Long-Term Neurodevelopmental and Functional Outcomes of Infants Born Very Preterm and/or with a Very Low Birth Weight

Background: Birth weight (BW) is often used as a proxy for gestational age (GA) in studies on preterm birth. Recent findings indicate that, in addition to perinatal outcomes, subjects born very preterm (VP; GA <32 weeks) differ from those with a very low birth weight (VLBW; BW <1,500 g) in postnatal growth up to their final height. Objective: To study whether neurodevelopmental and functional outcomes at the age of 19 years differ in VP and/or VLBW subjects. Methods: 705 19-year-old subjects from the Project on Preterm and Small-for-Gestational-Age Infants (POPS) cohort were classified as (1) VP+/VLBW+ (n = 354), (2) VP+/VLBW– (n = 144), or (3) VP–/VLBW+ (n = 207), and compared with regard to IQ as assessed with the Multicultural Capacity Test-intermediate level; neuromotor function using Touwen’s examination of mild neurologic dysfunction; hearing loss; self- and parent-reported behavioral and emotional functioning; educational achievement and occupation; and self-assessed health using the Health Utilities Index and the London Handicap Scale. Results: VP+/VLBW– infants, on average, had 3.8-point higher IQ scores (95% confidence interval [CI] 0.5– 7.1), a trend towards higher educational achievement, 3.3- dB better hearing (95% CI 1.2–5.4), and less anxious behavior, attention problems, and internalizing behavior than to VP+/VLBW+ subjects. VP–/VLBW+ infants reported 1.8 increased odds (95% CI 1.2–2.6) of poor health compared to VP+/VLBW+ subjects. Conclusions: At the age of 19 years, subjects born VP+/VLBW+, VP+/VLBW–, and VP-/VLBW+ have different neurodevelopmental and functional outcomes, although effect sizes are small. Hence, the terms VP and VLBW are not interchangeable. We recommend, at least for industrialized countries, to base inclusion in future studies on preterm populations on GA instead of on B

Long-term stability of cortisol production and metabolism throughout adolescence: longitudinal twin study

Life-course experiences have been postulated to program hypothalamus-pituitary-adrenal (HPA) axis activity, suggesting that HPA axis activity is, at least partially, stable over time. Yet, there is paucity of data on the long-term stability of cortisol production and metabolism. We performed a prospective follow-up study in twins recruited from a nationwide register to estimate the stability of cortisol production and metabolism over time, and the contribution of genetic and environmental factors to this stability. In total, 218 healthy mono- and dizygotic twins were included. At the ages of 9, 12 and 17 years, morning urine samples were collected for assessment (by gas chromatography-tandem mass spectrometry) of cortisol metabolites, enabling the calculation of cortisol metabolite excretion rate and cortisol metabolism activity. Our results showed a low stability for both cortisol metabolite excretion rate (with correlations <.20) and cortisol metabolism activity indices (with correlations of .25 to .46 between 9 and 12 years, -.02 to .15 between 12 and 17 years and .09 to .28 between 9 and 17 years). Because of the low stability over time, genetic and environmental contributions to this stability were difficult to assess, although it seemed to be mostly determined by genetic factors. The low stability in both cortisol production and metabolism between ages 9 and 17 years reflects the dynamic nature of the HPA axis

Exploring the Temporal Relation between Body Mass Index and Corticosteroid Metabolite Excretion in Childhood

