Respiratory symptoms and lung function in aborigines from tropical Western Australia

Association between perinatal and early life exposures and lung function in Australian Indigenous young adults: The Aboriginal Birth Cohort study

BACKGROUND AND OBJECTIVE

Despite the high burden of respiratory disease amongst Indigenous populations, prevalence data on spirometric deficits and its determinants are limited. We estimated the prevalence of abnormal spirometry in young Indigenous adults and determined its relationship with perinatal and early life factors.

METHODS

We used prospectively collected data from the Australian Aboriginal Birth Cohort, a birth cohort of 686 Indigenous Australian singletons. We calculated the proportion with abnormal spirometry (z-score <-1.64) and FEV1 below the population mean (FEV1 % predicted 0 to -2SD) measured in young adulthood. We evaluated the association between perinatal and early life exposures with spirometry indices using linear regression.

RESULTS

Fifty-nine people (39.9%, 95%CI 31.9, 48.2) had abnormal spirometry; 72 (49.3%, 95%CI 40.9, 57.7) had a FEV1 below the population mean. Pre-school hospitalisations for respiratory infections, younger maternal age, being overweight in early childhood and being born remotely were associated with reduced FEV1 and FVC (absolute, %predicted and z-score). The association between maternal age and FEV1 and FVC were stronger in women, as was hospitalization for respiratory infections before age 5. Being born remotely had a stronger association with reduced FEV1 and FVC in men. Participants born in a remote community were over 6 times more likely to have a FEV1 below the population mean (odds ratio [OR] 6.30, 95%CI 1.93, 20.59).

CONCLUSION

Young Indigenous adults have a high prevalence of impaired lung function associated with several perinatal and early life factors, some of which are modifiable with feasible interventions.

Implications of using the GLI-2012, GOLD and Australian COPD-X recommendations in assessing the severity of airflow limitation on spirometry among an Indigenous population with COPD: an Indigenous Australians perspective study

Background

Assessment of airflow limitation (AFL) is crucial in the clinical evaluation of patients with chronic obstructive pulmonary disease (COPD). However, in the absence of normative reference values among adult Australian Indigenous population, the implications of utilising the Global Lung Function Initiative (GLI-2012), Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the Australian concise COPD-X recommended severity classifications is not known. Moreover, spirometry values (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁)) are observed to be 20%–30% lower in an apparently healthy Indigenous population in comparison to Caucasian counterparts.

Methods

Adult Indigenous patients diagnosed to have COPD on spirometry (postbronchodilator (BD) FEV₁/FVC <0.7 ((GOLD, (COPD-X)) and ≤lower limit of normal (others/mixed reference equations) for GLI-2012) were assessed for AFL severity classifications on Post-BD FEV₁ values (mild, moderate, severe, very severe) as per the recommended classifications.

Results

From a total of 742 unique patient records of Indigenous Australians, 253 were identified to have COPD via GOLD/COPD-X criteria (n=238) or GLI-2012 criteria (n=238) with significant agreeance between criteria (96%, κ=0.901). Of these, the majority were classified as having moderate or severe/very-severe AFL with significant variability across classification criteria (COPD-X (40%–43%), GOLD (33%–65%), GLI-2012 (18%–75%)). The FVC and FEV₁ values also varied significantly between classification criterion (COPD-X/GOLD/GLI-2012) within the same AFL category, with COPD-X ‘moderate’ AFL almost matching ‘severe’ AFL categorisation by GOLD or GLI-2012.

Conclusions

Health professionals caring for Indigenous patients with COPD should be aware of the clinical implications and consequences of utilising various recommended AFL classifications in the absence of validated spirometry reference norms among adult Indigenous patients.

Critical analysis of spirometric patterns in correlation to chest computed tomography among adult Indigenous Australians with chronic airway diseases

Background: There is sparse literature evidence in the spirometric patterns of adult Indigenous Australians with and without chest computed tomography (CT)-proven chronic airway diseases (CADs).Methods: Participants spirometry testing graded as acceptable for quality and had a chest CT scan showing radiographic evidence of CADs were included for analysis.Results: Of the 1350 spirometric tests performed between 2012 and 2020, a total of 212 patients with a mean age of 53 years and 54% females were eligible to be included. One-third (30%) had normal chest CT (without CADs), 35% had predominant COPD, 19% bronchiectasis and 16% combined COPD and bronchiectasis. Percentage predicted values for forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) both pre- and post- bronchodilator were significantly reduced for all participants - FVC: CT-normal 64%, 65%; COPD 58%, 62%; bronchiectasis 54%, 54%; combined COPD and bronchiectasis 50%, 53%. FEV₁: CT-normal 62%, 65%; COPD 46%, 49%; bronchiectasis 48%,51%; combined COPD and bronchiectasis 36%,40%. FEV₁/FVC was only reduced for CT abnormality patients - CT-normal 96%,98%; COPD 77%,77%; bronchiectasis 87%,89%; combined COPD and bronchiectasis 71%,72%.Conclusions: Restrictive spirometric pattern is common and an obstructive pattern with COPD, in isolation or when COPD coexists with bronchiectasis.

