Impact of critical illness and withholding of early parenteral nutrition in the pediatric intensive care unit on long-term physical performance of children: a 4-year follow-up of the PEPaNIC randomized controlled trial.

BACKGROUND: Many critically ill children face long-term developmental impairments. The PEPaNIC trial attributed part of the problems at the level of neurocognitive and emotional/behavioral development to early use of parenteral nutrition (early-PN) in the PICU, as compared with withholding it for 1 week (late-PN). Insight in long-term daily life physical functional capacity after critical illness is limited. Also, whether timing of initiating PN affects long-term physical function of these children remained unknown. METHODS: This preplanned follow-up study of the multicenter PEPaNIC randomized controlled trial subjected 521 former critically ill children (253 early-PN, 268 late-PN) to quantitative physical function tests 4 years after PICU admission in Leuven or Rotterdam, in comparison with 346 age- and sex-matched healthy children. Tests included handgrip strength measurement, timed up-and-go test, 6-min walk test, and evaluation of everyday overall physical activity with an accelerometer. We compared these functional measures for the former critically ill and healthy children and for former critically ill children randomized to late-PN versus early-PN, with multivariable linear or logistic regression analyses adjusting for risk factors. RESULTS: As compared with healthy children, former critically ill children showed less handgrip strength (p < 0.0001), completed the timed up-and-go test more slowly (p < 0.0001), walked a shorter distance in 6 min (p < 0.0001) during which they experienced a larger drop in peripheral oxygen saturation (p ≤ 0.026), showed a lower energy expenditure (p ≤ 0.024), performed more light and less moderate physical activity (p ≤ 0.047), and walked fewer steps per day (p = 0.0074). Late-PN as compared with early-PN did not significantly affect these outcomes. CONCLUSIONS: Four years after PICU admission, former critically ill children showed worse physical performance as compared with healthy children, without impact of timing of supplemental PN in the PICU. This study provides further support for de-implementing the early use of PN in the PICU. Trial registration ClinicalTrials.gov, NCT01536275 ; registered on February 22, 2012.

Physical, Emotional/Behavioral, and Neurocognitive Developmental Outcomes From 2 to 4 Years After PICU Admission: A Secondary Analysis of the Early Versus Late Parenteral Nutrition Randomized Controlled Trial Cohort.

OBJECTIVES: PICU patients face long-term developmental impairments, partially attributable to early parenteral nutrition (PN) versus late-PN. We investigated how this legacy and harm by early-PN evolve over time. DESIGN: Preplanned secondary analysis of the multicenter PEPaNIC-RCT (ClinicalTrials.gov, NCT01536275) that enrolled 1,440 critically ill children from 2012 to 2015 and its 2- (2014-2018) and 4-year (2016-2019) cross-sectional follow-up studies. SETTING: PICUs of Leuven (Belgium), Rotterdam (The Netherlands), and Edmonton (Canada). PATIENTS: Patients and demographically matched healthy control children that underwent longitudinal assessment for physical/emotional/behavioral/neurocognitive functions at both follow-up time points. INTERVENTIONS: In the PEPaNIC-RCT, patients were randomly allocated to early-PN versus late-PN. MEASUREMENTS AND MAIN RESULTS: This within-individual longitudinal study investigated changes in physical/emotional/behavioral/neurocognitive functions from 2 to 4 years after PICU admission for 614 patients (297 early-PN and 317 late-PN, tested at mean ± sd age 5.4 ± 4.2 and 7.3 ± 4.3 yr) and for 357 demographically matched healthy children tested at age 5.6 ± 4.3 and 7.5 ± 4.3 years. We determined within-group time-courses, interaction between time and group, and independent impact of critical illness and early-PN on these time-courses. Most deficits in patients versus healthy children remained prominent over the 2 years ( p ≤ 0.01). Deficits further aggravated for height, body mass index, the executive function metacognition, intelligence, motor coordination (alternating/synchronous tapping), and memory learning-index, whereas verbal memory deficits became smaller (working/immediate/delayed memory) ( p ≤ 0.05). Adjustment for risk factors confirmed most findings and revealed that patients "grew-into-deficit" for additional executive functions (flexibility/emotional control/total executive functioning) and "grew-out-of-deficit" for additional memory functions (recognition/pictures) ( p ≤ 0.05). Time-courses were largely unaffected by early-PN versus late-PN, except for weight loss and limited catch-up for visual-motor integration and alertness in early-PN patients ( p ≤ 0.05). CONCLUSIONS: From 2- to 4-year post-PICU admission, developmental impairments remained prominent. Within that time-window, impaired growth in height, executive functioning and intelligence aggravated, and impaired memory and harm by early-PN only partially recovered. Impact on development into adulthood requires further investigation.

