Sacha la Bastide-van Gemert

Construct validity of the Infant Motor Profile: relation with prenatal, perinatal, and neonatal risk factors.

Aim  The Infant Motor Profile (IMP) is a qualitative assessment of motor behaviour of infants aged 3 to 18 months. The aim of this study was to investigate construct validity of the IMP through the relation of IMP scores with prenatal, perinatal, and neonatal variables, including the presence of brain pathology indicated by neonatal ultrasound imaging of the brain.

Effectiveness of seasonal influenza vaccination in community-dwelling elderly people: an individual participant data meta-analysis of test-negative design case-control studies

BACKGROUND Several aggregate data meta-analyses have provided estimates of the effectiveness of influenza vaccination in community-dwelling elderly people. However, these studies ignored the effects of patient-level confounders such as sex, age, and chronic diseases that could bias effectiveness estimates. We aimed to assess the confounder-adjusted effectiveness of influenza vaccines on laboratory-confirmed influenza among elderly people by conducting a global individual participant data meta-analysis. METHODS In this individual participant data meta-analysis, we considered studies included in a previously conducted aggregate data meta-analysis that included test-negative design case-control studies published up to July 13, 2014. We contacted all authors of the included studies on Dec 1, 2014, to request individual participant data. Patients were excluded if their unique identifier was missing, their vaccination status was unknown, their outcome status was unknown, or they had had suspected influenza infection more than once in the same influenza season. Cases were patients with influenza-like illness symptoms who tested positive for at least one of A H1N1, A H1N1 pdm09, A H3N2, or B viruses; controls were patients with influenza-like illness symptoms who tested negative for these virus types or subtypes. Influenza vaccine effectiveness against overall and subtype-specific laboratory-confirmed influenza were the primary and secondary outcomes. We used a generalised linear mixed model to calculate adjusted vaccine effectiveness according to vaccine match to the circulating strains of influenza virus and intensity of the virus activity (epidemic or non-epidemic). Vaccine effectiveness was defined as the relative reduction in risk of laboratory-confirmed influenza in vaccinated patients compared with unvaccinated patients. We did subgroup analyses to estimate vaccine effectiveness according to hemisphere, age category, and health status. FINDINGS We received 23 of the 53 datasets included in the aggregate data meta-analysis. Furthermore, six additional datasets were provided by data collaborators, which resulted in individual participant data for a total of 5210 participants. A total of 4975 patients had the required data for analysis. Of these, 3146 (63%) were controls and 1829 (37%) were cases. Influenza vaccination was significantly effective during epidemic seasons irrespective of vaccine match status (matched adjusted vaccine effectiveness 44·38%, 95% CI 22·63-60·01; mismatched adjusted vaccine effectiveness 20·00%, 95% CI 3·46-33·68; analyses in the imputed dataset). Seasonal influenza vaccination did not show significant effectiveness during non-epidemic seasons. We found substantial variation in vaccine effectiveness across virus types and subtypes, with the highest estimate for A H1N1 pdm09 (53·19%, 10·25-75·58) and the lowest estimate for B virus types (-1·52%, -39·58 to 26·16). Although we observed no significant differences between subgroups in each category (hemisphere, age, and health status), influenza vaccination showed a protective effect among elderly people with cardiovascular disease, lung disease, or aged 75 years and younger. INTERPRETATION Influenza vaccination is moderately effective against laboratory-confirmed influenza in elderly people during epidemic seasons. More research is needed to investigate factors affecting vaccine protection (eg, brand-specific or type-specific vaccine effectiveness and repeated annual vaccination) in elderly people. FUNDING University Medical Center Groningen.

Reliability and concurrent validity of the Infant Motor Profile

The Infant Motor Profile (IMP) is a qualitative assessment of motor behaviour in infancy. It consists of five domains: movement variation, variability, fluency, symmetry, and performance. The aim of this study was to assess interobserver reliability and concurrent validity of the IMP with the Alberta Infant Motor Scale (AIMS) and an age‐specific neurological examination.