Comparison of diffusing capacity of carbon monoxide (DLCO) and total lung capacity (TLC) between Indigenous Australians and Australian Caucasian adults

Background and objective

Currently there is paucity of evidence in the literature in relation to normative values for diffusing capacity of carbon monoxide (DLCO) and total lung capacity (TLC) among Indigenous Australians. Hence, in this study we assessed the DLCO and TLC parameters among Indigenous Australians in comparison to Australian Caucasian counterparts.

Methods

DLCO and TLC values were assessed and compared between Indigenous Australians and Australian Caucasians matched for age, sex and body mass index, with normal chest radiology.

Results

Of the 1350 and 5634 pulmonary function tests assessed in Indigenous Australian and Australian Caucasian adults respectively, a total of 129 Indigenous Australians and 197 Australian Caucasians met the inclusion criteria. Absolute DLCO and TLC values for Indigenous Australians were a mean 4.3 ml/min/mmHg (95% CI 2.86, 5.74) and 1.03 L (95% CI 0.78, 1.27) lower than Australian Caucasians (p<0.01). Percentage predicted values were 15.38 (95% CI 11.59, 19.17) and 16.63 (95% CI 13.59, 19.68) points lower for DLCO and TLC, respectively. Lower limit of normal (LLN) values did not significantly differ between groups, however a significantly greater proportion of Indigenous Australians recorded values below the LLN in comparison to Australian Caucasians for DLCO (64 vs. 25%, p<0.01) and TLC (66 vs. 21%, p<0.01). Significant differences for the interaction of sex on DLCO and TLC were noted in Australian Caucasians, with reduced or absent sex differentiation among Indigenous Australians.

Conclusions

There are significant differences in DLCO and TLC parameters between Indigenous Australian compared to Australian Caucasians. Appropriate DLCO and TLC norms need to be established for Indigenous Australians.

Lung function parameters among Australian Aboriginal 'apparently healthy' adults: an Australian Caucasian and Global Lung Function Initiative (GLI-2012) various ethnic norms comparative study

Background: There is sparse literature evidence evaluating the applicability of the GLI-2012 spirometric norms for Australian Aboriginal adults.Methods: Lung function parameters (LFPs) were compared between Australian Aboriginal and Australian Caucasians, and the fit of Australian Aboriginals LFPs with various ethnic GLI equations was tested.Results: Of 1350 and 5634 Pulmonary function tests (PFTs) in Australian Aboriginal and Australian Caucasian adults, 153 and 208 PFTs matched for anthropometrics and normal chest radiology, respectively. Absolute FVC and FEV₁ values were 20% lower in Australian Aboriginals compared to Australian Caucasians. Differences remained significant after accounting for age, sex, height, weight and smoking status in multivariate regression (FVC -0.84 L (-0.98, -0.71), FEV₁ - 0.72 L (-0.84, -0.59), but with nearly preserved FEV₁/FVC. GLI-2012 transformation resulted in z-scores significantly below zero for each of FVC, FEV₁ and FEV₁/FVC with z-scores ranging from -4.52 (-4.87, -4.16) for North East Asian FVC transformation for males, to -0.34 (-0.73, 0.05) for Black FVC transformation for females.Conclusions: Australian Aboriginal adults had 20% lower values for FVC and FEV₁ but nearly preserved absolute FEV₁/FVC in comparison to Australian Caucasians. The GLI-2012 spirometric norms do not appear to fit for Australian Aboriginal adults regardless of which ethnicity options selected, including 'others/mixed'.

Prevalence and nature of lung function abnormalities among Indigenous Australians referred to specialist respiratory outreach clinics in the Northern Territory

BACKGROUND

Poor lung function is a predictor of future all-cause mortality. In Australia, respiratory diseases are particularly prevalent among the indigenous population, especially in remote communities. However, there are little published pulmonary function tests' (PFT) data of remote-based adult indigenous patients.

AIM

To evaluate the severity of airflow obstruction and other PFT abnormalities of adults referred to specialist respiratory clinics in remote indigenous communities.

METHODS

Retrospective analysis of PFT (pre- and post-bronchodilator spirometry, total lung capacity (TLC) and diffusing capacity to carbon monoxide (DLCO)) of indigenous patients collected during specialist respiratory clinics in remote Northern Territory (NT) indigenous communities (Australia) between 2013 and 2015. The National Health and Nutrition Examination Survey (NHANES) III without ethnic correction was used as the reference.

RESULTS

Of the 357 patients, 150 had acceptable spirometry, and 71 had acceptable DLCO and TLC studies. Despite the relatively young age (mean = 49 years, SD = 12.9), their lung function was generally low; mean % predicted values were FEV₁ = 55% (SD = 20.5%), FVC = 61% (SD = 15.6%), DLCO = 64.0% (SD = 19.7%) and TLC = 70.1% (SD = 18.2%). Mean FEV₁ /FVC ratio was preserved (0.71, SD = 0.16). Post-bronchodilator airflow obstruction (FEV₁ /FVC < 0.7) was observed in 37% of patients, where a large proportion (67%) demonstrated at least a severe airflow obstruction, with a mean FEV₁ of 41% predicted.

CONCLUSION

In this first study of PFT findings of indigenous adults from a remote-based clinical service, we found a high rate of at least moderate airflow limitation and low FVC along with preserved FEV1/FVC ratio. Increased awareness and screening for reduced lung function needs to be considered in this population.

