Influence of Imidacloprid and Horticultural Oil on Spider Abundance on Eastern Hemlock in the Southern Appalachians

Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), in the eastern United States. Two commonly used insecticides to manage adelgid are imidacloprid, a systemic neonicotinoid insecticide, and horticultural oil, a refined petroleum oil foliar spray. We have investigated the influence of imidacloprid and horticultural oil on spider abundance at different canopy strata in eastern hemlock. In total, 2,084 spiders representing 11 families were collected from the canopies of eastern hemlock. In beat-sheet and direct observation samples, the families Theridiidae, Araneidae, Salticidae, and Anyphaenidae were the most abundant. Significantly higher numbers of spiders were recorded on untreated control trees compared with trees treated with imidacloprid using soil drench and soil injection applications. Spider abundance in trees injected with imidacloprid and horticultural oil applications did not significantly differ from control trees. Spider abundance was significantly greater in the top and middle strata of the canopy than in the bottom stratum, where imidacloprid concentrations were the highest. Regression analysis showed that spider abundance was inversely associated with imidacloprid concentration. This research demonstrates that imidacloprid, when applied with selected methods, has the potential to result in reductions of spider densities at different strata. However, slight reductions in spider abundance may be an acceptable short-term ecological impact compared with the loss of an untreated hemlock and all the associated ecological benefits that it provides. Future studies should include investigations of long-term impact of imidacloprid on spiders associated with eastern hemlock.

The association between A Body Shape Index and mortality: Results from an Australian cohort

It is well recognised that obesity increases the risk of premature death. A Body Shape Index (ABSI) is a formula that uses waist circumference (WC), body mass index (BMI) and height to predict risk of premature mortality, where a high score (Quartile 4) indicates that a person's WC is more than expected given their height and weight. Our study examines the association between ABSI quartiles and all-cause-, cardiovascular- and cancer-related mortality, and primary cause of death. Self-reported demographic and biomedically measured health-related risk factor and weight data was from the baseline stage of the North West Adelaide Health Study (1999-2003, n = 4056), a longitudinal cohort of Australian adults. Death-related information was obtained from the National Death Index. Primary cause of death across ABSI quartiles was examined. The association between mortality and ABSI (quartile and continuous scores) was investigated using a Cox proportional hazards survival model and adjusting for socioeconomic, and self-reported and biomedical risk factors. The proportion of all three types of mortality steadily increased from ABSI Quartile 1 through to Quartile 4. After adjusting for demographic and health-related risk factors, the risk of all-cause mortality was higher for people in ABSI Quartile 4 (HR 2.64, 95% CI 01.56-4.47), and ABSI Quartile 3 (HR 1.95, 95% CI 1.15-3.33), with a moderate association for the continuous ABSI score (HR 1.32, 95% CI 1.18-1.48). ABSI is therefore positively associated with mortality in Australian adults. Different combined measures of obesity such as the ABSI are useful in examining mortality risk.

Associations of Undiagnosed Obstructive Sleep Apnea and Excessive Daytime Sleepiness With Depression: An Australian Population Study

STUDY OBJECTIVES

To determine whether undiagnosed obstructive sleep apnea (OSA) and/or excessive daytime sleepiness are associated with symptomatic depression in Australian men.

METHODS

Participants were randomly selected, urban community dwelling men aged 40 to 88 years without a prior diagnosis of OSA. Clinically significant depressive symptoms were assessed using the Beck Depression Inventory-1A or Centre for Epidemiological Studies Depression Scale (2007-2010). A random sample of men (n = 788) undertook full at-home unattended polysomnography (Embletta X100, Broomfield, Colorado, United States) and completed the Epworth Sleepiness Scale questionnaire (2010-2012).

RESULTS

Undiagnosed severe obstructive sleep apnea (apnea-hypopnea index ≥ 30 events/h) was associated with depressive symptoms (adjusted odds ratio = 1.98; 95% confidence interval [CI] 1.05-3.73; P = .036). However, a significant interaction was observed between obstructive sleep apnea and excessive daytime sleepiness (P = .03) such that individuals with OSA and excessive daytime sleepiness (Epworth Sleepiness Scale score of 10 or higher) exhibited the strongest associations with depression (mild-moderate apnea: adjusted odd ratio = 3.86; 95% CI 1.87-7.95; severe apnea: adjusted odd ratio = 4.82; 95% CI 1.42-16.35) when compared to individuals without apnea.

CONCLUSIONS

Depressive symptoms in men were associated with undiagnosed OSA in the community. It is important that clinicians and primary care practitioners consider screening for depression in men with severe OSA and for OSA in men with depression. Screening for depression should also be considered in men with excessive daytime sleepiness regardless of OSA severity.

Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Abundance and Hemlock Canopy Health Numerous Years After Imidacloprid Basal Drench Treatments: Implications for Management Programs

Hemlock woolly adelgid (Adelges tsugae [Annand]), an invasive insect in the eastern United States, has caused widespread decline of eastern hemlock, Tsuga canadensis (L.) Carriére. Imidacloprid basal drench treatments were assessed 4-7 yr after a single treatment to determine hemlock woolly adelgid population suppression and effects on hemlock canopy health. The effects of sampling site, years post-treatment, and hemlock diameter at breast height (DBH) size classes were evaluated relative to imidacloprid treatment on hemlock woolly adelgid populations and hemlock canopy health characteristics. The influence of hemlock woolly adelgid populations on canopy health characteristics was also assessed. Imidacloprid treatments resulted in low-level hemlock woolly adelgid populations 7 yr post-treatment. Hemlock woolly adelgid was present on more hemlocks 7 yr compared with 4-6 yr post-treatment. Smaller hemlocks, dosed with 0.7 g active ingredient (AI)/2.5 cm DBH, had higher populations of hemlock woolly adelgid than the largest size class, which were treated at twice that dosage. Concentrations of imidacloprid and its olefin metabolite below the LC₅₀ were sufficient for suppression of hemlock woolly adelgid populations, which suggests an additive effect of imidacloprid and olefin that compounds hemlock woolly adelgid mortality over many generations. Hemlock woolly adelgid populations observed in this study were too low to have an observable effect on hemlock canopy health, indicating that application intervals of up to 7 yr may be adequate to protect hemlocks.

The association of obstructive sleep apnea (OSA) and nocturnal hypoxemia with the development of abnormal HbA1c in a population cohort of men without diabetes

AIM

To examine the relationship between indices of undiagnosed OSA and the development of abnormal glycaemic control in community-dwelling men free of diabetes.

METHODS

The Men, Androgens, Inflammation, Lifestyle, Environment, and Stress (MAILES) Study is a population-based cohort study in Adelaide, South Australia. Clinic visits at baseline (2002-06) and follow-up (2007-10) identified abnormal glycaemic metabolism [HbA1c 6.0 to <6.5% (42 to <48mmol/mol)] in men without diabetes. At follow-up (2010-11), n=837 underwent assessment of OSA by full in-home unattended polysomnography (Embletta X100).

RESULTS

Development of abnormal glycaemic metabolism over 4-6 years (n=103 "incident" cases, 17.0%) showed adjusted associations [odds ratio (95% CI)] with the 1st [1.7 (0.8-3.8)], 2nd [2.4 (1.1-4.9)], and 3rd [2.3 (1.1-4.8)] quartiles of mean oxygen saturation (SaO2) compared to the highest quartile. Prevalent abnormal glycaemic metabolism (n=140, 20.8%) was independently associated with the third and fourth quartiles of percentage of sleep time with oxygen saturation <90% and lowest quartile of mean SaO2. Linear regression analysis showed a significant reduction in HbA1c [unstandardized B, 95% CI: -0.02 (-0.04, -0.002), p=0.034] per percentage point increase in mean SaO2. OSA as measured by the apnea-hypopnea index showed no adjusted relationship with abnormal glycaemic metabolism.

CONCLUSIONS

Development of abnormal glycaemic metabolism was associated with nocturnal hypoxemia. Improved management of OSA and glycaemic control may occur if patients presenting with one abnormality are assessed for the other.

Assessment of Imidacloprid and Its Metabolites in Foliage of Eastern Hemlock Multiple Years Following Treatment for Hemlock Woolly Adelgid, Adelges tsugae (Hemiptera: Adelgidae), in Forested Conditions

Widespread decline and mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, have been caused by hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae). The current study is a retrospective analysis conducted in collaboration with Great Smoky Mountains National Park (GRSM) to determine longevity of imidacloprid and its insecticidal metabolites (imidacloprid olefin, 5-hydroxy, and dihydroxy) in GRSM's HWA integrated pest management (IPM) program. Foliage samples were collected from three canopy strata of hemlocks that were given imidacloprid basal drench treatments 4-7 yr prior to sampling. Foliage was analyzed to assess concentrations in parts per billion (ppb) of imidacloprid and its metabolites. Imidacloprid and its olefin metabolite were present in most, 95 and 65%, respectively, branchlets 4-7 yr post-treatment, but the 5-hydroxy and dihydroxy metabolites were present in only 1.3 and 11.7%, respectively, of the branchlets. Imidacloprid and olefin concentrations significantly decreased between 4 and 7 yr post-treatment. Concentrations of both imidacloprid and olefin were below the LC50 for HWA 5-7 yr post-treatment. Knowledge of the longevity of imidacloprid treatments and its metabolite olefin can help maximize the use of imidacloprid in HWA IPM programs.

