Association of common maternal infections with birth outcomes: a multinational cohort study

PURPOSE

It is unclear whether common maternal infections during pregnancy are risk factors for adverse birth outcomes. We assessed the association between self-reported infections during pregnancy with preterm birth and small-for-gestational-age (SGA) in an international cohort consortium.

METHODS

Data on 120,507 pregnant women were obtained from six population-based birth cohorts in Australia, Denmark, Israel, Norway, the UK and the USA. Self-reported common infections during pregnancy included influenza-like illness, common cold, any respiratory tract infection, vaginal thrush, vaginal infections, cystitis, urinary tract infection, and the symptoms fever and diarrhoea. Birth outcomes included preterm birth, low birth weight and SGA. Associations between maternal infections and birth outcomes were first assessed using Poisson regression in each cohort and then pooled using random-effect meta-analysis. Risk ratios (RR) and 95% confidence intervals (CI) were calculated, adjusted for potential confounders.

RESULTS

Vaginal infections (pooled RR, 1.10; 95% CI, 1.02-1.20) and urinary tract infections (pooled RR, 1.17; 95% CI, 1.09-1.26) during pregnancy were associated with higher risk of preterm birth. Similar associations with low birth weight were also observed for these two infections. Fever during pregnancy was associated with higher risk of SGA (pooled RR, 1.07; 95% CI, 1.02-1.12). No other significant associations were observed between maternal infections/symptoms and birth outcomes.

CONCLUSION

Vaginal infections and urinary infections during pregnancy were associated with a small increased risk of preterm birth and low birth weight, whereas fever was associated with SGA. These findings require confirmation in future studies with laboratory-confirmed infection diagnosis.

Association of Ideal Cardiovascular Health in Youth with Cancer Risk in Adulthood: Cardiovascular Risk in Young Finns Study

BACKGROUND

Lifestyle factors may affect cancer risk. This study aimed to identify whether American Heart Association (AHA) Ideal Cardiovascular Health (ICH) score and its individual variables in youth associate with subsequent cancer incidence.

METHODS

Study comprised of participants of the Cardiovascular Risk in Young Finns Study free of cancer at analysis baseline in 1986 (n=1873). Baseline age was 12-24 years and the follow-up occurred between 1986-2018.

RESULTS

Among 1873 participants (mean age 17.3±4.1 years; 53.4% females at baseline), 72 incident cancer cases occurred during the follow-up (mean follow-up time 31.4±3.4 years). Baseline ICH score was not associated with future cancer risk (HR 0.96, 95% CI 0.78-1.12 per 1-point increment). Of individual ICH score variables, ideal physical activity (PA) was inversely associated with cancer incidence (age- and sex-adjusted HR 0.45 (0.23-0.88) per 1-category change [nonideal/ideal]), and remained significant in multivariable-adjusted model including also BMI, smoking, diet and socioeconomic status. A continuous physical activity index at ages 9-24 years and moderate to vigorous physical activity in youth were also related to decreased cancer incidence (p<0.05). BMI, smoking, diet, total cholesterol, glucose and blood pressure were not related to cancer risk. Of the dietary components, meat consumption was associated with cancer incidence (p=0.023).

CONCLUSIONS

These findings indicate that higher PA levels in youth associate with a reduced subsequent cancer incidence whereas AHA´s ICH score in youth does not.

IMPACT

This finding supports the efforts in promoting healthy lifestyle and encourages in physical activity during childhood yielding in subsequent healthier life.

Non-High-Density Lipoprotein Cholesterol Levels From Childhood to Adulthood and Cardiovascular Disease Events

Importance

Elevated non-high-density lipoprotein cholesterol (non-HDL-C; a recommended measure of lipid-related cardiovascular risk) is common in children and increases risk of adult cardiovascular disease (CVD). Whether resolution of elevated childhood non-HDL-C levels by adulthood is associated with reduced risk of clinical CVD events is unknown.

Objective

To examine the associations of non-HDL-C status between childhood and adulthood with incident CVD events.

Design, Setting, and Participants

Individual participant data from 6 prospective cohorts of children (mean age at baseline, 10.7 years) in the US and Finland. Recruitment took place between 1970 and 1996, with a final follow-up in 2019.

Exposures

Child (age 3-19 years) and adult (age 20-40 years) non-HDL-C age- and sex-specific z scores and categories according to clinical guideline-recommended cutoffs for dyslipidemia.

Main Outcomes and Measures

Incident fatal and nonfatal CVD events adjudicated by medical records.

Results

Over a mean length of follow-up of 8.9 years after age 40 years, 147 CVD events occurred among 5121 participants (60% women; 15% Black). Both childhood and adult non-HDL-C levels were associated with increased risk of CVD events (hazard ratio [HR], 1.42 [95% CI, 1.18-1.70] and HR, 1.50 [95% CI, 1.26-1.78] for a 1-unit increase in z score, respectively), but the association for childhood non-HDL-C was reduced when adjusted for adult levels (HR, 1.12 [95% CI, 0.89-1.41]). A complementary analysis showed that both childhood non-HDL-C levels and the change between childhood and adulthood were independently associated with the outcome, suggesting that from a preventive perspective, both childhood non-HDL-C levels and the change into adulthood are informative. Compared with those whose non-HDL-C levels remained within the guideline-recommended range in childhood and adulthood, participants who had incident non-HDL-C dyslipidemia from childhood to adulthood and those with persistent dyslipidemia had increased risks of CVD events (HR, 2.17 [95% CI, 1.00-4.69] and HR, 5.17 [95% CI, 2.80-9.56], respectively). Individuals who had dyslipidemic non-HDL-C in childhood but whose non-HDL-C levels were within the guideline-recommended range in adulthood did not have a significantly increased risk (HR, 1.13 [95% CI, 0.50-2.56]).

Conclusions and Relevance

Individuals with persistent non-HDL-C dyslipidemia from childhood to adulthood had an increased risk of CVD events, but those in whom dyslipidemic non-HDL-C levels resolve by adulthood have similar risk to individuals who were never dyslipidemic. These findings suggest that interventions to prevent and reduce elevated childhood non-HDL-C levels may help prevent premature CVD.

Modelling the replacement of red and processed meat with plant-based alternatives and the estimated effect on insulin sensitivity in a cohort of Australian adults

Dietary guidelines are increasingly promoting mostly plant-based diets, limits on red meat consumption, and plant-based sources of protein for health and environmental reasons. It is unclear how the resulting food substitutions associate with insulin resistance, a risk factor for type 2 diabetes. We modelled the replacement of red and processed meat with plant-based alternatives and the estimated effect on insulin sensitivity. We included 783 participants (55 % female) from the Childhood Determinants of Adult Health study, a population-based cohort of Australians. In adulthood, diet was assessed at three time points using FFQ: 2004–2006, 2009–2011 and 2017–2019. We calculated the average daily intake of each food group in standard serves. Insulin sensitivity was estimated from fasting glucose and insulin concentrations in 2017–2019 (aged 39–49 years) using homoeostasis model assessment. Replacing red meat with a combination of plant-based alternatives was associated with higher insulin sensitivity (β = 10·5 percentage points, 95 % CI (4·1, 17·4)). Adjustment for waist circumference attenuated this association by 61·7 %. Replacing red meat with either legumes, nuts/seeds or wholegrains was likewise associated with higher insulin sensitivity. Point estimates were similar but less precise when replacing processed meat with plant-based alternatives. Our modelling suggests that regularly replacing red meat, and possibly processed meat, with plant-based alternatives may associate with higher insulin sensitivity. Further, abdominal adiposity may be an important mediator in this relationship. Our findings support advice to prioritise plant-based sources of protein at the expense of red meat consumption.

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

BACKGROUND

Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.

METHODS

We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5-19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median).

FINDINGS

From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness.

INTERPRETATION

The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

FUNDING

UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union.

Determining pathways of effect between correlates and outcomes of transport-related physical activity at differing timepoints across the lifecourse: A structural equation modelling approach

Transport-related physical activity levels differ across the lifecourse; however, the nature of these differences is poorly understood. This study examined the relationship between correlates of transport-related physical activity and how they differ in strength, pathway, and direction across the lifecourse. Structural Equation Modelling assessed relationships between correlates (e.g., age, smoking, education) and transport-related physical activity (assessed via the International Physical Activity Questionnaire) at four timepoints of the Australian Childhood Determinants of Adult Health study: childhood (7-15y; n = 6302), early-adulthood (26-36y; n = 2700), early/mid-adulthood (31-41y; n = 1649), and mid-adulthood (36-49y; n = 1794). Several pathways were consistent across the lifecourse. Self-rated health directly associated with transport-related physical activity across all timepoints. During adulthood greater body mass index and smoking frequency were indirectly associated with lower levels of transport-related physical activity via self-rated health; similarly, lower educated adults, who smoked more frequently, and had poorer health, had lower transport-related physical activity. Urban residence was directly associated with greater transport-related physical activity in childhood and early-adulthood; having more children in early/mid- and mid-adulthood was directly associated with less transport-related physical activity. This is the first study to report pathways of direct and indirect association between correlates and transport-related physical activity at key lifecourse stages. The pathways highlighted can inform policy and practice to aid in the development of age-specific lifecourse interventions.

Childhood Non-HDL Cholesterol and LDL Cholesterol and Adult Atherosclerotic Cardiovascular Events

BACKGROUND

Although low-density lipoprotein cholesterol (LDL-C) remains the primary cholesterol target in clinical practice in children and adults, non-high-density lipoprotein cholesterol (non-HDL-C) has been suggested as a more accurate measure of atherosclerotic cardiovascular disease (ASCVD) risk. We examined the associations of childhood non-HDL-C and LDL-C levels with adult ASCVD events and determined whether non-HDL-C has better utility than LDL-C in predicting adult ASCVD events.

