Attrition in Long-Term Nutrition Research Studies: A Commentary by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition Early Nutrition Research Working Group

Enduring impact of childhood adversity: Affective modulation of acoustic startle response during pregnancy and postpartum

BACKGROUND

Women with a history of adverse childhood experiences (ACEs) enter pregnancy and the postpartum with a physiologic system programmed by early life stress, potentially reflected in psychophysiologic reactivity.

METHODS

We enrolled pregnant, psychiatrically healthy women ≥18 years old. Using the ACE Questionnaire, women were categorized as high (≥2 ACEs; n = 77) or low ACE (<2 ACEs; n = 72). Participants completed an affective modulation of acoustic startle response (ASR) task during pregnancy and postpartum, in which ASR magnitude was measured while participants viewed pleasant, unpleasant, and neutral pictures. Two types of control trials were included (habituation trials presented at baseline and intertrial interval trials presented when no picture was present).

RESULTS

Among high ACE women, ASR was significantly higher postpartum compared with pregnancy in the unpleasant (p = 0.002, β = 0.46, 95% CI [0.18, 0.74], χ2 = 10.12, z = 3.18) and intertrial interval trials (p = 0.002, β = 0.44, 95% CI [0.16, 0.73], χ2 = 9.25, z = 3.04), accounting for multiple comparisons using a Bonferroni correction at p < 0.005. Among low ACE women, ASR was similar in pregnancy and postpartum.

CONCLUSIONS

Physiological reactivity increased in high ACE women from pregnancy to postpartum, but no change was observed in low ACE women.

Different protein intake in the first year and its effects on adiposity rebound and obesity throughout childhood: 11 years follow-up of a randomized controlled trial

BACKGROUND AND OBJECTIVES

Infant feeding affects child growth and later obesity risk. We examined whether protein supply in infancy affects the adiposity rebound, body mass index (BMI) and overweight and obesity up to 11 years of age.

METHODS

We enrolled healthy term infants from five European countries in a double blind randomized trial, with anticipated 16 examinations within 11 years follow-up. Formula-fed infants (n = 1090) were randomized to isoenergetic formula with higher or lower protein content within the range stipulated by EU legislation in 2001. A breastfed reference group (n = 588) was included. Adiposity rebound and BMI trajectories were estimated by generalized additive mixed models in 917 children, with 712 participating in the 11 year follow-up.

RESULTS

BMI trajectories were elevated in the higher compared to the lower protein group, with significantly different BMI at adiposity rebound (0.24 kg/m², 0.01-0.47, p = 0.040), and an increased risk for overweight at 11 years (adjusted Odds Ratio 1.70; 1.06-2.73; p = 0.027) but no significant difference for obesity (adjusted Odds Ratio 1.47; 0.66-3.27). The two formula groups did not differ in the timing of adiposity rebound, but all children with obesity at 11 years had an early adiposity rebound before four years.

CONCLUSIONS

Compared to conventional high protein formula, feeding lower protein formula in infancy lowers BMI trajectories up to 11 years and achieves similar BMI values at adiposity rebound as observed in breastfed infants.

Strengthening Research that Answers Nutrition Questions of Public Health Importance: Leveraging the Experience of the USDA Nutrition Evidence Systematic Review Team

The Nutrition Evidence Systematic Review (NESR) team conducts nutrition- and public health-related systematic reviews and is within the USDA's Center for Nutrition Policy and Promotion. NESR has collaborated with scientific experts to conduct systematic reviews on nutrition and public health topics for more than a decade and is uniquely positioned to share recommendations with the research community to strengthen research quality and impact, especially the evidence base that supports public health nutrition guidance, including future editions of the Dietary Guidelines for Americans. Leveraging the expertise of NESR and its systematic review process resulted in the following recommendations for the research community: a) use the strongest study design feasible with sufficient sample size(s); b) enroll study participants who reflect the diversity of the population of interest and report participant characteristics; c) use valid and reliable dietary assessment methods; d) describe the interventions or exposures of interest and use standard definitions to promote consistency; e) use valid and reliable health outcome measures; f) account for variables that may impact the relationship between nutrition-related interventions or exposures and health outcomes; g) carry out studies for a sufficient duration and include repeated measures, as appropriate; and h) report all relevant information to inform accurate interpretation and evaluation of study results. Implementing these recommendations can strengthen nutrition and public health evidence and increase its utility in future public health nutrition systematic reviews. However, implementation will require additional support from the entire research community, including scientific journals and funding agencies.