Parental Midlife Body Shape and Association with Multiple Adult Offspring Obesity Measures: North West Adelaide Health Study

There is compelling evidence that parental weight is a strong determinant of offspring weight status. The study used cross-sectional self-reported and measured data from a longitudinal cohort of Australian adults (n = 2128) from Stage 3 (2008-10) of the North West Adelaide Health Study (1999-2003, baseline n = 4056) to investigate the association between midlife parental body shape and four indicators of obesity and fat distribution. The analysis used measured body mass index (BMI), waist circumference (WC), waist hip ratio (WHR) and waist height ratio (WHtR) of adult offspring, together with pictograms for recall of parental body shape. Compared to both parents being a healthy weight, offspring were more likely to be overweight or obese if both parents were an unhealthy weight at age 40 (OR 2.14, 95% CI 1.67-2.76) and further, those participants whose mother was an unhealthy weight were more likely to be overweight or obese themselves (OR 1.50, 95% CI 1.14-1.98). There were similar but lower results for those with an overweight/obese father (OR 1.44, 95% CI 1.08-1.93). The effect of one or both parents being overweight or obese tended to be stronger for daughters than for sons across BMI, WC and WHtR. BMI showed the strongest association with parental body shape (OR 2.14), followed by WC (OR 1.78), WHtR (OR 1.71) and WHR (OR 1.45). WHtR (42-45%) and BMI (35-36%) provided the highest positive predictive values for overweight/obesity from parental body shape. Parental obesity increases the risk of obesity for adult offspring, both for overall body shape and central adiposity, particularly for daughters. Pictograms could potentially be used as a screening tool in primary care settings to promote healthy weight among young adults.

Nocturnal Hypoxemia and Severe Obstructive Sleep Apnea are Associated with Incident Type 2 Diabetes in a Population Cohort of Men

STUDY OBJECTIVES

Studies examining the longitudinal association of untreated obstructive sleep apnea (OSA) with diabetes in population samples are limited. This study therefore examined the relationship between previously undiagnosed OSA with incident type 2 diabetes in community-dwelling men aged ≥ 40 y.

METHODS

The Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) Study is a longitudinal population-based cohort in Adelaide, South Australia. Clinic assessments at baseline and follow-up identified diabetes (self-reported doctor diagnosed, fasting plasma glucose ≥ 7.0 mmol/L, glycated hemoglobin ≥ 6.5% or diabetes medication use) and included anthropometry. At cohort follow-up (2010-2012), n = 837 underwent full in-home unattended polysomnography (PSG, Embletta X100, Broomfield, CO).

RESULTS

Of 736 men free of diabetes at baseline, incident diabetes occurred in 66 (9.0%) over a mean follow-up time of 56 mo (standard deviation = 5, range: 48-74 mo). Incident diabetes was associated with current oxygen desaturation index (3%) ≥ 16 events/h (odds ratio [OR]: 1.85 [1.06-3.21]), and severe OSA [OR: 2.6 (1.1-6.1)], in adjusted models including age, percentage total body fat, and weight gain (> 5 cm waist circumference). An age-adjusted association of incident diabetes with percentage of total sleep time with oxygen saturation < 90% did not persist after adjustment for percentage of body fat. No modification of these relationships by excessive daytime sleepiness was observed.

CONCLUSIONS

Severe undiagnosed OSA and nocturnal hypoxemia were independently associated with the development of diabetes. A reduction in the burden of undiagnosed OSA and undiagnosed diabetes is likely to occur if patients presenting with one disorder are assessed for the other.

Mental health in immigrant men and women in Australia: the North West Adelaide Health Study

Background

There is conflicting evidence of the healthy migrant effect with respect to mental health. This study aims to determine if there are differences in mental health and service use between Australian-born and foreign-born individuals living in South Australia and to consider the differing role of socio-demographic characteristics for Australian-born and foreign-born men and women.

Methods

Data from the North West Adelaide Health study was used to compare foreign-born men and women from English and non-English speaking backgrounds with Australian born men and women on four measures of mental health and service use. A series of logistic regression analyses were conducted.

Results

There were no differences between Australian-born and foreign-born individuals from English-speaking backgrounds on any measures. Men from non-English speaking backgrounds had higher odds of depression. Employment and general health were important protectors of mental health for both Australian and foreign-born individuals, while being married was protective for foreign-born men only. Income was generally inversely related to mental health among Australians but the relationship was weaker and less consistent for those born abroad.