METHODS

This prospective cohort study included 21 126 participants from the i3C Consortium (International Childhood Cardiovascular Cohorts). Proportional hazards regressions were used to estimate the risk for incident fatal and fatal/nonfatal ASCVD events associated with childhood non-HDL-C and LDL-C levels (age- and sex-specific z scores; concordant/discordant categories defined by guideline-recommended cutoffs), adjusted for sex, Black race, cohort, age at and calendar year of child measurement, body mass index, and systolic blood pressure. Predictive utility was determined by the C index.

RESULTS

After an average follow-up of 35 years, 153 fatal ASCVD events occurred in 21 126 participants (mean age at childhood visits, 11.9 years), and 352 fatal/nonfatal ASCVD events occurred in a subset of 11 296 participants who could be evaluated for this outcome. Childhood non-HDL-C and LDL-C levels were each associated with higher risk of fatal and fatal/nonfatal ASCVD events (hazard ratio ranged from 1.27 [95% CI, 1.14-1.41] to 1.35 [95% CI, 1.13-1.60] per unit increase in the risk factor z score). Non-HDL-C had better discriminative utility than LDL-C (difference in C index, 0.0054 [95% CI, 0.0006-0.0102] and 0.0038 [95% CI, 0.0008-0.0068] for fatal and fatal/nonfatal events, respectively). The discordant group with elevated non-HDL-C and normal LDL-C had a higher risk of ASCVD events compared with the concordant group with normal non-HDL-C and LDL-C (fatal events: hazard ratio, 1.90 [95% CI, 0.98-3.70]; fatal/nonfatal events: hazard ratio, 1.94 [95% CI, 1.23-3.06]).

CONCLUSIONS

Childhood non-HDL-C and LDL-C levels are associated with ASCVD events in midlife. Non-HDL-C is better than LDL-C in predicting adult ASCVD events, particularly among individuals who had normal LDL-C but elevated non-HDL-C. These findings suggest that both non-HDL-C and LDL-C are useful in identifying children at higher risk of ASCVD events, but non-HDL-C may provide added prognostic information when it is discordantly higher than the corresponding LDL-C and has the practical advantage of being determined without a fasting sample.

A Pregnancy and Childhood Epigenetics Consortium (PACE) meta-analysis highlights potential relationships between birth order and neonatal blood DNA methylation

Higher birth order is associated with altered risk of many disease states. Changes in placentation and exposures to in utero growth factors with successive pregnancies may impact later life disease risk via persistent DNA methylation alterations. We investigated birth order with Illumina DNA methylation array data in each of 16 birth cohorts (8164 newborns) with European, African, and Latino ancestries from the Pregnancy and Childhood Epigenetics Consortium. Meta-analyzed data demonstrated systematic DNA methylation variation in 341 CpGs (FDR adjusted P < 0.05) and 1107 regions. Forty CpGs were located within known quantitative trait loci for gene expression traits in blood, and trait enrichment analysis suggested a strong association with immune-related, transcriptional control, and blood pressure regulation phenotypes. Decreasing fertility rates worldwide with the concomitant increased proportion of first-born children highlights a potential reflection of birth order-related epigenomic states on changing disease incidence trends.

Tracking of Cardiorespiratory Fitness from Childhood to Mid-adulthood

High cardiorespiratory fitness (CRF) in adulthood is important for survival from major chronic diseases and preserving good health. We examined how childhood CRF tracks, or persists, into adulthood. Among a cohort of 748 school children followed over 34 years, we found child CRF correlated with young- (r = 0.30) and mid-adulthood (r = 0.16) CRF.

Exploring the direct and indirect effects of cardiovascular disease risk factors on exercise blood pressure

OBJECTIVE

Exaggerated exercise blood pressure (BP) is independently associated with cardiovascular disease (CVD) outcomes. However, it is unknown how individual CVD risk factors may interact with one another to influence exercise BP. The aim of this study was to quantify direct and indirect associations between CVD risk factors and exercise BP, to determine what CVD risk factor/s most-strongly relate to exercise BP.

METHODS

In a cross-sectional design, 660 participants (44 ± 2.6 years, 54% male) from the population-based Childhood Determinants of Adult Health Study had BP measured during low-intensity fixed-workload cycling. CVD risk factors were measured, including body composition, clinic (rest) BP, blood biomarkers, and cardiorespiratory fitness. Associations between CVD risk factors and exercise BP were assessed using linear regression, with direct and indirect pathways of association assessed via structural equation model.

RESULTS

Sex, waist-to-hip ratio, fitness, and clinic BP were independently associated with exercise systolic BP (SBP), and along with age, had direct associations with exercise SBP (p < 0.05 all). Most CVD risk factors were indirectly associated with exercise SBP via a relation with clinic BP (p < 0.05 all). Clinic BP, waist-to-hip ratio, and fitness were most-strongly associated (direct and indirect association) with exercise SBP (β[95% CI]: 9.35 [8.04, 10.67], 4.91 [2.56, 7.26], and -2.88 [-4.25, -1.51] mm Hg/SD, respectively).

CONCLUSION

Many CVD risk factors are associated with exercise BP, mostly with indirect effects via clinic BP. Clinic BP, body composition, and fitness were most-strongly associated with exercise BP. These results may elucidate how lifestyle modification could be a primary strategy to decrease exaggerated exercise BP-related CVD risk.

Association of body mass index from childhood to mid-adulthood with health-related quality of life in mid-adulthood

PURPOSE

Most studies regarding the association of obesity with health-related quality of life (HRQoL) have assessed obesity at only one or two time points. We aimed to examine the associations of life course body mass index (BMI) from childhood with health-related quality of life (HRQoL) in mid-adulthood.

METHODS

Data were from a cohort study of Australian children (n = 2254, mean baseline age 12.0 (2.0) years in 1985, 46.8% male). Weight and height were measured at baseline and measured or self-reported on average 20, 25, and 30 years later. Age and sex-standardised BMI-z score was calculated at each time point. Physical and mental HRQoL and health state utilities (HSUs) were measured by SF-12 and SF-6D at the last adult follow-up. Linear regression was used to examine the associations adjusting for age, sex, and childhood health status.

RESULTS

Higher BMI-z score in childhood (βadjusted - 1.39, 95% CI - 1.73 to - 1.05) and increasing BMI-z score from childhood to young adulthood (βadjusted - 1.82, 95% CI - 2.17 to - 1.46) and from young to mid-adulthood (βadjusted - 1.77, 95% CI - 2.28 to - 1.26) were associated with lower physical HRQoL in mid-adulthood. Similar results were found for mid-adulthood HSUs (βadjusted ranged - 0.006 to - 0.014, all P < 0.05). Only increasing BMI-z score from young to mid-adulthood significantly related to poorer mental HRQoL (βadjusted - 0.74, 95% CI - 1.29 to - 0.19) in mid-adulthood.

CONCLUSION

High BMI from childhood to mid-adulthood had only modest associations with HRQoL and HSUs, with effects on physical HRQoL most apparent.

Sex differences in the association between stroke risk factors and pre-clinical predictors of stroke in the childhood determinants of Adult Health study

BACKGROUND AND AIMS

It is unclear why blood pressure (BP), metabolic markers and smoking increase stroke incidence in women more than men. We examined these associations with carotid artery structure and function in a prospective cohort study.

METHODS

Participants in the Australian Childhood Determinants of Adult Health study at ages 26-36 years (2004-06) were followed-up at 39-49 years (2014-19). Baseline risk factors included smoking, fasting glucose, insulin, systolic and diastolic BP. Carotid artery plaques, intima-media thickness [IMT], lumen diameter and carotid distensibility [CD] were assessed at follow up. Log binomial and linear regression with risk factor × sex interactions predicted carotid measures. Sex-stratified models adjusting for confounders were fitted when significant interactions were identified.

RESULTS

Among 779 participants (50% women), there were significant risk factor × sex interactions with baseline smoking, systolic BP and glucose associated with carotid measures in women only. Current smoking was associated with incidence of plaques (RRunadjusted 1.97 95% CI 1.4, 3.39), which reduced when adjusted for sociodemographics, depression, and diet (RRadjusted 1.82 95% CI 0.90, 3.66). Greater systolic BP was associated with lower CD adjusted for sociodemographics (βadjusted -0.166 95% CI -0.233, -0.098) and hypertension with greater lumen diameter (βunadjusted 0.131 95% CI 0.037, 0.225), which decreased when adjusted for sociodemographics, body composition and insulin (βadjusted 0.063 95% CI -0.052, 0.178). Greater glucose (βunadjusted -0.212 95% CI -0.397, -0.028) was associated with lower CD, which decreased when adjusted for sociodemographics, BP, depression and polycystic ovary syndrome (βadjusted -0.023 95% CI -0.249, 0.201).

CONCLUSIONS

Smoking, SBP and glucose affect carotid structure and function more in women than men with some of this risk due to co-occurring risk factors.

Tracking handgrip strength asymmetry from childhood to mid-life

AIM

Determine if asymmetric handgrip strength exists in childhood and adulthood and quantify the degree of tracking of handgrip strength asymmetry over time.

METHODS

Participants from the Childhood Determinants of Adult Health Study had their right and left handgrip strength measured using handgrip dynamometry in childhood (1985: 9-15 y), young adulthood (2004-06: 26-36 y) and/or mid-adulthood (2014-19: 36-49 y). Handgrip strength asymmetry was calculated as: strongest handgrip strength/strongest handgrip strength on the other hand. Participants were categorised based on the degree of their asymmetry (0.0%-10.0%, 10.1%-20.0%, 20.1%-30.0%, >30.0%). Tracking was quantified using Spearman's correlations and log binomial regression.

