2'-fucosyllactose, was investigated for associations with infant outcomes.

RESULTS

Our population consisted of 21 (14.7%) non-secretor and 122 (85.3%) secretor mothers. Maternal age was significantly associated with higher 3'SL concentrations; gestational age was associated with LNT, 6'SL and LNFP-I. Pre-pregnancy BMI was negatively associated with LNnT only in non-secretors. The growth velocity of non-secretors' children was inversely associated with LNnT at 3 months to 1 year (R = 0.95 [0.90, 0.99], p = 0.014), 1 to 2 years (R = 0.80 [0.72, 0.88], p < 0.001) and 5 to 6 years (R = 0.71 [0.57, 0.87], p = 0.002). 2'FL was negatively associated with BMI consistently, reaching statistical significance at 3 months and 4 and 5 years. Children of non-secretors showed higher BMI at 3 months, 6 months, and 3, 6, and 7 years of age.

CONCLUSION

We found that some associations between HMO and infant growth may extend beyond the infancy and breastfeeding periods. They highlight the importance of both maternal and infant parameters in the understanding of the underlying associations.

TRIAL REGISTRATION

The study is registered with ClinicalTrial.gov: NCT02550236 .

Age-Related Association of Calcitonin with Parameters of Anthropometry, Bone and Calcium Metabolism during Childhood

INTRODUCTION

The thyroid parafollicular hormone calcitonin (CT) shows particularly high blood levels in early childhood, a period of high bone turnover, which decrease with increasing age. Data about the physiological role of CT during infancy, childhood, and adolescence are contradictory or lacking.

OBJECTIVE

We hypothesize that CT demonstrates age-related correlations with parameters of bone growth and turnover as well as with parameters of calcium homeostasis.

METHODS

5,410 measurements of anthropometric data and venous blood samples were collected from 2,636 participants of the LIFE Child study, aged 2 months-18 years. Univariate correlations and multiple regression analysis were performed between serum CT and anthropometric indicators (height standard deviation scores [SDS] and BMI-SDS), markers of calcium (Ca) homeostasis (Ca, parathyroid hormone, 25-OH vitamin D, and phosphate [P]), bone formation (procollagen type 1 N-terminal propeptide [P1NP], osteocalcin), and bone resorption (β-CrossLaps).

RESULTS

CT was significantly associated with Ca (β = 0.26, p < 0.05) and P1NP/100 (β = 0.005, p < 0.05) in children aged 2 months-1.1 years. These relations were independent of age and sex and could not be confirmed in children aged 1.1-8 years. Independent of age, sex, puberty, P, and height SDS CT showed a significant positive relation to Ca (β = 0.26; p < 0.001) in children aged 8-18 years.

CONCLUSIONS

Our findings suggest a unique association between CT and Ca in periods of rapid bone growth and point to a possible involvement of CT in promoting bone formation during the first year of life.

Maternal depressive symptoms and stress during pregnancy as predictors of gestational age at birth and standardized body mass index from birth up to 2 years of age

Background

While depressive symptoms and stress during pregnancy are known to affect gestational age and weight at birth, evidence on their impact on child anthropometric development in the long term remains limited, showing inconsistent effects. Importantly, previous research indicated a substantially stronger impact of categorically rather than dimensionally assessed mental health problems on birth outcomes and child development.

Methods

The Patient Health Questionnaire was used to assess depressive symptoms and stress during the 2nd trimester of pregnancy dimensionally and categorically, with scores ≥10 indicating clinical significance. Gestational age at birth and BMI-SDS from birth up to 2 years of age were examined as dependent variables. Structural equation modeling was used to examine the prediction of birth outcomes and child anthropometry by mental health problems while controlling for multiple maternal and child characteristics in 322 mother-child dyads.

Results

Dimensionally assessed mental health problems did not significantly predict birth outcomes. While categorical depressive symptoms significantly predicted a higher child BMI-SDS, categorical stress significantly predicted a lower gestational age at birth. Neither categorical nor dimensional mental health problems significantly predicted child BMI-SDS at 6, 12, and 24 months postpartum.

Conclusions

Depressive symptoms and stress during pregnancy seem to differentially affect birth outcomes, and only if clinically relevant. The results implicate the importance to timely treat pregnant women that are greatly affected by mental health problems to potentially reduce adverse birth outcomes.

Changes in diet from pregnancy to one year after birth: a longitudinal study

Background

Pregnancy and the first year after giving birth are marked by physiological and psychological changes. While it is well known that energy requirements change during this time, the question of how a woman’s diet actually changes from pregnancy until 1 year postpartum has been left virtually unexplored. The present study employs a longitudinal design to investigate these changes.