Conclusions

Men from non-English speaking backgrounds men may be at increased risk of mental health problems but do not have higher levels of treatment. Help-seeking may need to be encouraged among this group, particularly among unmarried, unemployed men from non-English speaking backgrounds.

Vitamin D levels in an Australian population

BACKGROUND

Levels of vitamin D in the population have come under increasing scrutiny, however there are only a few studies in Australia which measure levels in the general population. The aim of this study was to measure the levels of vitamin D within a large population cohort and examine the association with seasons and selected demographic and health risk factors.

METHODS

A longitudinal cohort study of 2413 participants in the northwest suburbs of Adelaide, South Australia conducted between 2008 and 2010 was used to examine serum levels of 25-hydroxy vitamin D (25(OH)D) in relation to demographic characteristics (age, sex, income, education and country of birth), seasons, the use of vitamin D supplements and selected health risk factors (physical activity, body mass index and smoking). Both unadjusted and adjusted mean levels of serum 25(OH)D were examined, as were the factors associated with the unadjusted and adjusted prevalence of serum 25(OH)D levels below 50 and 75 nmol/L.

RESULTS

Overall, the mean level of serum 25(OH)D was 69.2 nmol/L with 22.7% of the population having a serum 25(OH)D level below 50 nmol/L, the level which is generally recognised as vitamin D deficiency. There were significantly higher levels of 25(OH)D among males compared to females (t = 4.65, p < 0.001). Higher levels of 25(OH)D were also measured in summer and autumn compared with winter and spring. Generally, mean levels of 25(OH)D were lower in those classified as obese. Smokers and those undertaking no or less than 150 minutes/week of physical activity also had lower levels of serum vitamin D. Obesity (as classified by body mass index), season and undertaking an insufficient level of physical activity to obtain a health benefit were significantly associated with the prevalence of vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency is prevalent in South Australia, affecting almost one quarter of the population and levels are related to activity, obesity and season even when adjusted for confounding factors. Improved methods of addressing vitamin D levels in population are required.

Factors affecting establishment and recovery of Sasajiscymnus tsugae (Coleoptera: Coccinellidae), an introduced predator of hemlock woolly adelgid (Hemiptera: Adelgidae) on eastern hemlock (Pinales: Pinaceae)

To reduce populations of hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), >500,000 Sasajiscymnus tsugae (Sasaji and McClure) (Coleoptera: Coccinellidae) have been released in the Great Smoky Mountains National Park since 2002. To determine factors affecting establishment and recovery of these predatory beetles, 65 single release sites were sampled using beat sheets from 2008 to 2012. Several abiotic and biotic factors were evaluated for their association with establishment and recovery of S. tsugae. Information on predatory beetle releases (location, year of release, number released, and season of release), topographic features (elevation, slope, Beers transformed aspect, and topographic relative moisture index), and temperature data (minimum and maximum temperatures 1 d after release and average minimum and maximum temperatures 7 d after release) were obtained from Great Smoky Mountains National Park personnel. These factors were evaluated using stepwise logistic regression and Pearson correlation. S. tsugae was recovered from 13 sites 2 to 10 yr after release, and the greatest number was recovered from 2002 release sites. Regression indicated establishment and recovery was negatively associated with year of release and positively associated with the average maximum temperature 7 d after release and elevation (generally, recovery increased as temperatures increased). Several significant correlations were found between presence and number of S. tsugae and year of release, season of release, and temperature variables. These results indicate that releases of S. tsugae should be made in warmer (≍10-25°C) temperatures and monitored for at least 5 yr after releases to enhance establishment and recovery efforts.

Cohort profile: The men androgen inflammation lifestyle environment and stress (MAILES) study

The Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) Study was established in 2009 to investigate the associations of sex steroids, inflammation, environmental and psychosocial factors with cardio-metabolic disease risk in men. The study population consists of 2569 men from the harmonisation of two studies: all participants of the Florey Adelaide Male Ageing Study (FAMAS) and eligible male participants of the North West Adelaide Health Study (NWAHS). The cohort has so far participated in three stages of the MAILES Study: MAILES1 (FAMAS Wave 1, from 2002-2005, and NWAHS Wave 2, from 2004-2006); MAILES2 (FAMAS Wave 2, from 2007-2010, and NWAHS Wave 3, from 2008-2010); and MAILES3 (a computer-assisted telephone interview (CATI) survey of all participants in the study, conducted in 2010). Data have been collected on a comprehensive range of physical, psychosocial and demographic issues relating to a number of chronic conditions (including cardiovascular disease, diabetes, arthritis and mental health) and health-related risk factors (including obesity, blood pressure, smoking, diet, alcohol intake and inflammatory markers), as well as on current and past health status and medication.

