Child Health CheckPoint: cohort summary and methodology of a physical health and biospecimen module for the Longitudinal Study of Australian Children

The effects of adverse and positive experiences on cardiovascular health in Australian children

BACKGROUND

Limited evidence suggests that positive experiences in childhood may promote cardiovascular health, providing additional opportunities for prevention and early intervention. This study aimed to examine the effects of adverse and positive experiences on cardiovascular health in late childhood.

METHODS

Data sources: Longitudinal Study of Australian Children (N = 1874).

EXPOSURES

Adverse and positive experiences assessed repeatedly (age 0-11 years).

OUTCOMES

Cardiovascular health (high versus low or moderate) quantified by four health behaviors (diet, physical activity, cigarette smoking, and sleep) and four health factors (body mass index, non-high-density lipoprotein, blood pressure, and blood glucose) (age 11-12 years) as per the American Heart Association's Life's Essential 8 metrics.

ANALYSES

Separate generalized linear models with log-Poisson links were used to estimate the effects of adverse and positive experiences on cardiovascular health, adjusting for confounders.

RESULTS

Children exposed to multiple adverse experiences (≥ 2) were less likely to have high cardiovascular health (RR = 0.82, 95% CI = 0.67 to 1.02) than those not exposed. Children exposed to multiple positive experiences (≥ 2) were more likely to have high cardiovascular health (RR = 1.14, 95% CI = 0.94 to 1.38) than those not exposed. Stratified analyses suggested that exposure to multiple positive experiences might buffer the detrimental effects of multiple adverse experiences on cardiovascular health.

CONCLUSIONS

Both adverse and positive experiences were found to be modestly associated with cardiovascular health in Australian children. Future research and practice should not only consider addressing childhood adversity but also use a strengths-based approach to promoting positive experiences to improve cardiovascular health.

Time use and dimensions of healthy sleep: A cross-sectional study of Australian children and adults

BACKGROUND

Sleep is increasingly recognized as a multidimensional construct that occurs within the 24-hour day. Despite advances in our understanding, studies continue to consider the relationship between sleep, sedentary time and physical activity separately, and not as part of the 24-hour day.

AIMS

To determine the association between the 24-hour activity composition and dimensions of healthy sleep.

METHODS

This study examined data on 1168 children (mean age 12years; 49% female) and 1360 adults (mean age 44years; 87% female) collected as part of the Child Health CheckPoint study. Participants were asked to wear a GENEActiv monitor (Activinsights, Cambs, UK) on their nondominant wrist for eight consecutive days to measure 24-hour time-use. Compositional data analysis was used to examine the association between time use (actigraphy-derived sleep duration, sedentary time, light physical activity and moderate-vigorous physical activity) and dimensions of healthy sleep. Healthy sleep was conceptualized in terms of continuity/efficiency, timing, alertness/sleepiness, satisfaction/quality, and regularity. Time allocations were also examined.

RESULTS

The 24-hour activity composition was significantly associated with all objectively measured and self-report dimensions of healthy sleep in both children and adults. Allocating more time to sleep was associated with earlier sleep onsets, later sleep offsets, less efficient and more consistent sleep patterns for both children and adults.

CONCLUSION

This study highlights the integral relationship between daily activities and dimensions of sleep. Considering sleep within the 24-hour day activity composition framework may help inform lifestyle decisions to improve sleep health.

The Accumulative Effect of Multiple Postnatal Risk Factors with the Risk of Being Overweight/Obese in Late Childhood

Most past studies focused on the associations of prenatal risk factors with the risks of childhood overweight/obesity. Instead, more postnatal risk factors are modifiable, with less knowledge of their cumulative effects on childhood obesity. We analyzed data of 1869 children in an Australian birth cohort. Key postnatal risk factors included: maternal and paternal overweight/obesity during the child's infancy, tobacco exposure, low family socioeconomic score, breastfeeding duration < 6 months, early introduction of solid foods, and rapid weight gain during infancy. The risk score was the sum of the number of risk factors. The primary outcome is overweight/obesity in late childhood (11-12 years); secondary outcomes are high-fat mass index (FMI), body fat percentage (BF%), and waist-to-height ratio (WHtR). Poisson regression models were used in the analyses. Children with higher risk scores had higher risks of overweight/obesity (p-for-trends < 0.001). After adjusting covariates, compared with those with 0-1 risk factors, children with 4-6 risk factors had 4.30 (95% confidence interval: 2.98, 6.21) times higher risk of being overweight/obesity; the relative risks for high FMI, BF%, and WHtR were 7.31 (3.97, 13.45), 4.41 (3.00, 6.50), and 6.52 (3.33, 12.74), respectively. Our findings highlighted that multiple postnatal risk factors were associated with increased risks of being overweight/obesity in late childhood.

Impact of Distinct Anti-Androgen Exposures on the Plasma Metabolome in Feminizing Gender-Affirming Hormone Therapy

CONTEXT

The plasma metabolome is a functional readout of metabolic activity and is associated with phenotypes exhibiting sexual dimorphism, such as cardiovascular disease. Sex hormones are thought to play a key role in driving sexual dimorphism.

OBJECTIVE

Gender-affirming hormone therapy (GAHT) is a cornerstone of transgender care, but longitudinal changes in the plasma metabolome with feminizing GAHT have not been described.

METHODS

Blood samples were collected at baseline and after three and six months of GAHT from transgender women (n = 53). Participants were randomized to different anti-androgens, cyproterone acetate or spironolactone. NMR-based metabolomics was used to measure 249 metabolic biomarkers in plasma. Additionally, we used metabolic biomarker data from an unrelated cohort of children and their parents (n = 3,748) to identify sex- and age-related metabolite patterns.

RESULTS

We identified 43 metabolic biomarkers altered after six months in both anti-androgen groups, most belonging to the very low- or low-density lipoprotein subclasses, with all but one showing a decrease. We observed a cyproterone acetate-specific decrease in glutamine, glycine, and alanine levels. Notably, of the metabolic biomarkers exhibiting the most abundant 'sex- and age-related' pattern (higher in assigned female children and lower in assigned female adults, relative to assigned males), 80% were significantly lowered after GAHT, reflecting a shift toward the adult female profile.

CONCLUSION

Our results suggest an anti-atherogenic signature in the plasma metabolome after the first six months of feminizing GAHT, with cyproterone acetate also reducing specific plasma amino acids. This study provides novel insight into the metabolic changes occurring across feminizing GAHT.

Knowledge of Common Symptoms of Rheumatic Diseases and Causes of Delayed Diagnosis in Saudi Arabia

Purpose

The aim of this study is to determine the general population's knowledge on the different symptoms of rheumatic diseases, the key factors for diagnosis delays from the patient's perspective, the length of delay from the onset of symptoms to the diagnosis, and the effect this holds on the disease activity, response to therapy, and the development of complications and nonreversible deformities in patients diagnosed with rheumatic diseases.

Patients and Methods

This is a cross-sectional study. Our target study population were the residents of Saudi Arabia. Data were collected via an online questionnaire and analyzed with SPSS.

Results

The overall prevalence of rheumatic disease in our cohort was 8.7%. Joint pain (75.7%), joint swelling (47.1%) and morning stiffness (32.9%) were the first and most common presenting symptom. Persistence of symptoms (N=32, 45.7%) and symptom worsening (N=21, 30.0%) was the predominant cause to visit rheumatologist. The duration between first symptom and rheumatic disease diagnosis is significantly longer for patients aged <50 years compared to that of those with ≥50 years of age. Results show that 36.4% of patients aged ≥50 years had delayed diagnosis due to late appointment compared with 5.7% of patients aged <50 years. In addition, patients with longer duration of symptoms were likely to have more visits to the rheumatologist. Most of the participants of <50 years significantly agreed that rheumatologists treat autoimmune diseases, only a few approved that they treat muscle problems.

Conclusion

Most participants in our study have lesser knowledge about their symptoms and they did not know where to consult for the treatment of their disease. This caused unnecessary delays and worsening and aggravation of the symptoms. There is an increased need to organize an awareness campaign in the general population regarding autoimmune and rheumatic diseases.

Polygenic Risk Scores and the Risk of Childhood Overweight/Obesity in Association With the Consumption of Sweetened Beverages: A Population-Based Cohort Study

Background: Sugar-sweetened beverage (SSB) and non-nutritive sweetened beverage (NNSB) consumption is associated with obesity and are targets for population-level dietary interventions. In children (<16 years), we evaluate whether SSB or NNSB consumption is associated with subsequent (2 years later) overweight and/or obesity, and the effect of consumption on subsequent overweight/obesity differs by BMI polygenic risk score (BMI-PRS). Methods: The nationally representative Longitudinal-Study-of-Australian-Children had biennial data collection from birth (n = 5107) until age 14/15 years (n = 3127). At age 11/12 years, a comprehensive biomedical assessment, including PRS assessment, was undertaken (n = 1422). Parent- or self-reported beverage consumption (SSBs: soft drinks, energy drinks, and/or juice; NNSBs: diet drinks) was measured as any/none over previous 24 hours. BMI-PRS was derived using published results (high PRS ≥75th percentile). At ages 4/5-14/15 children were classified as having obesity, overweight/obesity, or not having overweight/obesity using BMI z-score (CDC cut points). Results: SSB consumption had limited association with subsequent overweight/obesity. NNSB consumption was associated with ∼8% more children with subsequent overweight/obesity at most ages. In older children with high BMI-PRS, associations between NNSB consumption and subsequent overweight/obesity strengthened with age [at age 14-15 for high BMI-PRS, difference in proportion with overweight/obesity among NNSB consumers vs. nonconsumers = 0.38 (95% confidence interval: 0.22 to 0.55, p ≤ 0.001)]. There was limited association between SSB consumption and BMI-PRS. Conclusion: NNSB consumption was associated with increased risk of overweight/obesity for children with greater genetic risk at older ages (12-15 years). Focused intervention among children with high genetic risk could target NNSB consumption; however, reverse causality (children with genetic risk and/or high BMI consume more NNSBs) cannot be excluded.

