Transferability of Alzheimer's disease progression subtypes to an independent population cohort

In the past, methods to subtype or biotype patients using brain imaging data have been developed. However, it is unclear whether and how these trained machine learning models can be successfully applied to population cohorts to study the genetic and lifestyle factors underpinning these subtypes. This work, using the Subtype and Stage Inference (SuStaIn) algorithm, examines the generalisability of data-driven Alzheimer's disease (AD) progression models. We first compared SuStaIn models trained separately on Alzheimer's disease neuroimaging initiative (ADNI) data and an AD-at-risk population constructed from the UK Biobank dataset. We further applied data harmonization techniques to remove cohort effects. Next, we built SuStaIn models on the harmonized datasets, which were then used to subtype and stage subjects in the other harmonized dataset. The first key finding is that three consistent atrophy subtypes were found in both datasets, which match the previously identified subtype progression patterns in AD: 'typical', 'cortical' and 'subcortical'. Next, the subtype agreement was further supported by high consistency in individuals' subtypes and stage assignment based on the different models: more than 92% of the subjects, with reliable subtype assignment in both ADNI and UK Biobank dataset, were assigned to an identical subtype under the model built on the different datasets. The successful transferability of AD atrophy progression subtypes across cohorts capturing different phases of disease development enabled further investigations of associations between AD atrophy subtypes and risk factors. Our study showed that (1) the average age is highest in the typical subtype and lowest in the subcortical subtype; (2) the typical subtype is associated with statistically more-AD-like cerebrospinal fluid biomarkers values in comparison to the other two subtypes; and (3) in comparison to the subcortical subtype, the cortical subtype subjects are more likely to associate with prescription of cholesterol and high blood pressure medications. In summary, we presented cross-cohort consistent recovery of AD atrophy subtypes, showing how the same subtypes arise even in cohorts capturing substantially different disease phases. Our study opened opportunities for future detailed investigations of atrophy subtypes with a broad range of early risk factors, which will potentially lead to a better understanding of the disease aetiology and the role of lifestyle and behaviour on AD.

Early Risk Factors for Obesity in the First 1000 Days-Relationship with Body Fat and BMI at 2 Years

(1) Background: Obesity is defined as an excessive accumulation of body fat. Several early developmental factors have been identified which are associated with an increased risk of childhood obesity and increased adiposity in childhood. The primary objective of the present study is to analyse the effect of various early risk factors on Body Mass Index (BMI) and body fat percentage at 2 years of age. (2) Methods: A prospective cohort study design was used, with the sample consisting of 109 mother-child pairs from whom data were collected between early pregnancy and 2 years old. Adiposity was determined based on skinfold measurements using the Brooks and Siri formulae. Mean comparison tests (Student's t-test and ANOVAs) and multiple linear regression models were used to analyse the relationship between early programming factors and dependent variables. (3) Results: Maternal excess weight during early pregnancy (β = 0.203, p = 0.026), gestational smoking (β = 0.192, p = 0.036), and accelerated weight gain in the first 2 years (β = - 0.269, p = 0.004) were significantly associated with high body fat percentage. Pre-pregnancy BMI and accelerated weight gain in the first 2 years were associated with high BMI z-score (β = 0.174, p = 0.047 and β = 0.417, p = 0.000 respectively). The cumulative effect of these variables resulted in high values compared to the baseline zero-factor group, with significant differences in BMI z-score (F = 8.640, p = 0.000) and body fat percentage (F = 5.402, p = 0.002) when three factors were present. (4) Conclusions: The presence of several early risk factors related to obesity in infancy was significantly associated with higher BMI z-score and body fat percentage at 2 years of age. The presence of more than one of these variables was also associated with higher adiposity at 2 years of age. Early prevention strategies should address as many of these factors as possible.

Aberrant Early in Life Stimulation of the Stress-Response System Affects Emotional Contagion and Oxytocin Regulation in Adult Male Mice