Is ovarian hyperstimulation associated with higher blood pressure in 4-year-old IVF offspring? Part II: an explorative causal inference approach

STUDY QUESTION What causal relationships underlie the associations between ovarian stimulation, the IVF procedure, parental-, fertility- and child characteristics, and blood pressure (BP) and anthropometrics of 4-year-old IVF children? SUMMARY ANSWER Causal models compatible with the data suggest the presence of positive direct effects of controlled ovarian hyperstimulation as applied in IVF (COH-IVF) on systolic blood pressure (SBP) percentiles and subscapular skinfold thickness. WHAT IS KNOWN ALREADY Increasing evidence suggests that IVF is associated with higher blood pressure and altered body fat distribution in offspring, but underlying mechanisms describing the causal relationships between the variables are largely unknown. STUDY DESIGN, SIZE, DURATION In this assessor-blinded follow-up study, 194 children were assessed. The attrition rate until the 4-year-old assessment was 10%. PARTICIPANTS/MATERIALS, SETTING, METHODS We measured blood pressure and anthropometrics of 4-year-old singletons born following COH-IVF (n = 63), or born following modified natural cycle IVF (MNC-IVF, n = 52) or born to subfertile couples who conceived naturally (Sub-NC, n = 79). Primary outcome measures were the SBP and diastolic blood pressure (DBP) percentiles. Anthropometrics included triceps and subscapular skinfold thickness. Causal inference search algorithms and structural equation modeling were applied. MAIN RESULTS AND THE ROLE OF CHANCE Explorative analyses suggested a direct effect of COH on SBP percentiles and on subscapular skinfold thickness. This hypothesis needs confirmation with additional, preferably larger, studies. LIMITATIONS, REASONS FOR CAUTION Search algorithms were used as explorative tools to generate hypotheses on the causal mechanisms underlying fertility treatment, blood pressure, anthropometrics and other variables. More studies using larger groups are needed to draw firm conclusions. WIDER IMPLICATIONS OF THE FINDINGS Our findings are in line with other studies describing adverse effects of IVF on cardiometabolic outcome, but this is the first study suggesting a causal mechanism underlying this association. Perhaps ovarian hyperstimulation negatively influences cardiometabolic outcome via changes in the early environment of the oocyte and/or embryo, possibly resulting in epigenetic modifications of key metabolic systems that are involved in BP regulation. Future research needs to confirm the role of ovarian stimulation in poorer cardiometabolic outcome and should investigate the underlying mechanisms. Our proposed causal models provide research hypotheses to be tested with new data from preferably larger studies. STUDY FUNDING/COMPETING INTEREST(S) The authors have no conflicts of interest to declare. The study was supported by the University Medical Center Groningen, the Cornelia Foundation and the school for Behavioral- and Cognitive Neurosciences. The sponsors of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report.

Blood pressure and anthropometrics of 4-y-old children born after preimplantation genetic screening: follow-up of a unique, moderately sized, randomized controlled trial

Background:Recent studies suggest that in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are associated with suboptimal cardiometabolic outcome in offspring. It is unknown whether preimplantation genetic screening (PGS), which involves embryo biopsy, affects blood pressure (BP), anthropometrics, and the frequency of received medical care.Methods:In this prospective multicenter follow-up study, we assessed BP, anthropometrics, and received medical care of 4-y-old children born to women who were randomly assigned to IVF/ICSI with PGS (n = 49) or without PGS (controls; n = 64). We applied linear and generalized linear mixed-effects models to investigate possible effects of PGS.Results:BP in the PGS and control groups was similar: 102/64 and 100/64 mm Hg, respectively. Main anthropometric outcomes in the PGS vs. control group were: BMI: 16.1 vs. 15.8; triceps skinfold: 108 vs. 98 mm; and subscapular skinfold: 54 vs. 53 mm (all P values > 0.05). More PGS children than controls had received paramedical care (speech, physical, or occupational therapy: 14 (29%) vs. 9 (14%); P = 0.03 in multivariable analysis). The frequency of medicial treatment was comparable.Conclusion:PGS does not seem to affect BP or anthropometrics in 4-y-old children. The higher frequency of received paramedical care after PGS may suggest an effect of PGS on subtle developmental parameters.