Raw Acceleration from Wrist- and Hip-Worn Accelerometers Corresponds with Mechanical Loading in Children and Adolescents

The purpose of this study was to investigate associations between peak magnitudes of raw acceleration (g) from wrist- and hip-worn accelerometers and ground reaction force (GRF) variables in a large sample of children and adolescents. A total of 269 participants (127 boys, 142 girls; age: 12.3 ± 2.0 yr) performed walking, running, jumping (<5 cm; >5 cm) and single-leg hopping on a force plate. A GENEActiv accelerometer was worn on the left wrist, and an Actigraph GT3X+ was worn on the right wrist and hip throughout. Mixed-effects linear regression was used to assess the relationships between peak magnitudes of raw acceleration and loading. Raw acceleration from both wrist and hip-worn accelerometers was strongly and significantly associated with loading (all p's < 0.05). Body mass and maturity status (pre/post-PHV) were also significantly associated with loading, whereas age, sex and height were not identified as significant predictors. The final models for the GENEActiv wrist, Actigraph wrist and Actigraph hip explained 81.1%, 81.9% and 79.9% of the variation in loading, respectively. This study demonstrates that wrist- and hip-worn accelerometers that output raw acceleration are appropriate for use to monitor the loading exerted on the skeleton and are able to detect short bursts of high-intensity activity that are pertinent to bone health.

Branched-chain amino acids and sleep: a population-derived study of Australian children aged 11-12 years and their parents

Micronutrients, particularly amino acids, are thought to play an important role in sleep regulation and maintenance. While tryptophan is a known predictor of sleep, less is known about branched-chain amino acids (BCAAs), which compete with tryptophan for transport across the blood-brain barrier. The aim of this study was to determine the association between BCAAs and actigraphy-derived sleep duration, timing and efficiency, and self-reported trouble sleeping. This study examined data on children and adults collected as part of the Child Health CheckPoint study. Linear mixed models, adjusted for geographic clustering, were used to determine the association between BCAAs and sleep characteristics. Complete-case analysis was conducted for 741 children aged 11-12 years old (51% females) and 941parents (87% mothers). While BCAAs were significantly associated with children's sleep duration, timing and self-reported trouble sleeping, no associations were observed in adults, in fully adjusted models. In children, higher levels of BCAAs are associated with shorter sleep duration, delayed sleep timing, and more frequent reports of trouble sleeping.

Association of Polygenic Risk Scores for Hearing Difficulty in Older Adults With Hearing Loss in Mid-Childhood and Midlife: A Population-Based Cross-sectional Study Within the Longitudinal Study of Australian Children

Importance

Although more than 200 genes have been associated with monogenic congenital hearing loss, the polygenic contribution to hearing decline across the life course remains largely unknown.

Objective

To examine the association of polygenic risk scores (PRSs) for self-reported hearing difficulty among adults (40-69 years) with measured hearing and speech reception abilities in mid-childhood and early midlife.

Design, Setting, and Participants

This was a population-based cross-sectional study nested within the Longitudinal Study of Australian Children that included 1608 children and 1642 adults. Pure tone audiometry, speech reception threshold against noise, and genetic data were evaluated. Linear and logistic regressions of PRSs were conducted for hearing outcomes. Study analysis was performed from March 1 to 31, 2022.

Main Outcomes and Measures

Genotypes were generated from saliva or blood using global single-nucleotide polymorphisms array and PRSs derived from published genome-wide association studies of self-reported hearing difficulty (PRS1) and hearing aid use (PRS2). Hearing outcomes were continuous using the high Fletcher index (mean hearing threshold, 1, 2, and 4 kHz) and speech reception threshold (SRT); and dichotomized for bilateral hearing loss of more than 15 dB HL and abnormal SRT.

Results

Included in the study were 1608 children (mean [SD] age, 11.5 [0.5] years; 812 [50.5%] male children; 1365 [84.9%] European and 243[15.1%] non-European) and 1642 adults (mean [SD] age, 43.7 [5.1] years; 1442 [87.8%] female adults; 1430 [87.1%] European and 212 [12.9%] non-European individuals). In adults, both PRS1 and PRS2 were associated with hearing thresholds. For each SD increment in PRS1 and PRS2, hearing thresholds were 0.4 (95% CI, 0-0.8) decibel hearing level (dB HL) and 0.9 (95% CI, 0.5-1.2) dB HL higher on the high Fletcher index, respectively. Each SD increment in PRS increased the odds of adult hearing loss of more than 15 dB HL by 10% to 30% (OR for PRS1, 1.1; 95% CI, 1.0-1.3; OR for PRS2, 1.3; 95% CI, 1.1-1.5). Similar but attenuated patterns were noted in children (OR for PRS1, 1.1; 95% CI, 0.8-1.2; OR for PRS2, 1.2; 95% CI, 1.0-1.5). Both PRSs showed minimal evidence of associations with speech reception thresholds or abnormal SRT in children or adults.

Conclusions and Relevance

This population-based cross-sectional study of PRSs for self-reported hearing difficulty among adults found an association with hearing ability in mid-childhood. This adds to the evidence that age-related hearing loss begins as early as the first decade of life and that polygenic inheritance may play a role together with other environmental risk factors.

Sleep-disordered breathing in children seeking orthodontic care-an Australian perspective

BACKGROUND

The prevalence of sleep-disordered breathing in children is underestimated due to impediments in detection and diagnosis. Consequently, delayed management may affect the quality of life and the growth and development of a child. Due to their patient demographic, orthodontists are optimally positioned to identify those at risk of sleep-disordered breathing and make referrals for investigation and management. This study aims to determine the prevalence of children at risk of sleep-disordered breathing in an Australian orthodontic population.

METHODS

A 1-year retrospective study was conducted in an urban Western Australian private orthodontic practice with two branches in similar socioeconomic demographics. The responses of new patients to a modified paediatric sleep questionnaire and standard medical history form were recorded.

RESULTS

In 1209 patients (4-18 years), 7.3% were at risk of sleep-disordered breathing. An association between sex and the potential risk of sleep-disordered breathing was found with 11% of males at risk of sleep-disordered breathing compared to 7% of females (P = 0.012).

CONCLUSIONS

The relatively high prevalence of children at risk of sleep-disordered breathing presenting for orthodontic care presents an opportunity to identify at-risk individuals through routine use of the paediatric sleep questionnaire. This would facilitate early referral for diagnosis and management of sleep-disordered breathing.

Effect of common pregnancy and perinatal complications on offspring metabolic traits across the life course: a multi-cohort study

BACKGROUND

Common pregnancy and perinatal complications are associated with offspring cardiometabolic risk factors. These complications may influence multiple metabolic traits in the offspring and these associations might differ with offspring age.

METHODS

We used data from eight population-based cohort studies to examine and compare associations of pre-eclampsia (PE), gestational hypertension (GH), gestational diabetes (GD), preterm birth (PTB), small (SGA) and large (LGA) for gestational age (vs. appropriate size for gestational age (AGA)) with up to 167 plasma/serum-based nuclear magnetic resonance-derived metabolic traits encompassing lipids, lipoproteins, fatty acids, amino acids, ketones, glycerides/phospholipids, glycolysis, fluid balance, and inflammation. Confounder-adjusted regression models were used to examine associations (adjusted for maternal education, parity age at pregnancy, ethnicity, pre/early pregnancy body mass index and smoking, and offspring sex and age at metabolic trait assessment), and results were combined using meta-analysis by five age categories representing different periods of the offspring life course: neonates (cord blood), infancy (mean ages: 1.1-1.6 years), childhood (4.2-7.5 years); adolescence (12.0-16.0 years), and adulthood (22.0-67.8 years).

RESULTS

Offspring numbers for each age category/analysis varied from 8925 adults (441 PTB) to 1181 infants (135 GD); 48.4% to 60.0% were females. Pregnancy complications (PE, GH, GD) were each associated with up to three metabolic traits in neonates (P≤0.001) with some evidence of persistence to older ages. PTB and SGA were associated with 32 and 12 metabolic traits in neonates respectively, which included an adjusted standardised mean difference of -0.89 standard deviation (SD) units for albumin with PTB (95% CI: -1.10 to -0.69, P=1.3×10^-17) and -0.41 SD for total lipids in medium HDL with SGA (95% CI: -0.56 to -0.25, P=2.6×10^-7), with some evidence of persistence to older ages. LGA was inversely associated with 19 metabolic traits including lower levels of cholesterol, lipoproteins, fatty acids, and amino acids, with associations emerging in adolescence, (e.g. -0.11 SD total fatty acids, 95% CI: -0.18 to -0.05, P=0.0009), and attenuating with older age across adulthood.

CONCLUSIONS

These reassuring findings suggest little evidence of wide-spread and long-term impact of common pregnancy and perinatal complications on offspring metabolic traits, with most associations only observed for newborns rather than older ages, and for perinatal rather than pregnancy complications.

Fat-Soluble Vitamers: Parent-Child Concordance and Population Epidemiology in the Longitudinal Study of Australian Children

Fat-soluble vitamers (FSV) are a class of diverse organic substances important in a wide range of biological processes, including immune function, vision, bone health, and coagulation. Profiling FSV in parents and children enables insights into gene-environment contributions to their circulating levels, but no studies have reported on the population epidemiology of FSV in these groups as of yet. In this study, we report distributions of FSV, their parent-child concordance and variation by key characteristics for 2490 children (aged 11-12 years) and adults (aged 28-71 years) in the Child Health CheckPoint of the Longitudinal Study of Australian Children. Ten A, D, E and K vitamers were quantified using a novel automated LC-MS/MS method. All three K vitamers (i.e., K1, MK-4, MK-7) and 1-α-25(OH)₂D₃ were below the instrument detection limit and were removed from the present analysis. We observed a strong vitamer-specific parent-child concordance for the six quantifiable A, D and E FSVs. FSV concentrations all varied by age, BMI, and sex. We provide the first cross-sectional population values for multiple FSV. Future studies could examine relative genetic vs. environmental determinants of FSV, how FSV values change longitudinally, and how they contribute to future health and disease.

The effect of adverse and positive experiences on inflammatory markers in Australian and UK children

Background

The relationship between childhood adversity and inflammation is well-established. Examination of positive experiences can provide a more complete understanding of intervention opportunities. We investigated associations of adverse and positive experiences, and their intersection, with inflammation in children and adolescents.

