Rationale, design and methods for a community-based study of clustering and cumulative effects of chronic disease processes and their effects on ageing: the Busselton healthy ageing study

Help-seeker satisfaction with diagnosis and treatment of tinnitus

OBJECTIVE

To examine help-seeker satisfaction with the first communication of a tinnitus diagnosis by a healthcare provider, whether help-seekers undertook treatment and how they rated this treatment.

DESIGN

A survey design assessed tinnitus characteristics and distress, health status, help-seeking, diagnosis communication, treatment and patient satisfaction.

STUDY SAMPLE

A self-selected cohort and a population-based cohort.

RESULTS

Satisfaction scores were examined against demographic, clinical factors, and type of healthcare provider. A total of 281 adults participated (median age 61.6, IQR = 10.8 years), 52.3% sought help for tinnitus and 22.4% received treatment. The most frequently seen healthcare providers were general practitioners (34.0%), audiologists (29.3%) and ear, nose and throat specialists (25.9%). About two-thirds (64.1%) of help-seekers were unsatisfied with the first communication of a tinnitus diagnosis they received, and 56.5% rated their first tinnitus treatment as poor. Help-seekers were significantly more satisfied with audiologists than other providers regarding the communication of the first tinnitus diagnosis. Higher tinnitus distress scores were significantly associated with lower patient satisfaction with communication of first tinnitus diagnosis. No other factors were associated with patient satisfaction.

CONCLUSION

There are significant communication barriers along the tinnitus clinical pathway. Identifying and addressing these barriers could improve patient satisfaction.

The art of aging well: a study of the relationship between recreational arts engagement, general health and mental wellbeing in cohort of Australian older adults

Introduction

Evidence of the benefits of arts engagement to community wellbeing has been mounting since the 1990s. However, large scale, quantitative, epidemiological studies of the "arts-healthy aging" relationship, or the types of arts older adults voluntarily choose to engage in as part of their everyday life, for enjoyment, entertainment or as a hobby (vs. therapy or interventions) are limited. The aims of this study were to describe older adult recreational arts engagement via the Busselton Healthy Ageing Study (BHAS) cohort, and to determine if there was an association between arts engagement, general health and mental wellbeing.

Methods

Overall, 2,843 older adults (born 1946-1964) from the BHAS cohort (n = 5,107) who had completed a supplementary arts survey (n = 3,055, 60%) and had data on required variables were included in this study (93% of those eligible). The dependent variable was general health (SF12) and subjective mental wellbeing (Warwick-Edinburgh Mental Wellbeing Scale, WEMWBS). The independent variable was hours engaged in recreational arts in the last 12 months. A descriptive analysis followed by a linear regression analysis was conducted.

Results

The prevalence of recreational arts engagement in the last 12 months was 85% (mean = 132 h/year). Older adults engaged in the arts in a number of ways including attending events (79%), actively participating/making art (40%), as an arts society/club/organization member (20%), by learning about the arts (13%) or by volunteering/working in the arts (non-professional, 11%). When general health was assessed via the SF12, the average physical component score (PCS) was 50.1 (SD 8.9) and the average mental component score (MCS) was 53.6 (SD 8.3). When mental wellbeing was assessed, the average WEMWBS score was 54.9 (SD = 8.6). After adjustment for 12 demographic and lifestyle covariates, it was found that older adults who engaged in any recreational arts in the last 12 months had significantly higher WEMWBS scores and higher SF12 physical component scores than those who did not engage in the arts (0 h/year).

Discussion

Evidence of an arts-health relationship was found in this study. The suitability of the arts as a population based, healthy aging strategy to influence the mental wellbeing and general health of older adults should be investigated further.

Relationships between longitudinal changes in body composition and bone mineral density in middle-to-older aged Australians

There are limited longitudinal data regarding relationships between changes in body composition and bone mineral density (BMD). In 3671 participants aged 46-70 years at baseline, ∆lean mass was a stronger determinant than ∆fat mass of ∆BMD over 6 years. Maintained or increased lean mass may slow down age-related bone loss.

PURPOSE

There are limited longitudinal data regarding relationships between changes in body composition and bone mineral density (BMD) with ageing. We examined these in the Busselton Healthy Ageing Study.

METHODS

We studied 3671 participants (2019 females) aged 46-70 years at baseline with body composition and BMD assessments by dual-energy x-ray absorptiometry at baseline and after ~6 years. Relationships between changes in total body mass (∆TM), lean mass (∆LM) and fat mass (∆FM) with ∆BMD at total hip, femoral neck and lumbar spine were evaluated using restricted cubic spline modelling (accounting for baseline covariates) and mid-quartile least square means were compared.

RESULTS

∆TM was positively associated with ∆BMD of total hip and femoral neck in both sexes, and spine in females; in females but not males, associations plateaued at ∆TM above ~5kg for all sites. In females, ∆LM was positively associated with ∆BMD of all three sites with plateauing of the relationship at ∆LM above ~1kg. Women in the highest quartile of ∆LM (Q4, mid-quartile value +1.6 kg) had 0.019-0.028 g/cm2 less reduction in BMD than those in the lowest quartile (Q1, -2.1 kg). In males, ∆LM was positively associated with ∆BMD of total hip and femoral neck; men in Q4 (+1.6 kg) had 0.015 and 0.011 g/cm2 less bone loss, respectively, compared with Q1 (-2.7 kg). ∆FM was positively associated with ∆BMD of total hip only in both sexes.

CONCLUSION

∆LM is a stronger determinant than ∆FM of ∆BMD. Maintained or increased LM is associated with less age-related bone loss.

Plasma lipoprotein subclass variation in middle-aged and older adults: Sex-stratified distributions and associations with health status and cardiometabolic risk factors

BACKGROUND

Circulating lipids and lipoproteins mediate cardiovascular risk, however routine plasma lipid biochemistry provides limited information on pro-atherogenic remnant particles.

OBJECTIVE

We analysed plasma lipoprotein subclasses including very low-density and intermediate-density lipoprotein (VLDL and IDL); and assessed their associations with health and cardiometabolic risk.

METHODS

From 1,976 community-dwelling adults aged 45-67 years, 114/1071 women (10.6%) and 153/905 men (16.9%) were categorised as very healthy. Fasting plasma lipoprotein profiles comprising 112 parameters were measured using 1H nuclear magnetic resonance (NMR) spectroscopy, and associations with health status and cardiometabolic risk factors examined.

RESULTS

HDL cholesterol was higher, and IDL and VLDL cholesterol and triglycerides lower, in very healthy women compared to other women, and women compared to men. IDL and VLDL cholesterol and triglyceride were lower in very healthy men compared to other men. HDL cholesterol and apolipoprotein (apo) A-I were inversely, and IDL and VLDL cholesterol, apoB-100, and apoB-100/apoA-I ratio directly associated with body mass index (BMI) in women and men. In women, LDL, IDL and VLDL cholesterol increased with age. Women with diabetes and cardiovascular disease had higher cholesterol, triglycerides, phospholipids and free cholesterol across IDL and VLDL fractions, with similar trends for men with diabetes.

CONCLUSION

Lipoprotein subclasses and density fractions, and their lipid and apolipoprotein constituents, are differentially distributed by sex, health status and BMI. Very healthy women and men are distinguished by favorable lipoprotein profiles, particularly lower concentrations of VLDL and IDL, providing reference intervals for comparison with general populations and adults with cardiometabolic risk factors.