Methods

Data were collected within the framework of the LIFE Child study (Leipzig, Germany). The diet composition and culture of eating of 110 women were assessed at 3 time points: in the 24th week of pregnancy, 3 months after giving birth (breastfeeding period), and 12 months after giving birth (after weaning). We assessed differences in nutritional health (Nutritional Health Score, NHS) and the consumption of different food items at each of these time points. We also investigated associations between nutritional health and age, socio-economic status (SES), BMI before pregnancy, and previous births at all three time points.

Results

The analyses revealed high correlations in the NHS values between the three time points (rho_t0/t1 = .55, rho_t0/t2 = .60). On average, nutritional health was lower in the breastfeeding period than during pregnancy. In more detail, women reported less healthy levels of treats and white bread consumption and a higher frequency of snacking in the breastfeeding period than during pregnancy. In contrast, overall nutritional health did not differ significantly between pregnancy and the time after weaning. Increased age was associated with a healthier diet during pregnancy, and a high SES was associated with healthier diet after weaning. Furthermore, the increase in nutritional health from the breastfeeding period to the time after weaning was significantly stronger in women with a higher BMI. We observed no significant associations between dietary nutritional health and previous births.

Conclusions

The present findings suggest that higher energy requirements in the breastfeeding period are met by consuming high-calorie and unhealthy food products rather than healthy and nutrient-rich food. Young mothers should be supported in taking care of their own nutritional health during the challenging time of breastfeeding and caring for a newborn child.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04038-3.

Associations of prenatal exposure to phthalates and one phthalate substitute with anthropometric measures in early life: Results from the German LIFE Child cohort study

Exposure to phthalates is widespread and especially early life stages represent a critical window of exposure. In the present study, we investigated the effect of prenatal exposure to phthalates on birth outcomes and weight development in early life. In 130 mother-child pairs, we estimated the association of concentrations of 13 phthalates in spot-urine samples collected during pregnancy and birth outcomes and weight gain in the first two years of life using robust linear regression. High molecular weight phthalates were inversely associated with birth weight in girls but not in boys. Thus, prenatal exposure to phthalates may affect birth weight in a sex-specific manner.

Pediatric Reference Intervals for Thyrotropin, Free Triiodothyronine, and Free Thyroxine and the Relevance of Body Mass Index and Puberty in Measurement Interpretation

Background: The present study aimed to establish age- and sex-specific reference intervals for serum concentrations of thyrotropin (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) in healthy children and adolescents. Additionally, we investigated the association of TSH, fT3, and fT4 with putative influencing factors, such as sex, body mass index (BMI), and puberty. Methods: A total of 9404 blood serum samples from 3140 children and adolescents without thyroid affecting diseases were included in determining TSH, fT3, and fT4 levels and age- and sex-specific reference ranges. To investigate the association of TSH, fT3, and fT4 with age, sex, weight status, and the role of puberty-based changes, the hormone levels and BMI values were converted to standard deviation scores (SDS). Results: In general, TSH, fT3, and fT4 were found to be age- and sex-dependent. Puberty was accompanied by decreased TSH, decreased fT3 with a temporary peak in males, and a temporary nadir of fT4 in Tanner stage 3 for both sexes. BMI-SDS was positively associated with TSH-SDS (β = 0.081, p < 0.001); the effect was more pronounced in overweight subjects (β = 0.142, p < 0.01) and insignificantly negative in underweight subjects (β = -0.047, p > 0.05). BMI-SDS was positively associated with fT3-SDS (β = 0.066, p < 0.001) and negatively associated with fT4-SDS (β = -0.135, p < 0.001), with the effect insignificantly less negative in overweight children (β = -0.055, p > 0.05). Conclusions: Age- and sex-specific reference intervals are important for the interpretation of measurements of TSH, fT3, and fT4 in children and adolescents. Influencing factors such as BMI and puberty should be taken into consideration when using measurements of TSH and thyroid hormones in the diagnosis, treatment, and monitoring of thyroid diseases. Clinical Trial Registration number: NCT02550236.

Dynamic alterations in linear growth and endocrine parameters in children with obesity and height reference values

BACKGROUND

Obesity can affect linear growth of children but there is uncertainty regarding the dynamics and potential causes.

METHODS

In the population-based LIFE Child and the obesity-enriched Leipzig Obesity Childhood cohorts (8,629 children, 37,493 measurements), recruited from 1999 to 2018 in Germany, we compared height, growth, and endocrine parameters between normal-weight and children with obesity (0-20 years). Derived from the independent German CrescNet registry (12,703 children) we generated height reference values specific for children with obesity (data collected from 1999 to 2020).