RESULTS

Handgrip strength asymmetry was present in childhood and adulthood (>30.0% asymmetry: childhood = 6%, young adulthood = 3%, mid-adulthood = 4%). Handgrip strength asymmetry did not track between childhood and young- (r = 0.06, 95% CI = -0.02, 0.12) and mid-adulthood (r = 0.01, 95% CI = -0.09, 0.10). Tracking was more apparent between young- and mid-adulthood (r = 0.16, 95% CI = 0.09, 0.22). Participants with >30.0% asymmetry were at greater risk to maintain this status between childhood and young- (RR = 3.53, 95% CI = 1.15, 10.87) and mid-adulthood (RR = 2.14, 95% CI = 0.45, 10.20).

CONCLUSION

Although handgrip strength asymmetry tracked relatively poorly, asymmetric handgrip strength was apparent in children and adults. Handgrip strength asymmetry does not exclusively affect older adults and should be considered in protocols to better understand its role across the life course.

Metabolic Syndrome and Inflammation from Young to Mid-Adulthood and Subclinical Kidney Damage in Middle-Aged Australians

Background: Relationships between metabolic syndrome (MetS), inflammation, and chronic kidney disease (CKD) have been reported, but long-term follow-up studies are limited. This study aimed to investigate whether MetS and C-reactive protein (CRP) from young adulthood associated with the risk of subclinical kidney damage (SKD), a surrogate measure for CKD, in mid-adulthood. Materials and Methods: One thousand fifteen participants from the Childhood Determinants of Adult Health study aged 26-36 years at baseline (2004-2006) were followed up at age 36-49 (2014-2019). Log-binomial regression was used to determine whether MetS and high CRP in young adulthood and from young to mid-adulthood predicted the risk of SKD (an estimated glomerular filtration rate [eGFR] of 30-60 mL/min/1.73 m2 or an eGFR >60 mL/min/1.73 m2 with a urine albumin-creatinine ratio ≥2.5 mg/mmol [males] or ≥3.5 mg/mmol [females]) in midlife. Results: Having MetS in young adulthood was associated with an increased risk of SKD in midlife (adjusted relative risk [aRR] = 2.67, 95% confidence interval [CI]: 1.24-5.76). Participants with MetS and high CRP as young adults had a greater risk of having SKD in midlife (aRR = 4.27, 95% CI: 1.61-11.30) compared with those without MetS and high CRP. Furthermore, for participants with persistent MetS, the aRR of SKD in midlife was 4.08 (95% CI: 1.84-9.05) compared with those without MetS from young to mid-adulthood. No significant associations were found between CRP in young adulthood, or change in CRP from young to mid-adulthood, and SKD in midlife. Conclusions: MetS in young adulthood, with and without high CRP, and persistent MetS were associated with an increased risk of SKD in middle midlife.

Distinct patterns of adult transport-related physical activity (TRPA) behaviour exist independent of the TRPA behaviours of childhood: the childhood determinants of adult health study

BACKGROUND

Transport-related physical activity (TRPA) is recognised as a potential means of increasing total physical activity participation that may yield substantial health benefits. Public health campaigns focusing on promoting TRPA from a young age aim to develop life-long healthy habits. However, few studies have examined how TRPA changes across the lifecourse and whether childhood TRPA levels influence those observed later in life.

METHODS

Using the Australian Childhood Determinants of Adult Health study (baseline, 1985), latent class growth mixture modelling with adjustment for time-varying covariates was performed using four timepoints (ranging from 7 to 49 years) to assess behavioural patterns and retention of TRPA across the lifecourse. As child and adult adjusted TRPA measures could not be harmonised, trajectories of adult TRPA (n = 702) were instead identified, and log-binomial regression analysis was performed to determine whether childhood levels of TRPA (high/medium/low) influenced these trajectories.

RESULTS

Two stable groups of adult TRPA trajectories were identified: persistently low (n = 520; 74.2%), and increasingly high TRPA (n = 181; 25.8%). There was no significant relationship between childhood TRPA levels and patterns in adulthood (relative risk of high childhood TRPA yielding high adult TRPA trajectory membership = 1.06; 95% confidence interval = 0.95-1.09).

CONCLUSION

This study found childhood TRPA levels were not associated with TRPA patterns in adulthood. These findings suggest that while TRPA in childhood may have health, social, and environmental benefits, it does not appear to impact adult TRPA directly. Therefore, further intervention is required beyond childhood to promote the implementation of healthy TRPA behaviours into adulthood.

Sex-Specific Associations of MDM2 and MDM4 Variants with Risk of Multiple Primary Melanomas and Melanoma Survival in Non-Hispanic Whites

MDM2-SNP309 (rs2279744), a common genetic modifier of cancer incidence in Li-Fraumeni syndrome, modifies risk, age of onset, or prognosis in a variety of cancers. Melanoma incidence and outcomes vary by sex, and although SNP309 exerts an effect on the estrogen receptor, no consensus exists on its effect on melanoma. MDM2 and MDM4 restrain p53-mediated tumor suppression, independently or together. We investigated SNP309, an a priori MDM4-rs4245739, and two coinherited variants, in a population-based cohort of 3663 primary incident melanomas. Per-allele and per-haplotype (MDM2_SNP309-SNP285; MDM4_rs4245739-rs1563828) odds ratios (OR) for multiple-melanoma were estimated with logistic regression models. Hazard ratios (HR) for melanoma death were estimated with Cox proportional hazards models. In analyses adjusted for covariates, females carrying MDM4-rs4245739*C were more likely to develop multiple melanomas (ORper-allele = 1.25, 95% CI 1.03-1.51, and Ptrend = 0.03), while MDM2-rs2279744*G was inversely associated with melanoma-death (HRper-allele = 0.63, 95% CI 0.42-0.95, and Ptrend = 0.03). We identified 16 coinherited expression quantitative loci that control the expression of MDM2, MDM4, and other genes in the skin, brain, and lungs. Our results suggest that MDM4/MDM2 variants are associated with the development of subsequent primaries and with the death of melanoma in a sex-dependent manner. Further investigations of the complex MDM2/MDM4 motif, and its contribution to the tumor microenvironment and observed associations, are warranted.

Association Between Risk Factors in Childhood and Sex Differences in Prevalence of Carotid Artery Plaques and Intima-Media Thickness in Mid-Adulthood in the Childhood Determinants of Adult Health Study

Background The origins of sex differences in cardiovascular diseases are not well understood. We examined the contribution of childhood risk factors to sex differences in adult carotid artery plaques and intima-media thickness (carotid IMT). Methods and Results Children in the 1985 Australian Schools Health and Fitness Survey were followed up when they were aged 36 to 49 years (2014-19, n=1085-1281). Log binomial and linear regression examined sex differences in adult carotid plaques (n=1089) or carotid IMT (n=1283). Childhood sociodemographic, psychosocial, and biomedical risk factors that might contribute to sex differences in carotid IMT/plaques were examined using purposeful model building with additional adjustment for equivalent adult risk factors in sensitivity analyses. Women less often had carotid plaques (10%) than men (17%). The sex difference in the prevalence of plaques (relative risk [RR] unadjusted 0.59 [95% CI, 0.43 to 0.80]) was reduced by adjustment for childhood school achievement and systolic blood pressure (RR adjusted 0.65 [95% CI, 0.47 to 0.90]). Additional adjustment for adult education and systolic blood pressure further reduced sex difference (RR adjusted 0.72 [95% CI, 0.49 to 1.06]). Women (mean±SD 0.61±0.07) had thinner carotid IMT than men (mean±SD 0.66±0.09). The sex difference in carotid IMT (β unadjusted -0.051 [95% CI, -0.061 to -0.042]) reduced with adjustment for childhood waist circumference and systolic blood pressure (β adjusted -0.047 [95% CI, -0.057 to -0.037]) and further reduced with adjustment for adult waist circumference and systolic blood pressure (β adjusted -0.034 [95% CI, -0.048 to -0.019]). Conclusions Some childhood factors contributed to adult sex differences in plaques and carotid IMT. Prevention strategies across the life course are important to reduce adult sex differences in cardiovascular diseases.

A healthful plant-based eating pattern is longitudinally associated with higher insulin sensitivity in Australian adults

BACKGROUND

A healthful plant-based eating pattern is associated with lower type 2 diabetes risk; however, the association with its preceding state, compromised insulin sensitivity, is less well-established, particularly in younger populations with repeated measures of diet over time.

OBJECTIVE

We aimed to examine the longitudinal relationship between a healthful plant-based eating pattern and insulin sensitivity in young to middle-aged adults.

METHODS

We included 667 participants from the Childhood Determinants of Adult Health (CDAH) study, a population-based cohort in Australia. Healthful plant-based diet index (hPDI) scores were derived from food frequency questionnaire data. Plant foods considered 'healthful' were scored positively (e.g., whole grains, fruit, vegetables), with all remaining foods scored reversely (e.g., refined grains, soft drinks, meat). Updated homeostatic model assessment (HOMA2) estimated insulin sensitivity from fasting insulin and glucose concentrations. We used linear mixed-effects regression to analyse data from two time points: CDAH-1 (2004-06, aged 26-36 years) and CDAH-3 (2017-19, aged 36-49 years). hPDI scores were modelled as between- and within-person effects (i.e., a participant's overall mean and their deviation from said mean at each time point, respectively).

RESULTS

The median follow-up duration was 13 years. In our primary analysis, each 10-unit difference in hPDI score was associated with higher log-HOMA2 insulin sensitivity [95% confidence interval], with between-person (β = 0.11 [0.05, 0.17], P < .001) and within-person effects (β = 0.10 [0.04, 0.16], P = .001). The within-person effect persisted despite accounting for compliance with dietary guidelines. Adjustment for waist circumference attenuated the between-person effect by 70% (P = .26) and the within-person effect by 40% (P = .04).