Global Lung Function Initiative-2012 'other/mixed' spirometry reference equation provides the best overall fit for Australian Aboriginal and/or Torres Strait Islander children and young adults

BACKGROUND AND OBJECTIVE

Ethnic-specific reference equations are recommended when performing spirometry. In the absence of appropriate reference equations for Australian Aboriginal and/or Torres Strait Islanders (Indigenous), we determined whether any of the existing Global Lung Function Initiative (GLI)-2012 equations were suitable for use in Indigenous children/young adults.

METHODS

We performed spirometry on 1278 participants (3-25 years) who were identified as Aboriginal, Torres Strait Islander or 'both'. Questionnaires and medical records were used to identify 'healthy' participants. GLI2012_DataConversion software was used to apply the 'Caucasian', 'African-American' and 'other/mixed' equations.

RESULTS

We included 930 healthy participants. Mean z-scores for forced expiratory volume in 1 s (FEV₁ ) and forced vital capacity (FVC) were lower than the Caucasian predicted values (range: -0.53 to -0.60) and higher than African-American (range: 0.70 to 0.78) but similar to other/mixed (range: 0.00 to 0.08). The distribution of healthy participants around the upper and lower limits of normal (~5%) fit well for the other/mixed equation compared to the Caucasian and African-American equations.

CONCLUSION

Of the available GLI-2012 reference equations, the other/mixed reference equation provides the best overall fit for Indigenous Australian children and young adults (3-25 years). Healthy data from additional communities and adults around Australia will be required to confirm generalizability of findings.

Lung Function of Children at Three Sites of Varying Ambient Air Pollution Levels in Uganda: A Cross Sectional Comparative Study

Air pollution is a major cause of sub-optimal lung function and lung diseases in childhood and adulthood. In this study we compared the lung function (measured by spirometry) of 537 Ugandan children, mean age 11.1 years in sites with high (Kampala and Jinja) and low (Buwenge) ambient air pollution levels, based on the concentrations of particulate matter smaller than 2.5 micrometres in diameter (PM_2.5). Factors associated with lung function were explored in a multiple linear regression model. PM_2.5 level in Kampala, Jinja and Buwenge were 177.5 µg/m³, 96.3 µg/m³ and 31.4 µg/m³ respectively (p = 0.0000). Respectively mean forced vital capacity as % of predicted (FVC%), forced expiratory volume in one second as % of predicted (FEV₁%) and forced expiratory flow 25⁻75% as % of predicted (FEF_25⁻75%) of children in high ambient air pollution sites (Kampala and Jinja) vs. those in the low ambient air pollution site (Buwenge subcounty) were: FVC% (101.4%, vs. 104.0%, p = 0.043), FEV₁% (93.9% vs. 98.0, p = 0.001) and FEF_25⁻75% (87.8 vs. 94.0, p = 0.002). The proportions of children whose %predicted parameters were less than 80% predicted (abnormal) were higher among children living in high ambient air pollution than those living in lower low ambient air pollutions areas with the exception of FVC%; high vs. low: FEV1 < 80%, %predicted (12.0% vs. 5.3%, p = 0.021) and FEF_25⁻75 < 80%, %predicted (37.7% vs. 29.3%, p = 0.052) Factors associated with lung function were (coefficient, p-value): FVC% urban residence (-3.87, p = 0.004), current cough (-2.65, p = 0.048), underweight (-6.62, p = 0.000), and overweight (11.15, p = 0.000); FEV₁% underweight (-6.54, p = 0.000) and FEF_25⁻75% urban residence (-8.67, p = 0.030) and exposure to biomass smoke (-7.48, p = 0.027). Children in study sites with high ambient air pollution had lower lung function than those in sites with low ambient air pollution. Urban residence, underweight, exposure to biomass smoke and cough were associated with lower lung function.

Non-infectious skin disease in Indigenous Australians

The burden of non-infectious skin disease in the Indigenous Australian population has not been previously examined. This study considers the published data on the epidemiology and clinical features of a number of non-infectious skin diseases in Indigenous Australians. It also outlines hypotheses for the possible differences in the prevalence of such diseases in this group compared with the general Australian population. There is a paucity of literature on the topic but, from the material available, Indigenous Australians appear to have a reduced prevalence of psoriasis, type 1 hypersensitivity reactions and skin cancer but increased rates of lupus erythematosus, kava dermopathy and vitamin D deficiency when compared to the non-Indigenous Australian population. This article profiles the prevalence and presentation of non-infectious skin diseases in the Indigenous Australian population to synthesise our limited knowledge and highlight deficiencies in our understanding.

Prevalence of asthma and chronic obstructive pulmonary disease in Aboriginal and non-Aboriginal populations: a systematic review and meta-analysis of epidemiological studies

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) have considerable potential for inequities in diagnosis and treatment, thereby affecting vulnerable groups.

OBJECTIVE

To evaluate differences in asthma and COPD prevalence between adult Aboriginal and non-Aboriginal populations.

METHODS

MEDLINE, Embase, specialized databases and the grey literature up to October 2011 were searched to identify epidemiological studies comparing asthma and COPD prevalence between Aboriginal and non-Aboriginal adult populations. Prevalence ORs (PORs) and 95% CIs were calculated in a random-effects meta-analysis.

