Strength together: examining risk and protective factors associated with dementia and cognitive impairment in Aboriginal and Torres Strait Islander peoples through harmonisation of landmark studies.

BACKGROUND: Rates of dementia for Aboriginal and Torres Strait Islander peoples are three to five times greater compared to non-Indigenous Australians, with earlier age of onset. However, the risk and protective factors that drive these higher rates vary across existing cohort studies, with minimal findings on the role of vascular risk factors beyond stroke. Harmonisation of data across studies may offer greater insights through enhanced diversity and strengthened statistical capabilities. This study aims to combine three landmark cohort studies of Aboriginal and Torres Strait Islander participants to better understand the determinants of cognitive health and dementia. METHODS/DESIGN: Three cohort studies - the Kimberley Healthy Adults Project (KHAP, N = 363), Koori Growing Old Well Study (KGOWS, N = 336) and Torres Strait Dementia Prevalence Study (TSDPS, N = 274) - share a similar research methodology with demographic, medical history, psychosocial factors, cognitive tests and consensus clinical diagnoses of cognitive impairment and dementia. Associations between risk and protective factors of interest and the presence of dementia and/or cognitive impairment diagnoses will be evaluated by univariable and multivariable logistic regression in a harmonised cross-sectional cohort of 898 participants. Factors associated with incident dementia and/or cognitive impairment will be assessed in a subset of KHAP (n = 189) and KGOWS participants (n = 165) who were available in longitudinal follow-up, after exclusion of those with baseline dementia or cognitive impairment. Analyses in relation to outcome measure of death or dementia will be conducted to account for the competing risk of death. Logistic regression will be used to evaluate the association between the individual components of the 16-component Kimberley Indigenous Cognitive Assessment (KICA) tool and the presence of dementia and cognitive impairment determined by independent consensus diagnoses. Multivariable binary logistic regression will be used to adjust for the effect of confounding variables. Results will be reported as odds ratios (OR) with 95% confidence intervals (95% CI). DISCUSSION: Greater understanding of risk and protective factors of dementia and cognitive impairment relevant to Aboriginal and Torres Strait Islander peoples may improve approaches across the life course to delay cognitive decline and reduce dementia risk.

Title: Cross-sectional associations between nutrient intake and tooth decay in older Australian men: The Concord Health and Ageing in Men Project.

Poor nutrition is a risk factor for dental decay in younger people. However, except for sugar it is unclear if this is true in older age groups. The aim of this study was to analyze the possible associations between overall dietary intake of nutrients and diet quality and presence of dental decay in community dwelling older men. A cross-sectional analysis of a longitudinal study with a standardized validated diet history assessment and comprehensive oral health examination in 520 community dwelling men (mean age: 84 years) participating in the Concord Health and Ageing in Men Project. Nutrient Reference Values (NRVs) were used to determine if individual micronutrients and macronutrients were meeting recommendations. Acceptable Macronutrient Distribution Ranges (AMDR) were attained for fat and carbohydrate intakes and were incorporated into a dichotomous variable to determine if the participants were consuming a high fat and low carbohydrate diet. Diagnosis of coronal caries was based on visual criteria and inspection and was completed on each of the five coronal surfaces. Root surface caries was textual changes across four root surfaces. This diagnosis was used to categorize participants by presence and severity of coronal and root caries. Adjusted logistic regression showed not meeting the recommended intakes for thiamin (odds ratio (OR): 2.32 95% confidence interval (CI) 1.15 - 4.67), and zinc (OR: 3.33, 95% CI 1.71 - 6.48) were associated with presence of severe root decay. Adjusted analysis also showed that participants who were outside the recommended AMDR for fat (OR: 0.61, 95% CI 0.38 - 0.98), and those who consumed a high fat and low carbohydrate diet (OR: 0.56, 95% CI 0.35 - 0.91) were less likely to have coronal tooth decay. Our study shows associations between micronutrients and macronutrients and coronal and root surface decay. Although this study cannot prescribe causality or be generalized to all older adults, diet has a possible association with dental decay in older men.

Elongation factor 1A1 regulates metabolic substrate preference in mammalian cells.