Long-term impact of paediatric critical illness on the difference between epigenetic and chronological age in relation to physical growth.

BACKGROUND: Altered DNA-methylation affects biological ageing in adults and developmental processes in children. DNA-methylation is altered by environmental factors, trauma and illnesses. We hypothesised that paediatric critical illness, and the nutritional management in the paediatric intensive care unit (PICU), affects DNA-methylation changes that underly the developmental processes of childhood ageing. RESULTS: We studied the impact of critical illness, and of the early use of parenteral nutrition (early-PN) versus late-PN, on "epigenetic age-deviation" in buccal mucosa of 818 former PICU-patients (406 early-PN, 412 late-PN) who participated in the 2-year follow-up of the multicentre PEPaNIC-RCT (ClinicalTrials.gov-NCT01536275), as compared with 392 matched healthy children, and assessed whether this relates to their impaired growth. The epigenetic age-deviation (difference between PedBE clock-estimated epigenetic age and chronological age) was calculated. Using bootstrapped multivariable linear regression models, we assessed the impact hereon of critical illness, and of early-PN versus late-PN. As compared with healthy children, epigenetic age of patients assessed 2 years after PICU-admission deviated negatively from chronological age (p < 0.05 in 51% of bootstrapped replicates), similarly in early-PN and late-PN groups. Next, we identified vulnerable subgroups for epigenetic age-deviation using interaction analysis. We revealed that DNA-methylation age-deceleration in former PICU-patients was dependent on age at time of illness (p < 0.05 for 83% of bootstrapped replicates), with vulnerability starting from 6 years onwards. Finally, we assessed whether vulnerability to epigenetic age-deviation could be related to impaired growth from PICU-admission to follow-up at 2 and 4 years. Multivariable repeated measures ANOVA showed that former PICU-patients, as compared with healthy children, grew less in height (p = 0.0002) and transiently gained weight (p = 0.0003) over the 4-year time course. Growth in height was more stunted in former PICU-patients aged ≥ 6-years at time of critical illness (p = 0.002) than in the younger patients. CONCLUSIONS: As compared with healthy children, former PICU-patients, in particular those aged ≥ 6-years at time of illness, revealed epigenetic age-deceleration, with a physical correlate revealing stunted growth in height. Whether this vulnerability around the age of 6 years for epigenetic age-deceleration and stunted growth years later relates to altered endocrine pathways activated at the time of adrenarche requires further investigation.

Assessment of aberrant DNA methylation two years after paediatric critical illness: a pre-planned secondary analysis of the international PEPaNIC trial.