Abdominal adiposity and obstructive airway disease: testing insulin resistance and sleep disordered breathing mechanisms

BACKGROUND

This study examined associations of abdominal adiposity with lung function, asthma symptoms and current doctor-diagnosed asthma and mediation by insulin resistance (IR) and sleep disordered breathing (SDB).

METHODS

A random sample of 2500 households was drawn from the community of Whyalla, South Australia (The Whyalla Intergenerational Study of Health, WISH February 2008 - July 2009). Seven-hundred twenty-two randomly selected adults (≥18 years) completed clinical protocols (32.2% response rate). Lung function was measured by spirometry. Post-bronchodilator FEV1/FVC was used to measure airway obstruction and reversibility of FEV1 was calculated. Current asthma was defined by self-reported doctor-diagnosis and evidence of currently active asthma. Symptom scores for asthma (CASS) and SDB were calculated. Intra-abdominal fat (IAF) was estimated using dual-energy x-ray absorptiometry (DXA). IR was calculated from fasting glucose and insulin concentrations.

RESULTS

The prevalence of current doctor-diagnosed asthma was 19.9% (95% CI 16.7 - 23.5%). The ratio of observed to expected cases given the age and sex distribution of the population was 2.4 (95%CI 2.1, 2.9). IAF was not associated with current doctor-diagnosed asthma, FEV1/FVC or FEV1 reversibility in men or women but was positively associated with CASS independent of IR and SDB in women. A 1% increase in IAF was associated with decreases of 12 mL and 20 mL in FEV1 and FVC respectively in men, and 4 mL and 7 mL respectively in women. SDB mediated 12% and 26% of these associations respectively in men but had minimal effects in women.

CONCLUSIONS

In this population with an excess of doctor-diagnosed asthma, IAF was not a major factor in airway obstruction or doctor-diagnosed asthma, although women with higher IAF perceived more severe asthma symptoms which did not correlate with lower FEV1. Higher IAF was significantly associated with lower FEV1 and FVC and in men SDB mechanisms may contribute up to one quarter of this association.

Proximal correlates of metabolic phenotypes during 'at-risk' and 'case' stages of the metabolic disease continuum

OBJECTIVE

To examine the social and behavioural correlates of metabolic phenotypes during 'at-risk' and 'case' stages of the metabolic disease continuum.

DESIGN

Cross-sectional study of a random population sample.

PARTICIPANTS

A total of 718 community-dwelling adults (57% female), aged 18-92 years from a regional South Australian city.

MEASUREMENTS

Total body fat and lean mass and abdominal fat mass were assessed by dual energy x-ray absorptiometry. Fasting venous blood was collected in the morning for assessment of glycated haemoglobin, plasma glucose, serum triglycerides, cholesterol lipoproteins and insulin. Seated blood pressure (BP) was measured. Physical activity and smoking, alcohol and diet (96-item food frequency), sleep duration and frequency of sleep disordered breathing (SDB) symptoms, and family history of cardiometabolic disease, education, lifetime occupation and household income were assessed by questionnaire. Current medications were determined by clinical inventory.

RESULTS

36.5% were pharmacologically managed for a metabolic risk factor or had known diabetes ('cases'), otherwise were classified as the 'at-risk' population. In both 'at-risk' and 'cases', four major metabolic phenotypes were identified using principal components analysis that explained over 77% of the metabolic variance between people: fat mass/insulinemia (FMI); BP; lipidaemia/lean mass (LLM) and glycaemia (GLY). The BP phenotype was uncorrelated with other phenotypes in 'cases', whereas all phenotypes were inter-correlated in the 'at-risk'. Over and above other socioeconomic and behavioural factors, medications were the dominant correlates of all phenotypes in 'cases' and SDB symptom frequency was most strongly associated with FMI, LLM and GLY phenotypes in the 'at-risk'.

CONCLUSION

Previous research has shown FMI, LLM and GLY phenotypes to be most strongly predictive of diabetes development. Reducing SDB symptom frequency and optimising the duration of sleep may be important concomitant interventions to standard diabetes risk reduction interventions. Prospective studies are required to examine this hypothesis.