Results over the last decades have provided evidence suggesting that HPA axis dysfunction is a major risk factor predisposing to the development of psychopathological behaviour. This susceptibility can be programmed during developmental windows of marked neuroplasticity, allowing early-life adversity to convey vulnerability to mental illness later in life. Besides genetic predisposition, also environmental factors play a pivotal role in this process, through embodiment of the mother's emotions, or via nutrients and hormones transferred through the placenta and the maternal milk. The aim of the current translational study was to mimic a severe stress condition by exposing female CD-1 mouse dams to abnormal levels of corticosterone (80 µg/mL) in the drinking water either during the last week of pregnancy (PreCORT) or the first one of lactation (PostCORT), compared to an Animal Facility Rearing (AFR) control group. When tested as adults, male mice from PostCORT offspring and somewhat less the PreCORT mice exhibited a markedly increased corticosterone response to acute restraint stress, compared to perinatal AFR controls. Aberrant persistence of adolescence-typical increased interest towards novel social stimuli and somewhat deficient emotional contagion also characterised profiles in both perinatal-CORT groups. Intranasal oxytocin (0 or 20.0 µg/kg) generally managed to reduce the stress response and restore a regular behavioural phenotype. Alterations in density of glucocorticoid and mineralocorticoid receptors, oxytocin and µ- and κ-opioid receptors were found. Changes differed as a function of brain areas and the specific age window of perinatal aberrant stimulation of the HPA axis. Present results provided experimental evidence in a translational mouse model that precocious adversity represents a risk factor predisposing to the development of psychopathological behaviour.

Identifying and predicting criminal career profiles from adolescence to age 39

Few longitudinal studies are capable of identifying criminal career profiles using both self-report and official court data beyond the 30s. The current study aims to identify criminal career profiles across three developmental periods using self-report data, validate these profiles with official court records and determine early childhood predictors. Data came from the Seattle Social Development Project (n = 808). Latent Class Analysis was used to examine criminal careers from self-reported data during adolescence (aged 14-18), early adulthood (aged 21-27) and middle adulthood (aged 30-39). Official court records were used to validate the classes. Childhood risk and promotive factors measured at ages 11-12 were used to predict classes. Findings revealed four career classes: non-offending (35.6%), adolescence-limited (33.2%), adult desister (18.3%) and life-course/persistent (12.9%). Official court records are consistent with the description of the classes. Early life school and family environments as well as having antisocial beliefs and friends differentiate membership across the classes. The results of this study, with a gender-balanced and racially diverse sample, bolster the current criminal career knowledge by examining multiple developmental periods into the 30s using both self-report and official court data.

Childhood Predictors of Violent Victimization at Age 17 Years: The Role of Early Social Behavioral Tendencies

OBJECTIVE

To assess the relation between early social behavioral tendencies and the risk of violent victimization in late adolescence.

STUDY DESIGN

We analyzed 5 waves of data from the Zurich Project on the Social Development from Childhood into Adulthood (z-proso), a longitudinal sample of Swiss first graders (N = 1138). Early social behavioral tendencies were measured at age 7 years and included internalizing problems, externalizing behavior, prosocial behavior, negative peer relations, competent problem solving, dominance, and sensation seeking. Path analyses were conducted of the association between these tendencies and violent victimization at age 17 years, and mediation through intermediate victimization at ages 11, 13, and 15 years was examined.

RESULTS

Several childhood social behavioral tendencies predicted victimization 10 years later. Though this was the case for both sexes, the number and type of significant risk factors differed. For male children, sensation seeking, externalizing behavior, high prosociality, and negative peer relations at age 7 years increased later victimization, whereas for female children, dominance and externalizing behavior were predictive. In addition, results showed that the relation between early risk factors and age 17 years victimization was mediated by intermediate victimization, showing that differences in victimization risk in early adolescence are carried forward into late adolescence.

CONCLUSIONS

Childhood social behavioral tendencies predict victimization 10 years later. Incorporating this finding into early prevention programs could reduce victimization over the life course.

Early Risk Factors for Daily Cannabis Use in Young Adults

OBJECTIVES

Daily cannabis use can portend problematic use or dependence. We aimed to identify early risk factors for daily cannabis use in young adults.

METHODS

Data were available in a longitudinal investigation of 1294 grade 7 students age 12 to 13 years at inception recruited in 10 secondary schools in Montreal, Canada, in 1999. Data on daily cannabis use were collected in mailed self-report questionnaires from 878 participants (67.9% of 1294) at age 20. The associations between each of 23 potential risk factors measured in grade 7 and daily cannabis use at age 20 were modeled using logistic regression.

RESULTS

At age 20, 44% of participants reported past-year cannabis use; 10% reported daily use. Older age; male sex; higher levels of family stress and other stress; use of alcohol, cigarettes, and other tobacco products; parent(s), sibling(s), and friend(s) smoke cigarettes; higher body mass index; higher impulsivity and novelty seeking; and lower self-esteem increased the odds of daily cannabis use.

CONCLUSIONS

Children at risk of daily cannabis use as young adults can be identified early. They may benefit from early intervention to prevent problematic cannabis use.