Critically ill children requiring intensive care suffer from impaired physical/neurocognitive development 2 y later, partially preventable by omitting early use of parenteral nutrition (early-PN) in the paediatric intensive-care-unit (PICU). Altered methylation of DNA from peripheral blood during PICU-stay provided a molecular basis hereof. Whether DNA-methylation of former PICU patients, assessed 2 y after critical illness, is different from that of healthy children remained unknown. In a pre-planned secondary analysis of the PEPaNIC-RCT (clinicaltrials.gov-NCT01536275) 2-year follow-up, we assessed buccal-mucosal DNA-methylation (Infinium-HumanMethylation-EPIC-BeadChip) of former PICU-patients (N = 406 early-PN; N = 414 late-PN) and matched healthy children (N = 392). CpG-sites differentially methylated between groups were identified with multivariable linear regression and differentially methylated DNA-regions via clustering of differentially methylated CpG-sites using kernel-estimates. Analyses were adjusted for technical variation and baseline risk factors, and corrected for multiple testing (false-discovery-rate <0.05). Differentially methylated genes were functionally annotated (KEGG-pathway database), and allocated to three classes depending on involvement in physical/neurocognitive development, critical illness and intensive medical care, or pre-PICU-admission disorders. As compared with matched healthy children, former PICU-patients showed significantly different DNA-methylation at 4047 CpG-sites (2186 genes) and 494 DNA-regions (468 genes), with most CpG-sites being hypomethylated (90.3%) and with an average absolute 2% effect-size, irrespective of timing of PN initiation. Of the differentially methylated KEGG-pathways, 41.2% were related to physical/neurocognitive development, 32.8% to critical illness and intensive medical care and 26.0% to pre-PICU-admission disorders. Two years after critical illness in children, buccal-mucosal DNA showed abnormal methylation of CpG-sites and DNA-regions located in pathways known to be important for physical/neurocognitive development.

Differential DNA methylation by early versus late parenteral nutrition in the PICU: a biological basis for its impact on emotional and behavioral problems documented 4 years later.

BACKGROUND: The PEPaNIC multicenter randomized controlled trial (RCT) has shown that early administration of supplemental parenteral nutrition (early-PN) as compared with withholding PN for 1 week (late-PN) induced long-term internalizing, externalizing and total emotional/behavioral problems in critically ill children, as observed 4 years later. Early-PN was further shown to alter the methylation status of 37 CpG-sites in leukocyte DNA between admission and discharge from the pediatric intensive care unit (PICU). In a preplanned subanalysis of the PEPaNIC trial, we now investigated whether the altered methylation of these CpG-sites could statistically explain the negative impact of early-PN on emotion/behavior documented 4 years after PICU admission. RESULTS: The combination of DNA methylation data and data on behavior 4 years after PICU admission was available for 403 of the 1440 patients (aged 0-17 years at PICU admission) who were included in the PEPaNIC RCT (192 early-PN and 211 late-PN patients). Mediation analyses with use of bootstrapped multivariable non-linear regression analyses adjusted for baseline risk factors revealed that the adverse alterations by early-PN in methylation of the 37 CpG-sites together statistically explained its harmful impact on internalizing, externalizing and total emotional/behavioral problems. When adding the methylation status of the 37 CpG-sites to the models, the explanatory power improved with a 1.710 to 1.851-fold increase, and the impact of the altered methylation status of the CpG-sites explained the impact of the randomization to early-PN versus late-PN. CONCLUSIONS: Abnormal DNA methylation induced by the early use of PN in the PICU provides a biological basis for its long-term harmful effect on emotion/behavior of critically ill children 4 years after PICU admission. Trial Registration ClinicalTrials.gov NCT01536275, registered February 17, 2012, https://clinicaltrials.gov/ct2/show/NCT01536275 .

Role of age of critically ill children at time of exposure to early or late parenteral nutrition in determining the impact hereof on long-term neurocognitive development: A secondary analysis of the PEPaNIC-RCT.