Methods

Data sources: Longitudinal Study of Australian Children (LSAC; N = 1237) and Avon Longitudinal Study of Parents and Children (ALSPAC; N = 3488). Exposures: Adverse and positive experiences assessed repeatedly (LSAC: 0-11 years; ALSPAC: 0-15 years). Outcomes: Inflammation quantified by high sensitivity C-reactive protein (hsCRP) and glycoprotein acetyls (GlycA) (LSAC: 11-12 years; ALSPAC: 15.5 years). Analyses: Linear regression on the log-transformed outcomes estimated the relative difference in inflammatory markers with adverse/positive experiences, adjusting for socio-demographics and concurrent positive/adverse experiences, respectively.

Results

Most associations were in the expected direction but differed in magnitude by exposure, outcome and cohort. Across both cohorts, adverse experiences were associated with up to 7.3% higher hsCRP (95% CI: -18.6%, 33.2%) and up to 2.0% higher GlycA (95% CI: 0.5%, 3.5%); while positive experiences were associated with up to 22.1% lower hsCRP (95% CI: -49.0%, 4.7%) and 1.3% lower GlycA (95% CI: -2.7%, 0.2%). In LSAC, the beneficial effect of positive experiences on inflammation was more pronounced among those with fewer concurrent adverse experiences.

Conclusion

Across two cohorts, we found small but directionally consistent associations between adverse experiences and higher inflammation, and positive experiences and lower inflammation, particularly for GlycA. Future research should give further consideration to positive experiences to complement the current focus on adversity and inform the design and evaluation of early life interventions.

Your best day: An interactive app to translate how time reallocations within a 24-hour day are associated with health measures

Reallocations of time between daily activities such as sleep, sedentary behavior and physical activity are differentially associated with markers of physical, mental and social health. An individual’s most desirable allocation of time may differ depending on which outcomes they value most, with these outcomes potentially competing with each other for reallocations. We aimed to develop an interactive app that translates how self-selected time reallocations are associated with multiple health measures. We used data from the Australian Child Health CheckPoint study (n = 1685, 48% female, 11–12 y), with time spent in daily activities derived from a validated 24-h recall instrument, %body fat from bioelectric impedance, psychosocial health from the Pediatric Quality of Life Inventory and academic performance (writing) from national standardized tests. We created a user-interface to the compositional isotemporal substitution model with interactive sliders that can be manipulated to self-select time reallocations between activities. The time-use composition was significantly associated with body fat percentage (F = 2.66, P < .001), psychosocial health (F = 4.02, P < .001), and academic performance (F = 2.76, P < .001). Dragging the sliders on the app shows how self-selected time reallocations are associated with the health measures. For example, reallocating 60 minutes from screen time to physical activity was associated with -0.8 [95% CI -1.0 to -0.5] %body fat, +1.9 [1.4 to 2.5] psychosocial score and +4.5 [1.8 to 7.2] academic performance. Our app allows the health associations of time reallocations to be compared against each other. Interactive interfaces provide flexibility in selecting which time reallocations to investigate, and may transform how research findings are disseminated.

Longitudinal association between caesarean section birth and cardio-vascular risk profiles among adolescents in Australia

OBJECTIVE

To examine the association of cesarean section (C-section) with cardiovascular disease (CVD) risk biomarkers among Australian children.

METHODS

The Longitudinal Study of Australian Children (LSAC) birth cohort was prospectively followed for body mass index (BMI) trajectory, and then linked with CVD risk indicators of children; waist circumference (WC), systolic blood pressure (SBP), blood glucose, high-density lipoprotein (HDL), triglyceride (TG), fat mass index (FMI) and composite metabolic syndrome (CMetS) score. Multivariable linear regression analysis was done to assess the association of C-sections with CVD risk biomarkers.

RESULTS

Of 1,874 study children, 30% had C-sections; the mean age (SD) was 11.50 (0.50) years, and 49% were female. Against the vaginally-born cohort, Caesarean-born children showed a higher Z- score for five of the seven CVD risk indicators in regression analysis; WC (0.15; p=0.003), SBP (0.16; p=0.003), inverse HDL (0.15; p=0.003), FMI (0.12; p=0.004), and CMetS (0.45; p=0.004) score. Children with accelerated BMI trajectory had higher CMetS scores for both the delivery types while the C-section cohort showed statistical association only (1.69; p=0.006) Conclusion: C-section was independently associated with increased CVD risk profiles of children, further increased with high BMI trajectory. Implication for public health: The chronic disease risk of C-sections should be discussed with families to reduce clinically unrequired C-sections.

Associations between meeting 24-hour movement guidelines and academic achievement in Australian primary school-aged children

BACKGROUND

Few studies have investigated associations between academic achievement and meeting recommendations from the 24-hour (24-h) movement guidelines. The specific guidelines associated with the most benefit academic achievement are unknown. Utilizing both self-report and objective movement data, this study examined associations between academic achievement and meeting individual recommendations and combinations of recommendations from the 24-h movement guidelines (sleep, physical activity, and screen time).

METHODS

Data from CheckPoint, a cross-sectional study nested between Waves 6 and 7 of the Longitudinal Study of Australian Children, were used. Movement behaviors were measured using 24-h wrist-worn accelerometry (GENEActiv (Activinsights, Kimbolton, UK)) and were self-reported by children using the Multimedia Activity Recall for Children and Adolescents. Academic achievement was measured using a nationally administered standardized test in literacy and numeracy. Analysis of covariance, with t tests with sequential Bonferroni adjustments, was used to compare academic achievement with all possible combinations of meeting recommendations, adjusting for demographic confounders. Two models were considered: guideline compliance assessed by self-report (n = 1270, mean age = 11.99 years, 52% males) and by accelerometry (for moderate-to-vigorous intensity physical activity (MVPA) and sleep)) and self-report (screen time) in combination (n = 927, mean age = 11.97 years, 52% males).

RESULTS

Literacy achievement significantly differed based on self-report (F_{(7, 1258)} = 3.08, p = 0.003) and accelerometer derived (F_{(7, 915)} = 2.40, p = 0.02) guideline compliance. Numeracy achievement significantly differed based on self-report (F_{(7, 1258)} = 2.92, p = 0.005) but not accelerometer derived guideline compliance (F_{(7, 915)} = 0.80, p = 0.58). When assessed by self-report, children who met all guidelines (t₍₃₃₄₎ = -4.05, p = 0.0001) or met the screen time and sleep guidelines in combination (t₍₁₂₅₎ = -5.02, p < 0.001) had superior literacy achievement. Meeting the self-report MVPA guideline in any combination was associated with higher numeracy scores (p < 0.05). Post-hoc analyses showed no differences in academic achievement for any category of accelerometer derived guideline compliance.

CONCLUSION

The findings suggest that limiting recreational screen time is important for literacy achievement and that encouraging compliance with the MVPA guideline is important for numeracy achievement.

Perceived green space quality, child biomarkers and health-related outcomes: A longitudinal study

Accumulating exposure to quality green space over time is posited to influence child health, yet longitudinal studies are scarce. This study aimed to examine the associations between trajectories of perceived green space quality and child health-related outcomes. We used data from 1874 childrenin the B-cohort of the Longitudinal Study of Australian Children who participated in the Child Health Checkpoint module at 11-12 years. Data on caregiver perceived green space quality measured biennially was assessed using discrete trajectory mixture models to group children by contrasting distributions in green space quality over time. Examination of associations between trajectory groups of perceived green space quality and child biomarkers (i.e., albumin-to-creatinine ratio, total, cholesterol, total triglycerides, and glucose), physical health and behavioural assessments (i.e., anthropometric measurements, blood pressure, sedentary behaviour, physical activity, sleep, aerobic work capacity, and general wellbeing), and health care use were assessed using multilevel models, adjusted for sociodemographic variables. Four perceived green space quality trajectories were identified: "decreasing quality from high to moderate"; "increasing quality from low to high"; "consistently high quality"; "consistently low quality". Compared with consistently low levels of quality green space, adjusted models indicated consistently high-quality green space was associated with lower total triglycerides (β -0.13; 95%CI -0.25, -0.01). Lower odds of hospital admission was observed among children who accumulated quality green space over time (OR 0.45; 95%CI 0.23, 0.87). These associations were observed in boys only in sex-stratified analyses. Moreover, boys accumulating quality green space through time tended to have lower diastolic blood pressure (β -2.76; 95%CI -5.17, -0.35) and girls who experienced loss in quality green space tended to have a higher percentage of body fat (β 2.81; 95%CI 0.43, 5.20). Accumulating quality green space over time is important for various aspects of child health, with contrasting benefits by sex.

Can adult polygenic scores improve prediction of body mass index in childhood?

BACKGROUND/OBJECTIVES

Modelling genetic pre-disposition may identify children at risk of obesity. However, most polygenic scores (PGSs) have been derived in adults, and lack validation during childhood. This study compared the utility of existing large-scale adult-derived PGSs to predict common anthropometric traits (body mass index (BMI), waist circumference, and body fat) in children and adults, and examined whether childhood BMI prediction could be improved by combining PGSs and non-genetic factors (maternal and earlier child BMI).

SUBJECTS/METHODS

Participants (n = 1365 children, and n = 2094 adults made up of their parents) were drawn from the Longitudinal Study of Australian Children. Children were weighed and measured every two years from 0-1 to 12-13 years, and adults were measured or self-reported measurements were obtained concurrently (average analysed). Participants were genotyped from blood or oral samples, and PGSs were derived based on published genome-wide association studies. We used linear regression to compare the relative utility of these PGSs to predict their respective traits at different ages.

RESULTS

BMI PGSs explained up to 12% of child BMI z-score variance in 10-13 year olds, compared with up to 15% in adults. PGSs for waist circumference and body fat explained less variance (up to 8%). An interaction between BMI PGSs and puberty (p = 0.001-0.002) suggests the effect of some variants may differ across the life course. Individual BMI measures across childhood predicted 10-60% of the variance in BMI at 12-13 years, and maternal BMI and BMI PGS each added 1-9% above this.

CONCLUSION

Adult-derived PGSs for BMI, particularly those derived by modelling between-variant interactions, may be useful for predicting BMI during adolescence with similar accuracy to that obtained in adulthood. The level of precision presented here to predict BMI during childhood may be relevant to public health, but is likely to be less useful for individual clinical purposes.