Childhood obesity is associated with alterations in hypothalamus–pituitary–adrenal (HPA) axis activity. However, it is unknown whether these alterations are a cause or a consequence of obesity. This study aimed to explore the temporal relationship between cortisol production and metabolism, and body mass index (BMI). This prospective follow-up study included 218 children (of whom 50% were male), born between 1995 and 1996, who were assessed at the ages of 9, 12 and 17 years. Morning urine samples were collected for assessment of cortisol metabolites by gas chromatography-tandem mass spectrometry, enabling the calculation of cortisol metabolite excretion rate and cortisol metabolic pathways. A cross-lagged regression model was used to determine whether BMI at various ages during childhood predicted later cortisol production and metabolism parameters, or vice versa. The cross-lagged regression coefficients showed that BMI positively predicted cortisol metabolite excretion (p = 0.03), and not vice versa (p = 0.33). In addition, BMI predicted the later balance of 11β-hydroxysteroid dehydrogenase (HSD) activities (p = 0.07), and not vice versa (p = 0.55). Finally, cytochrome P450 3A4 activity positively predicted later BMI (p = 0.01). Our study suggests that changes in BMI across the normal range predict alterations in HPA axis activity. Therefore, the alterations in HPA axis activity as observed in earlier studies among children with obesity may be a consequence rather than a cause of increased BMI

Falsely elevated plasma testosterone concentrations in neonates : importance of LC-MS/ MS measurements

CITATION: Hamer, H.M. et al. 2018. Falsely elevated plasma testosterone concentrations in neonates : importance of LC-MS/ MS measurements. Clinical Chemistry and Laboratory Medicine (CCLM), 56(6):e141–e143, doi:10.1515/cclm-2017-1028.The original publication is available at https://www.degruyter.com/view/j/cclmIn newborns with atypical genitalia, suspicious for a disorder of sex development (DSD), measurement of testosterone is an essential part in the diagnostic workup. Previously, direct testosterone immunoassays have proven to be inaccurate because they tend to overestimate testosterone concentrations in the lower ranges, such as those in females and infants, but specifically also in neonates. Based on the concern for cross-reactivity in neonatal samples, the recently revised UK guideline on the initial evaluation of DSD from the UK Society for Endocrinology recommends that steroids in plasma or serum are measured by either LC-MS/MS or immunoassays after organic solvent extraction. The use of LC-MS/MS was considered superior by a recent consensus meeting of DSD experts across Europe, although validation and quality control remain challenging.Publishers versio

Long-term effects of a modified, low-protein infant formula on growth and body composition:Follow-up of a randomized, double-blind, equivalence trial

Background & aim: High protein intake in early life is associated with an increased risk of childhood obesity. Feeding a modified lower-protein (mLP) infant formula (1.7 g protein/100 kcal) until the age of 6 months is safe and supports adequate growth. The aim of the present study is to assess longer-term anthropometry with BMI at 1 and 2 years as primary outcome parameter and body composition in children fed mLP formula. Methods: Healthy term-born infants received mLP or control formula (CTRL) (2.1 g protein/100 kcal) until 6 months of age in a double-blinded RCT. A breast-fed (BF) group served as a reference. Anthropometry data were obtained at 1 and 2 years of age. At the age of 2 years, body composition was measured with air-displacement plethysmography. Groups were compared using linear mixed model analysis. Results: At 1 and 2 years of age, anthropometry, including BMI, and body composition did not differ between the formula groups (n = 74 mLP; n = 69 CTRL). Compared to the BF group (n = 51), both formula-fed groups had higher z scores for weight for age, length for age, waist circumference for age, and mid-upper arm circumference for age at 1 year of age, but not at 2 years of age (except for z score of weight for age in the mLP group). In comparison to the BF group, only the mLP group had higher fat mass, fat-free mass, and fat mass index. However, % body fat did not differ between feeding groups. Conclusions: In this follow-up study, no significant differences in anthropometry or body composition were observed until 2 years of age between infants fed mLP and CTRL formula, despite the significantly lower protein intake in the mLP group during the intervention period. The observed differences in growth and body composition between the mLP group and the BF reference group makes it necessary to execute new trials evaluating infant formulas with improved protein quality together with further reductions in protein content. Clinical Trial Registry: This trial was registered in the Dutch Trial Register (Study ID number NTR4829, trial number NL4677). https://www.trialregister.nl/trial/4677

Sexual dimorphism in cortisol metabolism throughout pubertal development: a longitudinal study