The ORIGINS Project Biobank: A Collaborative Bio Resource for Investigating the Developmental Origins of Health and Disease

Early onset Non-Communicable Diseases (NCDs), including obesity, allergies, and mental ill-health in childhood, present a serious and increasing threat to lifelong health and longevity. The ORGINS Project (ORIGINS) addresses the urgent need for multidisciplinary efforts to understand the detrimental multisystem impacts of modern environments using well-curated large-scale longitudinal biological sample collections. ORGINS is a prospective community birth cohort aiming to enrol 10,000 pregnant people and follow each family until the children reach 5 years of age. A key objective is to generate a comprehensive biorepository on a sub-group of 4000 families invited to contribute blood, saliva, buccal cells, urine, stool, hair, house dust, cord blood, placenta, amniotic fluid, meconium, breastmilk, and colostrum over eight timepoints spanning the antenatal period and early childhood. Uniquely, ORIGINS includes a series of nested sub-projects, including interventions and clinical trials addressing different aspects of health. While this adds complexity as the project expands, it provides the opportunity for comparative studies. This research design promotes a multidisciplinary, multisystem approach to biological sample collection, analysis, and data sharing to ensure more integrated perspectives and solutions. This paper details the evolving protocol of our collaborative biobanking concept. Further, we outline our future visions for local, national, and ultimately international, comparative, and collaborative opportunities to advance our understanding of early onset NCDs and the opportunities to improve health outcomes for future generations.

A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

BACKGROUND

High myopia (HM), defined as a spherical equivalent refractive error (SER) ≤ -6.00 diopters (D), is a leading cause of sight impairment, through myopic macular degeneration (MMD). We aimed to derive an improved polygenic score (PGS) for predicting children at risk of HM and to test if a PGS is predictive of MMD after accounting for SER.

METHODS

The PGS was derived from genome-wide association studies in participants of UK Biobank, CREAM Consortium, and Genetic Epidemiology Research on Adult Health and Aging. MMD severity was quantified by a deep learning algorithm. Prediction of HM was quantified as the area under the receiver operating curve (AUROC). Prediction of severe MMD was assessed by logistic regression.

FINDINGS

In independent samples of European, African, South Asian and East Asian ancestry, the PGS explained 19% (95% confidence interval 17-21%), 2% (1-3%), 8% (7-10%) and 6% (3-9%) of the variation in SER, respectively. The AUROC for HM in these samples was 0.78 (0.75-0.81), 0.58 (0.53-0.64), 0.71 (0.69-0.74) and 0.67 (0.62-0.72), respectively. The PGS was not associated with the risk of MMD after accounting for SER: OR = 1.07 (0.92-1.24).

INTERPRETATION

Performance of the PGS approached the level required for clinical utility in Europeans but not in other ancestries. A PGS for refractive error was not predictive of MMD risk once SER was accounted for.

FUNDING

Supported by the Welsh Government and Fight for Sight (24WG201).

Comparison of Four Dietary Pattern Indices in Australian Baby Boomers: Findings from the Busselton Healthy Ageing Study

The assessment of dietary patterns comprehensively represents the totality of the diet, an important risk factor for many chronic diseases. This study aimed to characterise and compare four dietary pattern indices in middle-aged Australian adults. In 3458 participants (55% female) from the Busselton Healthy Ageing Study (Phase Two), a validated food frequency questionnaire was used to capture dietary data between 2016 and 2022. Four dietary patterns [Australian Dietary Guideline Index 2013 (DGI-2013); the Mediterranean Diet Index (MedDiet); the Literature-based Mediterranean Diet Index (Lit-MedDiet); and the EAT-Lancet Index], were calculated and compared by measuring total and sub-component scores, and concordance (𝜌_c). Cross-sectional associations between the dietary indices and demographic, lifestyle, and medical conditions were modelled with linear regression and restricted cubic splines. Participants had the highest standardised scores for the DGI-2013 followed by the EAT-Lancet Index and the MedDiet, with the lowest standardised scores observed for the Lit-MedDiet. The DGI-2013 had the lowest agreement with the other scores (𝜌_c ≤ 0.47). These findings indicate that the diets included in this Australian cohort align more closely with the Australian Dietary Guidelines than with the other international dietary patterns, likely due to the wide variation of individual food group weightings in the construction of these indices.

Longitudinal Stability of Vitamin D Status and Its Association With Bone Mineral Density in Middle-aged Australians

Context

The skeletal effects of vitamin D remain controversial and it is uncertain whether variation in serum 25-hydroxyvitamin D (25OHD) levels over time influences bone mineral density (BMD).

Objective

We evaluated longitudinal stability of serum 25OHD and associations with changes in BMD in participants aged 46-70 years at baseline.

Methods

We studied 3698 Busselton Healthy Ageing Study participants (2040 female) with serum 25OHD and dual-energy x-ray absorptiometry (DXA) BMD assessments at baseline and at ∼6 years follow-up. Restricted cubic splines were used to evaluate associations between changes in 25OHD and BMD.

Results

Mean season-corrected serum 25OHD was 81.3 ± 22.7 and 78.8 ± 23.1 nmol/L at baseline and 6 years, respectively, and showed moderate correlation (intraclass correlation coefficient: 0.724). Significant predictors of change in 25OHD concentration (Δ25OHD) included baseline 25OHD, change in body mass index and vitamin D supplementation at follow-up. Greater decline in serum 25OHD over time was associated with significantly greater reduction in BMD at total hip and femoral neck, but the magnitude of the differences was small (estimated differences 0.004 g/cm² and 0.005-0.007 g/cm², respectively, for lowest quartile of Δ25OHD compared with higher quartiles, adjusted for sex, baseline BMD, 25OHD, and demographics). No significant associations between Δ25OHD and lumbar spine BMD were observed. Increase in 25OHD levels was not associated with change in BMD.

Conclusions

In this predominantly vitamin D-replete middle-aged cohort, serum 25OHD showed moderate longitudinal stability. Declining serum 25OHD over time was associated with greater reduction in BMD at the total hip and femoral neck.

Establishing a Total Hip T-Score Threshold to Measure Contralateral Hip Bone Mineral Density: Avoiding Missed Diagnosis of Osteoporosis

Bone mineral density (BMD) of the hip is routinely measured unilaterally, but can differ between left and right. This study aimed to establish total hip T-score thresholds for measuring contralateral hip BMD, to avoid missing the diagnosis of osteoporosis. In 4914 participants (2709 females) in the Busselton Healthy Ageing Study, BMD of both hips and lumbar spine (L1-L4) was measured by dual-energy x-ray absorptiometry (DXA) using a GE Lunar Prodigy Pro densitometer. Least significant change (LSC) was calculated according to International Society for Clinical Densitometry recommendations. For participants whose left-right total hip BMD difference exceeded LSC, the 95th percentile of the difference in T-score was calculated, then added to -2.5 (the cut-off for osteoporosis) to derive T-score thresholds for measuring contralateral hip to avoid a missed diagnosis in 95% of individuals. Participant mean age (±SD) was 57.4 ± 5.8 years; total hip T-score was 0.7 ± 0.1 in males and -0.2 ± 1.1 in females. Left and right total hip BMD were highly correlated (r = 0.943 for males, 0.959 for females), but in 56.2% of males and 50.0% of females, the left-right difference exceeded the LSC of 0.026 g/cm². In these participants, the 95th percentile of difference in T-score between two hips was 0.872 in males and 0.742 in females. This gave T-score thresholds for measuring contralateral total hip BMD of -1.6 (males) and -1.8 (females). When total hip T-score is between -1.6 and -2.5 (males), or between -1.8 and -2.5 (females), measuring contralateral hip BMD could avoid a missed diagnosis of osteoporosis.