CONCLUSIONS

In young to middle-aged Australian adults, a healthful plant-based eating pattern (determined using hPDI scores) was longitudinally associated with higher insulin sensitivity, and therefore, potentially lower type 2 diabetes risk later in life.

Use of clinical scores in young Australian adults for prediction of atherosclerosis in middle age

We sought to apply a simple cardiovascular health tool not requiring laboratory tests (the Fuster-BEWAT score, FBS) to predict subclinical atherosclerosis. This study included 2657 young adults (< 40 years of age). In the prognostic group (n = 894, followed for 13 years until aged 40-50 years at follow-up), the primary outcome was presence of carotid plaque measured by carotid ultrasound at follow-up. Of these 894 participants, 86 (9.6%) had unilateral, and 23 participants (2.6%) had bilateral, carotid plaques at follow-up. The baseline FBS was predictive of carotid plaque at follow-up [odds ratio OR = 0.86 (95% CI 0.77-0.96) per 1-SD increase in FBS], similar to prediction from Pooled Cohort Equation [PCE, OR = 0.72 (0.61-0.85) per 1-SD decrease in PCE]. Risk scores at baseline predicted outcomes more strongly than those at follow-up, and did so independently of any changes over 13 years of follow-up. Similar discrimination for predicting carotid plaque after 13 years was found for both baseline FBS [C-statistic = 0.68 (95% CI 0.62-0.74)] and PCE [C-statistic = 0.69 (95% CI 0.63-0.75)]. Application of this FBS prognostic information to a contemporary cohort of 1763 young adults anticipates the future development of plaque in 305 (17.3%), especially in the 1494 participants (85%) with ≤ 2 metrics of ideal health. In conclusions, FBS measured in young adulthood predicted atherosclerosis 13 years later in middle age, independent of score changes over the follow-up period, emphasizing the importance of early damage to vascular health. FBS may be a simple and feasible risk score for engaging low-risk young people with reduction of future cardiovascular risk.

Evaluation of Maternal Infection During Pregnancy and Childhood Leukemia Among Offspring in Denmark

IMPORTANCE

Maternal infection is common during pregnancy and is an important potential cause of fetal genetic and immunological abnormalities. Maternal infection has been reported to be associated with childhood leukemia in previous case-control or small cohort studies.

OBJECTIVE

To evaluate the association of maternal infection during pregnancy with childhood leukemia among offspring in a large study.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used data from 7 Danish national registries (including the Danish Medical Birth Register, the Danish National Patient Registry, the Danish National Cancer Registry, and others) for all live births in Denmark between 1978 and 2015. Swedish registry data for all live births between 1988 and 2014 were used to validate the findings for the Danish cohort. Data were analyzed from December 2019 to December 2021.

EXPOSURES

Maternal infection during pregnancy categorized by anatomic locations identified from the Danish National Patient Registry.

MAIN OUTCOMES AND MEASURES

The primary outcome was any leukemia; secondary outcomes were acute lymphoid leukemia (ALL) and acute myeloid leukemia (AML). Offspring childhood leukemia was identified in the Danish National Cancer Registry. Associations were first assessed in the whole cohort using Cox proportional hazards regression models, adjusted for potential confounders. A sibling analysis was performed to account for unmeasured familial confounding.

RESULTS

This study included 2 222 797 children, 51.3% of whom were boys. During the approximately 27 million person-years of follow-up (mean [SD], 12.0 [4.6] years per person), 1307 children were diagnosed with leukemia (ALL, 1050; AML, 165; or other, 92). Children born to mothers with infection during pregnancy had a 35% increased risk of leukemia (adjusted hazard ratio [HR], 1.35 [95% CI, 1.04-1.77]) compared with offspring of mothers without infection. Maternal genital and urinary tract infections were associated with a 142% and 65% increased risk of childhood leukemia, with HRs of 2.42 (95% CI, 1.50-3.92) and 1.65 (95% CI, 1.15-2.36), respectively. No association was observed for respiratory tract, digestive, or other infections. The sibling analysis showed comparable estimates to the whole-cohort analysis. The association patterns for ALL and AML were similar to that for any leukemia. No association was observed for maternal infection and brain tumors, lymphoma, or other childhood cancers.

CONCLUSIONS AND RELEVANCE

In this cohort study of approximately 2.2 million children, maternal genitourinary tract infection during pregnancy was associated with childhood leukemia among offspring. If confirmed in future studies, our findings may have implications for understanding the etiology and developing preventive measures for childhood leukemia.

Common maternal infections during pregnancy and childhood leukaemia in the offspring: findings from six international birth cohorts

BACKGROUND

Previous epidemiological studies have found positive associations between maternal infections and childhood leukaemia; however, evidence from prospective cohort studies is scarce. We aimed to examine the associations using large-scale prospective data.

METHODS

Data were pooled from six population-based birth cohorts in Australia, Denmark, Israel, Norway, the UK and the USA (recruitment 1950s-2000s). Primary outcomes were any childhood leukaemia and acute lymphoblastic leukaemia (ALL); secondary outcomes were acute myeloid leukaemia (AML) and any childhood cancer. Exposures included maternal self-reported infections [influenza-like illness, common cold, any respiratory tract infection, vaginal thrush, vaginal infections and urinary tract infection (including cystitis)] and infection-associated symptoms (fever and diarrhoea) during pregnancy. Covariate-adjusted hazard ratio (HR) and 95% confidence interval (CI) were estimated using multilevel Cox models.

RESULTS

Among 312 879 children with a median follow-up of 13.6 years, 167 leukaemias, including 129 ALL and 33 AML, were identified. Maternal urinary tract infection was associated with increased risk of any leukaemia [HR (95% CI) 1.68 (1.10-2.58)] and subtypes ALL [1.49 (0.87-2.56)] and AML [2.70 ([0.93-7.86)], but not with any cancer [1.13 (0.85-1.51)]. Respiratory tract infection was associated with increased risk of any leukaemia [1.57 (1.06-2.34)], ALL [1.43 (0.94-2.19)], AML [2.37 (1.10-5.12)] and any cancer [1.33 (1.09-1.63)]; influenza-like illness showed a similar pattern but with less precise estimates. There was no evidence of a link between other infections and any outcomes.

CONCLUSIONS

Urinary tract and respiratory tract infections during pregnancy may be associated with childhood leukaemia, but the absolute risk is small given the rarity of the outcome.

Body-mass index trajectories from childhood to mid-adulthood and their sociodemographic predictors: Evidence from the International Childhood Cardiovascular Cohort (i3C) Consortium

Background

Understanding lifecourse trajectories of body-mass index (BMI) is important for identifying groups at high risk of poor health and potential target points for intervention. This study aimed to describe BMI trajectories from childhood to mid-adulthood in four population-based cohorts established in the 1970s and 1980s and to identify childhood sociodemographic factors related to trajectory membership.

Methods

Between Dec 17, 1970 and Dec 15, 1994, data were collected at the first visit from 9830 participants from the International Childhood Cardiovascular Cohort (i3C) Consortium, which includes participants from Australia (1985), Finland (1980) and the USA (1970-1994). Participants had at least three measures of height and weight, including one in childhood (6-18 years) and one in adulthood (>18 years), and were aged 30-49 years at last measurement. Latent Class Growth Mixture Modelling was used to identify lifecourse BMI trajectory groups and log multinomial regression models were fit to identify their childhood sociodemographic predictors.

Findings

Five consistent BMI trajectory groups were identified amongst the four cohorts: persistently low (35.9-58.6%), improving from high (0.7-4.8%), progressing to moderate (9.3-43.7%), progressing to high (1.1-6.0%), and progressing to very high (0.7-1.3%). An additional three BMI trajectory groups were identified in some, but not all, cohorts: adult onset high (three cohorts; 1.8-20.7%), progressing to moderate-high (two cohorts; 5.2-13.8%), and relapsing yo-yoers (alternating upward and downward; one cohort; 1.3%). In pooled analyses, each predictor variable in childhood, including age, gender, parental education and race, was associated with increased likelihood of belonging to the most (e.g., improving from high) and least (e.g., progressing to very high) favourable BMI trajectory groups, suggesting a U-shaped (or inverse U-shaped) pattern of association.

Interpretation

Five consistent BMI trajectory groups were identified across four cohorts from Australia, Finland, and the USA, mainly across two eras of birth. While most participants remained on a persistently low trajectory (50%), many demonstrated worsening BMI trajectories (47%), with only few demonstrating improving trajectories (<5%). Age, gender, parental education, and race appear to be important predictors of BMI trajectory group membership and need consideration in preventive and management strategies.

Funding

This study was supported by funding from the National Institutes of Health, National Heart, Lung and Blood Institute (grant number R01 HL121230).

Household size, T regulatory cell development, and early allergic disease: a birth cohort study

BACKGROUND

Children born to larger households have less allergic disease. T regulatory cell (Treg) development may be a relevant mechanism, but this has not been studied longitudinally.

OBJECTIVE

We aim to (i) describe how prenatal and postnatal environmental factors are associated with Treg development and (ii) investigate whether serial Treg measures predict allergic outcomes at 1 year of age.

METHODS

A birth cohort (n = 1074) with information on prenatal and postnatal early life factors. Both naïve Treg (nTreg) and activated Treg (aTreg) cell populations (as a proportion of CD4⁺ T cells) were available in 463 infants at birth (cord blood), 600 at 6 months, and 675 at 12 months. 191 infants had serial measures. Measures of allergic status at 12 months were polysensitization (sensitization to 2 or more allergens), clinically proven food allergy, atopic eczema, and atopic wheeze.