Objective: Sex differences in disease susceptibility might be explained by sexual dimorphism in hypothalamic-pituitary-adrenal axis activity, which has been postulated to emerge during puberty. However, studies conducted thus far lacked an assessment of Tanner pubertal stage. This study aimed to assess the contribution of pubertal development to sexual dimorphism in cortisol production and metabolism. Methods: Participants (n = 218) were enrolled from a population-based Netherlands Twin Register. At the ages of 9, 12 and 17 years, Tanner pubertal stage was assessed and early morning urine samples were collected. Cortisol metabolites were measured with GC-MS/MS and ratios were calculated, representing cortisol metabolism enzyme activities, such as A-ring reductases, 11β-HSDs and CYP3A4. Cortisol production and metabolism parameters were compared between sexes for pre-pubertal (Tanner stage 1), early pubertal (Tanner stage 2–3) and late-pubertal (Tanner stage 4–5) stages. Results: Cortisol metabolite excretion rate decreased with pubertal maturation in both sexes, but did not significantly differ between sexes at any pubertal stage, although in girls a considerable decrease was observed between early and late-pubertal stage (P < 0.001). A-ring reductase activity was similar between sexes at pre-and early pubertal stages and was lower in girls than in boys at late-pubertal stage. Activities of 11β-HSDs were similar between sexes at pre-pubertal stage and favored cortisone in girls at early and late-pubertal stages. Cytochrome P450 3A4 activity did not differ between sexes. Conclusions: Prepubertally, sexes were similar in cortisol parameters. During puberty, as compared to boys, in girls the activities of A-ring reductases declined and the balance between 11β-HSDs progressively favored cortisone. In addition, girls showed a considerable decrease in cortisol metabolite excretion rate between early and late-pubertal stages. Our findings suggest that the sexual dimorphism in cortisol may either be explained by rising concentrations of sex steroids or by puberty-induced changes in body composition

Diurnal rhythmicity in breast-milk glucocorticoids, and infant behavior and sleep at age 3 months

Purpose: In previous studies, associations between breast-milk cortisol levels obtained on one occasion and infant neurodevelopment were demonstrated. However, more recent evidence indicates that breast-milk cortisol and cortisone concentrations follow the diurnal rhythm of maternal hypothalamus-pituitary-adrenal axis, peaking in the early morning and with a nadir at midnight. We studied associations between breast-milk glucocorticoid (GC) rhythmicity, and infant behavior and sleep. Methods: We included 59 mothers, and their infants, of whom 17 had consulted an expert center during pregnancy for an increased risk of psychological distress. At 1 month postpartum, breast milk was sampled (on averag

Interpretation of glucocorticoids in neonatal hair: A reflection of intrauterine glucocorticoid regulation?

Background: Glucocorticoids (GCs) measured in neonatal hair might reflect intrauterine as well as postpartum GC regulation. We aimed to identify factors associated with neonatal hair GC levels in early life, and their correlation with maternal hair GCs. Methods: In a single-center observational study, mother-infant pairs (n = 107) admitted for >72 h at the maternity ward of a general hospital were included. At birth and an outpatient visit (OPV, n = 72, 44 ± 11 days postpartum), maternal and neonatal hair was analyzed for cortisol and cortisone levels by LC-MS/MS. Data were analyzed regarding: (1) neonatal GC levels postpartum and at the OPV, (2) associations of neonatal GC levels with maternal GC levels and (3) with other perinatal factors. Results: (1) Neonatal GC levels were >5 times higher than maternal levels, with a decrease in ±50% between birth and the OPV for cortisol. (2) Maternal and neonatal cortisol, but not cortisone, levels were correlated both at postpartum and at the OPV. (3) Gestational age was associated with neonatal GC postpartum (log-transformed β (95% CI): cortisol 0.07 (0.04-0.10); cortisone 0.04 (0.01-0.06)) and at the OPV (cortisol 0.08 (0.04-0.12); cortisone 0.00 (-0.04 to 0.04)), while weaker associations were found between neonatal GCs and other perinatal and maternal factors. Conclusions: Neonatal hair GCs mainly reflect the third trimester increase in cortisol, which might be caused by the positive feedback loop, a placenta-driven phenomenon, represented by the positive association with GA. Between birth and 1.5 months postpartum, neonatal hair cortisol concentrations decrease sharply, but still appear to reflect both intra- and extrauterine periods