DXA-Derived vs Standard Anthropometric Measures for Predicting Cardiometabolic Risk in Middle-Aged Australian Men and Women

It is not clear if dual-energy X-ray absorptiometry (DXA) adiposity measures are superior to standard anthropometric measures for predicting cardiometabolic (CM) risk factors in a middle-aged general population. In the Busselton Healthy Ageing Study, we assessed a range of standard anthropometric and DXA-derived adiposity measures to predict metabolic syndrome (MetS) and CM risk factors in 4831 "baby boomers" aged 45-69 yr. Anthropometric and whole body DXA (GE Lunar Prodigy) measures were collected. Cross-sectional relationships of overall adiposity (BMI; DXA fat mass index, body fat %), central adiposity (waist circumference (WC); DXA trunk fat, android fat, abdominal visceral adipose tissue (VAT)) and ratio index (waist-to-hip ratio; DXA trunk/legs fat, android/gynoid ratio, VAT/total fat) with MetS and its components (as both continuous and binary outcomes) were evaluated using linear and logistic regression adjusting for age and lifestyle factors. Youden's Index was used to determine the optimal cut-points for predicting MetS. In linear regression analyses, central adiposity measures showed stronger associations with MetS score and CM risk factors than overall adiposity measures and fat ratio index, and DXA-VAT provided stronger associations than WC. Logistic regression models showed similar findings. For MetS diagnosis present in 35.9% of males and 24.4% of females, the highest odds ratio (95% CI) per SD change was observed for DXA-VAT (males: 5.02 [4.28, 5.88]; females: 3.91 [3.40, 4.49]), which remained significant (all p < 0.001) after further adjustment for BMI (males: 3.27 [2.65, 4.02]; females: 3.37 [2.79, 4.06]) or WC (males: 2.46 [1.95, 3.10]; females: 2.75 [2.21, 3.43]). The optimal DXA-VAT mass cut-point for predicting MetS was 1608 grams in males and 893 grams in females. DXA-VAT was superior to standard anthropometric and other DXA-derived adiposity measures for prediction of cardiometabolic risk factors, and has clinical utility for identifying middle-aged individuals at increased risk of MetS.

Comparing self-reported and measured hypertension and hypercholesterolaemia at standard and more stringent diagnostic thresholds: the cross-sectional 2010-2015 Busselton Healthy Ageing study

Background

Population health behaviour and risk factor surveys most often rely on self-report but there is a lack of studies assessing the validity of self-report using Australian data. This study investigates the sensitivity, specificity and agreement of self-reported hypertension and hypercholesterolaemia with objective measures at standard and more stringent diagnostic thresholds; and factors associated with sensitivity and specificity of self-report at different thresholds.

Methods

This study was a secondary analysis of a representative community-based cross-sectional sample of 5,092 adults, aged 45–69 years, residing in Busselton, Western Australia, surveyed in 2010–2015. Participants completed a self-administered questionnaire. Blood pressure and serum cholesterol levels were measured.

Results

At currently accepted diagnostic thresholds, sensitivities of self-reported hypertension and hypercholesterolaemia were 58.5% and 39.6%, respectively and specificities were >90% for both. Agreement using Cohen’s kappa coefficient was 0.562 and 0.223, respectively. At two higher diagnostic thresholds, sensitivities of self-reported hypertension and hypercholesterolaemia improved by an absolute 14–23% and 15–25%, respectively and specificities remained >85%. Agreement was substantial for hypertension (kappa = 0.682–0.717) and moderate for hypercholesterolaemia (kappa = 0.458–0.533). Variables that were independently associated with higher sensitivity and lower specificity of self-report were largely consistent across thresholds and included increasing age, body mass index, worse self-rated health, diabetes and family history of hypertension.

Conclusions

Self-reported hypertension and hypercholesterolaemia often misclassify individuals’ objective status and underestimate objective prevalences, at standard diagnostic thresholds, which has implications for surveillance studies that rely on self-reported data. Self-reports of hypertension, however, may be reasonable indicators of those with blood pressures ≥160/100 mmHg or those taking anti-hypertensive medications. Self-reported hypercholesterolaemia data should be used with caution at all thresholds.

Prevalence of Toxoplasmic Retinochoroiditis in an Australian Adult Population: a Community-Based Study

OBJECTIVE

Toxoplasmic retinochoroiditis is the most common clinical manifestation of an infection with the protozoan parasite, Toxoplasma gondii. Up to 50% of the human population is estimated to be infected with T. gondii. However, the epidemiology of toxoplasmic retinochoroiditis is not widely reported. We sought to estimate the prevalence of toxoplasmic retinochoroiditis in Australia using data collected as part of the Busselton Healthy Ageing Study.

DESIGN

Cross-sectional, community-based, prospective cohort study.

PARTICIPANTS

5,020 Australian adults (2,264 men and 2,756 women; age range of 45-69 years and median age of 58 years).

METHODS

Retinal color photographs centered on the optic disc and macula were captured on a digital retinal camera following dilation of the pupils. Three uveitis-subspecialized ophthalmologists assessed each pigmented retinal lesion, and complete concordance of opinion was required to assign a toxoplasmic etiology. Serum T. gondii immunoglobulin (Ig)G levels were measured for those participants with retinal lesions judged to be toxoplasmic retinochoroiditis.

MAIN OUTCOME MEASURES

Prevalence of toxoplasmic retinochoroiditis.

RESULTS

Eight participants (0.16%) had retinal lesions that were considered to have the characteristic appearance of toxoplasmic retinochoroiditis, plus detectable serum T. gondii IgG, consistent with the diagnosis of toxoplasmic retinochoroiditis. On the assumption that 23.81% of retinal lesions occur at the posterior pole, as reported in a community-based survey conducted in Brazil (Sci Rep. 2021;11:3420), the prevalence of toxoplasmic retinochoroiditis was estimated at 0.67% or 1 per 149 persons.

CONCLUSIONS

Toxoplasmic retinochoroiditis is common in Australian adults. Efforts to quantify and address risk factors for human infection with T. gondii are justified.

Investigating Potential Dose-Response Relationships between Vitamin D Status and Cognitive Performance: A Cross-Sectional Analysis in Middle- to Older-Aged Adults in the Busselton Healthy Ageing Study

Low vitamin D status has been linked to adverse cognitive outcomes in older adults. However, relationships at higher levels remain uncertain. We aimed to clarify patterns of association between vitamin D status and cognitive performance, using flexible regression methods, in 4872 middle- to older-aged adults (2678 females) from the Busselton Healthy Ageing Study. Cross-sectional associations of serum levels of 25-hydroxyvitamin D (25OHD) and performance in cognitive domains were modelled using linear regression and restricted cubic splines, controlling for demographic, lifestyle, and health factors. Mean ± SD serum 25OHD levels were 78 ± 24 nM/L for women and 85 ± 25 nM/L for men. Increasing levels in women were associated with better global cognition (linear trend, p = 0.023) and attention accuracy (continuity of attention), with improvement in the latter plateauing around levels of 80 nM/L (nonlinear trend, p = 0.035). In men, increasing levels of serum 25OHD were associated with better attention accuracy (linear trend, p = 0.022), but poorer semantic verbal fluency (linear trend, p = 0.025) and global cognition (nonlinear trend, p = 0.015). We identified patterns of association between serum 25OHD levels and cognitive performance that may reflect early dose–response relationships, particularly in women. Longitudinal analyses extending through to older ages may help to clarify the nature, strength, and temporality of these relationships.

The prevalence and comorbidities of obstructive sleep apnea in middle-aged men and women: the Busselton Healthy Ageing Study

STUDY OBJECTIVES

Population surveys suggest the prevalence of obstructive sleep apnea (OSA) is high and increasing and that risk factors and outcomes differ between sexes. To explore these relationships we assessed current OSA prevalence, potential risk factors and comorbidities, and their changes relative to previous estimates in the same community.

METHODS

All adults on the Busselton, Australia, electoral roll born 1946-1964 were invited to participate in a general health survey. Of the 5,037 (62% response rate) respondents, 3,686 successfully completed overnight 2-channel (oximetry, airflow) sleep studies. These were scored and categorized as nil, mild, moderate, or severe OSA based on apnea-hypopnea index (< 5, ≥ 5 to < 15, ≥ 15 to < 30, and ≥ 30 events/h, respectively). Sleep scores were related to participant characteristics and health profiles. OSA prevalence was compared with previous surveys in the community.

RESULTS

Prevalences of any and moderate-severe OSA were 57.7% and 20.2% in males and 41.7% and 10.0% in females. Matched for age group, the prevalence of moderate-severe OSA was similar to that in 2007 (males 24.6%, females 9.8%) and was higher than in 1995 (males 4.7%). OSA was associated with age, body mass index, and alcohol intake in males and age and body mass index in females. Conditions associated with OSA included hypertension and current depression in males and hypertension, skin cancer, and diabetes in females.