RESULTS

Infants born to larger households (3 or more residents) had higher longitudinal nTreg proportions over the first postnatal year with a mean difference (MD) of 0.67 (95% CI 0.30-1.04)%. Higher nTreg proportions at birth were associated with a reduced risk of infant allergic outcomes. Childcare attendance and breastfeeding were associated with higher longitudinal nTreg proportions (MD 0.48 (95% CI 0.08-0.80)%.

CONCLUSION

Multiple prenatal and postnatal microbial factors are associated with nTreg and aTreg development. Larger household size was associated with higher nTreg at birth which in turn was associated with reduced allergic sensitization and disease at 12 months of age.

Childhood Cardiovascular Risk Factors and Adult Cardiovascular Events

BACKGROUND

Childhood cardiovascular risk factors predict subclinical adult cardiovascular disease, but links to clinical events are unclear.

METHODS

In a prospective cohort study involving participants in the International Childhood Cardiovascular Cohort (i3C) Consortium, we evaluated whether childhood risk factors (at the ages of 3 to 19 years) were associated with cardiovascular events in adulthood after a mean follow-up of 35 years. Body-mass index, systolic blood pressure, total cholesterol level, triglyceride level, and youth smoking were analyzed with the use of i3C-derived age- and sex-specific z scores and with a combined-risk z score that was calculated as the unweighted mean of the five risk z scores. An algebraically comparable adult combined-risk z score (before any cardiovascular event) was analyzed jointly with the childhood risk factors. Study outcomes were fatal cardiovascular events and fatal or nonfatal cardiovascular events, and analyses were performed after multiple imputation with the use of proportional-hazards regression.

RESULTS

In the analysis of 319 fatal cardiovascular events that occurred among 38,589 participants (49.7% male and 15.0% Black; mean [±SD] age at childhood visits, 11.8±3.1 years), the hazard ratios for a fatal cardiovascular event in adulthood ranged from 1.30 (95% confidence interval [CI], 1.14 to 1.47) per unit increase in the z score for total cholesterol level to 1.61 (95% CI, 1.21 to 2.13) for youth smoking (yes vs. no). The hazard ratio for a fatal cardiovascular event with respect to the combined-risk z score was 2.71 (95% CI, 2.23 to 3.29) per unit increase. The hazard ratios and their 95% confidence intervals in the analyses of fatal cardiovascular events were similar to those in the analyses of 779 fatal or nonfatal cardiovascular events that occurred among 20,656 participants who could be evaluated for this outcome. In the analysis of 115 fatal cardiovascular events that occurred in a subgroup of 13,401 participants (31.0±5.6 years of age at the adult measurement) who had data on adult risk factors, the adjusted hazard ratio with respect to the childhood combined-risk z score was 3.54 (95% CI, 2.57 to 4.87) per unit increase, and the mutually adjusted hazard ratio with respect to the change in the combined-risk z score from childhood to adulthood was 2.88 (95% CI, 2.06 to 4.05) per unit increase. The results were similar in the analysis of 524 fatal or nonfatal cardiovascular events.

CONCLUSIONS

In this prospective cohort study, childhood risk factors and the change in the combined-risk z score between childhood and adulthood were associated with cardiovascular events in midlife. (Funded by the National Institutes of Health.).

Muscular strength measured across the life-course and the metabolic syndrome

BACKGROUND AND AIMS

Low muscular strength associates with the metabolic syndrome (MetS). However, how muscular strength measured at different life stages contribute to the development of MetS is unknown. This study compared the contribution of muscular strength measured in youth, young- and mid-adulthood with MetS in midlife.

METHODS AND RESULTS

Prospective longitudinal study of 267 Childhood Determinants of Adult Health Study participants who between 1985 and 2019 had measures of muscular strength (dominant grip strength) at three life stages (youth = 9-15 years, young adulthood = 26-36 years, mid-adulthood = 36-49 years) and had their MetS status assessed in mid-adulthood. Bayesian relevant life-course exposure models quantified associations between muscular strength at each life stage with MetS and estimated the maximum accumulated effect of lifelong muscular strength. The contribution of muscular strength at each life stage with MetS was equal (youth = 38%, young adulthood = 28%, mid-adulthood = 34%). A one standard deviation increase in cumulative muscular strength was associated with 46% reduced odds of MetS. Of all MetS components, muscular strength was most strongly negatively associated with high waist circumference.

CONCLUSION

A life-course approach demonstrated reduced odds of MetS in midlife was associated with cumulatively high muscular strength since youth. This supports efforts to promote physical fitness throughout life.

A Pathway-Based Genetic Score for Oxidative Stress: An Indicator of Host Vulnerability to Phthalate-Associated Adverse Neurodevelopment

The developing brain is highly sensitive to environmental disturbances, and adverse exposures can act through oxidative stress. Given that oxidative stress susceptibility is determined partly by genetics, multiple studies have employed genetic scores to explore the role of oxidative stress in human disease. However, traditional approaches to genetic score construction face a range of challenges, including a lack of interpretability, bias towards the disease outcome, and often overfitting to the study they were derived on. Here, we develop an alternative strategy by first generating a genetic pathway function score for oxidative stress (gPFSox) based on the transcriptional activity levels of the oxidative stress response pathway in brain and other tissue types. Then, in the Barwon Infant Study (BIS), a population-based birth cohort (n = 1074), we show that a high gPFSox, indicating reduced ability to counter oxidative stress, is linked to higher autism spectrum disorder risk and higher parent-reported autistic traits at age 4 years, with AOR values (per 2 additional pro-oxidant alleles) of 2.10 (95% CI (1.12, 4.11); p = 0.024) and 1.42 (95% CI (1.02, 2.01); p = 0.041), respectively. Past work in BIS has reported higher prenatal phthalate exposure at 36 weeks of gestation associated with offspring autism spectrum disorder. In this study, we examine combined effects and show a consistent pattern of increased neurodevelopmental problems for individuals with both a high gPFSox and high prenatal phthalate exposure across a range of outcomes, including high gPFSox and high DEHP levels against autism spectrum disorder (attributable proportion due to interaction 0.89; 95% CI (0.62, 1.16); p < 0.0001). The results highlight the utility of this novel functional genetic score and add to the growing evidence implicating gestational phthalate exposure in adverse neurodevelopment.

Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts

Background

Although 10 000 steps per day is widely promoted to have health benefits, there is little evidence to support this recommendation. We aimed to determine the association between number of steps per day and stepping rate with all-cause mortality.

Methods

In this meta-analysis, we identified studies investigating the effect of daily step count on all-cause mortality in adults (aged ≥18 years), via a previously published systematic review and expert knowledge of the field. We asked participating study investigators to process their participant-level data following a standardised protocol. The primary outcome was all-cause mortality collected from death certificates and country registries. We analysed the dose–response association of steps per day and stepping rate with all-cause mortality. We did Cox proportional hazards regression analyses using study-specific quartiles of steps per day and calculated hazard ratios (HRs) with inverse-variance weighted random effects models.

Findings

We identified 15 studies, of which seven were published and eight were unpublished, with study start dates between 1999 and 2018. The total sample included 47 471 adults, among whom there were 3013 deaths (10.1 per 1000 participant-years) over a median follow-up of 7.1 years ([IQR 4.3–9.9]; total sum of follow-up across studies was 297 837 person-years). Quartile median steps per day were 3553 for quartile 1, 5801 for quartile 2, 7842 for quartile 3, and 10 901 for quartile 4. Compared with the lowest quartile, the adjusted HR for all-cause mortality was 0.60 (95% CI 0.51–0.71) for quartile 2, 0.55 (0.49–0.62) for quartile 3, and 0.47 (0.39–0.57) for quartile 4. Restricted cubic splines showed progressively decreasing risk of mortality among adults aged 60 years and older with increasing number of steps per day until 6000–8000 steps per day and among adults younger than 60 years until 8000–10 000 steps per day. Adjusting for number of steps per day, comparing quartile 1 with quartile 4, the association between higher stepping rates and mortality was attenuated but remained significant for a peak of 30 min (HR 0.67 [95% CI 0.56–0.83]) and a peak of 60 min (0.67 [0.50–0.90]), but not significant for time (min per day) spent walking at 40 steps per min or faster (1.12 [0.96–1.32]) and 100 steps per min or faster (0.86 [0.58–1.28]).

Interpretation

Taking more steps per day was associated with a progressively lower risk of all-cause mortality, up to a level that varied by age. The findings from this meta-analysis can be used to inform step guidelines for public health promotion of physical activity.

Prevalence Implications of the 2017 American Academy of Pediatrics Hypertension Guideline and Associations with Adult Hypertension

OBJECTIVE

To evaluate the impact of the 2017 American Academy of Pediatrics hypertension Clinical Practice Guideline (CPG), compared with the previous guideline ("Fourth Report"), on the frequency of hypertensive blood pressure (BP) measurements in childhood and associations with hypertension in adulthood using data from the International Childhood Cardiovascular Cohort Consortium.

STUDY DESIGN

Childhood BPs were categorized in normal, prehypertensive/elevated, and hypertensive (stage 1 and 2) ranges using the Fourth Report and the CPG. Participants were contacted in adulthood to assess self-reported hypertension. The associations between childhood hypertensive range BPs and self-reported adult hypertension were evaluated.