Relationship between life-time exposure to ambient fine particulate matter and carotid artery intima-media thickness in Australian children aged 11-12 years

Long-term exposure to air pollutants, especially particulates, in adulthood is related to cardiovascular diseases and vascular markers of atherosclerosis. However, whether vascular changes in children is related to exposure to air pollutants remains unknown. This study examined whether childhood exposure to air pollutants was related to a marker of cardiovascular risk, carotid intima-media thickness (CIMT) in children aged 11-12 years old. Longitudinal Study of Australian Children (LSAC) recruited parents and their children born in 2003-4. Among the participants, CheckPoint examination was conducted when the children were 11-12 years old. Ultrasound of the right carotid artery was performed using standardized protocols. Average and maximum far-wall CIMT, carotid artery distensibility, and elasticity were quantified using semiautomated software. Annual and life-time exposure to air pollutants was estimated using satellite-based land-use regression by residential postcodes. A total of 1063 children (50.4% girls) with CIMT data, serum cholesterol, and modeled estimates of NO₂ and PM_2.5 exposure for the period 2003 to 2015 were included. The average and maximum CIMT, carotid distensibility, and elasticity were 497 μm (standard deviation, SD 58), 580 μm (SD 44), 17.4% (SD 3.2), and 0.48%/mmHg (SD 0.09), respectively. The life-time average concentrations of PM_2.5 and NO₂ were 6.4 μg/m³ (SD 1.4) and 6.4 ppb (SD 2.4), respectively. Both average and maximum CIMT were significantly associated with average ambient PM_2.5 concentration (average CIMT: +5.5 μm per μg/m³, 95% confidence interval, CI 2.4 to 8.5, and maximum CIMT: +4.9 μm per μg/m³, CI 2.3 to 7.6), estimated using linear regression, adjusting for potential confounders. CIMT was not significantly related to NO₂ exposure. Carotid artery diameter, distensibility, and elasticity were not significantly associated with air pollutants. We conclude that life-time exposure to low levels of PM_2.5 in children might have measurable adverse impacts on vascular structure by age 11-12 years.

The association between markers of inflammation and retinal microvascular parameters: A systematic review and meta-analysis

BACKGROUND AND AIMS

Adverse changes to the microcirculation play an important role in the pathogenesis of cardiovascular disease (CVD), and inflammation is a key causal mechanism. We investigated the relationship between inflammatory markers and retinal microvascular parameters.

METHODS

Studies up to April 2021 were identified in Medline, Embase and PubMed with the following terms: retinal microvascular parameters, inflammatory markers, and observational studies. Correlation coefficients of inflammatory markers and retinal vascular caliber were pooled using the random-effects model.

RESULTS

Of 4783 studies identified, 36 met the inclusion criteria (general population 26, patients with diseases 10). C-reactive protein (CRP) and white blood cell count (WBC) were most frequently reported. We conducted meta-analysis with 12 CRP studies (22422 participants) and six WBC studies (15209 participants), and also performed a narrative review of all studies. There was consistent evidence of a modest association between CRP and venular caliber (r = 0.09, 95%CI 0.05 to 0.12), but little evidence of an association between CRP with retinal arteriolar caliber (r = 0.00, 95%CI -0.02 to 0.02). Similarly, WBC had stronger associations with venular (r = 0.18, 95%CI 0.05 to 0.31) than arteriolar caliber (r = 0.05, 95%CI 0.01 to 0.09). Narrative review of other inflammatory markers showed consistent findings. There was little evidence of associations between inflammation markers and other microvascular parameters, fractal dimension and tortuosity.

CONCLUSIONS

There was more evidence for an association of inflammation with retinal venular than with arterial caliber. The findings suggest a potential druggable mechanism contributing to microvascular damage that has been relatively overlooked in CVD pathogenesis and treatment.

Ear Infection Trajectories and Academic, Behavioral, and Quality-of-Life Outcomes: A Population-Based Longitudinal Study

OBJECTIVE

The purpose of this study was to investigate (1) typical trajectories of parent-reported ear infections throughout childhood and (2) their associations with child outcomes.

METHOD

Design and participants: Two parallel cohorts assessed biennially from 2004 to 2014 spanning ages 0-1 to 10-11 years (B cohort, n = 3721) and ages 4-5 to 14-15 years (K cohort, n = 3489) in the Longitudinal Study of Australian Children. Ear infection: Parent-reported ongoing ear infections (B: waves 1-6; K: waves 1, 2, 4, and 5). Outcomes (wave 6): National academic standardized test, teacher-reported learning, parent- and teacher-reported behavior, and self-reported quality of life. Analysis: Latent class models identified ear infection trajectories. Linear regression quantified associations between trajectories and outcomes.

RESULTS

Four probability trajectories of ear infections emerged in both cohorts: "consistently low" (B 86.2%, K 87.0%), "moderate to low" (5.5%, 9.7%), "low to moderate" (7.0%, 1.5%), and "consistently high" (1.4%, 1.8%). In K cohort, the "consistently high" group had the worst outcomes (effect sizes 0.2-0.8 SDs), with effect sizes largest for psychosocial and language outcomes. "Moderate to low" and "low to moderate" groups showed marginal to no academic associations, although behavior and quality-of-life scores were 0.2 to 0.3 SDs poorer than the "consistently low" group. Similar but attenuated associations were seen in B cohort.

CONCLUSION

Sizable adverse adolescent outcomes follow parent reports of persistent ongoing ear infections throughout childhood. Despite a possibility of reverse causation, this suggests that cumulative rather than age-specific ear infections are most important to outcomes. Clinicians may generally be reassuring about ongoing ear infections limited to either early or middle childhood but should proactively identify and manage the small subgroup whose early infections persist throughout the elementary school years.

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.

Diet quality trajectories and cardiovascular phenotypes/metabolic syndrome risk by 11-12 years

OBJECTIVE

To investigate associations between early-life diet trajectories and preclinical cardiovascular phenotypes and metabolic risk by age 12 years.

METHODS

Participants were 1861 children (51% male) from the Longitudinal Study of Australian Children. At five biennial waves from 2-3 to 10-11 years: Every 2 years from 2006 to 2014, diet quality scores were collected from brief 24-h parent/self-reported dietary recalls and then classified using group-based trajectory modeling as 'never healthy' (7%), 'becoming less healthy' (17%), 'moderately healthy' (21%), and 'always healthy' (56%). At 11-12 years: During children's physical health Child Health CheckPoint (2015-2016), we measured cardiovascular functional (resting heart rate, blood pressure, pulse wave velocity, carotid elasticity/distensibility) and structural (carotid intima-media thickness, retinal microvasculature) phenotypes, and metabolic risk score (composite of body mass index z-score, systolic blood pressure, high-density lipoproteins cholesterol, triglycerides, and glucose). Associations were estimated using linear regression models (n = 1100-1800) adjusted for age, sex, and socioeconomic position.

RESULTS

Compared to 'always healthy', the 'never healthy' trajectory had higher resting heart rate (2.6 bpm, 95% CI 0.4, 4.7) and metabolic risk score (0.23, 95% CI 0.01, 0.45), and lower arterial elasticity (-0.3% per 10 mmHg, 95% CI -0.6, -0.1) and distensibility (-1.2%, 95% CI -1.9, -0.5) (all effect sizes 0.3-0.4). Heart rate, distensibility, and diastolic blood pressure were progressively poorer for less healthy diet trajectories (linear trends p ≤ 0.02). Effects for systolic blood pressure, pulse wave velocity, and structural phenotypes were less evident.

CONCLUSIONS

Children following the least healthy diet trajectory had poorer functional cardiovascular phenotypes and metabolic syndrome risk, including higher resting heart rate, one of the strongest precursors of all-cause mortality. Structural phenotypes were not associated with diet trajectories, suggesting the window to prevent permanent changes remains open to at least late childhood.

Predictors of Parent Use of a Child Health Home-Based Record and Associations with Long-Term Child Health/Developmental Outcomes: Findings from the Longitudinal Study of Australian Children from 2004 to 2016

PURPOSE

This study aims to examine predictors of parent use of a child health home-based record and associations with child health/developmental outcomes.

DESIGN AND METHODS

Data for this study was obtained from a nationally representative study of Australian children from 2004 to 2016. The current study focuses on the kindergarten cohort of the Longitudinal Study of Australian Children, which enrolled children at the ages of 4-5 years. Logistic regression was used to analyse the data using Odds Ratio (OR) at 95% Confidence Interval (CI) and p-value of 0.05.

RESULTS

A total of 4983 parent-child pairs participated at the beginning of the study in 2004, which reduced to 3089 (62%) by 2016. The most significant predictor of home-based record use was co-parenting, with single parents less likely to use the record (Adjusted OR = 0.633-95%CI:0.518-0.772). Similarly, child up-to-date immunisation was 31% higher among parents who used the record (OR = 1.313-95%CI:1.049-1.644). Children without a home-based record had increased odds of having various health/developmental concerns (p < 0.05).

CONCLUSION

The findings suggest that using a home-based record may have a long-term impact on child health and development. It is also possible that home-based records are more likely to be used by parents of relatively healthy children. Further work is needed to consider if home-based records need to be modified for parents of children with health/development problems.

PRACTICE IMPLICATIONS

Nurses and other primary care providers at forefront of family health should ensure proper use of child health home-based records as well as promote its use by parents and caregivers of children.

Insights into adolescent well-being from computerised analysis of written language

AIM

To examine associations between patterns of language use and early adolescent well-being.

METHODS

Participants were 1763 Australian 11- to 12-year-olds in the Child Health CheckPoint. Six patterns of language use were identified from a writing activity using Linguistic Inquiry and Word Count and factor analysis: Acting in the present and future, Positive emotion, Gender and relationships, Self-aware, Inquisitive and time focused, and Confident. Well-being measures represented a spectrum from negatively to positively framed psychosocial health. Associations between language use and well-being were estimated using linear regression adjusted for age, sex and social disadvantage.