Eukaryotic elongation factor 1A1 (EEF1A1) is canonically involved in protein synthesis but also has noncanonical functions in diverse cellular processes. Previously, we identified EEF1A1 as a mediator of lipotoxicity and demonstrated that chemical inhibition of EEF1A1 activity reduced mouse liver lipid accumulation. These findings suggested a link between EEF1A1 and metabolism. Therefore, we investigated its role in regulating metabolic substrate preference. EEF1A1-deficient Chinese hamster ovary (2E2) cells displayed reduced media lactate accumulation. These effects were also observed with EEF1A1 knockdown in human hepatocyte-like HepG2 cells and in WT Chinese hamster ovary and HepG2 cells treated with selective EEF1A inhibitors, didemnin B, or plitidepsin. Extracellular flux analyses revealed decreased glycolytic ATP production and increased mitochondrial-to-glycolytic ATP production ratio in 2E2 cells, suggesting a more oxidative metabolic phenotype. Correspondingly, fatty acid oxidation was increased in 2E2 cells. Both 2E2 cells and HepG2 cells treated with didemnin B exhibited increased neutral lipid content, which may be required to support elevated oxidative metabolism. RNA-seq revealed a >90-fold downregulation of a rate-limiting glycolytic enzyme, hexokinase 2, which we confirmed through immunoblotting and enzyme activity assays. Pathway enrichment analysis identified downregulations in TNFA signaling via NFKB and MYC targets. Correspondingly, nuclear abundances of RELB and MYC were reduced in 2E2 cells. Thus, EEF1A1 deficiency may perturb glycolysis by limiting NFKB- and MYC-mediated gene expression, leading to decreased hexokinase expression and activity. This is the first evidence of a role for a translation elongation factor, EEF1A1, in regulating metabolic substrate utilization in mammalian cells.

Intra-generational social mobility and mortality among older men in the Concord Health and Ageing in Men Project: A cohort study.

Objectives: We examined associations between intra-generational social mobility (reflected in life-course socioeconomic trajectories) and mortality, among older men. Methods: Data came from a prospective Australian community-based cohort of older men. Social mobility was defined by socioeconomic indicators from three points in the life-course: educational attainment (late adolescence-early adulthood), occupation (mid-life), and current sources of income (older age). We defined indicators of social mobility trajectory (6 categories; reflecting the direction of social mobility) and social mobility status (2 categories; mobile or non-mobile). We used Cox regression to examine associations with mortality, adjusting for age, country of birth, and living arrangement. Results: We followed 1568 men (mean age 76.8, SD 5.4) for a mean duration of 9.1 years, with 797 deaths recorded. Moving upward was the predominant social mobility trajectory (36.0%), followed by mixed trajectories (25.1%), downward (15.1%), stable low (12.2%), stable high (7.6%), and stable middle (4.0%). Men with downward (Hazard ratio 1.58, 95% CI 1.13 to 2.19) and stable low socioeconomic trajectories (1.77, 1.25 to 2.50) had higher mortality risks than men with stable high socioeconomic trajectories, while men with upward trajectories had similar risks to those with stable high trajectories. 76.2% of the participants were classified as having mobile status; no associations were evident between binary social mobility status and mortality. Discussions: These findings suggest cumulative and persistent exposure to disadvantaged socioeconomic conditions across the life-course, rather than social mobility, is associated with increased mortality. For each stage of the life-course, addressing socioeconomic disadvantage may reduce inequities in mortality.

Deletion of p66Shc Dysregulates ERK and STAT3 Activity in Mouse Embryonic Stem Cells, Enhancing Their Naive-Like Self-Renewal in the Presence of Leukemia Inhibitory Factor.

The ShcA adapter protein is necessary for early embryonic development. The role of ShcA in development is primarily attributed to its 52 and 46 kDa isoforms that transduce receptor tyrosine kinase signaling through the extracellular signal regulated kinase (ERK). During embryogenesis, ERK acts as the primary signaling effector, driving fate acquisition and germ layer specification. P66Shc, the largest of the ShcA isoforms, has been observed to antagonize ERK in several contexts; however, its role during embryonic development remains poorly understood. We hypothesized that p66Shc could act as a negative regulator of ERK activity during embryonic development, antagonizing early lineage commitment. To explore the role of p66Shc in stem cell self-renewal and differentiation, we created a p66Shc knockout murine embryonic stem cell (mESC) line. Deletion of p66Shc enhanced basal ERK activity, but surprisingly, instead of inducing mESC differentiation, loss of p66Shc enhanced the expression of core and naive pluripotency markers. Using pharmacologic inhibitors to interrogate potential signaling mechanisms, we discovered that p66Shc deletion permits the self-renewal of naive mESCs in the absence of conventional growth factors, by increasing their responsiveness to leukemia inhibitory factor (LIF). We discovered that loss of p66Shc enhanced not only increased ERK phosphorylation but also increased phosphorylation of Signal transducer and activator of transcription in mESCs, which may be acting to stabilize their naive-like identity, desensitizing them to ERK-mediated differentiation cues. These findings identify p66Shc as a regulator of both LIF-mediated ESC pluripotency and of signaling cascades that initiate postimplantation embryonic development and ESC commitment.