RESULTS

Data were available for 34 014 youth (10.4 ± 3.1 years, 50.6% female) with 92 751 BP assessments. Compared with the Fourth Report, the CPG increased hypertensive readings from 7.6% to 13.5% and from 1.3% to 2.5% for stage 1 and 2 hypertensive range, respectively (P < .0001). Of 12 761 adults (48.8 ± 7.9 years, 43% male), 3839 (30.1%) had self-reported hypertension. The sensitivity for predicting adult hypertension among those with hypertensive range BPs at any point in childhood, as defined by the Fourth Report and the CPG, respectively, was 13.4% and 22.4% (specificity 92.3% and 85.9%, P < .001), with no significant impact on positive and negative predictive values. Associations with self-reported adult hypertension were similar and weak (c-statistic range 0.61-0.68) for hypertensive range BPs as defined by the Fourth Report and CPG.

CONCLUSIONS

The CPG significantly increased the prevalence of childhood BPs in hypertensive ranges and improved the sensitivity, without an overall strengthened association, of predicting self-reported adult hypertension.

Obesity during childhood is associated with higher cancer mortality rate during adulthood: the i3C Consortium

BACKGROUND

In high-income countries, cancer is the leading cause of death among middle-aged adults. Prospective data on the effects of childhood risk exposures on subsequent cancer mortality are scarce.

METHODS

We examined whether childhood body mass index (BMI), blood pressure, glucose and lipid levels were associated with adult cancer mortality, using data from 21,012 children enrolled aged 3-19 years in seven prospective cohort studies from the U.S., Australia, and Finland that have followed participants from childhood into adulthood. Cancer mortality (cancer as a primary or secondary cause of death) was captured using registries.

RESULTS

354 cancer deaths occurred over the follow-up. In age-, sex, and cohort-adjusted analyses, childhood BMI (Hazard ratio [HR], 1.13; 95% confidence interval [CI] 1.03-1.24 per 1-SD increase) and childhood glucose (HR 1.22; 95%CI 1.01-1.47 per 1-SD increase), were associated with subsequent cancer mortality. In a multivariable analysis adjusted for age, sex, cohort, and childhood measures of fasting glucose, total cholesterol, triglycerides, and systolic blood pressure, childhood BMI remained as an independent predictor of subsequent cancer mortality (HR, 1.24; 95%CI, 1.03-1.49). The association of childhood BMI and subsequent cancer mortality persisted after adjustment for adulthood BMI (HR for childhood BMI, 1.35; 95%CI 1.12-1.63).

CONCLUSIONS

Higher childhood BMI was independently associated with increased overall cancer mortality.

Associations between diet quality and DSM-IV mood disorders during young- to mid-adulthood among an Australian cohort

PURPOSE

Many studies have reported associations between diet and depression, but few have used formal diagnoses of mood disorder as the outcome measure. We examined if overall diet quality was associated cross-sectionally or longitudinally with DSM-IV mood disorders among an adult cohort.

METHODS

Participants from the Australian Childhood Determinants of Adult Health study were followed up during 2004-06 (n = 1974, age 26-36 years), 2009-11 (n = 1480, 31-41 years), and 2014-19 (n = 1191, 36-49 years). Dietary Guidelines Index (DGI) scores were calculated from food frequency questionnaires at each time-point (higher DGI reflects better diet quality). DSM-IV mood disorders (dysthymia or depression) during the periods between, and 12 months prior to each follow-up were determined using the Composite International Diagnostic Interview. Sex-stratified risk and prevalence ratios (PR) and 95% confidence intervals (CI) were estimated using log-binomial regression. Covariates included age, self-perceived social support index score, marital status, parenting status, education, occupation, physical activity, BMI, and usual sleep duration.

RESULTS

A 10-point higher DGI was cross-sectionally associated with lower prevalence of mood disorders at the third follow-up only (females PR = 0.73, 95% CI = 0.56, 0.95; males PR = 0.72, 95% CI = 0.53, 0.97), but was attenuated after covariate adjustment (females PR = 0.92, 95% CI = 0.73, 1.16; males PR = 0.92, 95% CI = 0.69, 1.22). Adjustment for social support in the final model had attenuated the association for both sexes from 18% reduced prevalence to 8%. DGI scores were not longitudinally associated with mood disorder risk.

CONCLUSIONS

Crude cross-sectional associations between diet quality and mood disorders at ages 36-49 years were explained by sociodemographic and lifestyle factors, particularly social support.

Associations of a healthy lifestyle score from childhood to adulthood with subclinical kidney damage in midlife: a population-based cohort study

Background

The relationships of healthy lifestyle scores (HLS) of various kinds in adulthood with the risk of chronic kidney disease (CKD) have been reported, but little is known about the association of childhood lifestyle with later life CKD. This study examined the relationship of HLS from childhood to adulthood with subclinical kidney damage (SKD) in midlife, a surrogate measure for CKD.

Methods

Data were collected in an Australian population-based cohort study with 33 years follow-up. 750 participants with lifestyle information collected in childhood (ages 10–15 years) and midlife (ages 40–50 years), and measures of kidney function in midlife were included. The HLS was generated from the sum scores of five lifestyle factors (body mass index, smoking, alcohol consumption, physical activity, and diet). Each factor was scored as poor (0 point), intermediate (1 point), or ideal (2 points). Log-binomial regression was used to investigate the relationship of HLS in childhood and from childhood to adulthood with SKD defined as either 1) estimated glomerular filtration rate (eGFR) 30–60 mL/min/1.73m² or 2) eGFR> 60 mL/min/1.73m² with urine albumin-creatinine ratio ≥ 2.5 mg/mmol (males) or 3.5 mg/mmol (females), adjusting for socio-demographic factors and the duration of follow-up.

Results

The average HLS was 6.6 in childhood and 6.5 in midlife, and the prevalence of SKD was 4.9% (n = 36). Neither HLS in childhood nor HLS from childhood to adulthood were significantly associated with the risk of SKD in midlife.

Conclusions

A HLS from childhood to adulthood did not predict SKD in this middle-aged, population-based Australian cohort.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02627-0.

Meta-analysis of epigenome-wide association studies in newborns and children show widespread sex differences in blood DNA methylation

BACKGROUND

Among children, sex-specific differences in disease prevalence, age of onset, and susceptibility have been observed in health conditions including asthma, immune response, metabolic health, some pediatric and adult cancers, and psychiatric disorders. Epigenetic modifications such as DNA methylation may play a role in the sexual differences observed in diseases and other physiological traits.

METHODS

We performed a meta-analysis of the association of sex and cord blood DNA methylation at over 450,000 CpG sites in 8438 newborns from 17 cohorts participating in the Pregnancy And Childhood Epigenetics (PACE) Consortium. We also examined associations of child sex with DNA methylation in older children ages 5.5-10 years from 8 cohorts (n = 4268).

RESULTS

In newborn blood, sex was associated at Bonferroni level significance with differences in DNA methylation at 46,979 autosomal CpG sites (p < 1.3 × 10-7) after adjusting for white blood cell proportions and batch. Most of those sites had lower methylation levels in males than in females. Of the differentially methylated CpG sites identified in newborn blood, 68% (31,727) met look-up level significance (p < 1.1 × 10-6) in older children and had methylation differences in the same direction.

CONCLUSIONS

This is a large-scale meta-analysis examining sex differences in DNA methylation in newborns and older children. Expanding upon previous studies, we replicated previous findings and identified additional autosomal sites with sex-specific differences in DNA methylation. Differentially methylated sites were enriched in genes involved in cancer, psychiatric disorders, and cardiovascular phenotypes.

Development of an intervention to manage knee osteoarthritis risk and symptoms following anterior cruciate ligament injury

INTRODUCTION

Anterior cruciate ligament (ACL) injury is a risk factor for developing knee osteoarthritis (OA). We developed an intervention to support people manage risk factors for OA.

METHODS

We conducted one-on-one interviews with 20 individuals with OA symptoms 6-15 years post ACL injury and used a nominal group process during a workshop with 40 patients and healthcare professionals (HCPs) to elicit information on the intervention content and delivery characteristics (timing, HCPs, and methods). Interview data were analyzed using content analysis. Nominal group ideas with importance ratings ≥5 of 7 met criteria for inclusion. Results were integrated, considering similarities and differences.

RESULTS

Eight content categories were identified: 1. understanding knee injury and expectations about recovery; 2. understanding OA risk; 3. understanding OA signs and symptoms; 4. managing OA risk; 5. managing knee OA symptoms; 6. information for influencers; 7. credible sources; and, 8. updates on new evidence and treatments. Delivery timing reflected a lifespan approach from time of injury through symptomatic knee OA management. Although multiple media for delivery were identified, introductory face-to-face discussions and opportunity for re-accessing HCPs were critical. All HCPs who treat people with ACL should be familiar with and able to deliver the intervention.

CONCLUSIONS

This co-development approach identified that an intervention to support people with ACL injury to limit and manage knee OA requires content embedded within an easily accessible, multi-media delivery model with capacity for check-back with HCPs that is appealing to different age groups and personal preferences over the lifespan post injury.

Disease-Associated Risk Variants in ANRIL Are Associated with Tumor-Infiltrating Lymphocyte Presence in Primary Melanomas in the Population-Based GEM Study

BACKGROUND

Genome-wide association studies have reported that genetic variation at ANRIL (CDKN2B-AS1) is associated with risk of several chronic diseases including coronary artery disease, coronary artery calcification, myocardial infarction, and type 2 diabetes mellitus. ANRIL is located at the CDKN2A/B locus, which encodes multiple melanoma tumor suppressors. We investigated the association of these variants with melanoma prognostic characteristics.

METHODS

The Genes, Environment, and Melanoma Study enrolled 3,285 European origin participants with incident invasive primary melanoma. For each of ten disease-associated SNPs at or near ANRIL, we used linear and logistic regression modeling to estimate, respectively, the per allele mean changes in log of Breslow thickness and ORs for presence of ulceration and tumor-infiltrating lymphocytes (TIL). We also assessed effect modification by tumor NRAS/BRAF mutational status.

