Can We Use Lung Function Thresholds and Respiratory Symptoms to Identify Pre-Chronic Obstructive Pulmonary Disease? A Prospective, Population-based Cohort Study.

Rationale: The term "pre-chronic obstructive pulmonary disease" ("pre-COPD") refers to individuals at high risk of developing COPD who do not meet conventional spirometric criteria for airflow obstruction. New approaches to identifying these individuals are needed, particularly in younger populations. Objectives: To determine whether lung function thresholds and respiratory symptoms can be used to identify individuals at risk of developing COPD. Methods: The Tasmanian Longitudinal Health Study comprises a population-based cohort first studied in 1968 (at age 7 yr). Respiratory symptoms, pre- and post-bronchodilator (BD) spirometry, diffusing capacity, and static lung volumes were measured in a subgroup at age 45, and the incidence of COPD was assessed at age 53. For each lung function measure, z-scores were calculated using Global Lung Function Initiative references. The optimal threshold for best discrimination of COPD incidence was determined by the unweighted Youden index. Measurements and Main Results: Among 801 participants who did not have COPD at age 45, the optimal threshold for COPD incidence by age 53 was pre-BD FEV1/FVC z-score less than -1.264, corresponding to the lowest 10th percentile. Those below this threshold had a 36-fold increased risk of developing COPD over an 8-year follow-up period (risk ratio, 35.8; 95% confidence interval, 8.88 to 144), corresponding to a risk difference of 16.4% (95% confidence interval, 3.7 to 67.4). The sensitivity was 88%, and the specificity was 87%. Positive and negative likelihood ratios were 6.79 and 0.14, respectively. Respiratory symptoms, post-BD spirometry, diffusing capacity, and static lung volumes did not improve on the classification achieved by pre-BD FEV1/FVC alone. Conclusions: This is the first study, to our knowledge, to evaluate the discriminatory accuracy of spirometry, diffusing capacity, and static lung volume thresholds for COPD incidence in middle-aged adults. Our findings support the inclusion of pre-BD spirometry in the physiological definition of pre-COPD and indicate that pre-BD FEV1/FVC at the 10th percentile accurately identifies individuals at high risk of developing COPD in community-based settings.

Longitudinal Asthma Phenotypes from Childhood to Middle-Age: A Population-based Cohort Study.

Rationale: Asthma is a heterogeneous condition, and longitudinal phenotyping may provide new insights into the origins and outcomes of the disease. Objectives: We aimed to characterize the longitudinal phenotypes of asthma between the first and sixth decades of life in a population-based cohort study. Methods: Respiratory questionnaires were collected at seven time points in the TAHS (Tasmanian Longitudinal Health Study) when participants were aged 7, 13, 18, 32, 43, 50, and 53 years. Current-asthma and ever-asthma status was determined at each time point, and group-based trajectory modeling was used to characterize distinct longitudinal phenotypes. Linear and logistic regression models were fitted to investigate associations of the longitudinal phenotypes with childhood factors and adult outcomes. Measurements and Main Results: Of 8,583 original participants, 1,506 had reported ever asthma. Five longitudinal asthma phenotypes were identified: early-onset adolescent-remitting (40%), early-onset adult-remitting (11%), early-onset persistent (9%), late-onset remitting (13%), and late-onset persistent (27%). All phenotypes were associated with chronic obstructive pulmonary disease at age 53 years, except for late-onset remitting asthma (odds ratios: early-onset adolescent-remitting, 2.00 [95% confidence interval (CI), 1.13-3.56]; early-onset adult-remitting, 3.61 [95% CI, 1.30-10.02]; early-onset persistent, 8.73 [95% CI, 4.10-18.55]; and late-onset persistent, 6.69 [95% CI, 3.81-11.73]). Late-onset persistent asthma was associated with the greatest comorbidity at age 53 years, with increased risk of mental health disorders and cardiovascular risk factors. Conclusions: Five longitudinal asthma phenotypes were identified between the first and sixth decades of life, including two novel remitting phenotypes. We found differential effects of these phenotypes on risk of chronic obstructive pulmonary disease and nonrespiratory comorbidities in middle age.

Life course BMI trajectories from childhood to mid-adulthood are differentially associated with anxiety and depression outcomes in middle age.