Lung-gut axis of microbiome alterations following co-exposure to ultrafine carbon black and ozone.

BACKGROUND: Microbial dysbiosis is a potential mediator of air pollution-induced adverse outcomes. However, a systemic comparison of the lung and gut microbiome alterations and lung-gut axis following air pollution exposure is scant. In this study, we exposed male C57BL/6J mice to inhaled air, CB (10 mg/m3), O3 (2 ppm) or CB + O3 mixture for 3 h/day for either one day or four consecutive days and were euthanized 24 h post last exposure. The lung and gut microbiome were quantified by 16 s sequencing. RESULTS: Multiple CB + O3 exposures induced an increase in the lung inflammatory cells (neutrophils, eosinophils and B lymphocytes), reduced absolute bacterial load in the lungs and increased load in the gut. CB + O3 exposure was more potent as it decreased lung microbiome alpha diversity just after a single exposure. CB + O3 co-exposure uniquely increased Clostridiaceae and Prevotellaceae in the lungs. Serum short chain fatty acids (SCFA) (acetate and propionate) were increased significantly only after CB + O3 co-exposure. A significant increase in SCFA producing bacterial families (Ruminococcaceae, Lachnospiraceae, and Eubacterium) were also observed in the gut after multiple exposures. Co-exposure induced significant alterations in the gut derived metabolite receptors/mediator (Gcg, Glp-1r, Cck) mRNA expression. Oxidative stress related mRNA expression in lungs, and oxidant levels in the BALF, serum and gut significantly increased after CB + O3 exposures. CONCLUSION: Our study confirms distinct gut and lung microbiome alterations after CB + O3 inhalation co-exposure and indicate a potential homeostatic shift in the gut microbiome to counter deleterious impacts of environmental exposures on metabolic system.

Aging and memory are altered by genetically manipulating lactate dehydrogenase in the neurons or glia of flies.

The astrocyte-neuron lactate shuttle hypothesis posits that glial-generated lactate is transported to neurons to fuel metabolic processes required for long-term memory. Although studies in vertebrates have revealed that lactate shuttling is important for cognitive function, it is uncertain if this form of metabolic coupling is conserved in invertebrates or is influenced by age. Lactate dehydrogenase (Ldh) is a rate limiting enzyme that interconverts lactate and pyruvate. Here we genetically manipulated expression of Drosophila melanogaster lactate dehydrogenase (dLdh) in neurons or glia to assess the impact of altered lactate metabolism on invertebrate aging and long-term courtship memory at different ages. We also assessed survival, negative geotaxis, brain neutral lipids (the core component of lipid droplets) and brain metabolites. Both upregulation and downregulation of dLdh in neurons resulted in decreased survival and memory impairment with age. Glial downregulation of dLdh expression caused age-related memory impairment without altering survival, while upregulated glial dLdh expression lowered survival without disrupting memory. Both neuronal and glial dLdh upregulation increased neutral lipid accumulation. We provide evidence that altered lactate metabolism with age affects the tricarboxylic acid (TCA) cycle, 2-hydroxyglutarate (2HG), and neutral lipid accumulation. Collectively, our findings indicate that the direct alteration of lactate metabolism in either glia or neurons affects memory and survival but only in an age-dependent manner.

Relationship Between Visceral Adipose Tissue and Bone Mineral Density in Older People: Results from AHAP Study.