RESULTS

Rs518394, rs10965215, and rs564398 passed false discovery and were each associated (P ≤ 0.005) with TILs, although only rs564398 was independently associated (P = 0.0005) with TILs. Stratified by NRAS/BRAF mutational status, rs564398*A was significantly positively associated with TILs among NRAS/BRAF mutant, but not wild-type, cases. We did not find SNP associations with Breslow thickness or ulceration.

CONCLUSIONS

ANRIL rs564398 was associated with TIL presence in primary melanomas, and this association may be limited to NRAS/BRAF-mutant cases.

IMPACT

Pathways related to ANRIL variants warrant exploration in relationship to TILs in melanoma, especially given the impact of TILs on immunotherapy and survival.

Prediction of future atherosclerosis in 13 years from young asymptomatic adults

Aim

To compare the Pooled Cohort Equation (PCE) and Ideal Cardiovascular Health Score (ICHS) with a simpler cardiovascular risk score not requiring laboratory tests (the Fuster-BEWAT score, FBS) in predicting the presence and extent of subclinical atherosclerosis 13 years later.

Methods

Data included 894 adults (48% male) who were aged 26–36 years at baseline and 40–50 years at follow-up. The primary outcome was the presence of carotid plaque measured by ultrasound at follow-up. Secondary outcomes were number of arteries affected, plaque thickness and plaque area. All three scores were calculated at both baseline and follow-up.

Results

At follow-up, 86 participants (9.6%) had unilateral carotid plaques and 23 participants (2.6%) had bilateral carotid plaques. At baseline, all three scores were predictive of the presence of carotid plaque at follow-up (PCE odds ratio (OR) = 1.42 [95% CI: 1.19–1.70], ICHS OR=0.87 [0.77–0.99], FBS OR=0.86 [95% CI: 0.77–0.96]) and all secondary outcomes. All baseline scores predicted outcomes more strongly than those at follow-up, and did so independent of any changes over 13 years of follow-up. Similar levels of discriminatory power were found for all three baseline scores in predicting the presence of carotid plaque after 13 years (PCE C-statistic = 0.69 [95% CI: 0.63–0.75], ICHS C-statistic = 0.67 [95% CI: 0.61–0.74] and FBS C-statistic = 0.68 [95% CI: 0.62–0.74])

Conclusions

All baseline scores predicted subclinical atherosclerosis 13 years later. The similar discrimination of the scores highlights the benefit of using FBS as a simpler and more feasible risk score for predicting future cardiovascular risk in low-risk young people.

Funding Acknowledgement

Type of funding sources: None.

Risk factors for left ventricular dysfunction in adulthood: role of low birth weight

Aims

This study aimed to determine the relationship of low birth weight (LBW) with adult cardiac structure and function and investigate potential causal pathways.

Methods and results

A population‐based sample of 925 Australians (41.3% male) were followed from childhood (aged 7–15 years) to young adulthood (aged 26–36 years) and mid‐adulthood (aged 36–50 years). Left ventricular (LV) global longitudinal strain (GLS, %), LV mass index (LVMi, g/m^2.7), LV filling pressure (E/e′), and left atrial volume index (g/m²) were measured by transthoracic echocardiography in mid‐adulthood. Birth weight category was self‐reported in young adulthood and classified as low (≤5 lb or ≤2270 g), normal (5–8 lb or 2271–3630 g), and high (>8 lb or >3630 g). Of the 925 participants, 7.5% (n = 69) were classified as LBW. Compared with participants with normal birth weight, those with LBW had 2.01‐fold (95% confidence interval: 1.19, 3.41, P = 0.009) higher risks of impaired GLS (GLS > −18%) and 2.63‐fold (95% confidence interval: 0.89, 7.81, P = 0.08) higher risks of LV hypertrophy (LVMi > 48 g/m^2.7 in men or >44 g/m^2.7 in women) in adulthood, independent of age, sex, and any socio‐economic factors. Participants with LBW significantly increased body fat from childhood to adulthood relative to their peers and had greater levels of triglycerides, fasting glucose, and arterial stiffness in adulthood. These risk factors were the strongest mediators and explained 54% of the LBW effect size on adult GLS and 33% of the LBW effect size on LVMi. The remaining of these associations was independent of any of the measured risk factors.

Conclusions

Low birth weight was associated with impaired cardiac structure and function in mid‐adulthood. This association was only partially explained by known risk factors.

Reallocation of time between device-measured movement behaviours and risk of incident cardiovascular disease

OBJECTIVE

To improve classification of movement behaviours in free-living accelerometer data using machine-learning methods, and to investigate the association between machine-learned movement behaviours and risk of incident cardiovascular disease (CVD) in adults.

METHODS

Using free-living data from 152 participants, we developed a machine-learning model to classify movement behaviours (moderate-to-vigorous physical activity behaviours (MVPA), light physical activity behaviours, sedentary behaviour, sleep) in wrist-worn accelerometer data. Participants in UK Biobank, a prospective cohort, were asked to wear an accelerometer for 7 days, and we applied our machine-learning model to classify their movement behaviours. Using compositional data analysis Cox regression, we investigated how reallocating time between movement behaviours was associated with CVD incidence.

RESULTS

In leave-one-participant-out analysis, our machine-learning method classified free-living movement behaviours with mean accuracy 88% (95% CI 87% to 89%) and Cohen's kappa 0.80 (95% CI 0.79 to 0.82). Among 87 498 UK Biobank participants, there were 4105 incident CVD events. Reallocating time from any behaviour to MVPA, or reallocating time from sedentary behaviour to any behaviour, was associated with lower CVD risk. For an average individual, reallocating 20 min/day to MVPA from all other behaviours proportionally was associated with 9% (95% CI 7% to 10%) lower risk, while reallocating 1 hour/day to sedentary behaviour from all other behaviours proportionally was associated with 5% (95% CI 3% to 7%) higher risk.

CONCLUSION

Machine-learning methods classified movement behaviours accurately in free-living accelerometer data. Reallocating time from other behaviours to MVPA, and from sedentary behaviour to other behaviours, was associated with lower risk of incident CVD, and should be promoted by interventions and guidelines.

Cardiovascular risk factors before and during pregnancy: Does pregnancy unmask or initiate risk?

OBJECTIVES

To understand if pregnancy unmasks previously silent cardiovascular (CV) adverse factors, or initiates lasting injury.

METHODS

Pre-pregnancy and during pregnancy CV risk factors (blood pressure, fasting lipids, and glucose) from 296 women belonging to studies in the International Childhood Cardiovascular Cohort (i3C) Consortium, a group of studies assessing the relationship between child and adolescent CV risk factors and adult outcomes, were used. Correlation coefficients between the pre- and during pregnancy measures were calculated, and the mean difference between the measures was modeled with adjustment for age, body mass index, race, smoking, and study.

RESULTS

Measures were strongly correlated at pre- and during-pregnancy visits (p < 0.01), with r of between 0.30 and 0.55. In most cases, the difference between pre-pregnancy and during-pregnancy did not differ significantly from 0 after adjustment for confounders. Stratification by gestational age indicated stronger correlations with measurements obtained during the first and second trimesters than the third. The correlation did not differ by the time elapsed between the pre-pregnancy and pregnancy visits.

CONCLUSIONS

Pre- and during-pregnancy CV risk factors are moderately well correlated. This may indicate that susceptible women enter pregnancy with higher risk rather than pregnancy inducing new vascular or metabolic effects.

Correction: Accelerometer measured physical activity and the incidence of cardiovascular disease: Evidence from the UK Biobank cohort study

[This corrects the article DOI: 10.1371/journal.pmed.1003487.].

904Physical fitness across the life-course and the metabolic syndrome in mid-adulthood

Background

Low physical fitness, including muscular strength and cardiorespiratory fitness (CRF), is a risk factor for the metabolic syndrome (MetS). However, it is unknown how physical fitness at different life stages contributes to the development of MetS.

Methods

Included were 783 Childhood Determinants of Adult Health Study participants who between 1985 and 2019 had measures of physical fitness (muscular strength: dominant grip strength; CRF: 1.6km run or physical work capacity at 170 beats per minute) at three life stages (childhood=7–15 years, young-adulthood=26–36 years, mid-adulthood=36–49 years) and had their MetS status assessed using the harmonised definition in mid-adulthood. The Bayesian relevant life-course exposure model, a novel statistical analytic technique, quantified associations between physical fitness at each life stage with MetS and estimated the maximum accumulated effect of physical fitness across the life-course.

Results

The contribution of muscular strength at each life stage with MetS in mid-adulthood was equal (childhood=36%, young-adulthood=31%, mid-adulthood=33%), whereas for CRF the greatest contribution was from childhood and mid-adulthood (childhood=41%, young-adulthood=20%, mid-adulthood=39%). A one standard deviation increase in cumulative physical fitness across the life-course was associated with 36–55% reduced odds of MetS (muscular strength: OR = 0.64, 95%Credible Interval=0.40,0.95; CRF: OR = 0.45, 95%Credible Interval=0.30,0.64).

Conclusions

As physical fitness at each life stage was associated with MetS in mid-adulthood, strategies aimed at increasing both childhood and adult physical fitness levels could improve future health.

Key messages

Increased participation in both aerobic and muscle-strengthening activities, beginning in childhood and extending into adulthood, could be encouraged to help prevent MetS.

684Childhood Risk Factors and Adult Cardiovascular Disease Outcomes The International Childhood Cardiovascular Cohort (i3C) Consortium

Background

Atherosclerosis develops silently for decades before adult cardiovascular disease (aCVD) occurs. There is currently no evidence directly linking childhood risk factors to aCVD outcomes.