BACKGROUND/OBJECTIVE: Obesity is a risk factor for multimorbidity, including depression and possibly anxiety. However, it is currently unclear how patterns of change in BMI over the life course differentially influence the magnitude in risk of depression and anxiety in mid-adulthood. We aimed to examine associations between BMI trajectories from childhood to adulthood and the risk of depression and anxiety in middle age. METHODS: In the Tasmanian Longitudinal Health Study (n = 2416), five distinct BMI trajectories were previously defined from age 5 to 45 years using group-based modelling. At age 53, current depression and anxiety were assessed using the Patient Health Questionnaire and the Generalized Anxiety Disorder scale, respectively. Logistic regression models adjusted for potential confounders estimated associations between BMI trajectories and these outcomes. RESULTS: Those belonging to the child average-increasing (OR = 2.24; 95%CI: 1.24, 4.06) and persistently high (OR = 2.64; 1.26, 5.52) trajectories were more likely to have depression in middle age, compared to the persistently average trajectory. However, the odds of experiencing greater severity of depressive symptoms was highest in the child average-increasing group (OR = 2.36; 1.59, 3.49). Despite finding no evidence of association between BMI trajectories and current anxiety, we observed less severe symptoms in the child high-decreasing trajectory (OR = 0.68; 0.51, 0.91). CONCLUSION: We found an increased risk of depression in middle age among individuals with a persistently high BMI from childhood to mid-adulthood and individuals with an average BMI in childhood which then increased consistently throughout adulthood. Encouragingly, resolving childhood adiposity by adulthood was associated with lesser anxiety symptoms. Taken together, these findings highlight the need to target mental health screening and treatment towards high-risk BMI trajectory groups and the importance of early interventions to prevent and resolve excess weight.

Biomarkers of asthma relapse and lung function decline in adults with spontaneous asthma remission: A population-based cohort study.

BACKGROUND: The extent to which biomarkers of asthma activity persist in spontaneous asthma remission and whether such markers are associated with future respiratory outcomes remained unclear. We investigated the association between sub-clinical inflammation in adults with spontaneous asthma remission and future asthma relapse and lung function decline. METHODS: The Tasmanian Longitudinal Health Study is a population-based cohort (n = 8583). Biomarkers of systemic inflammation were measured on participants at age 45, and latent profile analysis was used to identify cytokine profiles. Bronchial hyperresponsiveness (BHR) and nitric oxide products in exhaled breath condensate (EBC NOx) were measured at age 50. Participants with spontaneous asthma remission at ages 45 (n = 466) and 50 (n = 318) were re-evaluated at age 53, and associations between baseline inflammatory biomarkers and subsequent asthma relapse and lung function decline were assessed. RESULTS: We identified three cytokine profiles in adults with spontaneous asthma remission: average (34%), Th2-high (42%) and Th2-low (24%). Compared to the average profile, a Th2-high profile was associated with accelerated decline in post-BD FEV1 /FVC (MD -0.18% predicted per-year; 95% CI -0.33, -0.02), while a Th2-low profile was associated with accelerated decline in both post-BD FEV1 (-0.41%; -0.75, -0.06) and post-BD FVC (-0.31%; -0.62, 0.01). BHR and high TNF-α during spontaneous remission were associated with an increased risk of asthma relapse. In contrast, we found no evidence of association between EBC NOx and either asthma relapse or lung function decline. CONCLUSION: BHR and serum inflammatory cytokines have prognostic value in adults with spontaneous asthma remission. At-risk individuals with BHR, Th2-high or Th2-low cytokine profiles may benefit from closer monitoring and on-going follow-up.

Household use of biomass fuel, especially traditional stove is associated with childhood wheeze and eczema: a cross sectional study of rural communities in Kandy, Sri Lanka.

BACKGROUND: Most households in low- and middle-income countries (LMICs) rely on biomass fuel for daily cooking. Studies investigating the association between early life exposure to household air pollution and health outcomes in children in LMICs are limited. OBJECTIVE: To investigate the effects of biomass fuel for cooking and different types of stoves on wheeze and allergies in children of rural Sri Lankan communities. METHODS: A cross-sectional study was conducted on 452 children aged 5 years and younger in Kandy, Sri Lanka. Mothers completed a questionnaire on the use of biomass fuel and respiratory and allergic outcomes in children. The associations between biomass fuel and outcomes were analyzed using logistic regression models, adjusting for potential confounders. RESULTS: Use of biomass fuel for cooking was associated with increased risk of childhood wheeze (aOR 2.29; 95% CI 1.04-5.08) and eczema (aOR 4.57; 95% CI 1.24-16.89) compared with households that used clean fuel (liquid petroleum gas (LPG), electricity and/or biogas). Among households that used biomass fuel, use of traditional biomass stoves was associated with a higher risk of childhood wheeze (aOR 2.95; 95% CI 1.19-7.33), allergic rhinitis (aOR 3.01; 95% CI 1.42-6.39), and eczema (aOR 7.39; 95% CI 1.70-32.06) compared with households that used clean stoves. CONCLUSION: Children living in households that use biomass fuel, especially traditional biomass cookstoves, have a higher risk of wheeze and allergic diseases. Access to affordable clean energy sources that reduce air pollution may help improve the health of children in rural LMICs.Supplemental data for this article is available online at at www.tandfonline.com/ijas .