A comparison of the cumulative incidence and early risk factors for psychotic disorder in young adults in the Northern Finland Birth Cohorts 1966 and 1986

AIMS

Few studies have compared time trends for the incidence of psychosis. To date, the results have been inconsistent, showing a decline, an increase or no significant change. As far as we know, no studies explored changes in prevalence of early risk factors. The aim of this study was to investigate differences in early risk factors and cumulative incidences of psychosis by type of psychosis in two comparable birth cohorts.

METHODS

The Northern Finland Birth cohorts (NFBCs) 1966 (N = 12 058) and 1986 (N = 9432) are prospective general population-based cohorts with the children followed since mother's mid-pregnancy. The data for psychoses, i.e. schizophrenia (narrow, spectrum), bipolar disorder with psychotic features, major depressive episode with psychotic features, brief psychosis and other psychoses (ICD 8-10) were collected from nationwide registers including both inpatients and outpatients. The data on early risk factors including sex and place of birth of the offspring, parental age and psychosis, maternal education at birth were prospectively collected from the population registers. The follow-up reached until the age of 27 years.

RESULTS

An increase in the cumulative incidence of all psychoses was seen (1.01% in NFBC 1966 v. 1.90% in NFBC 1986; p < 0.001), which was due to an increase in diagnosed affective and other psychoses. Earlier onset of cases and relatively more psychoses in women were observed in the NFBC 1986. Changes in prevalence of potential early risk factors were identified, but only parental psychosis was a significant predictor in both cohorts (hazard ratios ≥3.0; 95% CI 1.86-4.88). The difference in psychosis incidence was not dependent on changes in prevalence of studied early risk factors.

CONCLUSIONS

Surprisingly, increase in the cumulative incidence of psychosis and also changes in the types of psychoses were found between two birth cohorts 20 years apart. The observed differences could be due to real changes in incidence or they can be attributable to changes in diagnostic practices, or to early psychosis detection and treatment.

Early clinical and laboratory risk factors of intensive care unit requirement during 2004-2008 dengue epidemics in Singapore: a matched case-control study

BACKGROUND

Dengue infection can result in severe clinical manifestations requiring intensive care. Effective triage is critical for early clinical management to reduce morbidity and mortality. However, there is limited knowledge on early risk factors of intensive care unit (ICU) requirement. This study aims to identify early clinical and laboratory risk factors of ICU requirement at first presentation in hospital and 24 hours prior to ICU requirement.

METHOD

A retrospective 1:4 matched case-control study was performed with 27 dengue patients who required ICU, and 108 dengue patients who did not require ICU from year 2004-2008, matched by year of dengue presentation. Univariate and multivariate conditional logistic regression were performed. Optimal predictive models were generated with statistically significant risk factors identified using stepwise forward and backward elimination method.

RESULTS

ICU dengue patients were significantly older (P=0.003) and had diabetes (P=0.031), compared with non-ICU dengue patients. There were seven deaths among ICU patients at median seven days post fever. At first presentation, the WHO 2009 classification of dengue severity was significantly associated (P<0.001) with ICU, but not the WHO 1997 classification. Early clinical risk factors at presentation associated with ICU requirement were hematocrit change ≥20% concurrent with platelet <50 K [95% confidence-interval (CI)=2.46-30.53], hypoproteinemia (95% CI=1.09-19.74), hypotension (95% CI=1.83-31.79) and severe organ involvement (95% CI=3.30-331). Early laboratory risk factors at presentation were neutrophil proportion (95% CI=1.04-1.17), serum urea (95% CI=1.02-1.56) and alanine aminotransferase level (95% CI=1.001-1.06). This predictive model has sensitivity and specificity up to 88%. Early laboratory risk factors at 24 hours prior to ICU were lymphocyte (95% CI=1.03-1.38) and monocyte proportions (95% CI=1.02-1.78), pulse rate (95% CI=1.002-1.14) and blood pressure (95% CI=0.92-0.996). This predictive model has sensitivity and specificity up to 88.9% and 78%, respectively.

CONCLUSIONS

This is the first matched case-control study, to our best knowledge, that identified early clinical and laboratory risk factors of ICU requirement during hospitalization. These factors suggested differential pathophysiological background of dengue patients as early as first presentation prior to ICU requirement, which may reflect the pathogenesis of dengue severity. These risk models may facilitate clinicians in triage of patients, after validating in larger independent studies.