Effect of nutritionally modified infant formula on academic performance: linkage of seven dormant randomised controlled trials to national education data

OBJECTIVE

To compare differences in academic performance between adolescents who were randomised in infancy to modified or standard infant formula.

DESIGN

Linkage of seven dormant randomised controlled trials to national education data.

SETTING

Five hospitals in England, 11 August 1993 to 29 October 2001, and schools in England, September 2002 to August 2016.

PARTICIPANTS

1763 adolescents (425 born preterm, 299 born at term and small for gestational age, 1039 born at term) who took part in one of seven randomised controlled trials of infant formula in infancy.

INTERVENTIONS

Nutrient enriched versus standard term formula (two trials), long chain polyunsaturated fatty acid (LCPUFA) supplemented versus unsupplemented formula (two trials), high versus low iron follow-on formula (one trial), high versus low sn-2 palmitate formula (one trial), and nucleotide supplemented versus unsupplemented formula (one trial).

MAIN OUTCOME MEASURES

The primary outcome, determined by linkage of trial data to school data, was the mean difference in standard deviation scores for mandated examinations in mathematics at age 16 years. Secondary outcomes included differences in standard deviation scores in English (16 and 11 years) and mathematics (11 years). Analysis was by intention to treat with multiple imputation for participants missing the primary outcome.

RESULTS

1607 (91.2%) participants were linked to school records. No benefit was found for performance in mathematics examinations at age 16 years for any modified formula: nutrient enriched in preterm infants after discharge from hospital, standard deviation score 0.02 (95% confidence interval -0.22 to 0.27), and nutrient enriched in small for gestational age term infants -0.11 (-0.33 to 0.12); LCPUFA supplemented in preterm infants -0.19 (-0.46 to 0.08) and in term infants -0.14 (-0.36 to 0.08); iron follow-on formula in term infants -0.12 (-0.31 to 0.07); and sn-2 palmitate supplemented formula in term infants -0.09 (-0.37 to 0.19). Participants from the nucleotide trial were too young to have sat their General Certificate of Secondary Education (GCSE) examinations at the time of linkage to school data. Secondary outcomes did not differ for nutrient enriched, high iron, sn-2 palmitate, or nucleotide supplemented formulas, but at 11 years, preterm and term participants randomised to LCPUFA supplemented formula scored lower in English and mathematics.

CONCLUSIONS

Evidence from these randomised controlled trials indicated that the infant formula modifications did not promote long term cognitive benefit compared with standard infant formulas.

Improving long-term health outcomes of preterm infants: how to implement the findings of nutritional intervention studies into daily clinical practice

Preterm-born children are at risk for later neurodevelopmental problems and cardiometabolic diseases; early-life growth restriction and suboptimal neonatal nutrition have been recognized as risk factors. Prevention of these long-term sequelae has been the focus of intervention studies. High supplies of protein and energy during the first weeks of life (i.e., energy > 100 kcal kg-1 day-1 and a protein-to-energy ratio > 3 g/100 kcal) were found to improve both early growth and later neurodevelopmental outcome. Discontinuation of this high-energy diet is advised beyond 32-34 weeks postconceptional age to prevent excess fat mass and possible later cardiometabolic diseases. After discharge, nutrition with a higher protein-to-energy ratio (i.e., > 2.5-3.0 g/100 kcal) may improve growth and body composition in the short term.Conclusion: Preterm infants in their first weeks of life require a high-protein high-energy diet, starting shortly after birth. Subsequent adjustments in nutritional composition, aimed at achieving optimal body composition and minimizing the long-term cardiometabolic risks without jeopardizing the developing brain, should be guided by the growth pattern. The long-term impact of this strategy needs to be studied. What is Known: • Preterm infants are at risk for nutritional deficiencies and extrauterine growth restriction. • Extrauterine growth restriction and suboptimal nutrition are risk factors for neurodevelopmental problems and cardiometabolic disease in later life. What is New: • Postnatally, a shorter duration of high-energy nutrition may prevent excess fat mass accretion and its associated cardiometabolic risks and an early switch to a protein-enriched diet should be considered from 32-34 weeks postconceptional age. • In case of formula feeding, re-evaluate the need for the continuation of a protein-enriched diet, based on the infant's growth pattern.