Methods

i3C is an international consortium of 7 cohorts involving 40,709 participants enrolled between 1970-95 in childhood (age 3-19) who underwent measurement for BMI, SBP, total cholesterol, and triglycerides, and smoking (the last mostly in adolescence). Participants were followed by direct contact and review of medical records or death registry ascertainment through adulthood in 2014-19. 20,560 participants were found and interviewed or had died in the approximately 40 years since enrollment; 738 had a CVD event, confirmed by medical record review (n = 449) or death certificate ICD code (n = 289).

Results

Estimated hazard ratios (HRs) for childhood risk factors and their confidence intervals are displayed in the table below. The CIs excluded 1.0 for all these variables in the univariable analysis and, although the HRs were reduced in multivariable analysis which included all of these risk factors, the CIs still excluded 1.0.

Conclusion

Exposure to CVD risk factors in youth predicts adult CVD with implications for primordial CVD prevention.

Key messages

Intervention to reduce CVD risk factors in childhood is likely to reduce risk of adult CVD

357Infant pacifier sanitization and risk of food allergy: the Barwon Infant Study

Background

Environmental microbial exposure and human gut microbiota play a role in development of the immune system and susceptibility to food allergy. Pacifier use has been inconsistently associated with allergy, but the association between sanitization and food allergy is unknown. We investigated the association between infant pacifier use, with a consideration of sanitization, and food allergy at age 1 in the Barwon Infant Study (BIS).

Methods

Questionnaire data were collected prospectively from pregnant mothers from the Barwon region of south-east Australia at baseline and at infant ages 1, 6, and 12 months. Pacifier sanitization was defined as the joint exposure of a pacifier and cleaning methods (antiseptic, mouth, tap water, boiling). Challenge-proven food allergy was determined at age 1.

Results

Any pacifier use at 6 months was associated with food allergy (aOR, 1.94; 95% CI, 1.04-3.61), but not at other ages. This overall association was driven by the joint exposure pacifier-antiseptic use (aOR, 5.90; 95% CI, 2.18-15.97) compared to no pacifier use. Among pacifier users, pacifier-antiseptic was still associated with food allergy (aOR, 3.88; 95% CI, 1.55-9.72) when compared to pacifier-no antiseptic use. Further, increased use of pacifier-antiseptic at 0, 1 or 2 interviews over the first 6 months was associated with higher food allergy risk (ptrend=0.005).

Conclusions

Joint exposure to antiseptics and pacifiers at 6 months increased the odds of food allergy, showing a trend with increased use over time.

Key messages

This is the first report of pacifiers used with antiseptic being positively associated with challenge-proven food allergy.

Abstract P146: Sex Differences In The Association Between Systolic Blood Pressure And Carotid Distensibility In Adults

Background and Aim: We explored sex differences in the association between systolic and diastolic blood pressure (SBP), in early adulthood with carotid plaques, carotid IMT and carotid distensibility (CD) in mid-adulthood.

Methods: Participants in the Childhood Determinants of Adult Health study at ages 26-36 years were followed-up at ages 39-49 years. Systolic BP and diastolic BP and carotid ultrasound measures (plaques, IMT and CD) were performed in clinics. We used log binomial and linear regression models with risk factor*gender interactions for predicting these carotid measures. Sex-stratified models adjusted for sociodemographic, health-related behavior and biomedical factors were fitted when likelihood ratio tests suggested the effect of risk factors on outcomes differed by sex.

Results: Among 1,286 participants (53% women), men, compared to women, had higher prevalence of carotid plaques (17% vs. 10%), thicker carotid IMT (Mean 0.66 ± 0.09 vs. 0.61 ± 0.07) and lower CD (Mean 1.87 ± 0.60 vs. 2.37 ± 0.77). In women, greater SBP in early adulthood was sharply associated with significantly smaller CD (β -0.016 95%CI -0.023, -0.010 vs. β -0.006 95%CI -0.012, -0.001) than men in mid-adulthood adjusted for sociodemographic factors (Figure 1a). In analyses restricted to women, the effect of SBP on CD has decreased after adjusting for age, education, occupation, DBP and use of contraceptives (β -0.009 95%CI -0.019, 0.000) (Figure 1b).

Conclusion: CV health was worse in men than women. However, elevated SBP in women put them at greater risk of poorer CV health compared to men, which was partly explained by sociodemographic, biomedical and female-specific factors.

Genome erosion and evidence for an intracellular niche - exploring the biology of mycoplasmas in Atlantic salmon

Mycoplasmas are the smallest autonomously self-replicating life form on the planet. Members of this bacterial genus are known to parasitise a wide array of metazoans including vertebrates. Whilst much research has been significant targeted at parasitic mammalian mycoplasmas, very little is known about their role in other vertebrates. In the current study, we aim to explore the biology of mycoplasmas in Atlantic Salmon, a species of major significance for aquaculture, including cellular niche, genome size structure and gene content. Using fluorescent in-situ hybridisation (FISH), mycoplasmas were targeted in epithelial tissues across the digestive tract (stomach, pyloric caecum and midgut) from different development stages (eggs, parr, subadult) of farmed Atlantic salmon (Salmo salar), and we present evidence for an intracellular niche for some of the microbes visualised. Via shotgun metagenomic sequencing, a nearly complete, albeit small, genome (~0.57 MB) as assembled from a farmed Atlantic salmon subadult. Phylogenetic analysis of the recovered genome revealed taxonomic proximity to other salmon derived mycoplasmas, as well as to the human pathogen Mycoplasma penetrans (~1.36 Mb). We annotated coding sequences and identified riboflavin pathway encoding genes and sugar transporters, the former potentially consistent with micronutrient provisioning in salmonid development. Our study provides insights into mucosal adherence, the cellular niche and gene catalog of Mycoplasma in the gut ecosystem of the Atlantic salmon, suggesting a high dependency of this minimalist bacterium on its host. Further study is required to explore and functional role of Mycoplasma in the nutrition and development of its salmonid host.

Prevalence and Clinical Significance of Residual or Reconverted Red Bone Marrow on Knee MRI

Background: Residual/reconverted red bone marrow (RBM) in adult knees is occasionally observed on routine knee magnetic resonance imaging (MRI). We aimed to identify its prevalence, distribution, and associations with lifestyle factors, knee structural abnormalities, and knee symptoms in young adults. Methods: Participants (n = 327; aged = 31–41 years) were selected from the Childhood Determinants of Adult Health (CDAH) knee study. They underwent T1-weighted and proton-density-weighted fat-suppressed MRI scans of knees. Residual/reconverted RBM in distal femur and proximal tibia were graded semi-quantitatively (grades: 0–3) based on the percentage area occupied. Knee structural abnormalities were graded semi-quantitatively using previously published MRI scoring systems. Knee symptoms (pain, stiffness, and dysfunction) were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale during CDAH knee study (year: 2008–2010) and at 6–9-year follow-up during the CDAH-3 study (year: 2014–2019). Associations between definite RBM (grade ≥ 2) and lifestyle factors, knee symptoms, and structural abnormalities were described using log-binomial regressions. Results: Definite RBM was seen in females only, in 29 out of 154 cases (18.8%), with femoral involvement preceding tibial involvement. Definite RBM was associated with increased BMI (PR = 1.09/kg/m²; 95% CI: 1.03, 1.16), overweight status (PR = 2.19; 95% CI: 1.07, 4.51), and WOMAC knee pain (PR = 1.75; 95% CI: 1.11, 2.74) in cross-section analysis. However, there was no association between RBM and knee-pain after seven years (PR = 1.15; 95% CI: 0.66, 2.00). There were no associations between RBM and knee structural abnormalities. Conclusion: Presence of definite RBM in young adult knees was observed in females only. Definite RBM was associated with overweight measures, and the modest association with knee pain may not be causally related.

Goldilocks Days: optimising children's time use for health and well-being

BACKGROUND

One size rarely fits all in population health. Differing outcomes may compete for best allocations of time. Among children aged 11-12 years, we aimed to (1) describe optimal 24-hour time use for diverse physical, cognitive/academic and well-being outcomes, (2) pinpoint the 'Goldilocks Day' that optimises all outcomes and (3) develop a tool to customise time-use recommendations.

METHODS

In 2004, the Longitudinal Study of Australian Children recruited a nationally-representative cohort of 5107 infants with biennial follow-up waves. We used data from the cross-sectional Child Health CheckPoint module (2015-2016, n=1874, 11-12 years, 51% males). Time use was from 7-day 24-hour accelerometry. Outcomes included life satisfaction, psychosocial health, depressive symptoms, emotional problems, non-verbal IQ; vocabulary, academic performance, adiposity, fitness, blood pressure, inflammatory biomarkers, bone strength. Relationships between time use and outcomes were modelled using compositional regression.

RESULTS

Optimal daily durations varied widely for different health outcomes (sleep: 8.3-11.4 hours; sedentary: 7.3-12.2 hours; light physical activity: 1.7-5.1 hours; moderate-to-vigorous physical activity (MVPA): 0.3-2.7 hours, all models p≤0.04). In general, days with highest physical activity (predominantly MVPA) and low sedentary time were optimal for physical health, while days with highest sleep and lowest sedentary time were optimal for mental health. Days with highest sedentary time and lowest physical activity were optimal for cognitive health. The overall Goldilocks Day had 10 hours 21 min sleep, 9 hours 44 min sedentary time, 2 hours 26 min light physical activity and 1 hour 29 min MVPA. Our interactive interface allows personalisation of Goldilocks Days to an individual's outcome priorities.

CONCLUSION

'Goldilocks Days' necessitate compromises based on hierarchies of priorities for health, social and economic outcomes.