Exploration of associations between occupational exposures and current adult eczema.

OBJECTIVES: There is a scarcity of evidence on occupational exposures that may increase eczema in adults. We aimed to investigate potential associations between occupational exposures and eczema in middle-aged adults. METHODS: A lifetime work history calendar was collected from the Tasmanian Longitudinal Health Study participants when they were at age 53. Their work history was collated with the occupational asthma-specific job exposure matrix to define ever-exposure and cumulative exposure unit-years since no eczema job exposure matrix is available. Eczema was determined using the report of flexural rash that was coming and going for at least 6 months in the last 12 months. Skin prick tests were used to further subgroup eczema and atopic eczema (AE) or non-AE (NAE). Logistic and multinomial regression models were used to investigate the associations. RESULTS: Eczema prevalence was 9.1%. Current occupational exposure to animals (adjusted OR, aOR=3.06 (95% CI 1.43 to 6.58)), storage mites (aOR=2.96 (95% CI 1.38 to 6.34)) and endotoxin (aOR=1.95 (95% CI 1.04 to 3.64)) were associated with increased risk of current eczema. Furthermore, increased odds of NAE were associated with current exposure to animals (aOR=5.60 (95% CI 1.45 to 21.7)) and storage mites (aOR=5.63 (95% CI 1.45 to 21.9)). Current exposures to isocyanates (aOR=5.27 (95% CI 1.17 to 23.7)) and acrylates (aOR=8.41 (95% CI 1.60 to 44.3)) were associated with AE. There was no evidence of associations between cumulative exposures and eczema prevalence. Cumulative exposure to metalworking fluids (aOR=1.10 (95% CI 1.01 to 1.22)) was associated with NAE and acrylates (aOR=1.24 (95% CI 1.04 to 1.46)) with AE. CONCLUSIONS: In this exploratory assessment, multiple occupational exposures were associated with current eczema in middle-aged adults. Raising awareness and limiting these exposures during an individual's productive working life will likely have various health benefits, including reducing eczema prevalence.

Small for gestational age is associated with reduced lung function in middle age: A prospective study from first to fifth decade of life.

BACKGROUND AND OBJECTIVE: The association between birth weight, particularly relative to gestational age, and adult lung function is uncertain. We investigated the associations between birth weight relative to gestational age and measures of lung function in middle age, and mediation of these associations by adult height. METHODS: Participants in the Tasmanian Longitudinal Health Study who had both known birth weight and lung function assessment at age 45 years were included (n = 849). Linear regression models were fitted to investigate the association between small for gestational age and birth weight with post-bronchodilator lung function measures (forced expiratory volume in 1 second [FEV1 ], forced vital capacity [FVC], FEV1 /FVC, diffusing capacity for carbon monoxide [DL co], residual volume [RV] and total lung capacity [TLC]), adjusting for potential confounders. The contribution of adult height as a mediator of these associations was investigated. RESULTS: Compared with infants born with normal weight for gestational age, those born small for gestational age had reduced FEV1 (coefficient: -191 ml [95%CI: -296, -87]), FVC (-205 ml [-330, -81]), TLC (-292 ml [-492, -92]), RV (-126 ml [-253, 0]) and DL co (-0.42 mmol/min/kPa [-0.79, -0.041]) at age 45 years. However, they had comparable FEV1 /FVC. For every 1 kg increase in birth weight, lung function indices increased by an average of 117 ml (95%CI: 40, 196) for FEV1 , 124 ml (30, 218) for FVC, 215 ml (66, 365) for TLC and 0.36 mmol/min/kPa (0.11, 0.62) for DL co, independent of gestational age, but again not for FEV1 /FVC. These associations were significantly mediated by adult height (56%-90%). CONCLUSION: Small for gestational age was associated with reduced lung function that is likely due to smaller lungs with little evidence of any specific parenchymal impairment.