RESULTS

Of 132 studies, eight contained relevant data. Aboriginal populations included Native Americans, Canadian Aboriginals, Australian Aboriginals and New Zealand Maori. Overall, Aboriginals were more likely to report having asthma than non-Aboriginals (POR 1.41 [95% CI 1.23 to 1.60]), particularly among Canadian Aboriginals (POR 1.80 [95% CI 1.68 to 1.93]), Native Americans (POR 1.41 [95% CI 1.13 to 1.76]) and Maori (POR 1.64 [95% CI 1.40 to 1.91]). Australian Aboriginals were less likely to report asthma (POR 0.49 [95% CI 0.28 to 0.86]). Sex differences in asthma prevalence between Aboriginals and their non-Aboriginal counterparts were not identified. One study compared COPD prevalence between Native and non-Native Americans, with similar rates in both groups (POR 1.08 [95% CI 0.81 to 1.44]).

CONCLUSIONS

Differences in asthma prevalence between Aboriginal and non-Aboriginal populations exist in a variety of countries. Studies comparing COPD prevalence between Aboriginal and non-Aboriginal populations are scarce. Further investigation is needed to identify and account for factors associated with respiratory health inequalities among Aboriginal peoples.

The interplay between diet and emerging allergy: what can we learn from Indigenous Australians?

The pathophysiology of atopic diseases, including asthma and allergy, is the result of complex gene-environment interactions. Since European colonization the Indigenous population of Australia has undergone significant changes with respect to their lifestyle as hunter-gatherers. These changes have had a detrimental effect on Aboriginal health, in part due to immunological modification. This review provides a comparative look at both the traditional Aboriginal/Indigenous diet and modern Western diets, examines some common allergies increasingly reported in contemporary Indigenous populations, and reviews concepts such the effect of vitamin deficiencies and changes in gut microbiota on immune function.

Community-acquired pneumonia in the central desert and north-western tropics of Australia

BACKGROUND

Community-acquired pneumonia (CAP) results in significant morbidity in central and north-western Australia. However, the nature, management and outcome of CAP are poorly documented. The aim of the study was to describe CAP in the Kimberley and Central Desert regions of Australia.

METHODS

Prospective and retrospective cohort studies of inpatient management of adults with CAP at Alice Springs Hospital and six Kimberley hospitals were carried out. We documented demographic data, comorbidities, investigations, causes, CAP severity, outcome and concordance between prescribed and protocol-recommended antibiotics.

RESULTS

Two hundred and ninety-three subjects were included. Aboriginal Australians were overrepresented (relative risk 8.1). Patients were notably younger (median age 44.5 years) and disease severity lower than in urban Australian settings. Two patients died within 30 days of admission compared with expected mortality based on Pneumonia Severity Index predictions of seven deaths (chi(2), P= 0.09). Disease severity and outcome did not differ between regions. Management differences were identified, including significantly more investigations, higher rates of critical care and broader antibiotic cover in Central Australia compared with the Kimberley. Sputum culture results showed Gram-negative organisms in both regions. However, Streptococcus pneumoniae was the most frequent organism isolated in the Kimberley and Haemophilus influenzae in Central Australia.

CONCLUSION

CAP in this setting is an Aboriginal health issue. The low mortality observed and results of microbiology investigations support the use of existing antibiotic protocols. Larger studies investigating CAP aetiology are warranted. Addressing social and environmental disadvantage remains the key factors in dealing with the burden of CAP in this setting.

Respiratory health issues in the Asia-Pacific region: an overview

The Asia-Pacific region is home to a large heterogeneous population whose respiratory health is influenced by diverse social, economic and environmental factors. Despite this variability, the most prevalent causes of respiratory morbidity and mortality are tobacco smoking, infection, and air pollution. This review aims to summarize current respiratory health issues in the region including smoking-related diseases especially COPD, lung cancer and infectious problems such as pandemic influenza, the severe acute respiratory syndrome coronavirus, bacterial pneumonia and tuberculosis, as well as the contribution of air pollution to respiratory disease. Published data on trends in the epidemiology and management of respiratory diseases and are summarized; finally, the limitations of available data and projections for the future of respiratory health in the region are discussed.

Lung health care for Aboriginal and Torres Strait Islander Queenslanders: breathing easy is not so easy