CONCLUSIONS

Prevalence of OSA in a middle-aged, predominantly White population in 2010-2015 was high, has increased since 1995, and has remained stable since 2007. Sex differences exist in associated features, including potential risk factors and comorbidities.

CITATION

Cunningham J, Hunter M, Budgeon C, et al. The prevalence and comorbidities of obstructive sleep apnea in middle-aged men and women: the Busselton Healthy Ageing Study. J Clin Sleep Med. 2021;17(10):2029-2039.

Airway microbial communities, smoking and asthma in a general population sample

BACKGROUND

Normal airway microbial communities play a central role in respiratory health but are poorly characterized. Cigarette smoking is the dominant global environmental influence on lung function, and asthma has become the most prevalent chronic respiratory disease worldwide. Both conditions have major microbial components that are incompletely defined.

METHODS

We investigated airway bacterial communities in a general population sample of 529 Australian adults. Posterior oropharyngeal swabs were analyzed by sequencing of the 16S rRNA gene. The microbiota were characterized according to their prevalence, abundance and network memberships.

FINDINGS

The microbiota were similar across the general population, and were strongly organized into co-abundance networks. Smoking was associated with diversity loss, negative effects on abundant taxa, profound alterations to network structure and expansion of Streptococcus spp. By contrast, the asthmatic microbiota were selectively affected by an increase in Neisseria spp. and by reduced numbers of low abundance but prevalent organisms.

INTERPRETATION

Our study shows that the healthy airway microbiota in this population were contained within a highly structured ecosystem, suggesting balanced relationships between the microbiome and human host factors. The marked abnormalities in smokers may contribute to chronic obstructive pulmonary disease (COPD) and lung cancer. The narrow spectrum of abnormalities in asthmatics encourages investigation of damaging and protective effects of specific bacteria.

FUNDING

The study was funded by the Asmarley Trust and a Wellcome Joint Senior Investigator Award to WOCC and MFM (WT096964MA and WT097117MA). The Busselton Healthy Ageing Study is supported by the Government of Western Australia (Office of Science, Department of Health) the City of Busselton, and private donations.

Prevalence and patterns of multimorbidity in Australian baby boomers: the Busselton healthy ageing study

BACKGROUND AND OBJECTIVE

Chronic medical conditions accumulate within individuals with age. However, knowledge concerning the trends, patterns and determinants of multimorbidity remains limited. This study assessed the prevalence and patterns of multimorbidity using extensive individual phenotyping in a general population of Australian middle-aged adults.

METHODS

Participants (n = 5029, 55% female), born between 1946 and 1964 and attending the cross-sectional phase of the Busselton Healthy Ageing Study (BHAS) between 2010 and 2015, were studied. Prevalence of 21 chronic conditions was estimated using clinical measurement, validated instrument scores and/or self-reported doctor-diagnosis. Non-random patterns of multimorbidity were explored using observed/expected (O/E) prevalence ratios and latent class analysis (LCA). Variables associated with numbers of conditions and class of multimorbidity were investigated.

RESULTS

The individual prevalence of 21 chronic conditions ranged from 2 to 54% and multimorbidity was common with 73% of the cohort having 2 or more chronic conditions. (mean ± SD 2.75 ± 1.84, median = 2.00, range 0-13). The prevalence of multimorbidity increased with age, obesity, physical inactivity, tobacco smoking and family history of asthma, diabetes, myocardial infarct or cancer. There were 13 pairs and 27 triplets of conditions identified with a prevalence > 1.5% and O/E > 1.5. Of the triplets, arthritis (> 50%), bowel disease (> 33%) and depression-anxiety (> 33%) were observed most commonly. LCA modelling identified 4 statistically and clinically distinct classes of multimorbidity labelled as: 1) "Healthy" (70%) with average of 1.95 conditions; 2) "Respiratory and Atopy" (11%, 3.65 conditions); 3) "Non-cardiometabolic" (14%, 4.77 conditions), and 4) "Cardiometabolic" (5%, 6.32 conditions). Predictors of multimorbidity class membership differed between classes and differed from predictors of number of co-occurring conditions.

CONCLUSION

Multimorbidity is common among middle-aged adults from a general population. Some conditions associated with ageing such as arthritis, bowel disease and depression-anxiety co-occur in clinically distinct patterns and at higher prevalence than expected by chance. These findings may inform further studies into shared biological and environmental causes of co-occurring conditions of ageing. Recognition of distinct patterns of multimorbidity may aid in a holistic approach to care management in individuals presenting with multiple chronic conditions, while also guiding health resource allocation in ageing populations.

Change in the prevalence of myopia in Australian middle-aged adults across 20 years

BACKGROUND

The prevalence of myopia is increasing globally including in Europe and parts of Asia but Australian data are lacking. This study aim described the change in myopia prevalence in middle-aged Australian adults over approximately a 20-year period.

METHODS

Two contemporary Western Australian studies (conducted in mid-late 2010s): the coastal-regional Busselton Healthy Ageing Study (BHAS) and the urban Gen1 of the Raine Study (G1RS) were compared to two earlier studies (early-mid 1990s) in Australia: the urban Blue Mountains Eye Study (BMES) and urban/regional Melbourne Visual Impairment Project (MVIP). Refractive error was measured by autorefraction, vertometry, or subjective refraction. Participants (49-70 years) of European descent without self-reported/diagnosed cataract, corneal disease, or refractive or corneal surgery were included.

RESULTS

After exclusions, data were available from 2217, 1760, 700, 2987 and 756 participants from BMES, urban MVIP, regional MVIP, BHAS, and G1RS, respectively. The mean age ranged from 57.1 ± 4.6 years in the G1RS to 60.1 ± 6.0 years in the BMES; 44-48% of participants were male. When stratified by location, the contemporary urban G1RS cohort had a higher age-standardised myopia prevalence than the urban MVIP and BMES cohorts (29.2%, 16.4%, and 23.9%, p < 0.001). The contemporary coastal-regional BHAS had a higher age-standardised myopia prevalence than the regional MVIP cohort (19.4% vs. 13.8%, p = 0.001).

CONCLUSIONS

We report an increase in myopia prevalence in older adults in Australia born after World War ll compared to cohorts born before, accounting for urban/regional location. The prevalence of myopia remains relatively low in middle-aged Australian adults.

Prevalence of Hyperacusis and Its Relation to Health: The Busselton Healthy Ageing Study

Importance

The prevalence of hyperacusis and its relationship with mental and general health is unknown in a nonclinical sample. Therefore, we aimed to determine the prevalence of hyperacusis and its relation with hearing, general and mental health in a population‐based study.

Study Design

Prospective population‐based study.

Material and Methods

This study uses data from the Busselton Healthy Ageing Study (BHAS). A sample of 5,107 eligible inhabitants aged 45 to 70 years completed a detailed questionnaire and a clinical assessment. A positive answer to “Do you consider yourself sensitive or intolerant to everyday sounds” was used to indicate hyperacusis. Logistic regression was used to examine the association between hearing, mental and general health factors, and hyperacusis.

Results

Of 5,107 participants, 775 (15.2%) reported hyperacusis. The majority of participants with hyperacusis reported an occasional effect on daily life (72.0%). Being female, older in age, having a lower income, physical or mental health difficulties, more severe hearing loss, and tinnitus were all associated with the presence of hyperacusis. Individuals who experience hearing impairment, poorer general or mental health have a higher possibility of hyperacusis having an effect on their daily life.

Conclusions

In this community population‐based cohort study, we found a prevalence of hyperacusis of 15.2%. Individuals with hearing loss, mental health problems, and lower physical health have a higher possibility of experiencing effects on their daily life associated with their hyperacusis. Unravelling the relationship between hyperacusis hearing, general and mental health can be of major importance for a better understanding of the condition and its consequences.