Infant formula composition and educational performance: a protocol to extend follow-up for a set of randomised controlled trials using linked administrative education records

INTRODUCTION

The effect of infant nutrition on long-term cognition is important for parents and policy makers. However, most clinical trials typically have short follow-up periods, when measures of cognition are poorly predictive of later function. The few trials with longer-term follow-up have high levels of attrition, which can lead to selection bias, and in turn to erroneous interpretation of long-term harms and benefits of infant nutrition. We address the need for unbiased, long-term follow-up, by linking measures of educational performance from administrative education records. Educational performance is a meaningful marker of cognitive function in children and it is strongly correlated with IQ. We aim to evaluate educational performance for children who, as infants, were part of a series of trials that randomised participants to either nutritionally modified infant formula or standard formula. Most trialists anticipated positive effects of these interventions on later cognitive function.

METHODS AND ANALYSIS

Using data from 1923 participants of seven randomised infant formula trials linked to the English National Pupil Database (NPD), this study will provide new insights into the effect of nutrient intake in infancy on school achievement. Our primary outcome will be the mean differences in z-scores between intervention and control groups for a compulsory Mathematics exam sat at age 16. Secondary outcomes will be z-scores for a compulsory English exam at age 16 and z-scores for compulsory Mathematics and English exams at age 11. We will also evaluate intervention effects on the likelihood of receiving special educational needs (SEN) support. All analyses will be performed separately by trial.

ETHICS AND DISSEMINATION

Research ethics approval, and approval from the Health Research Authority Confidentiality Advisory Group, has been obtained for this study. The results of this study will be disseminated to scientific, practitioner, and lay audiences, submitted for publication in peer-reviewed journals, and will contribute towards a PhD dissertation.

Long-term (10-year) dental implant survival: A systematic review and sensitivity meta-analysis

OBJECTIVES

To identify and appraise the most recent studies reporting dental implant survival in adults (≥18 years) using contemporary implant systems (solid screw, roughened surface) for a period of 10 years; and explore new predictors of implant survival.

SOURCE

MEDLINE, Scopus, and the Cochrane Central Register of Controlled trials were searched from 1997 to January 2018 to focus on contemporary implant systems.

STUDY SELECTION

Only prospective observational studies with at least 10 participants and 35 implants were included. The unit of study was the 'absolute survival' rate of dental implants after 10 years in the oral cavity. Study quality was assessed utilising a modified Hoy risk of bias tool for prevalence studies. A sensitivity meta-analysis was undertaken utilising a plausibly imputed model for missing data.

DATA

18 studies met the inclusion criteria. The summary estimate for 10-year survival at the implant level was 96.4% (95% CI 95.2%-97.5%) and the prediction interval was 91.5%-99.4%. The sensitivity meta-analysis summary estimate of survival was 93.2% (95% CI 90.1% to 95.8%)p = 0.041 with a prediction interval of 76.6%-100%. Older age (≥ 65 years) was a significant predictor at 91.5%, p = 0.038 in the sensitivity meta-analysis.

CONCLUSIONS

A traditional analysis produced similar 10-year survival estimates to previous systematic reviews. A more realistic sensitivity meta-analysis accounting for loss to follow-up data and the calculation of prediction intervals demonstrated a possible doubling of the risk of implant loss in the older age groups.

CLINICAL SIGNIFICANCE

Improved analysis provides the clinician with better estimation of the real-world risk of implant failures so helping the clinician communicate the potential risk to patients.

Neurodevelopment of children born very preterm and/or with a very low birth weight: 8-Year follow-up of a nutritional RCT

BACKGROUND

Children born very preterm are at risk for cognitive deficits and motor impairment. Enhanced protein intake immediately after very preterm birth has been associated with favorable growth and improved neurodevelopment. It is unknown whether increased protein intake after discharge from the hospital affects long-term neurodevelopment.

OBJECTIVE

The primary objective was to assess neurodevelopment from infancy to 8 years in preterm-born children who received either protein-enriched formula (PDF), standard term formula (TF), or human milk (HM) after discharge. The secondary objective was to assess the correlation between outcomes obtained at 24 months corrected age (CA) and at 8 years.

METHODS

This RCT included 152 children born very preterm (gestational age ≤32 weeks) and/or with a very low birth weight (≤1500 g) of whom 102 were randomly assigned to receive PDF (n = 54) or TF (n = 48) from term age to 6 months CA. A control group of infants fed HM (n = 50) was also included. Neurodevelopmental outcomes were assessed at 24 months CA (cognitive and motor functioning; n = 123) and at 8 years (estimated Full Scale Intelligence Quotient, visual-motor skills, verbal memory, attention, and motor functioning; n = 76).