Early-Life Metabolic and Hormonal Markers in Blood and Growth until Age 2 Years:Results from a Randomized Controlled Trial in Healthy Infants Fed a Modified Low-Protein Infant Formula

Background: High protein intake in early life is associated with an increased risk of childhood obesity. Dietary protein intake may be a key mechanistic modulator through alterations in endocrine and metabolic responses. Objective: We aimed to determine the impact of different protein intake of infants on blood metabolic and hormonal markers at the age of four months. We further aimed to investigate the association between these markers and anthropometric parameters and body composition until the age of two years. Design: Term infants received a modified low-protein formula (mLP) (1.7 g protein/100 kcal) or a specifically designed control formula (CTRL) (2.1 g protein/100 kcal) until 6 months of age in a double blinded RCT. The outcomes were compared with a breast-fed (BF) group. Glucose, insulin, leptin, IGF-1, IGF-BP1, -BP2, and -BP3 levels were measured at the age of 4 months. Anthropometric parameters and body composition were assessed until the age of 2 years. Groups were compared using linear regression analysis. Results: No significant differences were observed in any of the blood parameters between the formula groups (n = 53 mLP; n = 44 CTRL) despite a significant difference in protein intake. Insulin and HOMA-IR were higher in both formula groups compared to the BF group (n = 36) (p < 0.001). IGF-BP1 was lower in both formula groups compared to the BF group (p < 0.01). We found a lower IGF-BP2 level in the CTRL group compared to the BF group (p < 0.01) and a higher IGF-BP3 level in the mLP group compared to the BF group (p = 0.03). There were no significant differences in glucose, leptin, and IGF-1 between the three feeding groups. We found specific associations of all early-life metabolic and hormonal blood parameters with long-term growth and body composition except for IGF-1. Conclusions: Reducing protein intake by 20% did not result in a different metabolic profile in formula-fed infants at 4 months of age. Formula-fed infants had a lower insulin sensitivity compared to breast-fed infants. We found associations between all metabolic and hormonal markers (except for IGF-1) determined at age 4 months and growth and body composition up to two years of age

Heritability of Urinary Amines, Organic Acids, and Steroid Hormones in Children

Variation in metabolite levels reflects individual differences in genetic and environmental factors. Here, we investigated the role of these factors in urinary metabolomics data in children. We examined the effects of sex and age on 86 metabolites, as measured on three metabolomics platforms that target amines, organic acids, and steroid hormones. Next, we estimated their heritability in a twin cohort of 1300 twins (age range: 5.7-12.9 years). We observed associations between age and 50 metabolites and between sex and 21 metabolites. The monozygotic (MZ) and dizygotic (DZ) correlations for the urinary metabolites indicated a role for non-additive genetic factors for 50 amines, 13 organic acids, and 6 steroids. The average broad-sense heritability for these amines, organic acids, and steroids was 0.49 (range: 0.25-0.64), 0.50 (range: 0.33-0.62), and 0.64 (range: 0.43-0.81), respectively. For 6 amines, 7 organic acids, and 4 steroids the twin correlations indicated a role for shared environmental factors and the average narrow-sense heritability was 0.50 (range: 0.37-0.68), 0.50 (range; 0.23-0.61), and 0.47 (range: 0.32-0.70) for these amines, organic acids, and steroids. We conclude that urinary metabolites in children have substantial heritability, with similar estimates for amines and organic acids, and higher estimates for steroid hormones