RESULTS

Positive emotion (high emotional tone, positive emotion) was associated with better general well-being (standardised regression coefficient (SRC) 0.05; 95% confidence interval 0.00 to 0.11; p = 0.04), life satisfaction (0.06; 0.01 to 0.11; p = 0.03), psychosocial health (0.07; 0.02 to 0.12; p = 0.01) and quality of life (QoL) (0.06; 0.01 to 0.11; p = 0.02). Similarly, Self-aware (high first person singular pronouns, authentic, low clout) was associated with better general well-being, life satisfaction and psychosocial health (SRC 0.05, 0.09, 0.08), but Confident (high clout, first person plural pronouns, affiliation) was associated with worse life satisfaction, psychosocial health and QoL (SRC -0.06, -0.09, -0.06).

CONCLUSION

If replicated in 'real-world' settings (e.g., social media), language patterns could provide naturalistic insights into early adolescents' well-being.

Oral health: Epidemiology and concordance in Australian children and parents

INTRODUCTION

Studying parent-child pair health provides the opportunity to identify risk factors and opportunities for oral health prevention and intervention focusing on the family context. The aim of this study was to describe the oral health of children aged 11-12 years and their parents in a national sample of parent-child dyads in Australia.

METHODS

The Child Health CheckPoint is a study of 11 to 12-year-old children and one parent nested within the Longitudinal Study of Australian Children, a nationally representative cohort study. In 2015-16, the study collected two-dimensional photographic intra-oral images and was scored using visual assessments of the teeth, oral hygiene and malocclusion.

RESULTS

Of the 1874 CheckPoint families, 1396 biological parent-child pairs had at least one oral health measure recorded. Over two-thirds of children had moderate to severe gingival inflammation (69.7%, 95%CI 64.7-74.9). Parents had a lower proportion of poor oral hygiene (2.1%, 95% CI 1.4-3.0) than children (13.0%, 95% CI 11.3-14.9). High concordance was seen in the Modified Gingival Index correlation coefficient 0.49 (95%CI 0.44-0.53).

CONCLUSION

The high concordance in gingival health between child-parent pairs supports the familial and behavioural links established in previous studies. Children had poorer oral hygiene but fewer visible dental caries lesions than their parents. As dental caries is a chronic and cumulative disease, preventive interventions targeting children's oral hygiene are needed.

Does an inflammatory diet affect mental well-being in late childhood and mid-life? A cross-sectional study

Inflammatory diets are increasingly recognised as a modifiable determinant of mental illness. However, there is a dearth of studies in early life and across the full mental well-being spectrum (mental illness to positive well-being) at the population level. This is a critical gap given that inflammatory diet patterns and mental well-being trajectories typically establish by adolescence. We examined the associations of inflammatory diet scores with mental well-being in 11-12-year-olds and mid-life adults. Throughout Australia, 1759 11-12-year-olds (49 % girls) and 1812 parents (88 % mothers) contributed cross-sectional population-based data. Alternate inflammatory diet scores were calculated from a twenty-six-item FFQ, based on the prior literature and prediction of inflammatory markers. Participants reported negatively and positively framed mental well-being via psychosocial health, quality of life and life satisfaction surveys. We used causal inference modelling techniques via generalised linear regression models (mean differences and risk ratios (RR)) to examine how inflammatory diets might influence mental well-being. In children and adults, respectively, a 1 sd higher literature-derived inflammatory diet score conferred between a 44 % (RR 95 % CI 1·2, 1·8) to 57 % (RR 95 % CI 1·3, 2·0) and 54 % (95 % CI 1·2, 2·0) to 86 % (RR 95 % CI 1·4, 2·4) higher risk of being in the worst mental well-being category (i.e. <16th percentile) across outcome measures. Results for inflammation-derived scores were similar. BMI mediated effects (21-39 %) in adults. Inflammatory diet patterns were cross-sectionally associated with mental well-being at age 11-12 years, with similar effects observed in mid-adulthood. Reducing inflammatory dietary components in childhood could improve population-level mental well-being across the life course.

Reflection on modern methods: planned missing data designs for epidemiological research

Taking advantage of the ability of modern missing data treatments in epidemiological research (e.g. multiple imputation) to recover power while avoiding bias in the presence of data that is missing completely at random, planned missing data designs allow researchers to deliberately incorporate missing data into a research design. A planned missing data design may be done by randomly assigning participants to have missing items in a questionnaire (multiform design) or missing occasions of measurement in a longitudinal study (wave-missing design), or by administering an expensive gold-standard measure to a random subset of participants while the whole sample is administered a cheaper measure (two-method design). Although not common in epidemiology, these designs have been recommended for decades by methodologists for their benefits-notably that data collection costs are minimized and participant burden is reduced, which can increase validity. This paper describes the multiform, wave-missing and two-method designs, including their benefits, their impact on bias and power, and other factors that must be taken into consideration when implementing them in an epidemiological study design.

Equivalence Curves for Healthy Lifestyle Choices

BACKGROUND

Understanding equivalence of time-use trade-offs may inform tailored lifestyle choices. We explored which time reallocations were associated with equivalent changes in children's health outcomes.

METHODS

Participants were from the cross-sectional Child Health CheckPoint Study (N = 1179; 11-12 years; 50% boys) nested within the population-based Longitudinal Study of Australian Children. Outcomes were adiposity (bioelectrical impedance analysis, BMI and waist girth), self-reported health-related quality of life (HRQoL; Pediatric Quality of Life Inventory), and academic achievement (standardized national tests). Participants' 24-hour time use (sleep, sedentary behavior, light physical activity, and moderate-to-vigorous physical activity [MVPA]) from 8-day 24-hour accelerometry was regressed against outcomes by using compositional log-ratio linear regression models.

RESULTS

Children with lower adiposity and higher HRQoL had more MVPA (both P ≤ .001) and sleep (P = .001; P < .02), and less sedentary time (both P < .001) and light physical activity (adiposity only; P = .03), each relative to remaining activities. Children with better academic achievement had less light physical activity, relative to remaining activities (P = .003). A 0.1 standardized decrease in adiposity was associated with either 52 minutes more sleep, 56 minutes less sedentary time, 65 minutes less light physical activity, or 17 minutes more MVPA. A 0.1 standardized increase in HRQoL was associated with either 68 minutes more sleep, 54 minutes less sedentary time, or 35 minutes more MVPA.

CONCLUSIONS

Equivalent differences in outcomes were associated with several time reallocations. On a minute-for-minute basis, MVPA was 2 to 6 times as potent as sleep or sedentary time.

Population epidemiology and concordance for plasma amino acids and precursors in 11-12-year-old children and their parents

Amino acid (AA) concentrations are influenced by both exogenous (e.g. diet, lifestyle) and endogenous factors (e.g. genetic, transcriptomic, epigenetic, and metabolomic). Fasting plasma AA profiles in adulthood are predictive of diabetes risk over periods of up to 12 years. Data on AA profiles in cross-generational cohorts, including individuals from shared gene-environment settings are scarce, but would allow the identification of the contribution of heritable and environmental factors characterising the levels of circulating AAs. This study aimed to investigate parent–child (familial dyad) concordance, absolute differences between generations- (children versus adults), age- (in adults: 28–71 years), and sex-dependent differences in plasma AA concentrations. Plasma AA concentrations were measured by UHPLC/MS–MS in 1166 children [mean (SD) age 11 (0.5) years, 51% female] and 1324 of their parents [44 (5.1) years, 87% female]. AA concentrations were variably concordant between parents and their children (5–41% of variability explained). Most AA concentrations were higher in adults than children, except for the non-essential AAs arginine, aspartic acid, glutamine, hydroxy-proline, proline, and serine. Male adults and children typically had higher AA concentrations than females. The exceptions were alanine, glutamine, glycine, hydroxy-proline, serine, and threonine in girls; and glycine and serine in women. Age, sex, and shared familial factors are important determinants of plasma AA concentrations.

Relationship between chewing tobacco, smoking, consuming alcohol and cognitive impairment among older adults in India: a cross-sectional study

BACKGROUND

Physical aging increases the sensitivity to the effects of substance use, elevating the risk for cognitive impairment among older adults. Since studies on the association of substance use with cognitive ability in later years are scant in India, we aimed to explore the factors associated with cognitive impairment especially, alcohol consumption, smoking, and chewing tobacco later in life.

METHODS

The present research used nationally representative data from Building a Knowledge Base on Population Aging in India (BKPAI) that was conducted in 2011, across seven states of India (N=9,453). Sample distribution along with percentage distribution was calculated for cognitive impairment over explanatory variables. For finding the association between cognitive impairment over explanatory variables, binary logistic regression models were estimated.

RESULTS

About 16.5 percent of older adults in rural areas consumed smoked tobacco compared to 11.7 percent in urban areas. Nearly, 23.7 percent of rural older adults consumed smokeless tobacco in comparison to 16 percent in urban areas. Alcohol consumption was high among rural residents (7.9%) than urban counterparts (6.7%). The prevalence of cognitive impairment was 62.8% and 58% among older adults from rural and urban areas respectively. Older adults who smoked tobacco had a 24 percent significantly higher likelihood to have cognitive impairment with reference to older adults who did not smoke [OR: 1.24, CI: 1.02-1.49]. Moreover, older adults who consumed alcohol had a 30 percent significantly higher likelihood to have cognitive impairment [OR: 1.02, 1.65]. It was also found that older adults who had smoked along with consuming alcohol were at risk of worse cognitive outcomes than those who neither smoke nor drink alcohol [OR: 1.56, CI: 1.21-2.00] or consumed either of them unlike consuming smokeless tobacco only.

CONCLUSION

The encouragement of older people to stop smoking and smokeless tobacco use could be considered as part of a strategy to reduce the incidence of cognitive impairment. Further, appropriate measures should be taken for the detection of early stages of cognitive decline in older individuals and efforts should be made to improve the availability and quality of care for dementing older adults.

Associations of Retinal Vessel Caliber With Hearing Status in Childhood and Midlife: A Cross-Generational Population-Based Study

Importance

Microvascular phenotypes, which can be assessed using retinal imaging, may be informative about the life course pathogenesis of hearing loss.

Objective

To investigate whether differences in retinal vessel caliber (specifically wider venules and narrower arterioles) are associated with hearing threshold and hearing loss in mid-childhood and midlife.

Design, Setting, and Participants

A population-based cross-sectional study (Child Health CheckPoint) was nested within the Longitudinal Study of Australian Children. A total of 1281 children and 1255 attending parents were assessed using retinal microvasculature and air conduction audiometry data at a main assessment center in 7 large cities in Australia.