Host utilization of field-caged native and introduced thistle species by Rhinocyllus conicus

Rhinocyllus conicus Fröelich was introduced from Europe into North America as a biological control agent of the exotic weed Carduus nutans L. Concern exists over the feeding of this weevil on at least 25 species of native Cirsium thistles. Beginning in 2008, cage studies isolating adults of R. conicus on buds and flower heads of all eight thistle species (native and introduced) recorded from Tennessee were conducted to test if R. conicus could use these species for reproduction and what impacts larval feeding of R. conicus may have on seed production. Larvae of R. conicus completed development in heads of the native species C. carolinianum (Walter) Fernald and Schubert. and C. horridulum Michaux, and significant reductions in seed numbers of both species occurred during 2008. Rhinocyllus conicus oviposited on both C. carolinianum and C. horridulum at significantly greater levels than the introduced species C. arvense (L.) Scopoli and C. vulgare (Savi) Tenore. Infested heads of C. carolinianum contained numbers of R. conicus per centimeter of plant head width similar to Ca. nutans in 2008, and both native species contained numbers of R. conicus per centimeter of plant head width similar to C. arvense and C. vulgare in 2009. Body length was similar between R. conicus reared on native thistles and its target host Ca. nutans. This report is the first documentation of R. conicus feeding and reproducing on C. carolinianum and C. horridulum. Although R. conicus has been observed only on introduced thistles in naturally occurring populations in this region, the utilization of C. carolinianum and C. horridulum as host species in controlled conditions warrants continued monitoring of field populations and further investigation into factors that may influence nontarget feeding in the future.

Spatial prediction of habitat overlap of introduced and native thistles to identify potential areas of nontarget activity of biological control agents

Nontarget feeding of Rhinocyllus conicus Fröelich and Trichosirocalus horridus (Panzer) on native North American thistles in the genus Cirsium has been documented. Some species of these native thistles have shown greater infestation levels of R. conicus in populations that are in close proximity to the target plant species, Carduus nutans L. In 2005 a study was initiated to identify areas of potential nontarget feeding by R. conicus and T. horridus on thistle species by predicting habitats of two known introduced hosts [C. nutans and Cirsium vulgare (Savi) Tenore] and two native species [Cirsium carolinianum (Walter) Fernald and Schubert and C. discolor (Muhlenberg ex Willdenow) Sprengel] using Mahalanobis distance (D(2)). Cumulative frequency graphs showed that the D(2) models for all four plant species effectively identified site conditions that contribute to the presence of the respective species. Poisson regression showed an association between D(2) values and plant counts at field-test sites for C. nutans and C. carolinianum. However, negative binomial regression detected no association between D(2) values and plant counts for C. discolor or C. vulgare. Chi-square analysis indicated associations between both weevil species and sites where C. vulgare and Carduus nutans were found, but not between the weevil and native thistle species. Habitats of C. nutans and Cirsium carolinianum overlapped in ≈12% of the study area. Data-based habitat models may provide a powerful tool for land managers and scientists to monitor native plant populations for nontarget feeding by introduced biological control agents.

Gender differences in asthma prevalence: variations with socioeconomic disadvantage

BACKGROUND AND OBJECTIVE

Socioeconomic inequalities in health have been shown to vary for different diseases and by gender. This study aimed to examine gender differences in associations between asthma and socioeconomic disadvantage.

METHODS

Socioeconomic variables were assessed among men and women in the North West Adelaide Health Study, a representative population cohort (n = 4060) aged 18 years and over in metropolitan South Australia. Asthma was determined from spirometry and self-reported doctor diagnosis.

RESULTS

The prevalence of asthma was 12.0% (95% CI: 11.1-13.1), and was significantly higher among women (13.5%) than men (10.5%). For participants aged 18-64 years a higher prevalence of asthma was associated with an education level of secondary school or lower, or not being in the paid labour force among men, and with a gross annual household income of $20,000 or less among women. Among socioeconomically advantaged groups, the prevalence of asthma was significantly higher among women than men.

CONCLUSIONS

Socioeconomic disadvantage was associated with higher asthma prevalence, although this varied by gender depending on the indicator of socioeconomic position used. Men with low education or those not employed in the paid labour force had higher asthma prevalence than more socioeconomically advantaged men. Women with low income had higher asthma prevalence than those with higher income. Among all socioeconomically advantaged groups, and also the low-income group, women experienced a higher prevalence of asthma than men.

Gender-specific epidemiology of diabetes: a representative cross-sectional study

Background

Diabetes and its associated complications are part of a chronic disease global epidemic that presents a public health challenge. Epidemiologists examining health differences between men and women are being challenged to recognise the biological and social constructions behind the terms 'sex' and/or 'gender', together with social epidemiology principles and the life course approach. This paper examines the epidemiology of a population with diabetes from the north-west metropolitan region of South Australia.

Methods

Data were used from a sub-population with diabetes (n = 263), from 4060 adults aged 18 years and over living in the north-west suburbs of Adelaide, South Australia. Eligible respondents were asked to participate in a telephone interview, a self-report questionnaire and a biomedical examination. Diabetes (undiagnosed and diagnosed) was determined using self-reported information and a fasting blood test administered to participants. Data were analysed using SPSS (Version 10.0) and EpiInfo (Version 6.0).