Objectives. In Aboriginal and Torres Strait Islander peoples in Queensland, to (a) determine the disease burden of common chronic lung diseases and (b) identify areas of need with respect to lung health services. Methods. Literature reviews and analyses of hospitalisation and mortality data were used to describe disease epidemiology and available programs and services. Key stakeholder interviews and an online survey of health professionals were used to evaluate lung health services across the state and to identify services, needs and gaps. Results. Morbidity and mortality from respiratory diseases in the Indigenous population is substantially higher than the non-Indigenous population across all age groups and regions. There are inadequate clinical services and resources to address disease prevention, detection, intervention and management in an evidence-based and culturally acceptable fashion. There is a lack of culturally appropriate educational resources and management programs, insufficient access to appropriately engaged Indigenous health professionals, a lack of multi-disciplinary specialist outreach teams, fragmented information systems and inadequate coordination of care. Conclusions. Major initiatives are required at all levels of the healthcare system to adequately address service provision for Indigenous Queenslanders with lung diseases, including high quality research to investigate the causes for poor lung health, which are likely to be multifactorial. What is known about the topic? Chronic diseases, including lung disease contribute to, and influence outcomes of, the well-known health and socioeconomic disadvantage among Aboriginal and Torres Strait Islander Australians. Nationwide, the most common reason for hospitalisation of Indigenous Australians is for lung diseases (after renal dialysis). What does this paper add? There is currently no state- or nation-wide comprehensive review of chronic lung disease burden and the health services available to prevent, treat and manage lung disease. This review fills this gap in Queensland and has found that chronic lung disease burden is not homogenous. There are substantial gaps in, and barriers to, the provision of high quality, evidence based services and a paucity of well-designed research to inform policy and health service delivery. What are the implications for practitioners? Evidence-based strategies are needed at the primary, secondary and tertiary levels of the healthcare system. Fourteen recommendations relevant to practitioners and policy makers were formulated.

International variations in bronchial responsiveness in children: findings from ISAAC phase two

RATIONALE

Bronchial responsiveness is an objectively measurable trait related to asthma. Its prevalence and association with asthma symptoms among children in many countries are unknown.

OBJECTIVES

To investigate international variations in bronchial responsiveness (BR) and their associations with asthma symptoms and atopic sensitization.

METHODS

Bronchial challenge tests were conducted in 6,826 schoolchildren (aged 8-12 years) in 16 countries using hypertonic (4.5%) saline. FEV(1) was measured at baseline and after inhalation for 0.5, 1, 2, 4, and 8 min. BR was analyzed both as a dichotomous (bronchial hyperreactivity, BHR, at least 15% decline in FEV(1)) and as a continuous variable (time-response slope, BR slope, individual decline in FEV(1) per log(min)).

RESULTS

Prevalence of wheeze last year ranged from 4.4% in Tirana (Albania) to 21.9% in Hawkes Bay (New Zealand) and of BHR from 2.1% in Tirana to 48% in Mumbai (India). The geometric mean BR slope varied between 3.4%/log(min) in Tirana and 12.8%/log(min) in Mumbai and Rome (Italy). At the individual level, BHR was positively associated with wheeze during the past 12 months both in affluent countries (OR = 3.6; 95% CI: 2.7-5.0) and non-affluent countries (OR = 3.0; 1.6-5.5). This association was more pronounced in atopic children. There was a correlation (rho = 0.64, P = 0.002) between center-specific mean BR slope and wheeze prevalence in atopic, but not in non-atopic children.

CONCLUSIONS

BR to saline in children varied considerably between countries. High rates of BR were not confined to affluent countries nor to centers with high prevalences of asthma symptoms. The association between wheeze and BHR at the individual level differed across centers and this heterogeneity can be largely explained by effect modification by atopy. Pediatr. Pulmonol. 2010; 45:796-806. (c) 2010 Wiley-Liss, Inc.

A thymic stromal lymphopoietin gene variant is associated with asthma and airway hyperresponsiveness

BACKGROUND

The epithelial cell-derived protein thymic stromal lymphopoietin stimulates dendritic and mast cells to promote proallergic T(H)2 responses. Studies of transgenic expression of thymic stromal lymphopoietin and its receptor knockout mice have emphasized its critical role in the development of allergic inflammation. Association of genetic variation in thymic stromal lymphopoietin with IgE levels has been reported for human subjects.

OBJECTIVE

The aim of this study was to evaluate the relationship between variants of thymic stromal lymphopoietin and asthma and related phenotypes.

METHODS

We selected 6 single nucleotide polymorphisms in thymic stromal lymphopoietin and genotyped 5565 individuals from 4 independent asthma studies and tested for association with asthma, atopy, atopic asthma, and airway hyperresponsiveness by using a general allelic likelihood ratio test. P values were corrected for the effective number of independent single nucleotide polymorphisms and phenotypes.

RESULTS

The A allele of rs1837253, which is 5.7 kb upstream of the transcription start site of the gene, was associated with protection from asthma, atopic asthma, and airway hyperresponsiveness, with the odds ratios and corrected P values for each being 0.79 and 0.0058; 0.75 and 0.0074; and 0.76 and 0.0094, respectively. Associations between thymic stromal lymphopoietin and asthma-related phenotypes were the most statistically significant observations in our study, which has to date examined 98 candidate genes. Full results are available online at http://genapha.icapture.ubc.ca/.

CONCLUSIONS

A genetic variant in the region of the thymic stromal lymphopoietin gene is associated with the phenotypes of asthma and airway hyperresponsiveness.

Dyspnoea in children. Does development alter the perception of breathlessness?