Level of Evidence

2 Laryngoscope, 131:E2887–E2896, 2021

Tinnitus and its associations with general health, mental health and hearing loss

BACKGROUND

A deeper knowledge of tinnitus is essential in order to better manage and treat tinnitus and its effects. Most studies to date are based on small samples and/or conducted in clinical settings. In this study we assessed the associations between tinnitus, general and mental health, hearing status and demographics in a large population cohort study.

MATERIALS AND METHODS

The Busselton Healthy Aging Study recruited people born between 1946 and 1964. Data were collected between 2010 and 2015. Logistic regression was used to examine the associations between tinnitus and its effect on daily life, age, gender, hearing, self-reported mental and general health, and doctor diagnosed health conditions.

RESULTS

Of 5107 participants, 1154 (22.6%) reported experiencing tinnitus. Of those, 32.4% reported that their tinnitus had an occasional effect on their daily lives, while for a further 8.9% the effect on their daily life was frequent or constant. The odds ratio for having a SF12-PCS was (OR 1.02 (95%CI 1.01-1.03). Furthermore, individuals who experience their tinnitus as having an effect on their daily life, have an increased risk of having a lower general health (OR 1.04 (95%CI 1.02-1.03)) than those without tinnitus. Higher levels of depression, anxiety and stress, as well as doctor diagnosed depression, were all significant risk factors for tinnitus. There were statistically significant worse hearing thresholds related to the presence of tinnitus.

CONCLUSION

The outcomes raise the question for clinicians and researchers whether addressing the mental and general health of individuals will influence the presence or burden of tinnitus.

U-shaped association of vigorous physical activity with risk of metabolic syndrome in men with low lean mass, and no interaction of physical activity and serum 25-hydroxyvitamin D with metabolic syndrome risk

BACKGROUND

There is uncertainty over how lean mass, physical activity (PA) and 25-hydroxyvitamin D (25-OH-D) status interact on metabolic syndrome (MetS) risk in adults.

AIMS

To test the hypothesis that these factors additively influence MetS risk.

METHODS

Four thousand eight hundred and fifty-eight adults (54.6% female) mean ± SD age 58.0 ± 5.8 years, body mass index 28.1 ± 4.8 kg/m² , resident in Busselton, Western Australia. PA assessed by questionnaire (all/total and vigorous), lean mass using dual energy X-ray absorptiometry (% total body mass), serum 25-OH-D via immunoassay, analysed using multivariable logistic regression.

RESULTS

In men, lower total PA was associated with MetS (no vs >24 h/week odds ratio (OR) = 3.1; ≤8 vs >24 h/week OR = 1.8, both P < 0.001), as was lower lean mass (low vs high OR = 20.4; medium vs high OR = 7.4, both P < 0.001). Men with low lean mass exhibited a U-shaped relationship of vigorous PA with MetS risk (covariate-adjusted: 0 vs 4-8 h/week OR = 2.1, P = 0.037; >12 vs 4-8 h/week OR = 4.3, P = 0.002; interaction P = 0.039). In women, low PA (0 vs >24 h/week OR = 2.1, P = 0.003) and lean mass (low vs high OR = 13.1; medium vs high OR = 7.2, both P < 0.001) were associated with MetS risk. Low 25-OH-D status was associated with MetS in men (low vs high OR = 4.1; medium vs high OR = 2.3, both P < 0.001) and women (OR = 3.5 and 2.1 respectively, both P < 0.001) with no PA interaction.

CONCLUSIONS

Men and women with high lean mass have low risk of MetS regardless of PA. Low lean mass identifies men who may benefit most from increasing PA, with an optimal level associated with lowest risk. 25-OH-D and PA do not interact on MetS risk.

Relationship between visceral adipose tissue and bone mineral density in Australian baby boomers

Adiposity has a complex relationship with bone health. In 4865 Australian baby boomers (2642 females) aged 45-70 years, we found that higher visceral adipose tissue mass is associated with reduced bone density adjusting for body mass and lifestyle factors, suggesting that excess visceral fat may be deleterious to bone.

INTRODUCTION

Increased body mass is associated with higher bone mineral density (BMD), but higher visceral adipose tissue (VAT) may have a negative impact on bone health. In the Busselton Healthy Ageing Study, we examined associations between VAT mass and BMD in 4865 participants (2642 females) aged 45-70 years.

METHODS

VAT mass and BMD of whole body, total hip, femoral neck and lumbar spine were measured using DXA. VAT mass was examined as a continuous variable and in quartiles using sex-specific cut-offs.

RESULTS

The mean age was 58.0 ± 5.8 years. Males had significantly higher BMI (28.3 ± 3.7 vs 27.5 ± 4.9 kg/m²) and VAT mass (1675 ± 878 vs 882 ± 600 g) than females (both P < 0.001). In males, after adjustment for age, body mass, height and lifestyle factors, VAT mass negatively associated with total body, total hip and femoral neck BMD (β = - 0.153 to - 0.293, all P < 0.001). Males in the highest quartile of VAT mass (> 2200 g) had significantly lower BMD at all three sites than those in lower quartiles, with estimated BMD differences of 2.3-5.7% (all P < 0.05). In females, VAT mass negatively associated with total body, femoral neck and lumbar spine BMD (β = - 0.067 to - 0.178, all P < 0.05) and those in the highest quartile (> 1250 g) had significantly lower total body BMD than other quartiles (by 1.7-3.7%, all P < 0.05).

CONCLUSION

In middle-aged Australians, after covariate adjustment, higher DXA-derived VAT mass is associated with reduced bone density, suggesting that excess visceral fat may be deleterious to bone, especially in males.

Optic Disc Measures in Obstructive Sleep Apnea: A Community-based Study of Middle-aged and Older Adults

PRéCIS:: This study found an association between thinner superotemporal retinal nerve fiber layer (RNFL) and obstructive sleep apnea (OSA). However, the lack of association of sleep apnea with other disc measures does not support a link with glaucoma.

AIM

Previous findings on the link between OSA and increased glaucoma risk have been inconsistent. In a community-based study of middle-aged and older adults, we explored for differences in optic disc measures that may resemble preclinical glaucomatous changes in relation to OSA status and severity.

METHODS

A total of 865 participants (46 to 67 y; 45% male) underwent an at-home sleep study during which their apnea-hypopnea index (AHI) and sleep oxygen saturation level were measured. Participants were determined to have no OSA (AHI<5 events/h), mild (AHI 5 to 15), moderate (AHI 16 to 30), or severe OSA (AHI>30). At a 6-year follow-up visit, the optic discs of both eyes were imaged using spectral domain optic coherence tomography to measure the Bruch membrane opening-minimum rim widths and RNFL thicknesses.

RESULTS

On the basis of the AHI, 411 participants (48%) had OSA, of whom 92 (11% of total sample) and 26 (3%) had moderate and severe OSA, respectively. In the multivariate analysis, participants with severe OSA had thinner RNFL superotemporally than those without OSA or with mild OSA (P<0.001 and 0.001, respectively). In addition, superotemporal RNFL was inversely associated with AHI (P=0.004) and sleep time with oxygen saturation level <90% (P=0.005). There was no association between OSA measures and Bruch membrane opening-minimum rim widths.

CONCLUSIONS

Our findings do not provide strong evidence of a link between measures of OSA and the optic disc. However, the association between increased OSA severity and thinner superotemporal RNFL has been reported consistently in previous studies and thus warrants further evaluation.

Cognitive profiles in obstructive sleep apnea: a cluster analysis in sleep clinic and community samples

STUDY OBJECTIVES

Although cognitive dysfunction is a recognized consequence of untreated obstructive sleep apnea (OSA), the deficit pattern is heterogeneous. Understanding this heterogeneity may identify those at risk of cognitive deficits and guide intervention strategies. To facilitate understanding, we examined whether distinct profiles of neuropsychological performance were present in OSA and, if so, how they are related to other OSA features.