RESULTS

The PDF and TF groups were not significantly different in neurodevelopmental outcomes. The HM group had a better cognitive score compared with the PDF group: at 24 months CA 92.9 ± 12.5 vs. 105.2 ± 18.6, P < 0.001 and at 8 years 98.1 ± 11.3 vs. 105.8 ± 9.1, P = 0.017 (P = 0.002 and P = 0.080, respectively, after adjustment for parental educational level). Correlations between outcomes at 24 months CA and 8 years were weak: r = 0.35 and r = 0.37 for cognitive and motor outcomes, respectively.

CONCLUSIONS

PDF did not improve long-term neurodevelopmental outcomes as compared with TF. However, these results should be interpreted with caution considering the substantial attrition at follow-up. Furthermore, the correlation between outcomes at different ages was weak, emphasizing the need for long-term follow-up of nutritional intervention studies in preterm-born children.

Role of Incentives in Long-term Nutritional and Growth Studies in Children

Available published advice on use of incentives is limited and generally refers to short-term studies without longer follow-up, predominantly conducted in developed countries. We aim to summarize published information related to the use of incentives in long-term nutrition studies involving infants, children, and adolescents and the views of researchers in the field, to provide guidance on acceptable incentives. We conducted a literature review and a short online survey of researchers regarding their opinions on the use of incentives in paediatric long-term (follow-up) clinical studies. Responses from 38 researchers from 14 different countries indicated that 41% had used incentives to increase participation and 29% to 73%, depending on child's age and type of procedure, thought incentives may be used to increase compliance with follow-up visits. A small number of respondents thought incentives would not be approved by national ethics boards. Based on the literature review and the survey results, and European Society for Paediatric Gastroenterology, Hepatology and Nutrition working group concluded that incentives for children and adolescents up to the value of 30 Euros, based on average EU income levels, may be offered as cash, vouchers, or age-appropriate gifts or toys, in addition to reimbursing expenses. Additional incentives may be offered if a study includes more burdening procedures, techniques that may appear frightening for younger children, or requires sustained participation (eg, dietary diaries or activity monitoring). There was agreement that it is preferable to give toys or gifts rather than money to younger children.

Leptin and IGF-1 in relation to body composition and bone mineralization of preterm-born children from infancy to 8 years

OBJECTIVE

Preterm birth has been associated with altered body composition, especially increased fat mass (FM) and decreased bone mineralization, and leptin and IGF-1 have been suggested to be involved in the regulation of both. We aimed to study the interplay between leptin, IGF-1, FM and bone mineralization measured in infancy and childhood of children born preterm.

DESIGN

Observational study.

PATIENTS/SUBJECTS

Seventy-nine (40 boys) preterm-born children (gestational age ≤32 weeks and/or birth weight ≤1500 g) aged 8 years.

MEASUREMENTS

Serum leptin and IGF-1 were measured at term age, at 3- and 6-month corrected age (CA), and 8 years. Body composition (fat and lean mass) and bone parameters (bone area, mineral content and density) were measured by Dual-energy X-ray Absorptiometry (DXA) at term age, 6-month CA and 8 years.

RESULTS

Leptin was positively associated with FM at all time points and with bone parameters at term age and 6-month CA. IGF-1 was associated with body composition and bone density at most of the time points. Explained variation in bone mineralization increased significantly by adding bone area (BA) and height to the models.

CONCLUSIONS

During infancy and childhood, leptin and IGF-1 were associated with body composition in preterm-born children. In addition, leptin was associated with bone parameters in early infancy, but not in childhood. It is hypothesized that a complicated interplay between multiple pathways, which most likely changes over time, is involved in regulation of body composition and bone mineralization of preterm-born infants.

Chapter 7. The Contributions of the ESPGHAN Committees on Nutrition to Paediatric Nutrition

The first Committee on Nutrition (CoN) was founded in 1974. Two years later nutrition (N) was added to the society's name, which then became ESPGAN. The Committee systematised compositional and quality criteria for breast milk substitutes and food for special medical purposes, the first of many examples on how recommendations and comments published by the Committees on Nutrition (CsoN) were adopted by the European Economic Community, later the European Union and also influenced the World Health Organization/Food and Agriculture Organization of the United Nations Codex standards. A second CoN focusing on preterm infants was established in 1979 and its recommendations on nutrition of these infants were widely implemented. The third and standing CoN, established 1986, started to organise high-quality symposia at the annual meetings appreciating the need to enhance the expertise in nutritional research. From 1991 the CoN has organised Summer Schools in paediatric nutrition for young colleagues further emphasising its educational interest and more recently an annual, more specialised Nutrition Masterclass. Successively the interest of the CoN has expanded to other areas, such as highlighting dilemmas and uncertainties in the field of nutrition including the design, choice of outcomes and statistical analysis of trials in infant nutrition. The work of the CsoN have had great impact on paediatric nutrition and the committee will continue its important role by writing commentaries and systematic reviews and revising guidelines when required to inform and stimulate discussion among colleagues as well as stimulate training in paediatric nutrition by organising workshops and scientific meetings, training courses, and other approaches, and by interaction with other expert groups.