Main Outcomes and Measures

Air conduction audiometry was used to calculate the high Fletcher index (mean threshold of 1, 2, and 4 kHz), and bilateral hearing loss was defined as a high Fletcher index greater than 15 dB hearing level in the better-hearing ear. Retinal arteriolar and venular caliber were measured from fundus photographs using validated computer-based software. Linear and logistic regression quantified the associations of retinal vessel caliber with hearing threshold and hearing loss, respectively.

Results

Of the 1281 included children (mean age, 11.4 years; 49.1% boys), the mean (SD) high Fletcher index was 7.9 (5.8) dB hearing level. Of the 1255 included adults (mean age, 43.8 years; 86.6% women), the mean (SD) high Fletcher index was 13.0 (6.8) dB hearing level; 109 of 1281 children (8.5%) and 328 of 1255 adults (26.1%) had hearing loss. In adults, each 1-SD (18.6-μm) wider retinal venular caliber (worse) was associated with higher (worse) hearing threshold at lower individual frequencies (eg, 2 kHz: β = 0.63; 95% CI, 0.10-1.17) and overall high Fletcher index (eg, 2 kHz: β = 0.52; 95% CI, 0.07-0.96), as well as a 1.20-fold (95% CI, 1.03-1.40) higher odds of hearing loss. In children, patterns of venular associations were similar but smaller and less certain. Narrower retinal arteriolar caliber (worse) was associated with a 1.16-fold (95% CI, 1.00-1.37) higher odds of hearing loss in adults (per 1-SD [14.0-μm] narrower arteriolar caliber) but not in children.

Conclusions and Relevance

Adverse retinal microvascular characteristics are associated with hearing loss by midlife, with venular associations possibly emerging by age 11 to 12 years. Microvascular health may contribute to the pathogenesis of hearing loss across the life course, warranting replication and mechanistic studies to inform causal inference and prevention efforts.

Balancing time use for children's fitness and adiposity: Evidence to inform 24-hour guidelines for sleep, sedentary time and physical activity

PURPOSE

Daily time spent on one activity cannot change without compensatory changes in others, which themselves may impact on health outcomes. Optimal daily activity combinations may differ across outcomes. We estimated optimal daily activity durations for the highest fitness and lowest adiposity.

METHODS

Cross-sectional Child Health CheckPoint data (1182 11-12-year-olds; 51% boys) from the population-based Longitudinal Study of Australian Children were used. Daily activity composition (sleep, sedentary time, light physical activity [LPA], moderate-to-vigorous physical activity [MVPA]) was from 8-day, 24-hour accelerometry. We created composite outcomes for fitness (VO2max; standing long jump) and adiposity (waist-to-height ratio; body mass index; fat-to-fat-free log-ratio). Adjusted compositional models regressed activity log-ratios against each outcome. Best activity compositions (optimal time-use zones) were plotted in quaternary tetrahedrons; the overall optimal time-use composition was the center of the overlapping area.

RESULTS

Time-use composition was associated with fitness and adiposity (all measures p<0.001). Optimal time use differed for fitness and adiposity. While both maximized MVPA and minimized sedentary time, optimal fitness days had higher LPA (3.4 h) and shorter sleep (8.25 h), but optimal adiposity days had lower LPA (1.0 h) and longer sleep (10.9 h). Balancing both outcomes, the overall optimal time-use composition was (mean [range]): 10.2 [9.5; 10.5] h sleep, 9.9 [8.8; 11.2] h sedentary time, 2.4 [1.8; 3.2] h LPA and 1.5 [1.5; 1.5] h MVPA.

CONCLUSION

Optimal time use for children's fitness and adiposity involves trade-offs. To best balance both outcomes, estimated activity durations for sleep and LPA align with, but for MVPA exceed, 24-h guidelines.

Selecting life course frameworks to guide and communicate large new cohort studies: Generation Victoria (GenV) case study

While birth cohorts are shaped by underpinning life course frameworks, few if any report how they select them. This review aimed to (1) summarise publicly available frameworks relevant to planning and communicating large new early-life cohorts and (2) help select frameworks to guide and communicate Generation Victoria (GenV), a whole-of-state birth and parent cohort in planning in the state of Victoria, Australia. We identified potential frameworks from prior knowledge, networks and a pragmatic literature search in 2019. We considered for inclusion only frameworks with an existing visual graphic. We summarised each framework's concept, then judged it on a seven-item matrix (Scope, Dimensions, Outcomes, Life course, Mechanisms, Multi-age, and Visual Clarity) to be of high, intermediate or low relevance to GenV. We presented and evaluated 14 life course frameworks across research and policy. Two, nine and three frameworks, respectively, were ranked as high, intermediate and low relevance to GenV, although none totally communicated its scope and intent. Shonkoff's biodevelopmental framework was selected as GenV's primary framework, adapted to include ongoing feedback loops through the life course and influence of an individual's outcomes on the next generation. Because conceptual simplicity precluded the primary framework from capturing the wide range of relevant exposures, we selected the Australian Institute of Health and Welfare's person-centred model as a secondary framework. This summary of existing life course frameworks may prove helpful to other cohorts in planning. Our transparent process and focus on visual communication are already assisting in explaining and selecting measures for GenV. The feasibility, comprehension and validity of these frameworks could be further tested at implementation.

Trimethylamine N-oxide (TMAO) Is not Associated with Cardiometabolic Phenotypes and Inflammatory Markers in Children and Adults

BACKGROUND

Trimethylamine N-oxide (TMAO) is a diet- and microbiome-derived metabolite and a proposed biomarker of adverse cardiometabolic outcomes. TMAO studies have mainly been conducted in individuals with cardiometabolic disease, and studies in population-derived samples are limited.

OBJECTIVE

We aimed to investigate the associations between plasma TMAO concentrations and its precursors [carnitine, choline, betaine, and dimethylglycine (DMG)] with metabolic syndrome (MetS) scores, preclinical cardiovascular phenotypes, and inflammatory biomarkers (i.e. high-sensitivity C-reactive protein and serum glycoprotein acetyls) in a population-derived cohort of children and their parents.

METHODS

The concentrations of TMAO and its precursors were quantified using UHPLC coupled with tandem MS (UHPLC/MS-MS) in 1166 children (mean age 11 y ± 0.5 y, 51% female) and 1324 adults (44 y ± 5.1 y, 87% female) participating in The Growing Up in Australia's Child Health CheckPoint Study. We developed multivariable fractional polynomial models to analyze associations between TMAO, its precursors, MetS (adjusted for sex and age), and cardiovascular phenotypes (adjusted for sex, age, BMI, household income, and the urinary albumin to creatinine ratio). Pearson's correlations were computed to identify associations between TMAO, its precursors, and inflammatory biomarkers.

RESULTS

The concentrations of TMAO precursors, but not TMAO itself, were associated with MetS, cardiovascular phenotypes, and inflammatory biomarkers in children and adults.

CONCLUSIONS

TMAO precursors, but not TMAO itself, were associated with adverse cardiometabolic and inflammatory phenotypes in children and adults. TMAO precursor concentrations may better reflect cardiovascular health and inflammatory status within the wider population. Replication in other population settings and mechanistic studies are warranted.

Sleep and cardiometabolic health in children and adults: examining sleep as a component of the 24-h day

STUDY OBJECTIVES

Sleep, physical activity and sedentary time are all known to play a role in cardiometabolic health. Compositional data analysis (CoDA) enables us to examine associations between 24-h use of time and health outcomes.

METHODS

Data were collected in the Child Health CheckPoint study, a one-off national population-cohort study conducted between February 2015 and March 2016. Wrist-worn actigraphy monitors (GENEActiv Original, Cambs, UK) were used to measure activity behaviours (sleep, physical activity and sedentary time) and sleep characteristics (sleep variability, midsleep, efficiency). CoDA was applied to determine the association between 24-h use of time and cardiometabolic risk markers (blood pressure; body mass index; apolipoprotein B/A1; glycoprotein acetyls; and composite metabolic syndrome score). Substitution modelling (one-for-remaining and one-for-one) examined the associations of reallocating sleep time with other activity behaviours.

RESULTS

Data were available for 1073 Australian children aged 11-12 years (50% male) and 1337 adults (13% male). Strong association was found between 24-h use of time and all cardiometabolic health outcomes. Longer sleep was associated with more favourable cardiovascular health. Sleep characteristics other than duration (efficiency, timing, variability) were weakly and inconsistently associated with outcomes. Reallocating time from sleep to moderate-vigorous physical activity (MVPA) had favourable associations with cardiometabolic health, but reallocating from sleep to sedentary time was associated with less favourable cardiometabolic health.

CONCLUSION

The 24-h activity composition is strongly associated with cardiometabolic health in children and adults. Days with more sleep and MVPA are associated with improved cardiometabolic health.

The "Goldilocks Day" for Children's Skeletal Health: Compositional Data Analysis of 24-Hour Activity Behaviors

Optimization of children's activity behaviors for skeletal health is a key public health priority, yet it is unknown how many hours of moderate to vigorous physical activity (MVPA), light physical activity (LPA), sedentary behavior, or sleep constitute the best day-the "Goldilocks Day"-for children's bone structure and function. To describe the best day for children's skeletal health, we used data from the cross-sectional Child Health CheckPoint. Included participants (n = 804, aged 10.7 to 12.9 years, 50% male) underwent tibial peripheral quantitative CT to assesses cross-sectional area, trabecular and cortical density, periosteal and endosteal circumference, polar moment of inertia, and polar stress-strain index. Average daily time-use composition (MVPA, LPA, sedentary time, and sleep) was assessed through 8-day, 24-hour accelerometry. Skeletal outcomes were regressed against time-use compositions expressed as isometric log-ratios (with quadratic terms where indicated), adjusted for sex, age, pubertal status, and socioeconomic position. The models were used to estimate optimal time-use compositions (associated with best 5% of each skeletal outcome), which were plotted in three-dimensional quaternary figures. The center of the overlapping area was considered the Goldilocks Day for skeletal health. Children's time-use composition was associated with all skeletal measures (all p ≤ 0.001) except cross-sectional area (p = 0.72). Days with more sleep and MVPA, less sedentary time, and moderate LPA were beneficially associated with skeletal measures, except cortical density, which was adversely associated. The Goldilocks daily time-use composition for overall skeletal health was center (range): 10.9 (10.5 to 11.5) hours sleep; 8.2 (7.8 to 8.8) hours sedentary time; 3.4 (2.8 to 4.2) hours LPA, and 1.5 (1.3 to 1.5) hours MVPA. Estimated optimal sleep duration is consistent with current international guidelines (9 to 11 hours), while estimated optimal MVPA exceeds recommendations of at least 60 min/d. This first study to describe optimal durations of daily activities for children's skeletal health provides evidence to underpin guidelines. © 2020 American Society for Bone and Mineral Research (ASBMR).