METHODS

We studied sleep clinic (n = 121) and community (n = 398) samples with moderate-severe OSA (apnea-hypopnea index ≥ 15 events/h). Attention and memory were assessed using the Cognitive Drug Research system. Sleep was assessed using polysomnography in the clinic sample and dual channel (flow, oximetry) portable monitoring in the community sample. Latent profile analysis was used to determine structure of cognitive clusters. Discriminant function analysis was used to examine associations between nocturnal and diurnal features of OSA and profile membership.

RESULTS

Both samples were best characterized by a 3-profile solution: (1) strong thinkers (performed well across most domains and showed greater cognitive reserve); (2) inattentive fast thinkers (strong processing speed but poor ability to maintain attention); and (3) accurate slow thinkers (strengths in maintaining attention but poor processing speed). Profile membership was associated with mean overnight oxygen saturation and cognitive reserve in the clinic sample and the presence of cardiovascular disease and/or diabetes in the community sample.

CONCLUSIONS

These findings help explain the diversity of outcomes in previous studies of cognitive dysfunction in OSA by demonstrating that individual differences in cognitive reserve, nocturnal oxygen saturation, and comorbidities affect how cognition is impacted by OSA.

Type 2 Diabetes Mellitus is Associated with the Immunoglobulin G N-Glycome through Putative Proinflammatory Mechanisms in an Australian Population

Type 2 diabetes mellitus (T2DM) is a common complex trait arising from interactions among multiple environmental, genomic, and postgenomic factors. We report here the first attempt to investigate the association between immunoglobulin G (IgG) N-glycan patterns, T2DM, and their clinical risk factors in an Australian population. N-glycosylation of proteins is one of the most frequently observed co- and post-translational modifications, reflecting, importantly, the real-time status of the interplay between the genomic and postgenomic factors. In a community-based case-control study, 849 participants (217 cases and 632 controls) were recruited from an urban community in Busselton, Western Australia. We applied the ultraperformance liquid chromatography method to analyze the composition of IgG N-glycans. We then conducted Spearman's correlation analyses to explore the association between glycan biomarker candidates and clinical risk factors. We performed area under the curve (AUC) analysis of the receiver operating characteristic curves by fivefold cross-validation for clinical risk factors, IgG glycans, and their combination. Two directly measured and four derived glycan peaks were significantly associated with T2DM, after correction for extensive clinical confounders and false discovery rate, thus suggesting that IgG N-glycan traits are highly correlated with T2DM clinical risk factors. Moreover, adding the IgG glycan profiles to fasting blood glucose in the logistic regression model increased the AUC from 0.799 to 0.859. The AUC for IgG glycans alone was 0.623 with a 95% confidence interval 0.580-0.666. In addition, our study provided new evidence of diversity in T2DM complex trait by IgG N-glycan stratification. Six IgG glycan traits were firmly associated with T2DM, which reflects an increased proinflammatory and biological aging status. In summary, our study reports novel associations between the IgG N-glycome and T2DM in an Australian population and the putative role of proinflammatory mechanisms. Furthermore, IgG N-glycomic alterations offer future prospects as inflammatory biomarker candidates for T2DM diagnosis, and monitoring of T2DM progression to cardiovascular disease or renal failure.

Low 25-Hydroxyvitamin D Concentration Is Not Associated With Refractive Error in Middle-Aged and Older Western Australian Adults

Purpose

To investigate the association between serum 25-hydroxyvitamin D (25[OH]D) concentration and refractive error in a community-based cohort of adults aged 46 to 69 years.

Methods

Residents of the City of Busselton in Western Australia born between 1946 and 1964 were invited to participate. Participants underwent cycloplegic autorefraction and completed questionnaires on education, occupational sun exposure, and physical activity. Blood samples were collected and serum frozen at −80°C. Serum 25[OH]D concentration was measured by immunoassay. Data on 25[OH]D were deseasonalized and multivariate models built to analyze the association between 25[OH]D concentration and spherical equivalent and myopia, defined as spherical equivalent <−0.50 D.

Results

After exclusions, data were available for 4112 participants. Serum 25[OH]D concentration was not associated with spherical equivalent or myopia after adjustment for confounding factors (β = −0.01, 95% confidence interval [CI]: −0.03 to −0.008, P = 0.25, and odds ratio = 1.02, 95% CI: 0.99 to 1.05, P = 0.12, respectively). When participants were classified into 25[OH]D groups of lower (<50 nmol/L), medium (≥50 to <75 nmol/L), and upper (≥75 nmol/L), the upper group had slightly greater myopic refractive error than the medium group (P = 0.02) but not the lower group, after adjustment for confounders.

Conclusions

There was no substantial association between 25[OH]D levels and spherical equivalent or odds of myopia in this study. The association previously noted between low serum 25[OH]D level and myopia in younger Western Australians is not evident in later adulthood.

Translational Relevance

This study provides further evidence suggesting that vitamin D levels are unrelated to myopia risk in adults and thus not a suitable target for myopia intervention.

Longitudinal study of health, disease and access to care in rural Victoria: the Crossroads-II study: methods

Background

High quality, contemporary data regarding patterns of chronic disease is essential for planning by health services, policy makers and local governments, but surprisingly scarce, including in rural Australia. This dearth of data occurs despite the recognition that rural Australians live with high rates of ill health, poor health behaviours and restricted access to health services. Crossroads-II is set in the Goulburn Valley, a rural region of Victoria, Australia 100–300 km north of metropolitan Melbourne. It is primarily an irrigated agricultural area.

The aim of the study is to identify changes in the prevalence of key chronic health conditions including the extent of undiagnosed and undermanaged disease, and association with access to care, over a 15 year period.

Methods/design

This study is a 15 year follow up from the 2000–2003 Crossroads-I study (2376 households participated). Crossroads-II includes a similar face to face household survey of 3600 randomly selected households across four towns of sizes 6300 to 49,800 (50% sampled in the larger town with the remainder sampled equally from the three smaller towns). Self-reported health, health behaviour and health service usage information is verified and supplemented in a nested sub-study of 900 randomly selected adult participants in ‘clinics’ involving a range of additional questionnaires and biophysical measurements. The study is expected to run from October 2016 to December 2018.

Discussion

Besides providing epidemiological and health service utilisation information relating to different diseases and their risk factors in towns of different sizes, the results will be used to develop a composite measure of health service access. The importance of access to health services will be investigated by assessing the correlation of this measure with rates of undiagnosed and undermanaged disease at the mesh block level. Results will be shared with partner organisations to inform service planning and interventions to improve health outcomes for local people.

Vitamin D and respiratory health in the Busselton Healthy Ageing Study

BACKGROUND AND OBJECTIVE

The relationship between vitamin D and respiratory disease was examined by cross-sectional analysis of a large community-based sample.

METHODS

Serum 25-hydroxyvitamin D (25OHD) and history of respiratory disease, symptoms (recorded by questionnaire) and spirometry were measured in 5011 adults aged 45-69 years. Adjustments were made for age, sex, season and smoking (Model A), plus body mass index (BMI) and physical activity level (Model B), plus history of chronic diseases (Model C).

RESULTS

Mean (SD) age was 58 (SD 6) years with 45% males, 10% current smokers and 12% taking vitamin D supplements. The prevalence of 25OHD level <50 nmol/L was 8.0%. In all the three models, 25OHD <50 nmol/L was significantly associated with asthma (Model C: odds ratio (OR): 1.32; 95% CI: 1.00, 1.73), bronchitis (1.54; 1.17, 2.01), wheeze (1.37; 1.10, 1.71) and chest tightness (1.42; 1.10, 1.83). Participants with vitamin D level > 100 nmol/L had higher forced vital capacity (FVC) in all the three models (1.17% higher, compared with the 50-100 nmol/L group in Model C).

CONCLUSION

Low levels of serum 25OHD were independently associated with asthma, bronchitis, wheeze and chest tightness after three levels of adjustment for potential confounders. Higher vitamin D levels were associated with higher levels of lung function.

Associations between cardiovascular disease and its risk factors with hearing loss-A cross-sectional analysis

OBJECTIVES

To investigate the relationship between hearing loss and cardiovascular disease risk factors.