INTRODUCTION: Due to discrepancy of the relationship between visceral adipose tissue (VAT) and bone mineral density (BMD), this study was performed to determine the relationship between BMD and VAT in the elderly. METHODOLOGY: This cross-sectional study is part of the second wave of Amirkola Health and Ageing Project (AHAP), including 1,200 people aged 60 years and older. BMD and VAT were measured by dual-energy X-ray absorptiometry (DXA) in Hologic equipment. Based on the amount of VAT, individuals were divided into four quartiles. Then, the data were statistically analyzed by SPSS22 software using chi-square, ANOVA, Pearson correlation coefficient and logistic regression. RESULTS: The mean age of the participants was 69.6 ± 6.9 year and the mean VAT was 862.6 ± 337.8 gram. In this study, people with osteoporosis had less VAT (p<0.0001). Furthermore, with the increase in the amount of VAT, BMD increased in the femoral region and lumbar spine (p<0.0001). There was a positive and significant correlation between VAT and BMD in the femoral region (r = 0.267) and lumbar spine (r = 0.197) (p<0.0001). After performing multiple logistic regression analysis in the presence of factors such as age, gender, body mass index and especially lean mass, the protective role of VAT against osteoporosis was maintained (OR=0.510, CI95% (0.290-0.895)) (P = 0.019). CONCLUSIONS: This study has shown that VAT can independently have a positive association with BMD in the elderly.

Depression, childhood trauma, and physical activity in older Indigenous Australians.

OBJECTIVES: Indigenous Australians experience higher levels of psychological distress compared to the general population. Physical activity is a culturally acceptable approach, associated with reduction of depressive symptoms. The protective properties of physical activity for depressive symptoms are yet to be evaluated in older Indigenous Australians. DESIGN: A two-phase study design comprised of a qualitative thematic analysis following a quantitative regression and moderation analysis. PARTICIPANTS: Firstly, a total of 336 Indigenous Australians aged 60 years and over from five NSW areas participated in assessments on mental health, physical activity participation, and childhood trauma. Secondly, a focus group of seven Indigenous Australians was conducted to evaluate barriers and facilitators to physical activity. MEASUREMENTS: Regression and moderation analyses examined links between depression, childhood trauma, and physical activity. Thematic analysis was conducted exploring facilitators and barriers to physical activity following the focus group. RESULTS: Childhood trauma severity and intensity of physical activity predicted depressive symptoms. Physical activity did not affect the strength of the relationship between childhood trauma and depression. Family support and low impact activities facilitated commitment to physical activity. In contrast, poor mental health, trauma, and illness acted as barriers. CONCLUSION: Physical activity is an appropriate approach for reducing depressive symptoms and integral in maintaining health and quality of life. While situational factors, health problems and trauma impact physical activity, accessing low-impact group activities with social support was identified to help navigate these barriers.

Oral health-related quality of life of older Australian men.

OBJECTIVES: The aims of this study were to assess oral health-related quality of life (OHRQoL) in a cohort of older Australian men and explore the association between their general health conditions, socio-demographic factors and OHRQoL. METHODS: The Concord Health and Ageing in Men Project (CHAMP) is a cohort study of the health of a representative sample of Australian men, initiated in 2005-2006 with an initial sample of 1705 men 70 years or over. Participants completed a self-administered health and socio-demographic questionnaire and attended an interview and clinical assessment at baseline and each of three follow-up assessments. Information on oral health and responses to the Oral Health Impact Profile (OHIP-14) were collected in the 4th follow-up in which 778 men completed the OHIP-14 questionnaire and 614 men had a dental assessment. The prevalence of oral health impact was defined as a response of fairly often or very often to one or more of the OHIP-14 questions. Mean OHIP-14 scores were calculated for the 14 questions and used as the dependent variable in the regression analyses. Zero-inflated Poisson regression was used to estimate prevalence rate ratios (PRR). RESULTS: Only 10% of men presented oral health impacts. In multivariate regression modelling, being born in Italy/Greece (PRR: 2.16, 95% CI: 1.93-2.42) or in other countries (PRR: 2.12, 95% CI: 1.89-2.38), having poor self-rated general health (PRR: 1.38, 95% CI: 1.24-1.53), having poor mental wellbeing (PRR: 1.14, 95% CI: 1.04-1.24), having ≥6 depressive symptoms (PRR: 1.18, 95% CI: 1.05-1.32), being a current smoker (PRR: 1.34, 95% CI: 1.06-1.70) and having more decayed tooth surfaces (PRR:1.01, 95% CI: 1.00-1.02) were associated with higher impact scores. CONCLUSIONS: Overall, older Australian men exhibit good oral health-related quality of life. The inter-relationship between perceptions of general health and well-being, health and oral health variables and social background supports policy objectives of closer integration of general health and oral health services for older Australian men.

Mixed Evidence of an Association between Self-Rated Hearing Difficulties and Falls: Prospective Analysis of Two Longitudinal Studies.