Dyspnoea, the perception of an unpleasant and/or uncomfortable sensation of breathlessness, offers several physiological, anatomical and teleological analogies with pain. Pain perception has been shown to exist in the newborn, suggesting that dyspnoea may also occur from birth onwards. The perception of breathlessness will be subservient to developmental changes in the behaviour of sensors and lung and muscular receptors implicated in dyspnoea, some of which are known to be active at time of birth. For example, perinatal resetting of the arterial chemoreceptor could lead to transient depression of the dyspnoeic response to hypoxia. However, though early evoked ventilatory responses and peripheral receptor maturation do exist, dyspnoea will only occur if the corresponding central neural circuitry undergoes parallel maturation. Our knowledge of dyspnoea in later childhood is based on a small number of clinical or psychophysical studies, predominantly dealing with asthma and exercise. There is a thus a clear need for systematic assessment of the existence and severity of dyspnoea sensing in younger children that takes into account its role as an alarm mechanism for triggering adaptive and/or protective responses.

Stable prevalence of asthma symptoms in school-aged children in the Torres Strait region

BACKGROUND AND OBJECTIVE

To (i) determine if the prevalence of asthma has altered in two previously studied communities and (ii) obtain baseline measures in two further communities in the Torres Strait region, Australia.

METHODS

A population-based cross-sectional study of school-aged children was conducted. Five schools in four communities were selected: 361 children aged 5-17 years participated. The study used the same epidemiological tool that had been utilized to measure asthma prevalence (locally adapted International Study of Asthma and Allergy in Childhood questionnaire).

RESULTS

The overall response rate was 30%; response rates in individual communities ranged from 23% to 100%. The prevalence of self-reported wheezing in the last 12 months decreased from 10.7% to 6.6% (P = 0.109) on Thursday Island and from 3.1% to zero (P = 0.358) on Warraber Island. The percentage of children with asthma symptoms was lower in this current study but changes were not statistically significant. Overall self-reported prevalence of ever wheezing was 12.5%; 5.4% reported wheezing in the previous 12 months, 5.9% reported wheezing after exercise and 12.2% reported ever having asthma. There was considerable inter-community variation in the prevalence of symptoms.

CONCLUSIONS

Asthma prevalence in school-aged children living in the Torres Strait region remains high but, as in mainstream Australian children, the prevalence is stable.

Respiratory infections and lung function in an Australian Aboriginal community

BACKGROUND AND OBJECTIVE

To investigate the association between serological evidence of past infections with common respiratory pathogens and lung function in members of an isolated community of Aborigines from tropical coastal north-western Australia.

METHODS

FEV(1) and FVC were assessed by dry bellows spirometer. Serum IgG titres to 11 common respiratory pathogens were assayed. Smoking history was assessed by questionnaire. Reciprocal positive IgG titres were taken as >or=10 for all pathogens with the exception of Legionella spp. (>or=40) and Burkholderia pseudomallei (>or=20). Linear regression analysis examined associations between titres and lung function after adjustment for age, height, gender and smoking, separately for adults (age > 17 years) and children.

RESULTS

An increased total number of positive IgG titres was significantly associated with reduced FEV(1) (P = 0.01) and FEV(1)/FVC ratio (P = 0.01) suggesting the presence of airflow obstruction. This association was independent of age, gender, height, weight and smoking status.

CONCLUSIONS

The burden of past respiratory infections may be an important determinant of airway function in this Aboriginal community.

Distinctive immunoglobulin E anti-house dust allergen-binding specificities in a tropical Australian Aboriginal community

BACKGROUND

There is evidence that the specificity of the IgE binding in allergy tests can vary for different populations.

OBJECTIVE

We aimed to examine the allergenic specificity of IgE binding in sera from house dust mite (HDM)-atopic subjects in a tropical Australian Aboriginal community.

METHODS

Sera shown to contain IgE antibodies to an HDM extract of Dermatophagoides pteronyssinus were examined for IgE binding to a panel of nine purified HDM allergens from this mite species by quantitative microtitre assays. IgG antibody binding (IgG1 and IgG4) was also measured.

RESULTS

The IgE-binding activity in the sera from the Aboriginal community was not directed to the expected major groups 1 and 2 HDM allergens but instead to the group 4 amylase allergen. There was also little IgE binding to the potentially cross-reactive tropomyosin (Der p 10) or arginine kinase (Der p 20) allergens. The IgG4 antibody was rarely detected and limited to the Der p 4 allergen. IgG1 antibody binding was frequently measured to all the allergens regardless of an individual's atopic status, whereas in urban communities it is restricted to the major allergens and to atopic subjects.

CONCLUSION

The high IgE anti-HDM response of Australian Aboriginals predominantly bound Der p 4 and not the Der p 1 and 2 allergens, showing a distinctive allergy that could affect the disease outcome and diagnosis.

Risk factors for reduced lung function in Australian Aboriginal children

AIM

To determine the influence of perinatal and childhood exposures on lung function in a cohort of Australian Aboriginal children.

METHODS

This was a cross-sectional study of 547 Northern Territory Aboriginal children, aged 8-14 years, belonging to a birth cohort. Assessment included physical examination and spirometry as well as retrospective review of centralised hospital records. The effect of select perinatal and childhood exposures on lung function outcomes (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow between 25 and 75 s (FEF25-75)) adjusted for age, sex, height and other measures of size was examined using multiple regression.