DESIGN

Cross-sectional study.

METHODS

Participants were recruited between May 2010 and December 2015 and answered a health and risk factor questionnaire. Physical and biochemical assessments were performed.

SETTING

A community-based population.

PARTICIPANTS

A total of 5107 participants born within the years 1946-1964 enrolled in the Busselton Healthy Ageing Study.

MAIN OUTCOME MEASURES

Hearing was assessed behaviourally through the best ear pure-tone average (500, 1000, 2000, 4000 Hz), low-frequency average (250, 500, 1000 Hz) and high-frequency average (4000, 8000 Hz). Self-reported hearing loss, tinnitus and hyperacusis were assessed via questionnaire. Cardiovascular risk factors were assessed via a patient-completed questionnaire and objective measurements including blood pressure, body mass index, waist circumference, lipid profile and glycated haemoglobin.

RESULTS

Of the participants, 54% were female, with the mean age of 58 years (range 45-69 years). Age, sex and family history of hearing loss were consistently strong determinants of hearing loss outcomes. After adjusting for these, obesity, current smoking, peripheral arterial disease and history of cardiovascular disease were significantly associated with pure-tone, low-frequency and high-frequency hearing loss. In addition, high blood pressure, triglyceride and glycated haemoglobin were significantly associated with low-frequency hearing loss. There was a graded association between hearing loss and Framingham Risk Score for cardiovascular risk (P<0.001).

CONCLUSIONS

Established cardiovascular disease and individual and combined cardiovascular disease risk factors were found to be associated with hearing loss. Future research should prospectively investigate whether targeting cardiovascular disease can prevent hearing loss.

A population-based study of the association between dysglycaemia and hearing loss in middle age

AIMS

To investigate the independent associations between hearing loss and dysglycaemia in a sample of middle-aged adults, including separate analysis of those aged < 60 years.

METHODS

The first 2023 participants in the cross-sectional Busselton Health Ageing Survey were assessed for hearing loss ≥ 26 dB (better ear) for four-frequency average (4FA) of pure-tone thresholds at 500, 1000, 2000 and 4000 Hz, and high-frequency average (HFA) of pure-tone thresholds at 4000 and 8000 Hz.

RESULTS

Valid data from 1864 participants in the Busselton Health Ageing Survey [92.1%; mean ± sd age 56.2 ± 5.5 years, 46.0% men, 120 (7.0%) with diabetes, 274 (14.7%) with prediabetes] were analysed, of whom 103 (5.5%) had four-frequency average hearing loss and 561 (30.1%) had high-frequency average hearing loss. In multivariable analyses, glycaemic status was not independently associated with four-frequency or high-frequency average hearing loss. In the 1286 participants aged < 60 years, there was no relationship between dysglycaemia and high-frequency average hearing loss, but the prevalence of four-frequency average hearing loss increased from 2.3% (95% CI 1.5-3.4) in participants with normoglycaemia to 5.7% (95% CI 3.0-10.6) in those with prediabetes and 10.2% (4.2-21.5) in those with diabetes (trend P = 0.003). In multivariable analysis with normoglycaemia as reference, the odds ratios for four-frequency average hearing loss were 2.84 (95% CI 1.29-6.27) for prediabetes and 5.93 (95% CI 1.67-21.05) for diabetes (P ≤ 0.01) in the < 60 year age group.

CONCLUSIONS

There was progressively increasing mid-range hearing loss with worsening glucose tolerance in younger individuals, suggesting dysglycaemia-associated early-onset presbycusis.

Discordance between fat mass index and body mass index is associated with reduced bone mineral density in women but not in men: the Busselton Healthy Ageing Study

The obesity-BMD relationship is complex. In 3045 middle-aged adults, we found that in women (but not men) with discordant fat mass index (FMI)/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone.

INTRODUCTION

The relationship between obesity and BMD is complex. FMI (fat mass (kg) / height (m)²) is a more accurate measure of fatness than BMI, and depending on body composition, some individuals have discordant BMI/FMI categories. We examined associations between FMI, BMI and BMD in participants in the Busselton Healthy Ageing Study.

METHODS

Body composition and BMD of the hip, spine and total body were measured using DXA in 3045 participants (1644 females) aged 45-67 years. Using standard BMI/FMI categories, the participants were classified as underweight/fat deficit, normal, overweight/excess fat, obese I and obese II-III.

RESULTS

BMI and FMI categories were concordant in 77.3 % of females and 71.2 % of males. There were 12.9 % females and 13.2 % males in a higher FMI than BMI category (high body fat for BMI), whereas 9.8 % females and 15.6 % males were in a lower category (low body fat for BMI). Females with high body fat for BMI had significantly lower covariate-adjusted BMD at the femoral neck, total hip and total body (differences of 3.8, 5.1 and 2.6 %, respectively, all P < 0.05) than females with low body fat for BMI and lower total body BMD than women with concordant FMI/BMI (by 1.4 %, P = 0.04). In males, BMD did not differ significantly between those who were concordant or discordant for FMI/BMI categories.

CONCLUSION

In women (but not men) with discordant FMI/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone.

Distribution Characteristics of Air-Bone Gaps: Evidence of Bias in Manual Audiometry

OBJECTIVES

Five databases were mined to examine distributions of air-bone gaps obtained by automated and manual audiometry. Differences in distribution characteristics were examined for evidence of influences unrelated to the audibility of test signals.

DESIGN

The databases provided air- and bone-conduction thresholds that permitted examination of air-bone gap distributions that were free of ceiling and floor effects. Cases with conductive hearing loss were eliminated based on air-bone gaps, tympanometry, and otoscopy, when available. The analysis is based on 2,378,921 threshold determinations from 721,831 subjects from five databases.

RESULTS

Automated audiometry produced air-bone gaps that were normally distributed suggesting that air- and bone-conduction thresholds are normally distributed. Manual audiometry produced air-bone gaps that were not normally distributed and show evidence of biasing effects of assumptions of expected results. In one database, the form of the distributions showed evidence of inclusion of conductive hearing losses.

CONCLUSIONS

Thresholds obtained by manual audiometry show tester bias effects from assumptions of the patient's hearing loss characteristics. Tester bias artificially reduces the variance of bone-conduction thresholds and the resulting air-bone gaps. Because the automated method is free of bias from assumptions of expected results, these distributions are hypothesized to reflect the true variability of air- and bone-conduction thresholds and the resulting air-bone gaps.

Low level autoantibodies can be frequently detected in the general Australian population

The aim of this study was to determine the prevalence and type of autoantibodies in a general Australian population cohort. Samples collected from 198 individuals included in a cross sectional Busselton Health Study were tested using autoantibody assays routinely performed at Clinical Immunology, PathWest Laboratory Medicine, Western Australia. At least one autoantibody was detected in 51.5% of individuals (males = 45.1%, females = 58.3%). The most frequently detected serum autoantibodies were anti-beta-2-glycoprotein I (12.1%) followed by anti-smooth muscle (11.6%) and anti-thyroid peroxidase (8.6%). Vasculitis associated anti-neutrophil cytoplasmic antibodies were present in 5.1%, while anti-nuclear antibodies were detected in 8.6% of individuals. Notably, 65% of positive results were detected at low levels with the exception of anti-myeloperoxidase and anti-beta 2 glycoprotein I IgG antibodies. Autoantibodies are commonly detected at low levels in a predominantly Australian or European population cohort. No large Australian study has yet provided these data for contemporary routine tests. This paper gives important information on the background frequency of autoantibodies in the general population. Due to the nature of this study we are unaware of whether these individuals have subsequently developed an autoimmune disease, however this was not clinically diagnosed at the time of sample collection.

Hearing loss and cognition in the Busselton Baby Boomer cohort: An epidemiological study

OBJECTIVES/HYPOTHESIS

To determine the relationship between peripheral hearing loss (HL) in baby boomers (better-ear measure) and cognitive function, taking into account the impact of depression or cognitive reserve on this relationship and exploring binaural hearing.