BACKGROUND & AIMS: Early use of parenteral nutrition (early-PN), as compared with withholding it for one week (late-PN), in the PICU, has shown to slow down recovery from critical illness and impair long-term development of 6 neurocognitive/behavioural/emotional functions assessed 2 years later. Given that key steps in brain maturation occur at different times during childhood, we hypothesised that age at time of exposure determines long-term developmental impact of early-PN. METHODS: The 786 children who were neurocognitively tested 2 years after participation in the PEPaNIC-RCT were included in this study. First, for each studied long-term outcome, interaction between randomisation to early-PN versus late-PN and age was assessed with multivariable linear regression analysis. Subsequently, for outcomes with an interaction p ≤ 0.15, the impact of early-PN versus late-PN was analysed, after adjustment for risk factors, for 4 subgroups defined based on developmentally-relevant age at time of exposure [≤28 days (n = 121), 29 days to 11 months (n = 239), 11 months to <5 years (n = 223) and ≥5 years (n = 203)]. RESULTS: Interaction between randomisation and age was present for weight, and parent-reported inhibitory control, cognitive flexibility, working memory, planning/organisation, metacognition, total executive functioning, and internalising and total behavioural/emotional problems. Subgroup analyses revealed that none of the age-groups revealed benefit, whereas children aged 29 days to <11 months were most vulnerable to harm by early-PN for development of inhibitory control (p = 0.008), working memory (p = 0.009), planning/organisation (p = 0.004), metacognition (p = 0.008), and total executive functioning (p = 0.004), and for internalising (p = 0.005) and total behavioural/emotional problems (p = 0.01). Children aged 11 months to <5 years revealed harm by early-PN for development of inhibitory control (p = 0.003). In contrast, children aged ≥5 years and neonates aged ≤28 days appeared less vulnerable. CONCLUSIONS: Critically ill children aged 29 days to 11 months at time of exposure were identified as most vulnerable to developmental harm evoked by early-PN. CLINICAL TRIALS.GOV: NCT01536275.

Time course of altered DNA methylation evoked by critical illness and by early administration of parenteral nutrition in the paediatric ICU.

BACKGROUND: A genome-wide study identified de novo DNA methylation alterations in leukocytes of children at paediatric intensive care unit (PICU) discharge, offering a biological basis for their impaired long-term development. Early parenteral nutrition (early-PN) in PICU, compared with omitting PN in the first week (late-PN), explained differential methylation of 23% of the affected CpG-sites. We documented the time course of altered DNA methylation in PICU and the impact hereon of early nutritional management. RESULTS: We selected 36 early-PN and 36 late-PN matched patients, and 42 matched healthy children. We quantified DNA methylation on days 3, 5 and 7 for the 147 CpG-sites of which methylation was normal upon PICU admission in this subset and altered by critical illness at PICU discharge. Methylation in patients differed from healthy children for 64.6% of the 147 CpG-sites on day 3, for 72.8% on day 5 and for 90.5% on day 7 as revealed by ANOVA at each time point. Within-patients methylation time course analyses for each CpG-site identified different patterns based on paired t test p value and direction of change. Rapid demethylation from admission to day 3 occurred for 76.2% of the CpG-sites, of which 67.9% remained equally demethylated or partially remethylated and 32.1% further demethylated beyond day 3. From admission to day 3, 19.7% of the CpG-sites became hypermethylated, of which, beyond day 3, 34.5% remained equally hypermethylated or partially demethylated again and 65.5% further hypermethylated. For 4.1% of the CpG-sites, changes only appeared beyond day 3. Finally, for the CpG-sites affected by early-PN on the last PICU day, earlier changes in DNA methylation were compared for early-PN and late-PN patients, revealing that 38.9% were already differentially methylated by day 3, another 25.0% by day 5 and another 13.9% by day 7. CONCLUSIONS: Critical illness- and early-PN-induced changes in DNA methylation occurred mainly within 3 days. Most abnormalities were at least partially maintained or got worse with longer time in PICU. Interventions targeting aberrant DNA methylation changes should be initiated early.

Effect of early parenteral nutrition during paediatric critical illness on DNA methylation as a potential mediator of impaired neurocognitive development: a pre-planned secondary analysis of the PEPaNIC international randomised controlled trial.