INTRODUCTION: This study aimed to assess the extent to which a single item of self-reported hearing difficulties is associated with future risk of falling among community-dwelling older adults. METHODS: We used data from two Australian population-based cohorts: three waves from the PATH Through Life study (PATH; n = 2,048, 51% men, age 66.5 ± 1.5 SD years) and three waves from the Concord Health and Ageing in Men Project (CHAMP; n = 1,448, 100% men with mean age 77.3 ± 5.3 SD years). Hearing difficulties were recorded on a four-point ordinal scale in PATH and on a dichotomous scale in CHAMP. The number of falls in the past 12 months was reported at each wave in both studies. In CHAMP, incident falls were also ascertained by triannual telephone call cycles for up to four years. Multivariable-adjusted random intercept negative binomial regression models were used to estimate the association between self-reported hearing difficulties and number of falls reported at the following wave or 4-monthly follow-ups. RESULTS: In PATH, self-reported hearing difficulties were associated with a higher rate of falls at follow-up (incidence rate ratio = 1.15, 95% CI = 1.03-1.27 per a one-level increase in self-reported hearing difficulties), after adjusting for sociodemographic characteristics, health behaviours, physical functioning, balance, mental health, medical conditions, and medications. There were no significant associations between hearing difficulties and the rate of falls based on either repeated survey or 4-monthly follow-ups in CHAMP. CONCLUSION: Though we find mixed results, findings from PATH data indicate an ordinal measure of self-reported hearing loss may be predictive of falls incidence in young-old adults. However, the null findings in the male-only CHAMP preclude firm conclusions of a link between hearing loss and falls risk.

The future burden of oesophageal and stomach cancers attributable to modifiable behaviours in Australia: a pooled cohort study.

BACKGROUND: We quantified the individual and joint contribution of contemporaneous causal behavioural exposures on the future burden of oesophageal and stomach cancers and their subtypes and assessed whether these burdens differ between population groups in Australia, as such estimates are currently lacking. METHODS: We combined hazard ratios from seven pooled Australian cohorts (N = 367,058) linked to national cancer and death registries with exposure prevalence from the 2017-2018 National Health Survey to estimate Population Attributable Fractions (PAFs) with 95% confidence intervals (CIs), accounting for competing risk of death. RESULTS: Current and past smoking explain 35.2% (95% CI = 11.7-52.4%), current alcohol consumption exceeding three drinks/day 15.7% (95% CI = 0.9-28.4%), and these exposures jointly 41.4% (95% CI = 19.8-57.3%) of oesophageal squamous cell carcinomas in Australia. Current and past smoking contribute 38.2% (95% CI = 9.4-57.9%), obesity 27.0% (95% CI = 0.6-46.4%), and these exposures jointly 54.4% (95% CI = 25.3-72.1%) of oesophageal adenocarcinomas. Overweight and obesity explain 36.1% (95% CI = 9.1-55.1%), current and past smoking 24.2% (95% CI = 4.2-40.0%), and these exposures jointly 51.2% (95% CI = 26.3-67.8%) of stomach cardia cancers. Several population groups had a significantly higher smoking-attributable oesophageal cancer burden, including men and those consuming excessive alcohol. CONCLUSIONS: Smoking is the leading preventable behavioural cause of oesophageal cancers and overweight/obesity of stomach cancers.

Daily Low-Dose Aspirin and Risk of Serious Falls and Fractures in Healthy Older People: A Substudy of the ASPREE Randomized Clinical Trial.