RESULTS

Non-urban residence (FEV1 -5% (95% confidence interval, CI 0.91-0.99), FVC -9% (95% CI 0.87-0.95)), current cough (FEV1 -6% (95% CI 0.91-0.97), FVC -4% (95% CI 0.93-0.97), FEF25-75 -8% (95% CI 0.86-0.98)) and hospitalisations for respiratory disease (FEV1 -10% (95% CI 0.86-0.95), FEF25-75 -12% (95% CI 0.70-0.87)) all had significant negative effects on adjusted lung function measures. Children with a non-Aboriginal ancestor had significantly better lung function. No perinatal exposure other than neonatal lung disease had any significant effect on adjusted lung function.

CONCLUSIONS

For Northern Territory Aboriginal children factors related to the childhood environment are more important than perinatal factors in determining childhood lung function.

Respiratory symptoms and lung function of coke oven workers: a lung function surveillance system from 1990-2000

This study investigated the association of exposure to coke oven emissions with respiratory symptoms and with lung function. Data for respiratory symptoms and lung function were repeatedly collected from 764 male coke oven workers between 1990 and 2000. The data were analyzed cross-sectionally and longitudinally. Working in "Operation" increased the risk for cough (odds ratio [OR] = 2.37), phlegm (OR = 2.55), and shortness of breath (OR = 1.52). Cross-sectionally, each year of working in Operation was associated with a reduction in FEV1 of approximately 10 mL (P = 0.006) and in FVC of around 21 mL (P = 0.0001). From longitudinal analysis, each year of working in Operation was associated with an extra annual decline in FEV1 of 1.5 mL (P = 0.0012) and in FVC of around 1.8 mL (P = 0.0017). Exposure to coke oven emissions increased the risk for respiratory symptoms and adversely affected lung function.

Scabies: New Future for a Neglected Disease

Scabies is a disease of global proportions in both human and animal populations, resulting from infestation of the skin with the "itch" mite Sarcoptes scabiei. Despite the availability of effective chemotherapy the intensely itching lesions engender significant morbidity primarily due to secondary sepsis and post-infective complications. Some patients experience an extreme form of the disease, crusted scabies, in which many hundreds of mites may infest the skin causin severe crusting and hyperkeratosis. Overcrowded living conditions and poverty have been identified as significant confounding factors in transmission of the mite in humans. Control is hindered by difficulties with diagnosis, the cost of treatment, evidence for emerging resistance and lack of effective vaccines. Historically research on scabies has been extremely limited because of the difficulty in obtaining sufficient quantities of the organism. Recent molecular approaches have enabled considerable advances in the study of population genetics and transmission dynamics of S. scabiei. However, the most exciting and promising development is the potential exploitation of newly available data from S. scabiei cDNA libraries and EST projects. Ultimately this knowledge may aid early identification of disease, novel forms of chemotherapy, vaccine development and new treatment possibilities for this important but neglected parasite.

Respiratory morbidity and lung function in two Aboriginal communities in Western Australia

OBJECTIVE

To examine differences in the rates of respiratory symptoms, asthma and levels of lung function in two remote Aboriginal communities.

METHODOLOGY

Respiratory symptoms, smoking history, skin prick test responses to common allergens, serum IgE, lung function, airway responsiveness to methacholine and white blood cell counts were compared in two Aboriginal communities, one from the central desert (n = 84) and another from the tropical north (n = 209) of Western Australia.

RESULTS

Compared with the tropical community, chest tightness and dyspnoea were more frequent and forced expiratory volume in 1 s and forced vital capacity were lower in the desert community, despite similar levels of wheeze, doctor-diagnosed asthma and skin prick test responses and lower levels of airway responsiveness and smoking. The total white cell and neutrophil counts were greater in the desert community. Serum IgE was very high and similar in both communities.

CONCLUSIONS

Our findings show a low prevalence of asthma in children, a high prevalence of respiratory symptoms and low levels of lung function in remote Aboriginal communities. The greater prevalence of respiratory morbidity in the desert community was not explained by diagnosed asthma, airway hyperresponsiveness or cigarette smoking. The role of infection requires further investigation. The results suggest that the lower lung function observed in Aboriginal communities (compared with non-Aboriginal communities) results at least partly from environmental factors.

Pulmonary functions in atopic and nonatopic asthmatic children

BACKGROUND

we examined how lung function and certain clinical and laboratory characteristics in asthmatic children were changed according to skin test positivity to aeroallergens.

METHODS

a skin prick test was conducted using standardized extracts of 10 different allergens in 56 children with bronchial asthma, aged 5-15 years, in Dicle University Hospital. Lung function was measured by Microplus spirometer.

RESULTS

among the 56 subjects, asthma was classified as mild in 16, moderate in 42 and severe in 3. At least one skin prick test was positive (monosensitized) in 35 subjects (62 %) and positive reactivity to two or more aeroallergens (polysensitized) was found in 17 subjects (30 %). Positive skin test reactions to aeroallergens were associated with a decrease (as percentage of the predicted decrease) in FEV1, FVC and PEF values. Significant differences were also found between prick test-positive and -negative asthmatics in duration of breastfeeding (8.5 5 months vs 15 7 months, respectively, p < 0.007), age at which cow's milk had been started (5.7 1.6 vs 10.5 5.4, p = 0.004); total serum IgE concentration (350 221 IU/ml vs 234 164 IU/ml, p = 0.02), age at onset of asthma symptoms (2.5 1.9 years vs 4.1 2.2 years) and number of asthma attacks per year (7.0 3.1 vs 5.2 3.5, p = 0.012). When one-way ANOVA and a post-Hoc test were used, asthma attacks were more frequent and severe and allergic conjunctivitis symptoms were more frequent in the polysensitized group than in the nonsensitized and monosensitized groups (p = 0.03).