FINDINGS

Children with obesity were significantly taller than normal-weight peers, differing at maximum by 7·6 cm (1·4 height, standard deviation scores or SDS) at age 6-8 years. Already at birth, children with obesity were slightly taller and thereafter had increased growth velocities by up to 1·2 cm/year. This growth acceleration was unrelated to parental height, but was accompanied by increased levels of insulin-like growth factor-1 (IGF-1), insulin and leptin. During puberty, children with obesity showed a catch-down in height SDS. The reduction in pubertal growth velocity by up to 25% coincided with a decrease in levels of IGF-1 (by 17%) and testosterone (by 62%) in boys and estradiol (by 37%) in girls. We confirmed these alterations in growth in the independent CrescNet cohort and furthermore provide height reference values for children with obesity for open access.

INTERPRETATION

Dynamics of linear growth are altered distinctively in different developmental phases in children with obesity. Early emergence before other profound comorbidities implies predisposition, environmental, and/or endocrine factors affecting growth in early life. Height reference values for children with obesity may enhance the precision of clinical health surveillance.

FUNDING

German Research Foundation, German Diabetes Association, EU, ESF, ERDF, State of Saxony, ESPE, Hexal, Novo Nordisk, Pfizer Pharma.

Motor skills in relation to body-mass index, physical activity, TV-watching, and socioeconomic status in German four-to-17-year-old children

BACKGROUND

The present study describes motor skills in a large sample of German children and adolescents and investigates associations with age, gender, body-mass index, physical activity, television time, and socioeconomic status.

METHODS

2,106 children (1076 boys, 1030 girls) aged 4 to 17 years performed five different motor tests for strength (pushups, standing long jump), coordination (backward balancing, jumping side-to-side) and flexibility (forward bend) within the framework of the LIFE Child study (Leipzig, Germany). Anthropometric parameters were assessed through standardized measurement. Data on physical activity, television time, and socioeconomic status were collected via questionnaires. Linear regression analyses were applied to assess relations.

RESULTS

Strength and coordination performance were higher in older than in younger children. While boys showed a higher performance in strengths tests than girls, girls performed better in flexibility and coordination during precision tasks (backward balancing). In terms of coordination under time constraint (jumping side-to-side), both genders produced similar results. Lower body-mass index, higher physical activity, and higher socioeconomic status were significantly related to better motor skills. Longer television times were significantly associated with lower performance in long jump.

CONCLUSIONS

The present findings are similar to data collected at the beginning of the century, indicating that motor skills have hardly changed in recent years. The findings furthermore suggest that children from lower social strata, children with higher body weight, and children who move little have a higher risk of developing insufficient motor skills and should therefore be given special support.

Birth weight increases with birth order despite decreasing maternal pregnancy weight gain

AIM

We investigated whether birth order is an influencing factor for birth weight independent from maternal factors.

METHODS

Data were obtained from the longitudinal cohort study LIFE Child and included 1864 children, of which 526 were only children. The 1338 siblings were ranked into first-borns (n = 570), second-borns (n = 606) and third-or-later-borns (n = 162). Children born prematurely, suffering from chronic or syndromic diseases, were excluded. We performed intra-family comparisons to reduce bias and assessed the impact of perinatal parameters, such as birth order on birth weight, using mixed models.

RESULTS

Birth weight increased with birth order. In univariate analyses, birth order had a significant effect on birth weight-SDS with second-borns having 0.29 SDS (app. 130 g) and third-borns 0.40 SDS (app. 180 g) higher values than first-borns (P < .001). Maternal pregnancy weight gain was associated with higher birth weight-SDS (P < .01) in univariate analysis, though maternal pregnancy weight gain was lower for higher birth orders. Multivariate analyses revealed that being a second or third-or-later-born child had a stronger impact on birth weight than all maternal factors.

CONCLUSION

Birth order must be considered a potential risk factor for higher birth weight. Maternal pregnancy weight gain is not the driving factor for higher birth weight in siblings.

Feasibility and repeatability of ocular biometry measured with Lenstar LS 900 in a large group of children and adolescents

PURPOSE

To evaluate the feasibility and repeatability of Lenstar LS 900 biometry measurements in a paediatric population.

METHODS

Children were examined as part of the LIFE Child Study (Leipzig Research Centre for Civilization Diseases), a population-based study in Leipzig, Germany. Altogether, 1917 children, aged from 3.5 to 17.5 years, were assessed with the Haag Streit Lenstar LS 900. Three consecutive measurements of the right eye were analysed for axial length, central corneal thickness, anterior chamber depth, aqueous depth, lens thickness and flat and steep corneal radii. The number of successful measurements and repeatability were evaluated for each parameter and three age bands (3.5 to 6.5 years, 6.5 to 10.5 years and 10.5 to 17.5 years).

