Cardiometabolic health markers among Aboriginal adolescents from the Next Generation Youth Wellbeing Cohort Study.

OBJECTIVE: The objective of this study was to investigate cardiometabolic health markers among Aboriginal adolescents aged 10-24 years and relationships with age, gender, and body composition. METHODS: Baseline data (2018-2020) from the Next Generation Youth Wellbeing Cohort Study (Western Australia, New South Wales, and Central Australia) on clinically assessed body mass index, waist/height ratio, blood pressure, glycated haemoglobin (HbA1c), total and high-density lipoprotein cholesterol, total/high-density lipoprotein cholesterol ratio, and triglycerides were analysed. RESULTS: Among 1100 participants, the proportion with individual health markers within the ideal range ranged from 59% for total cholesterol to 91% for HbA1c. Four percent had high blood pressure, which was more common with increasing age and among males; 1% had HbA1c indicative of diabetes. Healthier body composition (body mass index and waist/height ratio) was associated with having individual health markers in the ideal range and with an ideal cardiometabolic profile. CONCLUSIONS: Most Aboriginal adolescents in this study had cardiometabolic markers within the ideal range, though markers of high risk were present from early adolescence. Ideal health markers were more prevalent among those with healthy body composition. IMPLICATIONS FOR PUBLIC HEALTH: Specific screening and management guidelines for Aboriginal adolescents and population health initiatives that support maintenance of healthy body composition could help improve cardiometabolic health in this population.

Health behaviours associated with healthy body composition among Aboriginal adolescents in Australia in the 'Next Generation: Youth Well-being study'.

This study described the distribution of healthy body composition among Aboriginal adolescents in Australia aged 10-24 years and examined associations with health behaviours and self-rated health. Data were cross-sectional from the 'Next Generation: Youth Well-being study' baseline (N = 1294). We used robust Poisson regression to quantify associations of self-reported health behaviours (physical activity, screen time, sleep, consumption of vegetables, fruit, soft drinks and fast food, and tobacco smoking and alcohol) and self-rated health to healthy body mass index (BMI) and waist/height ratio (WHtR). Overall, 48% of participants had healthy BMI and 64% healthy WHtR, with healthy body composition more common among younger adolescents. Higher physical activity was associated with healthy body composition (5-7 days last week vs none; adjusted prevalence ratio (aPR) healthy BMI 1.31 [95% CI 1.05-1.64], and healthy WHtR 1.30 [1.10-1.54]), as was recommended sleep duration (vs not; aPR healthy BMI 1.56 [1.19-2.05], and healthy WHtR 1.37 [1.13-1.67]). There was a trend for higher proportion of healthy body composition with more frequent fast food consumption. Healthy body composition was also associated with higher self-rated health ('very good/excellent' vs 'poor/fair'; aPR healthy BMI 1.87 [1.45-2.42], and healthy WHtR 1.71 [1.40-2.10]). Culturally appropriate community health interventions with a focus on physical activity and sleep may hold promise for improving body composition among Aboriginal adolescents.

Potential Determinants of Cardio-Metabolic Risk among Aboriginal and Torres Strait Islander Children and Adolescents: A Systematic Review.

Prevention initiatives during childhood and adolescence have great potential to address the health inequities experienced by Aboriginal and Torres Strait Islander (Indigenous) populations in Australia by targeting modifiable risk factors for cardio-metabolic diseases. We aimed to synthesize existing evidence about potential determinants of cardio-metabolic risk markers-obesity, elevated blood pressure, elevated blood glucose, abnormal lipids, or a clustering of these factors known as the metabolic syndrome (MetS)-for Indigenous children and adolescents. We systematically searched six databases for journal articles and three websites for relevant grey literature. Included articles (n = 47) reported associations between exposures (or interventions) and one or more of the risk markers among Indigenous participants aged 0-24 years. Data from 18 distinct studies about 41 exposure-outcome associations were synthesized (by outcome: obesity [n = 18]; blood pressure [n = 9]; glucose, insulin or diabetes [n = 4]; lipids [n = 5]; and MetS [n = 5]). Obesity was associated with each of the other cardio-metabolic risk markers. Larger birth size and higher area-level socioeconomic status were associated with obesity; the latter is opposite to what is observed in the non-Indigenous population. There were major gaps in the evidence for other risk markers, as well as by age group, geography, and exposure type. Screening for risk markers among those with obesity and culturally appropriate obesity prevention initiatives could reduce the burden of cardio-metabolic disease.