Results

Factors associated with diabetes for both men and women were being aged 40 years and over, and having a low gross annual household income, obesity and a family history of diabetes. In addition, being an ex-smoker and having low cholesterol levels were associated with diabetes among men. Among women, having a high waist-hip ratio, high blood pressure and reporting a previous cardiovascular event or mental health problem were associated with diabetes.

Conclusion

The results found that men and women with diabetes face different challenges in the management of their condition. Public health implications include a need for quality surveillance data, including epidemiological life course, social, behavioural, genetic and environmental factors. This will enrich the evidence base for health promotion professionals and allow policy makers to draw inferences and conclusions for interventions and planning purposes.

The increasing prevalence of diabetes in South Australia: The relationship with population ageing and obesity

OBJECTIVES

To use representative population surveillance data to monitor and project changes in the prevalence of diabetes for different age and body mass index (BMI) groups.

STUDY DESIGN

Representative, annual, face-to-face South Australian Health Omnibus Surveys, 1991-2003 (n=3000 per year).

METHODS

Trends in self-reported diabetes prevalence by age group and BMI were examined. Separate projections were made on the basis of predicted changes in population demography and diabetes prevalence.

RESULTS

The age-sex standardized absolute prevalence of self-reported diabetes among people aged 15 years and over increased from 3.5% in 1991 to 6.7% in 2003. If this current trend continues, the prevalence is expected to increase to 10.5% by 2016. The prevalence of diabetes was significantly higher among those classified as obese (6.5% in 1991 to 12.2% in 2003) than those with normal BMI. The greatest relative percentage increase in prevalence between 1991 and 2003 (169%) was seen among people aged 15-39 years. Taking both age group and BMI classification into account, the greatest relative percentage increases over this time were seen among those with normal BMI aged 60 years or older (148%), and those who were obese and aged less than 60 years (139%).

CONCLUSIONS

The prevalence of diabetes and obesity increased significantly between 1991 and 2003. Population ageing and an increase in diabetes prevalence in the future will further increase the burden of diabetes. Future increases in diabetes prevalence are not inevitable, however, if investments are made in public health prevention programmes, particularly those addressing obesity.

How valid are self-reported height and weight? A comparison between CATI self-report and clinic measurements using a large cohort study

OBJECTIVE

To examine the relationship between self-reported and clinical measurements for height and weight in adults aged 18 years and over and to determine the bias associated with using household telephone surveys.

METHOD

A representative population sample of adults aged 18 years and over living in the north-west region of Adelaide (n = 1,537) were recruited to the biomedical cohort study in 2002/03. A computer-assisted telephone interviewing (CATI) system was used to collect self-reported height and weight. Clinical measures were obtained when the cohort study participants attended a clinic for biomedical tests.

RESULT

Adults over-estimated their height (by 1.4 cm) and under-estimated their weight (by 1.7 kg). Using the self-report figures the prevalence of overweight/ obese was 56.0% but this prevalence estimate increased to 65.3% when clinical measurements were used. The discrepancy in self-reported height and weight is partly explained by 1) a rounding effect (rounding height and weight to the nearest 0 or 5) and 2) older persons (65+ years) considerably over-estimating their height.

CONCLUSION

Self-report is important in monitoring overweight and obesity; however, it must be recognised that prevalence estimates obtained are likely to understate the problem.

IMPLICATIONS

The public health focus on obesity is warranted, but self-report estimates, commonly used to highlight the obesity epidemic, are likely to be underestimations. Self-report would be a more reliable measure if people did not round their measurements and if older persons more accurately knew their height.

The North West Adelaide Health Study: detailed methods and baseline segmentation of a cohort for selected chronic diseases

The North West Adelaide Health Study is a population-based biomedical cohort study investigating the prevalence of a number of chronic conditions and health-related risk factors along a continuum. This methodology may assist with evidence-based decisions for health policy makers and planners, and inform health professionals who are involved in chronic disease prevention and management, by providing a better description of people at risk of developing or already diagnosed with selected chronic conditions for more accurate targeting groups for health gain and improved health outcomes. Longitudinal data will provide information on progression of chronic conditions and allow description of those who move forward and back along the continuum over time.

Detailed methods are provided regarding the random recruitment and examination of a representative sample of participants (n = 4060), including the rationale for various processes and valuable lessons learnt. Self-reported and biomedical data were obtained on risk factors (smoking, alcohol consumption, physical activity, family history, body mass index, blood pressure, cholesterol) and chronic conditions (asthma, chronic obstructive pulmonary disease, diabetes) to classify participants according to their status along a continuum. Segmenting this population sample along a continuum showed that 71.5% had at least one risk factor for developing asthma, chronic obstructive pulmonary disease or diabetes. Almost one-fifth (18.8%) had been previously diagnosed with at least one of these chronic conditions, and an additional 3.9% had at least one of these conditions but had not been diagnosed.