Exposure to adversity and inflammatory outcomes in mid and late childhood

BACKGROUND

We aimed to estimate the association between exposure to adversity and inflammatory markers in mid (4 years) and late (11-12 years) childhood, and whether effects differ by type and timing of exposure.

METHODS

Data sources: Barwon Infant Study (BIS; N = 510 analyzed) and Longitudinal Study of Australian Children (LSAC; N = 1156 analyzed). Exposures: Adversity indicators assessed from 0 to 4 (BIS) and 0-11 years (LSAC): parent legal problems, mental illness and substance abuse, anger in parenting responses, separation/divorce, unsafe neighborhood, and family member death; a count of adversities; and, in LSAC only, early (0-3), middle (4-7), or later (10-11) initial exposure. Outcomes: Inflammation quantified by high sensitivity C-reactive protein (hsCRP, Log (ug/ml)) and glycoprotein acetyls (GlycA, Log (umol/L)). Analyses: Linear regression was used to estimate relative change in inflammatory markers, adjusted for sociodemographic characteristics, with exposure to adversity. Outcomes were log-transformed.

RESULTS

Evidence of an association between adversity and hsCRP was weak and inconsistent (e.g., 3+ versus no adversity: BIS: 12% higher, 95%CI -49.4, 147.8; LSAC 4.6% lower, 95%CI: -36.6, 48.3). A small positive association between adversity and GlycA levels was observed at both 4 years (e.g., 3+ versus no adversity: 3.3% higher, 95%CI -3.0, 9.9) and 11-12 years (3.2% higher, 95%CI 0.8, 5.8). In LSAC, we did not find evidence that inflammatory outcomes differed by initial timing of adversity exposure.

CONCLUSIONS

Small positive associations between adversity and inflammation were consistently observed for GlycA, across two cohorts with differing ages. Further work is needed to understand mechanisms, clinical relevance, and to identify opportunities for early intervention.

Takeaway food, sugar-sweetened beverages and preclinical cardiometabolic phenotypes in children and adults

AIMS

To investigate relationships between takeaway food and sugar-sweetened beverage (SSB) consumption with cardiometabolic phenotypes during childhood and mid-adulthood.

METHOD

Design: Cross-sectional Child Health CheckPoint within the national population-representative Longitudinal Study of Australian Children. Participants: 1838 children (mean age 11.5 years; 49.1% female) and 1846 adults (mean age 43.7 years; 87.6% female). Exposures: Self-reported takeaway food and SSB consumption ('frequent': ≥ weekly). Outcomes: Functional (pulse wave velocity (PWV), blood pressure (BP)) and structural (carotid intima-media thickness, retinal microvascular calibre) preclinical cardiovascular phenotypes; lipids (total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides). Analysis: Linear regression (exposure: takeaway or SSB consumption, individually or together) adjusted for age, sex and socio-economic position; and mediation analysis for body mass index (BMI).

RESULTS

Associations were small among children (standardized mean difference (SMD) ≤0.15). In adults, associations were stronger with functional, but not structural, cardiovascular phenotypes and lipids, particularly for frequent takeaway food consumption (e.g. PWV (0.20 m/s; 95% confidence interval (CI) 0.03 to 0.37); systolic (3.3 mmHg; 95% CI 1.3 to 5.3) and diastolic BP (1.4 mmHg; 95% CI 0.2 to 2.6); LDL (0.10 mmol/L; 95% CI 0.02 to 0.18); HDL (-0.14 mmol/L; 95% CI -0.19 to -0.10) and triglycerides (0.30 mmol/L; 95% CI 0.12 to 0.48)]. BMI mediated associations between takeaway food consumption and PWV, BP, HDL and TG (proportion of mediation 34% to 75%), while mediation effects were smaller for SSB consumption.

CONCLUSIONS

Frequent takeaway food consumption in adults was associated with adverse blood lipids and vascular function (mainly via BMI). Lack of strong associations in children highlights opportunities for prevention.

Brachial-cuff excess pressure is associated with carotid intima-media thickness among Australian children: a cross-sectional population study

Reservoir pressure parameters (i.e., reservoir pressure [RP] and excess pressure [XSP]) independently predict cardiovascular events in adults, but this has not been investigated in children. This study aimed to determine (1) the association of reservoir pressure parameters with carotid intima-media thickness (carotid IMT), a preclinical vascular phenotype, and (2) whether a multivariable regression model with or without reservoir pressure parameters fits better for estimating carotid IMT in children. Study participants were 11-12-year-old children (n = 1231, 50% male) from the Child Health CheckPoint study, a cross-sectional substudy of the population-based Longitudinal Study of Australian Children. RP and XSP were obtained using brachial-cuff oscillometry (SphygmoCor XCEL, AtCor, Sydney). Carotid IMT was quantified by vascular ultrasonography. XSP was associated with carotid IMT after adjusting for confounders including age, sex, BMI z-score, heart rate, pubertal stage, moderate-to-vigorous physical activity, and mean arterial pressure (β = 0.93 µm, 95% CI 0.30-1.56 for XSP peak and β = 0.04 µm, 95% CI 0.01-0.08 for XSP integral). The results of the likelihood ratio test indicated a trend that the model with XSP and the above confounders fit better than a similar model without XSP for estimating carotid IMT. Our findings indicate that brachial-cuff device-measured XSP is associated with carotid IMT independent of conventional cardiovascular risk factors, including standard BP. This implies that a clinically convenient cuff approach could provide meaningful information for the early assessment of cardiovascular risk among children.

Analysing body composition as compositional data: An exploration of the relationship between body composition, body mass and bone strength

Human body composition is made up of mutually exclusive and exhaustive parts (e.g. %truncal fat, %non-truncal fat and %fat-free mass) which are constrained to sum to the same total (100%). In statistical analyses, individual parts of body composition (e.g. %truncal fat or %fat-free mass) have traditionally been used as proxies for body composition, and have been linked with a range of health outcomes. But analysis of individual parts omits information about the other parts, which are intrinsically co-dependent because of the constant sum constraint of 100%. Further, body mass may be associated with health outcomes. We describe a statistical approach for body composition based on compositional data analysis. The body composition data are expressed as logratios to allow relative information about all the compositional parts to be explored simultaneously in relation to health outcomes. We describe a recent extension to the logratio approach to compositional data analysis which allows absolute information about the total of the compositional parts (body mass) to be considered alongside relative information about body composition. The statistical approach is illustrated by an example that explores the relationships between adults' body composition, body mass and bone strength.

Cross-sectional metabolic profiles of mental health in population-based cohorts of 11- to 12-year-olds and mid-life adults: The Longitudinal Study of Australian Children

OBJECTIVE

Poorer mental health in adulthood is associated with increased risk of cardiovascular disease and reduced life expectancy. However, little is known of the molecular pathways underpinning this relationship and how early in life adverse metabolite profiles relate to self-reported variation in mental health. We examined cross-sectional associations between mental health and serum metabolites indicative of cardiovascular health, in large Australian population-based cohorts at two stages of the life-course.

METHODS

We characterised cross-sectional serum nuclear magnetic resonance metabolite profiles of positively and negatively framed mental health in a large population-based sample of Australian 11- to 12-year-olds (n = 1172; 51% girls) and mid-life adults (n = 1322; mean age 45 years; 87% women). We examined multiple standard self-report mental health scales, spanning psychosocial health, general well-being, life satisfaction, and health-related quality of life. Linear regression was used to investigate the cross-sectional association between mental health and each metabolite (n = 73) in children and adults separately, unadjusted and adjusted for age, sex, socioeconomic position and body mass index.

RESULTS

Better child and adult mental health were associated with lower levels of the inflammatory marker glycoprotein acetyls, and a favourable, less atherogenic lipid/lipoprotein profile. Patterns of association in children were generally weaker than in adults. Associations were generally modest and partially attenuated when adjusted for body mass index.

CONCLUSIONS

In general, metabolite profiles associated with better child and adult mental health closely aligned with those predictive of better cardiovascular health in adults. Our findings support previous evidence for the likely bidirectional relationship between mental health and cardiovascular disease risk, by extending this evidence base to the molecular level and in children.

Body Mass Index From Early to Late Childhood and Cardiometabolic Measurements at 11 to 12 Years

OBJECTIVES

To examine how overweight and obesity at specific ages and overall BMI growth patterns throughout childhood predict cardiometabolic phenotypes at 11 to 12 years.

METHODS

In a population-based sample of 5107 infants, BMI was measured every 2 years between ages 2 to 3 and 10 to 11 years. We identified 5 BMI trajectories using growth curve models. At ages 11 to 12 years, 1811 children completed assessments for metabolic syndrome risk scores, carotid-femoral pulse wave velocity, and carotid intima-media thickness. Multivariable regression models were used to estimate associations, adjusted for potential confounders (eg, age, sex, smoking exposure, and small for gestational age).

RESULTS

Overweight and obesity from early childhood onward were strongly associated with higher cardiometabolic risk at 11 to 12 years of age. At age 6 to 7 years, compared with those with a healthy weight, children with overweight had higher metabolic syndrome risk scores by 0.23 SD units (95% confidence interval 0.05 to 0.41) and with obesity by 0.76 SD units (0.51-1.01), with associations almost doubling by age 10 to 11 years. Obese (but not overweight) children had higher outcome pulse wave velocity (0.64-0.73 SD units) from ages 6 to 7 years and slightly higher outcome carotid intima-media thickness (0.20-0.30 SD units) at all ages. Cumulative exposure to high BMI from 2 to 3 years of age carried the greatest cardiometabolic risk, with a gradient of risk across trajectories.