Pregnancy and birth characteristics of Aboriginal twins in two Australian states: a data linkage study.

INTRODUCTION: Perinatal outcomes for singleton pregnancies are poorer, on average, for Aboriginal people than non-Aboriginal people, but little is known about Aboriginal multifetal pregnancies. Yet multifetal pregnancies and births are often more complicated and have poorer outcomes than singleton pregnancies. We describe the pregnancies, births and perinatal outcomes for Aboriginal twins born in Western Australia (WA) and New South Wales (NSW) with comparisons to Aboriginal singletons in both states and to non-Aboriginal births in NSW. MATERIALS AND METHODS: Whole-population birth records and birth and death registrations were linked for all births during 2000-2013 (WA) and 2002-2008 (NSW). Hospital records and the WA Register of Developmental Anomalies - Cerebral Palsy were linked for all WA births and hospital records for a subset of NSW births. Descriptive statistics are reported for maternal and child demographics, maternal health, pregnancy complications, births and perinatal outcomes. RESULTS: Thirty-four thousand one hundred twenty-seven WA Aboriginal, 32,352 NSW Aboriginal and 601,233 NSW non-Aboriginal births were included. Pregnancy complications were more common among mothers of Aboriginal twins than Aboriginal singletons (e.g. 17% of mothers of WA twins had hypertension/pre-eclampsia/eclampsia vs 8% of mothers of singletons) but similar to mothers of NSW non-Aboriginal twins. Most Aboriginal twins were born in a principal referral, women's or large public hospital. The hospitals were often far from the mother's home (e.g. 31% of mothers of WA Aboriginal twins gave birth at hospitals located more than 3 h by road from their home). Outcomes were worse for Aboriginal liveborn twins than Aboriginal singletons and non-Aboriginal twins (e.g. 58% of NSW Aboriginal twins were preterm compared to 9% of Aboriginal singletons and 49% non-Aboriginal twins). CONCLUSIONS: Mothers of Aboriginal twins faced significant challenges during the pregnancy, birth and the postnatal period in hospital and, in addition to accessible specialist medical care, these mothers may need extra practical and psychosocial support throughout their journey.

A large proportion of poor birth outcomes among Aboriginal Western Australians are attributable to smoking, alcohol and substance misuse, and assault.

BACKGROUND: Aboriginal infants have poorer birth outcomes than non-Aboriginal infants. Harmful use of tobacco, alcohol, and other substances is higher among Aboriginal women, as is violence, due to factors such as intergenerational trauma and poverty. We estimated the proportion of small for gestational age (SGA) births, preterm births, and perinatal deaths that could be attributed to these risks. METHODS: Birth, hospital, mental health, and death records for Aboriginal singleton infants born in Western Australia from 1998 to 2010 and their parents were linked. Using logistic regression with a generalized estimating equation approach, associations with birth outcomes and population attributable fractions were estimated after adjusting for demographic factors and maternal health during pregnancy. RESULTS: Of 28,119 births, 16% of infants were SGA, 13% were preterm, and 2% died perinatally. 51% of infants were exposed in utero to at least one of the risk factors and the fractions attributable to them were 37% (SGA), 16% (preterm) and 20% (perinatal death). CONCLUSIONS: A large proportion of adverse outcomes were attributable to the modifiable risk factors of substance use and assault. Significant improvements in Aboriginal perinatal health are likely to follow reductions in these risk factors. These results highlight the importance of identifying and implementing risk reduction measures which are effective in, and supported by, Aboriginal women, families, and communities.