Subfertility factors rather than assisted conception factors affect cognitive and behavioural development of 4-year-old singletons

Research on cognitive and behavioural development of children born after assisted conception is inconsistent. This prospective study aimed to explore underlying causal relationships between ovarian stimulation, in-vitro procedures, subfertility components and child cognition and behaviour. Participants were singletons born to subfertile couples after ovarian stimulation IVF (n = 63), modified natural cycle IVF (n = 53), natural conception (n = 79) and singletons born to fertile couples (reference group) (n = 98). At 4 years, cognition (Kaufmann-ABC-II; total IQ) and behaviour (Child Behavior Checklist; total problem T-score) were assessed. Causal inference search algorithms and structural equation modelling was applied to unravel causal mechanisms. Most children had typical cognitive and behavioural scores. No underlying causal effect was found between ovarian stimulation and the in-vitro procedure and outcome. Direct negative causal effects were found between severity of subfertility (time to pregnancy) and cognition and presence of subfertility and behaviour. Maternal age and maternal education acted as confounders. The study concludes that no causal effects were found between ovarian stimulation or in-vitro procedures and cognition and behaviour in childrenaged 4 years born to subfertile couples. Subfertility, especially severe subfertility, however, was associated with worse cognition and behaviour.

Causal inference algorithms can be useful in life course epidemiology

OBJECTIVES Life course epidemiology attempts to unravel causal relationships between variables observed over time. Causal relationships can be represented as directed acyclic graphs. This article explains the theoretical concepts of the search algorithms used for finding such representations, discusses various types of such algorithms, and exemplifies their use in the context of obesity and insulin resistance. STUDY DESIGN AND SETTING We investigated possible causal relations between gender, birth weight, waist circumference, and blood glucose level of 4,081 adult participants of the Prevention of REnal and Vascular ENd-stage Disease study. The latter two variables were measured at three time points at intervals of about 3 years. RESULTS We present the resulting causal graphs, estimate parameters of the corresponding structural equation models, and discuss usefulness and limitations of this methodology. CONCLUSION As an exploratory method, causal graphs and the associated theory can help construct possible causal models underlying observational data. In this way, the causal search algorithms provide a valuable statistical tool for life course epidemiological research.

Long-term Air Pollution Exposure, Genome-wide DNA Methylation and Lung Function in the LifeLines Cohort Study

Background: Long-term air pollution exposure is negatively associated with lung function, yet the mechanisms underlying this association are not fully clear. Differential DNA methylation may explain this association. Objectives: Our main aim was to study the association between long-term air pollution exposure and DNA methylation. Methods: We performed a genome-wide methylation study using robust linear regression models in 1,017 subjects from the LifeLines cohort study to analyze the association between exposure to nitrogen dioxide (NO2) and particulate matter (PM2.5, fine particulate matter with aerodynamic diameter ≤2.5μm; PM10, particulate matter with aerodynamic diameter ≤10μm) and PM2.5absorbance, indicator of elemental carbon content (estimated with land-use-regression models) with DNA methylation in whole blood (Illumina® HumanMethylation450K BeadChip). Replication of the top hits was attempted in two independent samples from the population-based Cooperative Health Research in the Region of Augsburg studies (KORA). Results: Depending on the p-value threshold used, we found significant associations between NO2 exposure and DNA methylation for seven CpG sites (Bonferroni corrected threshold p<1.19×10−7) or for 4,980 CpG sites (False Discovery Rate<0.05). The top associated CpG site was annotated to the PSMB9 gene (i.e., cg04908668). None of the seven Bonferroni significant CpG-sites were significantly replicated in the two KORA-cohorts. No associations were found for PM exposure. Conclusions: Long-term NO2 exposure was genome-wide significantly associated with DNA methylation in the identification cohort but not in the replication cohort. Future studies are needed to further elucidate the potential mechanisms underlying NO2-exposure–related respiratory disease. https://doi.org/10.1289/EHP2045

Cholesterol Efflux Pathways Suppress Inflammasome Activation, NETosis and Atherogenesis