This paper provides a novel opportunity to examine how a cohort study was born. It presents detailed methodology behind the selection, recruitment and examination of a cohort and how participants with selected chronic conditions can be segmented along a continuum that may assist with health promotion and health services planning.

Do people with risky behaviours participate in biomedical cohort studies?

Background

Analysis was undertaken on data from randomly selected participants of a bio-medical cohort study to assess representativeness. The research hypotheses was that there was no difference in participation and non-participations in terms of health-related indicators (smoking, alcohol use, body mass index, physical activity, blood pressure and cholesterol readings and overall health status) and selected socio-demographics (age, sex, area of residence, education level, marital status and work status).

Methods

Randomly selected adults were recruited into a bio-medical representative cohort study based in the north western suburbs of the capital of South Australia – Adealide. Comparison data was obtained from cross-sectional surveys of randomly selected adults in the same age range and in the same region. The cohort participants were 4060 randomly selected adults (18+ years).

Results

There were no major differences between study participants and the comparison population in terms of current smoking status, body mass index, physical activity, overall health status and proportions with current high blood pressure and cholesterol readings. Significantly more people who reported a medium to very high alcohol risk participated in the study. There were some demographic differences with study participants more likely to be in the middle level of household income and education level.

Conclusion

People with risky behaviours participated in this health study in the same proportions as people without these risk factors.

The health-related quality of life of male and female heavy smokers

OBJECTIVES

Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.

METHODS

South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36.

RESULTS

Of the smoking population 18% were classified as heavy smokers. There was a clear dose response relationship between amount smoked and deteriorating quality of life for all female smokers. Female heavy smokers were found to be significantly more impaired on all health-related quality of life dimensions, when compared to male heavy smokers.

CONCLUSIONS

The association of smoking with impaired quality of life is more marked in females than in males. There is a need to identify female smokers as a distinct target group in smoking cessation initiatives and programs.

The impact of incontinence on health-related quality of life in a South Australian population sample

OBJECTIVE

To assess prevalence of incontinence in a South Australian representative population sample and compare the health-related quality-of-life impact of incontinence with other chronic conditions.

METHOD

The 1998 South Australian Health Omnibus Survey interviewed 3,010 male and female respondents aged 15 to 97 years (response rate 70.2%). This representative population survey included questions to determine the prevalence of urinary (stress and urge), and anal (faecal and flatus) incontinence, and other chronic conditions. Respondents also completed the MOS SF-36 questionnaire.

RESULTS

Self-reported prevalence of all types of incontinence was 26.0%. The prevalence of anal and urinary incontinence were 10.5% and 20.3% respectively, with 4.8% of respondents experiencing both. Univariate analysis found the prevalence of incontinence was statistically significantly higher among females, and those who were older, widowed, had no post-school education, and lower incomes. After adjusting for differences in age and sex, it was found that people with incontinence were significantly impaired across all dimensions of the SF-36, scoring in the lowest 42% of the population, compared with those people without incontinence. People with incontinence exhibited different SF-36 profiles to those with other chronic conditions.

CONCLUSIONS

Incontinence is common in South Australia, affecting more than one-quarter of the population, particularly older women (56.2% for 60 years and over). The impact of incontinence on health-related quality of life is characteristically different to that demonstrated by other chronic conditions.

IMPLICATIONS

In an ageing population, identification of the impact of incontinence is necessary to direct policy development and resource allocation to this area.

The effects of vasectomy on the autonomic innervation of the human vas deferens

Neurohistochemical and fine structural techniques have been employed to examine the intramural autonomic innervation of the human vas deferens following surgical division of the duct one to 15 years previously. Samples from sites on the distal (testicular) and proximal (urethral) aspects of the original vasectomy have been compared with control specimens obtained at vasectomy as to the arrangement and distribution of autonomic nerves. In contrast with tissue from the proximal part and from controls, the distal samples revealed a marked reduction in the noradrenergic innervation of the muscle coat. In addition acetylcholinesterase-containing nerves associated with the basal aspect of the epithelium were usually absent from the distal portion of the vas deferens. These findings have been considered in relation to the contractile and secretory activities of the organ following vasovasostomy and may be of importance to the maturation and fertility of spermatozoa.

THE EXAMINATION AND CLASSIFICATION OF AVIATORS WITH SPECIAL REFERENCE TO THE EFFECTS OF HIGH ALTITUDES

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