Birth weight and postnatal growth in preterm born children are associated with cortisol in early infancy, but not at age 8 years

BACKGROUND

Preterm birth has been associated with altered hypothalamic-pituitary-adrenal (HPA-) axis activity as well as cardiometabolic diseases and neurodevelopmental impairments later in life. We assessed cortisol from term age to age 8 y in children born preterm, to explore the development of HPA-axis activity in association with intrauterine and early-postnatal growth until 6 mo. corrected age.

METHODS

In 152 children born at a gestational age ≤32 wks. and/or with a birth weight ≤1,500g, random serum cortisol was assessed at term age (n=150), 3 mo. (n=145) and 6 mo. corrected age (n=144), and age 8 y (n=59). Salivary cortisol was assessed at age 8 y (n=75): prior to bedtime, at awakening, 15min after awakening, and before lunch. Cortisol was analyzed in association with birth weight-standard deviation score (SDS), being born small for gestational age (SGA), and combinations of intrauterine and postnatal growth: appropriate for gestational age (AGA) with or without growth restriction (AGA GR+ or AGA GR-) at 6 mo. corrected age, and SGA with or without catch-up growth (SGA CUG+ or SGA CUG-) at 6 mo. corrected age. Cross-sectional associations at all time points were analyzed using linear regression, and longitudinal associations were analyzed using generalized estimating equations.

RESULTS

Longitudinally, birth weight-SDS was associated with cortisol (β [95%CI]): lower cortisol over time was seen in infants with a birth weight ≤-2 SDS (-50.69 [-94.27; -7.11], p=0.02), infants born SGA (-29.70 [-60.58; 1.19], p=0.06), AGA GR+ infants (-55.10 [-106.02; -4.17], p=0.03) and SGA CUG- infants (-61.91 [-104.73; -19.10], p=0.01). In cross-sectional analyses at age 8 y, no associations were found between either serum or salivary cortisol and birth weight-SDS, SGA-status, or growth from birth to 6 mo. corrected age.

CONCLUSION

In children born preterm, poor intrauterine and postnatal growth were associated with lower cortisol in early infancy, but not at age 8 y. Even though HPA-axis activity no longer differed between groups at age 8 y, or differences could not be confirmed due to attrition, it is unknown whether the differences found in early infancy could attribute to increased health risks later in life.

Follow-up of a randomized trial on postdischarge nutrition in preterm-born children at age 8 y

Background: Early nutritional interventions may modulate health risks in preterm-born infants. Previously, we showed that preterm-born infants fed an isocaloric protein- and mineral-enriched postdischarge formula (PDF) from term age to 6-mo corrected age (CA) gained more lean mass than did those fed term formula (TF). Long-term follow-up of randomized nutritional trials is important to test the hypothesis that short-term positive effects on health are sustainable.Objective: The aim of this follow-up study was to compare body size, body composition, and metabolic health at age 8 y in preterm-born children who were randomly assigned to receive either PDF or TF from term age until 6-mo CA.Design: A total of 79 of 152 children (52%) from the original randomized controlled trial were enrolled for follow-up at age 8 y. Weight, height, and head circumference were measured by using standard methods. Body composition, including fat mass, lean mass, bone mineral content, and bone mineral density, was determined by dual-energy X-ray absorptiometry. Blood pressure was measured in the supine position by using an automatic device. Metabolic variables, including glucose, insulin, insulin-like growth factor I, triglycerides, cholesterol, cortisol, and leptin, were measured after an overnight fast. Nutritional habits at age 8 y were assessed by using a 3-d nutritional diary.Results: At age 8 y, no differences were found in body size, body composition, bone variables, and metabolic health variables when comparing children fed PDF with those fed TF. Adjustment for known and possible confounders did not change these results.Conclusions: In this follow-up study in preterm-born children, we showed that the favorable effects of PDF at 6-mo CA either were not maintained or could not be confirmed because of attrition at the age of 8 y. We suggest that future research should focus on nutritional interventions in the pre- and postdischarge period as a continuum rather than as separate entities. This trial was registered at www.trialregister.nl as NTR 2972 (follow-up study [STEP-2 (Study Towards the Effects of Post-discharge Nutrition 2)]) and NTR 55 [original randomized controlled trial (STEP)].