Importance: Falls and fractures are frequent and deleterious to the health of older people. Aspirin has been reported to reduce bone fragility and slow bone loss. Objective: To determine if daily low-dose aspirin (100 mg) reduces the risk of fractures or serious falls (fall-related hospital presentations) in healthy older men and women. Design, Setting, and Participants: This substudy of a double-blind, randomized, placebo-controlled trial studied older adult men and women in 16 major sites across southeastern Australia. The ASPREE-FRACTURE substudy was conducted as part of the Australian component of the ASPREE trial. Between 2010 and 2014 healthy (free of cardiovascular disease, dementia or physical disability), community-dwelling volunteers aged 70 years or older were recruited to participate in the ASPREE trial. Potentially eligible participants were identified by medical practitioners and trial personnel and were then sent a letter of invitation to participate. Interested participants were screened for suitability. Eligible participants with medical practitioner authorization and adherent to a 4-week run-in medication trial were randomized. Data were analyzed from October 17, 2019, to August 31, 2022. Interventions: Participants in the intervention group received a daily dose of oral 100 mg enteric-coated (low-dose) aspirin. The control group received a daily identical enteric-coated placebo tablet. Main Outcomes and Measures: The primary outcome of ASPREE-FRACTURE was the occurrence of any fracture. The secondary outcome was serious fall resulting in hospital presentation. Results: In total, 16 703 people with a median (IQR) age of 74 (72-78) years were recruited, and 9179 (55.0%) were women. There were 8322 intervention participants and 8381 control participants included in the primary and secondary outcome analysis of 2865 fractures and 1688 serious falls over the median follow-up of 4.6 years. While there was no difference in the risk of first fracture between the intervention and control participants (hazard ratio, 0.97; 95% CI, 0.87-1.06; P = .50), aspirin was associated with a higher risk of serious falls (total falls 884 vs 804; incidence rate ratio, 1.17; 95% CI, 1.03-1.33; P = .01). Results remained unchanged in analyses that adjusted for covariates known to influence fracture and fall risk. Conclusions and Relevance: In this substudy of a randomized clinical trial, the failure of low-dose aspirin to reduce the risk of fractures while increasing the risk of serious falls adds to evidence that this agent provides little favorable benefit in a healthy, White older adult population. Trial Registration: This substudy is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000347561).

Using the urea cycle to shift astrocytes from harmful to helpful in Alzheimer's disease.

Astrocytes are brain cells that react to Alzheimer's disease pathology in ways that can have either beneficial or detrimental effects. In this issue of Cell Metabolism, Ju et al. outline a novel strategy for coercing astrocytes to a neuroprotective state by maintaining liver-like detoxification in the brain without producing damaging byproducts.

Socioeconomic Inequalities in Elective and Nonelective Hospitalizations in Older Men.

Importance: Among older adults, there is limited and inconsistent evidence on the association between socioeconomic position (SEP) and elective and nonelective hospitalization. Objective: To evaluate the association between SEP and all-cause and cause-specific elective and nonelective hospitalization and hospital length of stay among older men. Design, Setting, and Participants: This population-based, prospective cohort study used data from the Concord Health and Aging in Men Project (CHAMP). CHAMP recruited 1705 men aged 70 years or older between January 28, 2005, and June 4, 2007, in Sydney, Australia. Data were analyzed from February 1 to September 30, 2021. Exposures: Indicators of SEP, including education (university degree certificate, diploma or no postschool qualifications), occupation (professionals and managers; small employers and self-employed; or lower clerical, service, sales workers, skilled, and unskilled workers), and source of income (other sources of income than government pension, reliance on government pensions and other sources of income, or reliant solely on a government pension), and a cumulative SEP score (tertiles) as SEP indicators; 3-level variables present high, intermediate, and low SEP. Main Outcomes and Measures: All-cause and cause-specific elective and nonelective hospitalizations, number of hospitalizations, and length of stay were the study outcomes, ascertained through data linkage. Associations were quantified using competing-risks survival regression and negative binomial regression. Results: A total of 1566 men (mean [SD] age, 76.8 [5.4] years) were included. During a mean (SD) 9.07 (3.53) years of follow-up, 1067 men had at least 1 elective hospitalization, and 1255 men had at least 1 nonelective hospitalization. No associations were found between SEP and elective hospitalizations. Being in the lowest tertile for educational level (subhazard ratio [SHR], 1.32; 95% CI, 1.11-1.58), occupational position (SHR, 1.30; 95% CI, 1.12-1.50), sources of income (SHR, 1.33; 95% CI, 1.17-1.52), and cumulative SEP tertile groups (SHR, 1.45; 95% CI, 1.24-1.68) were all associated with having at least 1 nonelective hospitalization compared with those in the highest tertiles. Significant associations were found between being in the lowest SEP groups and increased numbers and longer length of stay of nonelective hospitalizations. Conclusions and Relevance: In this prospective cohort study, low SEP was inversely associated with nonelective hospitalizations but not elective hospitalization in older men in Australia. These findings point to the existence of socioeconomic inequalities in health care use, indicative of a need to take action to reduce these inequalities.

Changes in Dietary Total and Nonheme Iron Intake Is Associated With Incident Frailty in Older Men: The Concord Health and Aging in Men Project.