RESULTS

Best measurement feasibility was found for axial length and central corneal thickness (91% to 100%), followed by flat and steep corneal radii (86% to 100%), anterior chamber and aqueous depth (76% to 92%) and lens thickness (50% to 81%), with higher numbers for older children. Repeatability values (in mm) were: axial length 0.025 to 0.035; central corneal thickness 0.003 to 0.027; aqueous depth 0.024 to 0.058; anterior chamber 0.024 to 0.054; lens thickness 0.034 to 0.067. An overall trend showed better repeatability for older children, especially for central corneal thickness, aqueous depth and lens thickness.

CONCLUSIONS

For ocular biometry in the paediatric population, axial length, central corneal thickness, flat and steep corneal radii can be measured very reliably even in children from 4 years old onward using the Lenstar LS 900. Lens thickness can be quantified in a limited number of younger children. Repeatability was high for all variables investigated. Repeatability improved with age, reaching adult values in the adolescent age band. Established repeatability limits can be applied in future studies as a quality parameter.

Sleep-related difficulties in healthy children and adolescents

BACKGROUND

As sleep-related difficulties are a growing public health concern, it is important to gain an overview of the specific difficulty areas of the most vulnerable individuals: children. The current descriptive study presents the prevalence of sleep-related difficulties in two large samples of healthy children and adolescents and outlines the effects of age, gender, and socioeconomic status (SES) on various sleep-related difficulties.

METHODS

Participants were 855 4-9 year-old children (child sample) and 1,047 10-17 year-old adolescents (adolescent sample) participating 2011-2015 in the LIFE Child study, a population-based cohort study in Germany. Parents of the child participants completed the Children's Sleep Habits Questionnaire (CSHQ), whereas adolescents self-administered the Sleep Self Report (SSR). Familial SES was determined by a composite score considering parental education, occupational status, and income. Multiple regression analyses were carried out to address the research question.

RESULTS

Among 4-9 year-old children, the mean bedtime was reported to be 8 p.m., the mean wake-up time 7 a.m., and sleep duration decreased by 14 min/year of age. 22.6 % of the children and 20.0 % of the adolescents showed problematic amounts of sleep-related difficulties. In the child sample, bedtime resistance, sleep onset delay, sleep-related anxiety, night waking, and parasomnia were more frequent in younger than older children. In the adolescent sample, difficulties at bedtime were more frequent among the younger adolescents, whereas daytime sleepiness was more prominent in the older than the younger adolescents. Considering gender differences, sleep-related difficulties were more frequent among boys in the child sample and among girls in the adolescent sample. Lower SES was associated with increased sleep-related difficulties in the adolescent, but not the child sample.

CONCLUSIONS

The present results report sleep-related difficulties throughout both childhood and adolescence. Gender differences can already be observed in early childhood, while effects of SES emerge only later in adolescence. The awareness for this circumstance is of great importance for pediatric clinicians who ought to early identify sleep-related difficulties in particularly vulnerable individuals.

High-resolution pediatric reference intervals for 15 biochemical analytes described using fractional polynomials

OBJECTIVES

Assessment of children's laboratory test results requires consideration of the extensive changes that occur during physiological development and result in pronounced sex- and age-specific dynamics in many biochemical analytes. Pediatric reference intervals have to account for these dynamics, but ethical and practical challenges limit the availability of appropriate pediatric reference intervals that cover children from birth to adulthood. We have therefore initiated the multi-center data-driven PEDREF project (Next-Generation Pediatric Reference Intervals) to create pediatric reference intervals using data from laboratory information systems.

METHODS

We analyzed laboratory test results from 638,683 patients (217,883-982,548 samples per analyte, a median of 603,745 test results per analyte, and 10,298,067 test results in total) performed during patient care in 13 German centers. Test results from children with repeat measurements were discarded, and we estimated the distribution of physiological test results using a validated statistical approach (kosmic).

RESULTS

We report continuous pediatric reference intervals and percentile charts for alanine transaminase, aspartate transaminase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl-transferase, total protein, albumin, creatinine, urea, sodium, potassium, calcium, chloride, anorganic phosphate, and magnesium. Reference intervals are provided as tables and fractional polynomial functions (i.e., mathematical equations) that can be integrated into laboratory information systems. Additionally, Z-scores and percentiles enable the normalization of test results by age and sex to facilitate their interpretation across age groups.

CONCLUSIONS

The provided reference intervals and percentile charts enable precise assessment of laboratory test results in children from birth to adulthood. Our findings highlight the pronounced dynamics in many biochemical analytes in neonates, which require particular consideration in reference intervals to support clinical decision making most effectively.