Maternal fetal programming of birthweight among Australian Aboriginal infants: a population-based data linkage study.

BACKGROUND: Low birthweight, which is common among Australian Aboriginal infants, has been found to persist across generations because of shared genetic and environmental factors and possibly fetal programming. Fetal programming refers to the response of a fetus to hostile uterine conditions with lifelong effects and possibly, in turn, providing a poorer uterine environment for future offspring. Fetal programming might have a greater effect in populations that have undergone rapid lifestyle transitions-for example, Indigenous populations. Disentangling causal effects is difficult, but family-based approaches could provide insights. We explored whether poor maternal fetal growth caused low birthweight in Aboriginal infants. METHODS: In this data linkage study, we used linked administrative health records of 12 865 singleton Aboriginal infants born in Western Australia between 1980 and 2010 and their relatives (including siblings born in 2011). Electronic birth records included all births since 1980 with at least 20 weeks completed gestation or a birthweight of 400 g. We compared parental-offspring birthweight associations using three approaches-a regression analysis of the complete sample, adjusting for confounding variables; a comparison of the maternal-offspring and paternal-offspring associations; and a within-cousin group comparison. We used binary and continuous measures of birthweight. We categorised infants and their parents as small for gestational age (SGA) if their birthweight was below the first decile of birthweights for all singleton livebirths of the same sex and gestational age in Australia between 1998 and 2007. FINDINGS: The relative risk (RR) of SGA birth was higher for infants with SGA mothers than for those with non-SGA mothers (RR 1·65, 95% CI 1·49 to 1·83), after adjusting for grandmaternal parity. After additional adjustment for maternal height, the risk remained higher for those with non-SGA mothers (RR 1·51, 1·36 to 1·68). The maternal birthweight Z score coefficient was 0·17 (95% CI 0·14 to 0·20), compared with 0·13 (0·10 to 0·16) for paternal birthweight, a difference of 0·03 (-0·01 to 0·08). In the cousin analysis, the maternal-offspring association was fully attenuated (0·00, 95% CI -0·05 to 0·06). Conditions in the current pregnancy were strongly associated with offspring birthweight Z score. Smoking was associated with a mean decrease of 0·39 (95% CI -0·45 to -0·34) in offspring birthweight Z score, drug misuse with a decrease of 0·31 (-0·43 to -0·20), and diabetes with an increase of 0·58 (0·39 to 0·77). INTERPRETATION: We found little support for maternal fetal programming causing low offspring birthweight. The similar maternal and paternal influence on birthweight and our cousin analysis suggested transmission of genetic and environmental factors could explain much of the maternal-offspring birthweight association. Compared with other risk factors in the current pregnancy, fetal programming appears to have little or no role in the high numbers of infants with low birthweight among Aboriginal populations. FUNDING: National Health and Medical Research Council of Australia and Bellberry Ltd.

Use of family relationships improved consistency of identification of Aboriginal people in linked administrative data.

BACKGROUND AND OBJECTIVES: Algorithms are often used to improve identification of Aboriginal Australians in linked data sets with inconsistent and incomplete recording of Aboriginal status. We compared how consistently some common algorithms identified family members, developed a new algorithm incorporating relatives' information, and assessed the effects of these algorithms on health estimates. METHODS: The sample was people born 1980-2011 recorded as Aboriginal at least once (or a relative) in four Western Australian data sets and their relatives (N = 156,407). A very inclusive approach, ever-Aboriginal (EA/EA+, where + denotes children's records incorporated), and two more specific approaches, multistage median (MSM/MSM+) and last record (LR/LR+), were chosen, along with the new algorithm (MSM+Family). RESULTS: Ever-Aboriginal (EA) categorized relatives the least consistently; 25% of parent-child triads had incongruent Aboriginal statuses with EA+, compared with only 9% with MSM+. With EA+, 14% of full siblings had different statuses compared with 8% for MSM+. EA produced the lowest estimates of the proportion of Aboriginal people with poor health outcomes. Using relatives' records reduced the number of uncategorized people and categorized as Aboriginal more people who had few records (e.g., no hospital admissions). CONCLUSION: When many data sets are linked, more specific algorithms select more representative Aboriginal samples and identify Aboriginality of relatives more consistently.