BACKGROUND: Nutritional intake could influence the development of frailty. The aim was to evaluate the associations between dietary iron intakes and changes in dietary iron intakes with frailty. METHODS: Cross-sectional analyses involved 785 men with Fried frailty phenotype (FP) and 758 men with Rockwood frailty index (FI) data aged 75 years and older at nutrition assessment from the Concord Health and Ageing in Men Project prospective cohort study. Of these, 563 men who were FP robust or prefrail, and 432 men who were FI nonfrail were included in the longitudinal analyses for more than 3 years. Dietary intake was assessed at both timepoints using a validated diet history questionnaire. The dietary calculation was used to derive heme iron and nonheme iron intakes from total iron intakes. The associations were evaluated through binary logistic regression. RESULTS: Incidence of FP frailty was 15.3% (n = 86). In longitudinal analyses, maintaining total iron intakes (medium tertile -2.61-0.81 mg/d), increases in total iron and nonheme iron intakes (high tertiles ≥0.82 mg/d and ≥0.80 mg/d), and changes in nonheme iron intake (1 mg increment) were associated with reduced risks of incident FP frailty (OR: 0.47 [95% confindence interval (CI): 0.24, 0.93, p = .031], OR 0.48 [95% CI: 0.23, 0.99, p = .048], OR 0.41 [95% CI: 0.20, 0.88, p = .022], and OR 0.89 [95% CI: 0.82, 0.98, p = .017]). CONCLUSION: Maintaining or increases in total dietary iron and increases or changes in dietary nonheme iron intakes more than 3 years were associated with reduced incidence of FP frailty in older men.

Dementia Incidence, APOE Genotype, and Risk Factors for Cognitive Decline in Aboriginal Australians: A Longitudinal Cohort Study.

BACKGROUND AND OBJECTIVES: Aboriginal Australians are disproportionately affected by dementia, with incidence in remote populations approximately double that of non-Indigenous populations. This study aimed to identify dementia incidence and risk factors in Aboriginal Australians residing in urban areas, which are currently unknown. METHODS: A population-based cohort of Aboriginal Australians ≥60 years of age was assessed at baseline and 6-year follow-up. Life-course risk factors (baseline) were examined for incident dementia or mild cognitive impairment (MCI) through logistic regression analyses; adjustments were made for age. APOE genotyping was available for 86 people. RESULTS: Data were included from 155 participants 60 to 86 years of age (mean 65.70 years, SD 5.65 years; 59 male). There were 16 incident dementia cases (age-standardized rate 35.97/1,000 person-years, 95% confidence interval [CI] 18.34-53.60) and 36 combined incident MCI and dementia cases. Older age (odds ratio [OR] 2.29, 95% CI 1.42-3.70), male sex (OR 4.14, 95% CI 1.60-10.77), unskilled work history (OR 5.09, 95% CI 1.95-13.26), polypharmacy (OR 3.11, 95% CI 1.17-8.28), and past smoking (OR 0.24, 95% CI 0.08-0.75) were associated with incident MCI/dementia in the final model. APOE ε4 allele frequency was 24%; heterozygous or homozygous ε4 was associated with incident MCI/dementia (bivariate OR 3.96, 95% CI 1.25-12.50). DISCUSSION: These findings provide evidence for higher dementia incidence in Aboriginal Australians from urban areas, where the majority of Aboriginal people reside. This study also sheds light on sociodemographic, health, and genetic factors associated with incident MCI/dementia at older ages in this population, which is critical for targeted prevention strategies.

Hemoglobin, Frailty, and Long-term Cardiovascular Events in Community-Dwelling Older Men Aged ≥ 70 Years.