CONCLUSIONS

High early-childhood BMI is already silently associated with the development of cardiometabolic risk by 11 to 12 years, highlighting the urgent need for effective action to reduce overweight and obesity in early childhood.

Plasma Trimethylamine N-Oxide and Its Precursors: Population Epidemiology, Parent-Child Concordance, and Associations with Reported Dietary Intake in 11- to 12-Year-Old Children and Their Parents

BACKGROUND

Trimethylamine N-oxide (TMAO) is a microbiome- and diet-derived metabolite implicated in adverse cardiovascular outcomes. To date, studies of plasma TMAO concentrations have largely focused on individuals with metabolic disease. As such, data on TMAO concentrations in population settings and parent-child dyads are lacking.

OBJECTIVES

This study aimed to investigate parent-child concordance, age, and sex effects on plasma concentrations of TMAO and its precursors [l-carnitine, choline, betaine, and dimethylglycine (DMG)]. Associations between concentrations of TMAO and its precursors and self-reported dietary intakes of animal protein (i.e., red meat, meat products, chicken, fish, milk products, and cheese) and fast-food meals were also investigated.

METHODS

A total of 1166 children (mean ± SD age: 11 ± 0.5 y, 51% female) and 1324 parents (mean ± SD age: 44 ± 5.1 y, 87% female) had a biomedical assessment as part of Growing Up in Australia's Child Health Checkpoint. Plasma TMAO and precursor concentrations were quantified using ultra-high-pressure LC coupled with tandem MS.

RESULTS

Familial dyads significantly contributed to plasma TMAO and precursor concentrations (P < 0.0001), explaining 37% of variance for TMAO concentrations. Least-square mean ± SE plasma TMAO was lower in children (0.79 ± 0.02 µM on the log-scale) than in adults (1.22 ± 0.02 µM). By contrast, children's betaine (40.30 ± 0.34 µM) and DMG concentrations (1.02 ± 0.01 µM on the log-scale) were higher than adults' betaine (37.50 ± 0.32 µM) and DMG concentrations (0.80 ± 0.01 µM) (P < 0.0001). Mean values of all metabolites, except adult TMAO, were higher in males than in females (P < 0.001). Greater reported intake of red meat and fish was associated with higher TMAO concentrations in both children [estimates (95% CIs) for red meat: 0.06 (0.01, 0.10); fish: 0.11 (0.06, 0.17)] and adults [red meat: 0.13 (0.08, 0.17); meat products: 0.07 (0.03, 0.12); and fish: 0.09 (0.04, 0.14)].

CONCLUSIONS

Age, sex, and shared family factors, including diet, contribute to variation in plasma concentrations of TMAO and its precursors.

No obvious impact of caesarean delivery on childhood allergic outcomes: findings from Australian cohorts

BACKGROUND AND OBJECTIVE

As caesarean delivery and childhood allergy continue to rise, their inter-relationships may change. We examined whether caesarean delivery predicts allergic disease and impaired lung function in two contemporary harmonised population-based cohorts.

METHODS

Parent-reported asthma and eczema data were drawn from two prospective Australian infant cohorts, HealthNuts (n=5276, born 2006-2010) and the Longitudinal Study of Australian Children (LSAC, n=5107, born 2003-2004) at age 6-7 years, and spirometric lung function from LSAC's Child Health CheckPoint (n=1756) at age 11-12 years. Logistic regression estimated associations between delivery mode and current asthma and eczema at 6-7 years, and linear regression examined lung function at 11-12 years. Models were adjusted for potential confounding factors.

RESULTS

Complete case analysis included 3135 HealthNuts and 3654 LSAC children (32.2% and 30.9% born by caesarean, respectively). An association was evident between caesarean delivery and asthma at age 6-7 years in HealthNuts (adjusted OR (aOR) 1.25, 95% CI 1.00 to 1.57) but not in LSAC (aOR 1.05, 95% CI 0.86 to 1.28), while neither study showed clear associations with eczema (HealthNuts: aOR 1.09, 95% CI 0.88 to 1.35; LSAC: aOR 0.89, 95% CI 0.69 to 1.15). Spirometric lung function parameters at age 11-12 years were similar by delivery mode. Associations were not modified by duration of breast feeding, maternal history of asthma/eczema, childcare attendance, number of older siblings or pet exposure.

CONCLUSIONS

In two unselected populations using harmonised protocols, the likely association of caesarean delivery with developing childhood allergy was small.

Associations of retinal microvascular caliber with large arterial function and structure: A population-based study of 11 to 12 year-olds and midlife adults

OBJECTIVE

We examined associations between retinal microvascular and large arterial phenotypes to explore relationships between the micro- and macro-vasculature in childhood and midlife.

METHODS

Participants were 1288 children (11-12 years, 50.9% female) and 1264 adults (mean age 44 years, 87.6% female) in a cross-sectional population-based study. Exposures were retinal arteriolar and venular caliber quantified from retinal images. Outcomes included arterial function (pulse wave velocity; carotid arterial elasticity) and structure (carotid intima-media thickness). Multivariable regression models were performed adjusting for age, sex, and family socioeconomic position.

RESULTS

In children, one standard deviation wider arteriolar caliber was associated with slower pulse wave velocity (-0.15 SD, 95% CI -0.21, -0.09) and higher elasticity (0.13 SD, 95% CI 0.06, 0.20); per SD wider venular caliber was associated with faster pulse wave velocity (0.09 SD, 95% CI 0.03, 0.15) and lower elasticity (-0.07 SD, 95% CI -0.13, -0.01). The size of adult associations was approximately double. Wider arteriolar caliber was associated with smaller carotid intima-media thickness (-0.09 SD, 95% CI -0.16, -0.03) in adults but not children. Venular caliber and carotid intima-media thickness showed little evidence of association.

CONCLUSIONS

Narrower retinal arterioles and wider venules are associated with large arterial function as early as mid-childhood. Associations strengthen by midlife and also extend to arterial structure, although effect sizes remain small.

Do body mass index and waist-to-height ratio over the preceding decade predict retinal microvasculature in 11-12 year olds and midlife adults?

BACKGROUND/OBJECTIVES

Microvascular changes may contribute to obesity-associated cardiovascular disease. We examined whether body mass index (BMI) and waist-to-height ratio (WHtR) (1) at multiple earlier time points and (2) decade-long trajectories predicted retinal microvascular parameters in mid-childhood/adulthood.

METHODS

Participants/design: 1288 11-12 year olds (51% girls) and 1264 parents (87% mothers) in the population-based Child Health CheckPoint (CheckPoint) module within the Longitudinal Study of Australian Children (LSAC). LSAC exposure measures: biennial BMI z-score and WHtR for children at five time points from age 2-3 to 10-11 years and self-reported parent BMI at six time points from child age 0-1 years to 10-11 years. CheckPoint outcome measures: retinal arteriolar and venular caliber.

ANALYSES

BMI/WHtR trajectories were identified by group-based trajectory modeling; linear regression models estimated associations between BMI/WHtR at each time point/trajectories and later retinal vascular caliber, adjusted for age, sex, and family socioeconomic status.

RESULTS

In time point analyses, higher child BMI/WHtR from age 4 to 5 years was associated with narrower arteriolar caliber at the age of 11-12 years, but not venular caliber. For example, each standard deviation higher in BMI z-score at 4-5 years was associated with narrower arteriolar caliber at 11-12 years (standardized mean difference (SMD): -0.05, 95% confidence interval (CI): -0.10 to 0.01); by 10-11 years, associations had doubled to -0.10 (95% CI: -0.16 to -0.05). In adults, these finding were similar, except the magnitude of BMI and arteriolar associations were similar across all time points (SMD: -0.11 to -0.13). In child and adult BMI trajectory analyses, less favorable trajectories predicted narrower arteriolar (p-trend < 0.05), but not venular (p-trend > 0.1), caliber. Compared with those in the average BMI trajectory, SMDs in arterial caliber for children and adults in the highest trajectory were -0.25 (95% CI: -0.44 to -0.07) and -0.42 (95% CI: -0.73 to -0.10), respectively. Venular caliber showed late associations with child WHtR, but not with BMI in children or adults.

CONCLUSIONS

Associations of decade-long high BMI trajectories with narrowed retinal arteriolar caliber emerge in children, and are clearly evident by midlife. Adiposity appears to exert its early adverse life course impacts on the microcirculation more via arteriolar than venular mechanisms.

Inflammation and hearing status in mid-childhood and mid-life: a population-based cross-sectional study

BACKGROUND

Lifelong inflammation - known to be associated with many non-communicable diseases - has not been thoroughly investigated in hearing. We aimed to determine if glycoprotein A (GlycA), a novel biomarker of chronic inflammation, is associated with hearing acuity in mid-childhood and mid-life.

METHODS

Population-based cross-sectional study within the Longitudinal Study of Australian Children with plasma GlycA and audiometry data (1169 children and 1316 parents). We calculated high Fletcher Index (mean threshold across 1, 2 and 4 kHz), defining hearing loss as threshold >15 decibel hearing level (dB HL) (better ear). Linear/logistic regression quantified associations of GlycA with hearing threshold/loss.

RESULTS

Mean [standard deviation (SD)] high Fletcher Indices (dB HL) were 8.0 (5.7) for children and 13.1 (6.9) for adults, with 8.7% and 26.1% respectively showing hearing loss. 1-SD rise in GlycA (children 0.13 mmol/L, adults 0.17 mmol/L) predicted higher hearing thresholds for the lower individual frequencies [1 kHz: children β 0.8, 95% confidence interval (CI) 0.3-1.3; adults β 0.8, 95% CI 0.2-1.4]. This same pattern was evident for the high Fletcher Index (children β 0.7, 95% CI 0.3-1.1; adults β 0.8, 95% CI 0.3-1.4). This translated into 1-SD rise in GlycA predicting adult hearing loss [odds ratio (OR) 1.2, 95% CI 1.0-1.5] with similar but attenuated patterns in children.

CONCLUSIONS

GlycA is associated with poorer hearing by mid-childhood. This potentially reframes hearing loss as a life-course condition with inflammatory antecedents common to other non-communicable diseases. Replication and mechanistic studies could inform causal inference and early prevention efforts.