STUDY DESIGN

A prospective, epidemiology study.

METHODS

Data from 1,969 participants aged 45 to 66 years were collected in the Busselton Healthy Ageing Study. Participants were assessed using pure-tone air-conduction thresholds at octave frequencies (250; 500; 1,000; 2,000; 4,000; and 8,000 Hz). Hearing loss was grouped using 1) pure-tone averages across 4 frequencies (500 to 4000Hz) in the better ear (BE4FA) or 2) latent profile analysis (LPA) using all thresholds from both ears. Cognition was tested with the Cognitive Drug Research System, verbal fluency, and National Adult Reading Test (premorbid-IQ). Regression was used to determine the impact of HL relative to no HL on age and education-adjusted cognition, controlling for mood, sex, and premorbid-IQ.

RESULTS

According to BE4FA, 4.7% had mild (26-40 dB) HL; 0.8% had moderate (41-60 dB) HL; and 0.3% had severe (61-80 dB) HL. Based on the LPA, 20.5% had high-frequency HL; 7.8% had mid- to high-frequency HL; and 1.9% had significant HL across all frequencies. The HL group was not a predictor of cognitive performance in any domain using BE4FA and explained just 0.5% and 0.4% of variance in continuity-of-attention and speed-of-memory retrieval using LPA. Critically, those with the worst hearing did not differ cognitively from those with the best.

CONCLUSION

Hearing loss is not an important determinant of contemporaneous attention, memory, or executive function in middle-aged adults once age, education, depression, cognitive reserve, and sex are controlled.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:2367-2375, 2016.

Distribution characteristics of normal pure-tone thresholds

OBJECTIVE

This study examined the statistical properties of normal air-conduction thresholds obtained with automated and manual audiometry to test the hypothesis that thresholds are normally distributed and to examine the distributions for evidence of bias in manual testing.

DESIGN

Four databases were mined for normal thresholds. One contained audiograms obtained with an automated method. The other three were obtained with manual audiometry. Frequency distributions were examined for four test frequencies (250, 500, 1000, and 2000 Hz).

STUDY SAMPLE

The analysis is based on 317 569 threshold determinations of 80 547 subjects from four clinical databases.

RESULTS

Frequency distributions of thresholds obtained with automated audiometry are normal in form. Corrected for age, the mean thresholds are within 1.5 dB of reference equivalent threshold sound pressure levels. Frequency distributions of thresholds obtained by manual audiometry are shifted toward higher thresholds. Two of the three datasets obtained by manual audiometry are positively skewed.

CONCLUSIONS

The positive shift and skew of the manual audiometry data may result from tester bias. The striking scarcity of thresholds below 0 dB HL suggests that audiologists place less importance on identifying low thresholds than they do for higher-level thresholds. We refer to this as the Good enough bias and suggest that it may be responsible for differences in distributions of thresholds obtained by automated and manual audiometry.

Associations between body mass index, lean and fat body mass and bone mineral density in middle-aged Australians: The Busselton Healthy Ageing Study

Low BMI is a risk factor for osteoporosis, but it is not clear if relationships between BMI, lean mass (LM), fat mass (FM) and BMD are consistent across different levels of BMI. We studied 1929 Caucasian participants (1014 females) aged 45-66years in the Busselton Healthy Ageing Study in Western Australia. Body composition and BMD of total body, lumbar spine, total hip and femoral neck were measured using DXA. From generalized additive models, the positive relationships between BMI and BMD were weaker at high BMI, particularly at the spine and in males. In the entire cohort, adjusting for relevant covariates, LM and FM were significant predictors of all BMD measures in both genders. In men, analysis by tertiles of BMI showed that LM and FM (in kg) were positively associated with BMD (in mg/cm(2)) in tertile 1 except for LM and spine BMD (LM β: 5.18-6.80, FM β: 3.38-9.24, all P<0.05), but not in the middle or upper tertiles (LM β: -3.12-3.07, FM β: -4.75-1.82, P>0.05). In women, LM was positively associated with BMD in each tertile of BMI, except for spine BMD in the upper tertile, with regression coefficients lower in the upper tertile (β: 5.16-9.95, 5.76-9.56 and 2.80-5.78, respectively, all P<0.05). FM was positively associated with total body, spine and total hip BMD in women in BMI tertile 1 (β: 2.86-6.68, P<0.05); these associations were weaker or absent in the middle and upper tertiles. In conclusion, in middle-aged adults the positive relationships between lean or fat mass with BMD among those with higher BMI are absent in males and weaker in females.

A systematic review of medication exposure assessment in prospective cohort studies of community dwelling older australians

Introduction

It is not known to what extent medication use has been comprehensively assessed in prospective cohort studies of older Australians. Understanding the varying methods to assess medication use is necessary to establish comparability and to understand the opportunities for pharmacoepidemiological analysis. The objective of this review was to compare and contrast how medication-related data have been collected in prospective cohorts of community-dwelling older Australians.

Methods

MEDLINE and EMBASE (1990–2014) were systematically searched to identify prospective cohorts of ≥1000 older participants that commenced recruitment after 1990. The data collection tools used to assess medication use in each cohort were independently examined by two investigators using a structured approach.

Results

Thirteen eligible cohorts were included. Baseline medication use was assessed in participant self-completed surveys (n = 3), by an investigator inspecting medications brought to a clinic interview (n = 7), and by interviewing participants in their home (n = 3). Five cohorts sought participant consent to access administrative claims data. Six cohorts used multiple methods to assess medication use across one or more study waves. All cohorts assessed medication use at baseline and 12 cohorts in follow-up waves. Twelve cohorts recorded prescription medications by trade or generic name; 12 cohorts recorded medication strength; and 9 recorded the daily medication dose in at least one wave of the cohort. Seven cohorts asked participants about their “current” medication use without providing a definition of “current”; and nine cohorts asked participants to report medication use over recall periods ranging from 1-week to 3-months in at least one wave of the cohort. Sixty-five original publications, that reported the prevalence or outcomes of medication use, in the 13 cohorts were identified (median = 3, range 1–21).

Conclusion

There has been considerable variability in the assessment of medication use within and between cohorts. This may limit the comparability of medication data collected in these cohorts.

Back pain beliefs are related to the impact of low back pain in baby boomers in the Busselton Healthy Aging Study

BACKGROUND

Back pain beliefs (BPBs) are an important modifiable factor related to disability associated with low back pain (LBP). Back pain beliefs have not been characterized in baby boomers, a group at risk for decreased activity levels and reduced productivity.

OBJECTIVE

The aims of this study were: (1) to identify factors related to BPBs and (2) to evaluate the association between LBP disability and beliefs.

DESIGN

A cross-sectional survey of community-dwelling baby boomers (born 1946-1964) was conducted.

METHODS

Nine hundred fifty-eight baby boomers (mean age=56.2 years) participating in the Busselton Healthy Aging Study provided their history of LBP, BPBs, LBP behaviors related to care seeking (taking medication, seeking professional help) and activity modification (missing work, interference with normal activities, interference with recreational activities), LBP-related disability, and additional covariates with known associations with BPBs. Regression analyses were used to: (1) identify factors associated with more positive beliefs and (2) test the association between more positive BPBs and lower LBP disability, independent of other correlates of BPBs.

RESULTS

More positive BPBs were associated with younger age, better mental well-being, and higher income, whereas more negative BPBs were associated with receiving sickness or disability benefits and the experience of LBP in the previous month. In participants who reported experiencing LBP within the previous month, more positive BPBs were associated with lower disability scale scores and a decreased probability of interference with usual activities, independent of pain intensity, age, mental well-being, income, and employment status.

LIMITATIONS

Cross-sectional analysis limits assessment of causality.

CONCLUSIONS

Poorer BPBs were associated with greater disability. Characterization of the relationships between BPBs and LBP-associated behaviors and disability in baby boomers can assist in developing interventions to improve activity participation and productivity, potentially reducing the burden of LBP in this age group.