BACKGROUND: Anemia is associated with increased risk of all-cause mortality in older populations. However, the relationship between hemoglobin and major adverse cardiovascular events (MACE), and whether this is modulated by frailty, is unclear. METHODS: CHAMP (Concord Health and Ageing in Men Project) is a prospective study of community-dwelling men aged ≥ 70 years. The relationship between hemoglobin and 7-year MACE was analysed by means of Cox regression. The Youden index was used to determine the optimal hemoglobin cutoff point in predicting MACE. Frailty was assessed with the use of the Fried criteria. RESULTS: The cohort comprised 1604 men (mean ± SD age 76.9 ± 5.5 years). Decreasing hemoglobin was associated with increased comorbidity, frailty, and MACE (P < 0.001), with 140 g/L the optimal cutoff point for predicting MACE. Hemoglobin, age, and frailty independently predicted MACE (all P < 0.001). Each 10 g/L decrement in hemoglobin level was associated with increased risk of MACE (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.06-1.20; P < 0.001), all-cause mortality (HR 1.20, 95% CI 1.12-1.29; P < 0.001), cardiovascular mortality (HR 1.07, 95% CI 1.01-1.14; P = 0.025), myocardial infarction (HR 1.17, 95% CI 1.09-1.25; P < 0.001), and heart failure (HR 1.17, 95% CI 1.09-1.25; P < 0.001). When stratified into hemoglobin quintiles, men in the lowest 2 quintiles (Hb 133-140 g/L and < 132g/L, respectively) were at increased risk of MACE, cardiovascular mortality, myocardial infarction, and heart failure (all P < 0.05). This relationship for MACE was independent from frailty status, with the test for interaction between frailty and hemoglobin not reaching significance (P = 0.24). CONCLUSIONS: Low hemoglobin was associated with increased MACE in community-dwelling older men independently from frailty. A hemoglobin cutoff point of 140 g/L, a level that is above contemporary definitions of anemia, predicted long-term MACE.

Thyroid cancers potentially preventable by reducing overweight and obesity in Australia: A pooled cohort study.

Thyroid cancer incidence and the prevalence of overweight and obesity are increasing, but the future thyroid cancer burden attributable to contemporary levels of overweight and obesity has not been evaluated before. We quantified this burden in Australia, and assessed whether the overweight/obesity-attributable burden differed by sex or other population subgroupings. We estimated the strength of the associations of overweight and obesity with thyroid cancer with adjusted proportional hazards models using pooled data from seven Australian cohorts (N = 367 058) with 431 thyroid cancer cases ascertained from linked national cancer registry data during a maximum 22-year follow-up. We combined these estimates with nationally representative 2017 to 2018 estimates of overweight and obesity prevalence to estimate population attributable fractions (PAFs) of future thyroid cancers attributable to overweight and obesity, accounting for competing risk of death, and compared PAFs for population subgroups. Contemporary levels of overweight and obesity explain 18.6% (95% confidence interval [CI] = 5.2%-30.2%), and obesity alone 13.7% (95% CI: 5.2%-21.4%), of the future thyroid cancer burden. The obesity-attributable thyroid cancer burden is 21.4% (95% CI: 2.8%-36.5%) for men and 10.1% (95% CI: 0.8%-18.6%) for women. Were the currently obese overweight instead, 9.9% (95% CI: 1.0%-18.1%) of thyroid cancers could be avoided. The relative overweight/obesity-attributable burden is higher for those consuming on average more than two alcoholic drinks per day (63.4%) and for those who are not married/co-habiting (33.2%). In conclusion, avoiding excess weight, especially obesity, should be a priority for thyroid cancer prevention. Further studies, with findings stratified by tumour size, may reveal the potential role of overdiagnosis in our results.

Use of tricyclic antidepressants and other anticholinergic medicines by older Aboriginal Australians: association with negative health outcomes.

BACKGROUND: Aboriginal and Torres Strait Islander Australians have a relatively high prevalence of multimorbidity requiring treatment with medications. This study examines medication use and anticholinergic burden (ACB) among a cohort of older Aboriginal and Torres Strait Island people. METHOD: This cross-sectional study involving five Aboriginal communities (two in metropolitan Sydney and three on the mid-north coast of New South Wales) used a structured interview process to assess cognition, depression, and activities of daily living for a cohort of older adults (aged 60 years and over). Participants also reported on their health status, medical history, and prescription medications during the interview. ACB was calculated, and its association with adverse health outcomes including cognitive impairment, falls, hospitalization, and depressive symptoms were examined. RESULTS: Most participants (95%) were taking at least one regular medication with polypharmacy (≥5 medications) observed in 43% of participants; 12.2% had a significant ACB (≥3) with antidepressants being a major contributor. Anticholinergic medication use was associated with cognitive impairment, recent hospitalization (past 12 months), and depressive symptoms. After controlling for age, sex, and comorbidity, only the presence of depressive symptoms remained significantly associated with the use of anticholinergic medication (odds ratio 2.86; 95% confidence interval 1.48-5.51). CONCLUSIONS: Clinically significant ACB was common in older Aboriginal Australians and was largely attributable to inappropriate use of tricyclic antidepressants. Greater awareness of medication-related risk factors among both health care professionals and Aboriginal communities can play an important role in improving health and quality of life outcomes.