CONCLUSIONS

children with positive skin prick test results, especially those with combined sensitivity to dust mite, cat and dog, were at increase risk of more severe asthma.

Asthma and hayfever in Aboriginal and non-Aboriginal children living in non-remote rural towns

OBJECTIVE

To compare the prevalence and risk factors for wheeze, asthma diagnosis and hayfever in Aboriginal and non-Aboriginal children living in rural towns in Australia.

DESIGN AND SETTING

Cross-sectional study in two towns in rural NSW, Australia, 1997.

PARTICIPANTS

Primary school children (aged 7-12 years) classified by their parents as being of Aboriginal (n = 158) or of non-Aboriginal (n = 1,282) origin.

MAIN OUTCOME MEASURES

Atopy measured by skinprick tests and respiratory symptoms measured by parent-completed questionnaire.

RESULTS

Aboriginal children were less likely to be atopic (36.2% v 45.6%; 95% CI for the difference, -17.6 to -1.3) and to have hayfever (23.3% v 35.2%; 95% CI for the difference, -19.1 to -4.6) than non-Aboriginal children, but were equally likely to have had wheeze (31.0% v 27.3%) and asthma (39.4% v 39.3%). Among Aboriginal children, having had bronchitis before age two was a strong risk factor for wheeze (adjusted odds ratio (aOR), 9.3; 95% CI, 2.8-30.2) and asthma (aOR, 19.3; 95% CI, 4.7-79.3) and having a parent with hayfever was a strong risk factor for hayfever (aOR, 17.9; 95% CI, 3.5-90.8), but these risk factors were weaker among non-Aboriginal children.

CONCLUSIONS

Asthma and wheeze are equally prevalent in Aboriginal and non-Aboriginal children living in the same towns, but appear to have a different aetiology.

High prevalence of asthma in five remote indigenous communities in Australia

Data on the prevalence of asthma in children residing in remote indigenous communities in Australia are sparse, despite the many reports of high prevalence in nonindigenous children of this country. Two previous Australian studies have had poor participation rates, limiting interpretation of their results. A study of children in the Torres Strait and Northern Peninsula Area of Australia was conducted to document the prevalence of asthma symptoms. Five indigenous communities were randomly selected and trained interviewers, who were local indigenous health workers, recruited participants using a house-by-house approach. Information was collected by a structured face-to-face interview based on a standardized questionnaire constructed from the protocol International Study of Asthma and Allergy in Childhood; 1,650 children were included in the study with a 98% response rate. Overall, the prevalence of self-reported ever wheezing was 21%; 12% reported wheezing in the previous year; and 16% reported ever having asthma. There was significant variation in the prevalence of asthma symptoms between communities. It is concluded that there are significant intercommunity variations in the prevalence of asthma symptoms in remote communities and that the prevalence in these communities is as high as in nonindigenous groups.

Geographic variations in prevalence and underdiagnosis of COPD: results of the IBERPOC multicentre epidemiological study

OBJECTIVES

To ascertain the prevalence, diagnostic level, and treatment of COPD in Spain through a multicenter study comprising seven different geographic areas.

DESIGN AND PARTICIPANTS

This is an epidemiologic, multicenter, population-based study conducted in seven areas of Spain. A total of 4,035 men and women (age range, 40 to 69 years) who were randomly selected from a target population of 236,412 subjects participated in the study.

INTERVENTIONS

Eligible subjects answered the European Commission for Steel and Coal questionnaire. Spirometry was performed, followed by a bronchodilator test when bronchial obstruction was present.

RESULTS

The prevalence of COPD was 9.1% (95% confidence interval [CI], 8.1 to 10.2%), 15% in smokers (95% CI, 12.8 to 17.1%), 12.8% in ex-smokers (95% CI, 10.7 to 14.8%), and 4.1% in nonsmokers (95% CI, 3.3 to 5.1%). The prevalence in men was 14.3% (95% CI, 12.8 to 15. 9%) and 3.9% in women (95% CI, 3.1 to 4.8%). Marked differences were observed between sexes in smoking; the percentage of nonsmokers was 23% in men and 76.3% in women (p<0.0001). The prevalence of COPD varied among the areas, ranging from 4.9% (95% CI, 3.2 to 7.0%) in the area of the lowest prevalence to 18% (95% CI, 14.8 to 21.2%) in the area of the highest. There was no previous diagnosis of COPD in 78.2% of cases (284 of 363). Only 49.3% of patients with severe COPD, 11.8% of patients with moderate COPD, and 10% of patients with mild COPD were receiving some kind of treatment for COPD. Multivariate analysis showed that individuals had a higher probability of having received a previous diagnosis of COPD if they lived in urban areas, were of male gender, were > 60 years old, had higher educational levels, had > 15 pack-year smoking history, or had symptoms of chronic bronchitis.

CONCLUSIONS

COPD is a very frequent disease in Spain, and presents significant geographic variations and a very low level of previous diagnosis and treatment, even in the most advanced cases.