Background: The CANTOS trial (Canakinumab Antiinflammatory Thrombosis Outcome Study) showed that antagonism of interleukin (IL)–1&bgr; reduces coronary heart disease in patients with a previous myocardial infarction and evidence of systemic inflammation, indicating that pathways required for IL-1&bgr; secretion increase cardiovascular risk. IL-1&bgr; and IL-18 are produced via the NLRP3 inflammasome in myeloid cells in response to cholesterol accumulation, but mechanisms linking NLRP3 inflammasome activation to atherogenesis are unclear. The cholesterol transporters ATP binding cassette A1 and G1 (ABCA1/G1) mediate cholesterol efflux to high-density lipoprotein, and Abca1/g1 deficiency in myeloid cells leads to cholesterol accumulation. Methods: To interrogate mechanisms connecting inflammasome activation with atherogenesis, we used mice with myeloid Abca1/g1 deficiency and concomitant deficiency of the inflammasome components Nlrp3 or Caspase-1/11. Bone marrow from these mice was transplanted into Ldlr −/− recipients, which were fed a Western-type diet. Results: Myeloid Abca1/g1 deficiency increased plasma IL-18 levels in Ldlr −/− mice and induced IL-1&bgr; and IL-18 secretion in splenocytes, which was reversed by Nlrp3 or Caspase-1/11 deficiency, indicating activation of the NLRP3 inflammasome. Nlrp3 or Caspase-1/11 deficiency decreased atherosclerotic lesion size in myeloid Abca1/g1-deficient Ldlr −/− mice. Myeloid Abca1/g1 deficiency enhanced caspase-1 cleavage not only in splenic monocytes and macrophages, but also in neutrophils, and dramatically enhanced neutrophil accumulation and neutrophil extracellular trap formation in atherosclerotic plaques, with reversal by Nlrp3 or Caspase-1/11 deficiency, suggesting that inflammasome activation promotes neutrophil recruitment and neutrophil extracellular trap formation in atherosclerotic plaques. These effects appeared to be indirectly mediated by systemic inflammation leading to activation and accumulation of neutrophils in plaques. Myeloid Abca1/g1 deficiency also activated the noncanonical inflammasome, causing increased susceptibility to lipopolysaccharide-induced mortality. Patients with Tangier disease, who carry loss-of-function mutations in ABCA1 and have increased myeloid cholesterol content, showed a marked increase in plasma IL-1&bgr; and IL-18 levels. Conclusions: Cholesterol accumulation in myeloid cells activates the NLRP3 inflammasome, which enhances neutrophil accumulation and neutrophil extracellular trap formation in atherosclerotic plaques. Patients with Tangier disease, who have increased myeloid cholesterol content, showed markers of inflammasome activation, suggesting human relevance.

Movement variation in infants born following IVF/ICSI with and without ovarian hyperstimulation

BACKGROUND The effect of in vitro fertilisation (IVF) on neurodevelopment is not fully understood. Probably, IVF does not affect traditional measures of neurodevelopment in infancy. Recently, an instrument, the Infant Motor Profile (IMP), was developed that evaluates the quality of motor behaviour. It includes the evaluation of movement variation (i.e. movement repertoire size), a parameter reflecting the integrity of cortical connectivity. AIM To evaluate the effect of ovarian hyperstimulation and the in vitro procedure on movement variation during infancy. STUDY DESIGN Prospective cohort study. SUBJECTS Singletons born following IVF or intracytoplasmic sperm injection (ICSI) with conventional controlled ovarian hyperstimulation (COH-IVF/ICSI, n=68), in a modified natural cycle (MNC-IVF/ICSI, n=57) and natural conception born to subfertile couples (Sub-NC, n=90). OUTCOME MEASURES Children were assessed with the IMP at 4, 10 and 18 months, resulting in a total IMP score and five domain scores: variation, variability, symmetry, fluency and performance. Primary outcome was the domain score variation. RESULTS A significant effect of study group was observed for the variation score up until 18 months of age (p=0.039). COH-IVF/ICSI children had a significantly lower mean variation score than MNC-IVF/ICSI children (mean difference [95% confidence interval] -1.010 [-1.766; -0.254]). Mean variation scores of COH-IVF/ICSI and Sub-NC children were similar; the same held true for the comparison between MNC-IVF/ICSI and Sub-NC. Total IMP scores and other domain scores of the three groups were similar. CONCLUSION The present study did not demonstrate a clear effect of ovarian hyperstimulation and the in vitro procedure on movement variation throughout infancy.