Precursors of adolescent substance use from early childhood and early adolescence: testing a developmental cascade model

This study examined developmentally salient risk and protective factors of adolescent substance use assessed during early childhood and early adolescence using a sample of 310 low-income boys. Child problem behavior and proximal family risk and protective factors (i.e., parenting and maternal depression) during early childhood, as well as child and family factors and peer deviant behavior during adolescence, were explored as potential precursors to later substance use during adolescence using structural equation modeling. Results revealed that early childhood risk and protective factors (i.e., child externalizing problems, mothers' depressive symptomatology, and nurturant parenting) were indirectly related to substance use at the age of 17 via risk and protective factors during early and middle adolescence (i.e., parental knowledge and externalizing problems). The implications of these findings for early prevention and intervention are discussed.

Daily life behaviors and depression risk following stroke: a preliminary study using ecological momentary assessment

Approximately one-third of stroke survivors have symptoms of depression. A better understanding of the early risk factors implicated in this form of comorbidity may contribute to the development of early prevention strategies and to improving outcomes for this population. The current study uses ecological momentary assessment techniques to identify behavioral risk factors for depression 3 months after stroke. Thirty-six participants completed ambulatory monitoring of daily life circumstances (location, social environment, and activity) 5 times per day during a 1-week period after hospital discharge. Clinician-administered measures of depression were also provided before discharge and 3 months later. Ambulatory monitoring revealed that depression scores at 3 months were lower among individuals with more social interactions but higher among those who reported having sports activities and working in the week following hospital discharge. Daily life behaviors may have important implications for understanding the risk of poststroke depression, and mobile technologies may provide important contributions to their investigation.

A prospective study of childhood and adolescent antecedents of homelessness among a community population of African Americans

Much is known about contemporaneous correlates of homelessness from studies of homeless individuals. However, few studies have prospectively examined early antecedents and prevalence of homelessness in community populations. We use data from a 35-year study of a community population of African Americans to examine relationships between homelessness and prior structural, family, school, and behavioral influences. Nearly 22% of males and 16% of females reported homelessness between ages 15 and 42, providing a rare estimate within an African American urban community population. In bivariate analyses, lower school bonds, depressed mood, violent behavior, and running away in adolescence are predictive for both males and females. Teen parenting and angry mood are unique influences for females, while for males, poor first grade classroom conduct and adolescent substance use are unique risks. In multivariate analyses, poor classroom conduct and weaker school bonds predict homelessness among males, while teen parenting does so for females. Running away before age 15 is strongly predictive of later homelessness for both males and females. These results reveal the relative influence of multiple, interrelated early risks on homelessness and confirm our hypothesis that factors linked to other poor outcomes also relate to homelessness, underscoring another benefit to early prevention efforts.

Sex, temperament, and family context: how the interaction of early factors differentially predict adolescent alcohol use and are mediated by proximal adolescent factors

Adolescent alcohol use is common and has serious immediate and long-term ramifications. While concurrent individual and context factors are robustly associated with adolescent alcohol use, the influence of early childhood factors, particularly in interaction with child sex, are less clear. Using a prospective community sample of 362 (190 girls), this study investigated sex differences in the joint influence of distal childhood and proximal adolescent factors on Grade 10 alcohol use. All risk factors and two-way early individual-by-context interactions, and interactions of each of these with child sex, were entered into the initial regression. Significant sex interactions prompted the use of separate models for girls and boys. In addition to the identification of early (family socioeconomic status, authoritative parenting style) and proximal adolescent (mental health symptoms, deviant friends) risk factors for both girls and boys, results highlighted important sex differences. In particular, girls with higher alcohol consumption at Grade 10 were distinguished by the interaction of early temperamental disinhibition and exposure to parental stress; boys with higher alcohol consumption at Grade 10 were distinguished primarily by early temperamental negative affect. Results have implications for the timing and type of interventions offered to adolescents.

Identifying trajectories of adolescents' depressive phenomena: an examination of early risk factors

Few studies have examined risk factors of childhood and early adolescent depressive symptomatology trajectories. This study examined self-report depressive symptomatology across a 6-year time period from 2nd to 8th grade to identify latent groups of individuals with similar patterns of depressive phenomena in a sample of 951 children (440 girls, 511 boys). Analyses, using semiparametric group modeling (SGM), identified 5 trajectory groups for girls and boys: low depressed stables, low depressed risers, mildly depressed stables, moderately depressed changers, and moderately depressed risers. Individual risk factors, with the exception of shy/withdrawn behavior, were significantly different across trajectory group membership for boys and girls, as was low-income status for boys. Boys in the low depressed and mildly depressed stable trajectory groups had significantly higher levels of antisocial behavior, attention problems, and lower social competency compared to girls in similar groups. These results suggest that universal prevention programs implemented in early elementary school that target selected risk factors may be helpful in reducing future adolescent mental health problems, specifically depressive symptomatology.