No official identity: a data linkage study of birth registration of Aboriginal children in Western Australia.

OBJECTIVE: Evidence of identity, particularly a birth certificate, is essential to access many rights. However, the births of many Aboriginal Australians are not registered when they are infants. We examined factors related to birth registration among Western Australian children born to Aboriginal mothers. METHODS: All births to Aboriginal mothers in the Midwives Notification System in Western Australia (WA) from 1980 to 2010 were linked to birth registrations. Associations between registration and maternal and child characteristics were examined for children aged under 16 years in 2012. RESULTS: Among 49,694 births between 1980 and 2010, 18% of those aged under 16 years had unregistered births, compared to 3% of those aged 16-32 years. Unregistered births were most strongly associated with young maternal age at first birth (adjusted odds ratio [AOR] 5.22; 95%CI 3.07-8.86; for 16 years or younger vs 30 years or older, among non-smokers), remoteness (AOR 2.17; 95%CI 1.87-2.52; very remote vs major cities), mothers whose own birth was unregistered (AOR 3.00; 95%CI 1.78-5.07) and no private hospital insurance (AOR 0.19; 95%CI 0.11-0.31; insured vs uninsured). CONCLUSIONS: Unregistered births are common among WA Aboriginal children, particularly in disadvantaged families. IMPLICATIONS: Assistance before discharge from hospital may increase birth registrations.

Prostate cancer mortality outcomes and patterns of primary treatment for Aboriginal men in New South Wales, Australia.

OBJECTIVE: To compare prostate cancer mortality for Aboriginal and non-Aboriginal men and to describe prostate cancer treatments received by Aboriginal men. PATIENTS AND METHODS: We analysed cancer registry records for all men diagnosed with prostate cancer in New South Wales (NSW) in 2001-2007 linked to hospital inpatient episodes and deaths. More detailed information on androgen-deprivation therapy and radiotherapy was obtained from medical records for 87 NSW Aboriginal men diagnosed in 2000-2011. The main outcomes were primary treatment for, and death from, prostate cancer. Analysis included Cox proportional hazards regression and logistic regression. RESULTS: There were 259 Aboriginal men among 35,214 prostate cancer cases diagnosed in 2001-2007. Age and spread of disease at diagnosis were similar for Aboriginal and non-Aboriginal men. Prostate cancer mortality 5 years after diagnosis was higher for Aboriginal men (17.5%, 95% confidence interval (CI) 12.4-23.3) than non-Aboriginal men (11.4%, 95% CI 11.0-11.8). Aboriginal men were 49% more likely to die from prostate cancer (hazard ratio 1.49, 95% CI 1.07-1.99) after adjusting for differences in demographic factors, stage at diagnosis, health access and comorbidities. Aboriginal men were less likely to have a prostatectomy for localised or regional cancer than non-Aboriginal men (adjusted odds ratio 0.60, 95% CI 0.40-0.91). Of 87 Aboriginal men with full staging and treatment information, 60% were diagnosed with localised disease. Of these, 38% had a prostatectomy (± radiotherapy), 29% had radiotherapy only and 33% had neither. CONCLUSION: More research is required to explain differences in treatment and mortality for Aboriginal men with prostate cancer compared with non-Aboriginal men. In the meantime, ongoing monitoring and efforts are needed to ensure Aboriginal men have equitable access to best care.