BACKGROUND: Early use of parenteral nutrition in the paediatric intensive care unit (PICU) negatively affects development of executive functions, externalising behaviour, and visual-motor integration 2 years later, compared with omitting parenteral nutrition until PICU day 8 (late parenteral nutrition). The molecular basis of this finding is uncertain. We aimed to test the hypothesis that DNA methylation changes occur during critical illness and that early parenteral nutrition (or a specific macronutrient component hereof) contributes to these changes, which could explain its negative effects on neurocognitive development. METHODS: This pre-planned secondary analysis of the multicentre PEPaNIC trial (2012-18) included all patients with a last PICU day blood sample (n=825, aged 0-17 years at PICU admission) who were randomly allocated (1:1) to early parenteral nutrition or late parenteral nutrition, as compared with 352 demographically matched healthy children. Investigators were masked to treatment allocation. We used the Infinium Human MethylationEPIC BeadChip to determine the genome-wide peripheral blood leukocyte DNA methylation of 865 859 CpG sites, yielding high-quality results for 403 patients allocated to early parenteral nutrition and for 411 patients allocated to late parenteral nutrition. Applying a false discovery rate of less than 0·05, DNA methylation of patients on the last PICU day was compared with that of healthy children, after excluding all CpG sites differentially methylated upon PICU admission, because these reflected pre-admission conditions and altered leukocyte composition. We used bootstrapped multivariable linear and non-linear regression analyses to assess the effect of early parenteral nutrition versus late parenteral nutrition on illness-induced alterations in DNA methylation and to what extent differentially methylated CpG sites explained impaired neurocognitive development 2 years later. FINDINGS: During PICU stay, 159 CpG sites were methylated differently in patients admitted to the PICU than in healthy children, with mean effect sizes of 2·6% (SD 2·5) up to 21·6% (p<0·02). These differentially methylated CpG sites occurred in genes involved in brain development, plasticity, and signalling; neuronal differentiation, migration, and growth; metabolism; transcriptional regulation; physical development and locomotion; and several neurodegenerative and neuropsychiatric diseases. Early parenteral nutrition and, in particular, the dose of amino acids, independently contributed to the differential methylation of 37 (23%) of these 159 CpG sites (p=0·0001 to 0·050), which could explain the adverse effect of early parenteral nutrition on neurocognitive development at 2-year follow-up (R2 0·61 [SD 0·01]). INTERPRETATION: Early parenteral nutrition during paediatric critical illness altered DNA methylation, which suggests a plausible molecular basis for its negative effect on long-term neurocognitive development. Early administration of amino acids, rather than of glucose or lipids, mostly explained the aberrant DNA methylation-a finding that requires further investigation. FUNDING: European Research Council, Methusalem, Flanders Institute for Science and Technology, Research Foundation Flanders, Sophia Foundation, Stichting Agis Zorginnovatie, Erasmus Trustfonds, and European Society for Clinical Nutrition and Metabolism.

Long-term developmental effect of withholding parenteral nutrition in paediatric intensive care units: a 4-year follow-up of the PEPaNIC randomised controlled trial.

BACKGROUND: The PEPaNIC randomised controlled trial, which recruited 1440 critically ill infants and children in 2012-15, showed that withholding parenteral nutrition for 1 week (late-parenteral nutrition), compared with early supplementation within 24 h of admission to the paediatric intensive care unit (early-parenteral nutrition), prevented infections, accelerated recovery, and improved neurocognitive development assessed 2 years later. Because several neurocognitive domains can only be thoroughly assessed from age 4 years onwards, we aimed to determine the effect of late-parenteral nutrition versus early-parenteral nutrition on physical, neurocognitive, and emotional and behavioural development 4 years after randomisation. METHODS: This is a preplanned, blinded, 4-year follow-up study of participants included in the PEPaNIC trial (done at University Hospitals Leuven, Belgium; Erasmus Medical Centre Sophia Children's Hospital, Rotterdam, Netherlands; and Stollery Children's Hospital, Edmonton, AB, Canada) and of matched healthy children. Studied outcomes were anthropometrics; health status; parent-reported or caregiver-reported executive functions, and emotional and behavioural problems; and clinical tests for intelligence, visual-motor integration, alertness, motor coordination, and memory. Through multivariable linear and logistic regression analyses, after imputation for missing values (≤30%) and adjustment for risk factors, we investigated the effect of early-parenteral nutrition versus late-parenteral nutrition. This trial is registered with ClinicalTrials.gov, NCT01536275. FINDINGS: Between March 8, 2016, and Nov 8, 2019, 684 children from the original PEPaNIC trial (356 from the late-parenteral nutrition group and 328 from the early-parenteral nutrition group) were assessed for neurocognitive development at 4-years follow-up. Compared with the control group (369 healthy children), children who had critical illness had lower height (ß-estimate -2·11 [95% CI -3·15 to -1·06]; p<0·0001) and head circumference (-0·42 [-0·67 to -0·18]; p=0.00077); and worse health status (eg, hospital admission odds ratio 4·27 [95% CI 3·12 to 5·84]; p<0·0001), neurocognitive (eg, parent-reported or caregiver-reported total executive functioning ß-estimate 3·57 [95% CI 1·95 to 5·18], p<0·0001; total intelligence quotient -7·35 [-9·31 to -5·39], p<0·0001), and parent-reported or caregiver-reported emotional and behavioural developmental outcomes (internalising 2·73 [1·19 to 4·28], p=0·00055; externalising 1·63 [0·19 to 3·08], p=0·027; and total behavioural problems 2·95 [1·44 to 4·46], p=0·00013), adjusted for risk factors. Outcomes were never worse in the late-parenteral nutrition group compared with the early-parenteral nutrition group, but patients in the late-parenteral nutrition group had fewer parent-reported or caregiver-reported internalising (ß-estimate -1·88 [95% CI -3·69 to -0·07]; p=0·042), externalising (-1·73 [-3·43 to -0·03]; p=0·046), and total emotional and behavioural problems (-2·44 [-4·22 to -0·67]; p=0·0070) than patients who had received early-parenteral nutrition, after adjusting for risk factors, and were no longer different from healthy controls for these outcomes. INTERPRETATION: Omitting early parenteral nutrition use for critically ill children did not adversely affect long-term outcomes 4 years after randomisation and protected against emotional and behavioural problems, further supporting the deimplementation of early parenteral nutrition. FUNDING: European Research Council, Methusalem, Flanders Institute for Science and Technology, Research Foundation Flanders, Sophia Foundation, Stichting Agis Zorginnovatie, Erasmus Trustfonds, and the European Society for Clinical Nutrition and Metabolism.

Early Supplemental Parenteral Nutrition in Critically Ill Children: An Update.

In critically ill children admitted to pediatric intensive care units (PICUs), enteral nutrition (EN) is often delayed due to gastrointestinal dysfunction or interrupted. Since a macronutrient deficit in these patients has been associated with adverse outcomes in observational studies, supplemental parenteral nutrition (PN) in PICUs has long been widely advised to meeting nutritional requirements. However, uncertainty of timing of initiation, optimal dose and composition of PN has led to a wide variation in previous guidelines and current clinical practices. The PEPaNIC (Early versus Late Parenteral Nutrition in the Pediatric ICU) randomized controlled trial recently showed that withholding PN in the first week in PICUs reduced incidence of new infections and accelerated recovery as compared with providing supplemental PN early (within 24 hours after PICU admission), irrespective of diagnosis, severity of illness, risk of malnutrition or age. The early withholding of amino acids in particular, which are powerful suppressors of intracellular quality control by autophagy, statistically explained this outcome benefit. Importantly, two years after PICU admission, not providing supplemental PN early in PICUs did not negatively affect mortality, growth or health status, and significantly improved neurocognitive development. These findings have an important impact on the recently issued guidelines for PN administration to critically ill children. In this review, we summarize the most recent literature that provides evidence on the implications for clinical practice with regard to the use of early supplemental PN in critically ill children.