Parental preconception BMI trajectories from childhood to adolescence and asthma in the future offspring.

BACKGROUND: Recent evidence suggests that parental exposures before conception can increase the risk of asthma in offspring. OBJECTIVE: We investigated the association between parents' preconception body mass index (BMI) trajectories from childhood to adolescence and subsequent risk of asthma in their offspring. METHODS: Using group-based trajectory modeling from the Tasmanian Longitudinal Health Study, we identified BMI trajectories for index participants (parents) when aged 4 years to 15 years. Multinomial regression models adjusted for potential confounders were utilized to estimate the association between these early-life parents' BMI trajectories and asthma phenotypes in their subsequent offspring. RESULTS: The main analysis included 1822 parents and 4208 offspring. Four BMI trajectories from age 4 years to 15 years were identified as the best-fitting model: low (8.8%), normal (44.1%), above normal (40.2%), and high (7.0%). Associations were observed between father's high BMI trajectory and risk of asthma in offspring before the age of 10 years (relative risk ratio [RRR] =1.70 [95% CI = 0.98-2.93]) and also asthma ever (RRR = 1.72 [95% CI = 1.00-2.97]), especially allergic asthma ever (RRR = 2.05 [95% CI = 1.12-3.72]). These associations were not mediated by offspring birth weight. No associations were observed for maternal BMI trajectories and offspring asthma phenotypes. CONCLUSION: This cohort study over 6 decades of life and across 2 generations suggests that the high BMI trajectory in fathers, well before conception, increased the risk of asthma in their offspring.

Impact of lifetime body mass index trajectories on the incidence and persistence of adult asthma.

BACKGROUND: High body mass index (BMI) trajectories from childhood to adulthood are associated with the development of some chronic diseases, but whether such trajectories influence adult asthma has not been investigated to date. Therefore, we investigated associations between BMI trajectories from childhood to middle age (5-43 years) and incidence, persistence and relapse of asthma from ages 43 to 53 years. METHODS: In the Tasmanian Longitudinal Health Study (n=4194), weight and height were recorded at eight time-points between 5 and 43 years of age. BMI trajectories were developed using group-based trajectory modelling. Associations between BMI trajectories and asthma incidence, persistence and relapse from age 43 to 53 years, bronchial hyperresponsiveness (BHR) at age 50 years, and bronchodilator responsiveness at age 53 years were modelled using multiple logistic and linear regression. RESULTS: Five distinct BMI trajectories were identified: average, low, child high-decreasing, child average-increasing and high. Compared with the average trajectory, child average-increasing and high trajectories were associated with increased risk of incident asthma (OR 2.6, 95% CI 1.1-6.6 and OR 4.4, 95% CI 1.7-11.4, respectively) and BHR in middle age (OR 2.9, 95% CI 1.1-7.5 and OR 3.5, 95% CI 1.1-11.4, respectively). No associations were observed for asthma persistence or relapse. CONCLUSIONS: Participants with child average-increasing and high BMI trajectories from childhood to middle age were at higher risk of incident adult asthma. Thus, encouraging individuals to maintain a normal BMI over the life course may help reduce the burden of adult asthma.

Human milk oligosaccharide profiles and allergic disease up to 18 years.

BACKGROUND: Human milk oligosaccharides (HMO) are a diverse range of sugars secreted in breast milk that have direct and indirect effects on immunity. The profiles of HMOs produced differ between mothers. OBJECTIVE: We sought to determine the relationship between maternal HMO profiles and offspring allergic diseases up to age 18 years. METHODS: Colostrum and early lactation milk samples were collected from 285 mothers enrolled in a high-allergy-risk birth cohort, the Melbourne Atopy Cohort Study. Nineteen HMOs were measured. Profiles/patterns of maternal HMOs were determined using LCA. Details of allergic disease outcomes including sensitization, wheeze, asthma, and eczema were collected at multiple follow-ups up to age 18 years. Adjusted logistic regression analyses and generalized estimating equations were used to determine the relationship between HMO profiles and allergy. RESULTS: The levels of several HMOs were highly correlated with each other. LCA determined 7 distinct maternal milk profiles with memberships of 10% and 20%. Compared with offspring exposed to the neutral Lewis HMO profile, exposure to acidic Lewis HMOs was associated with a higher risk of allergic disease and asthma over childhood (odds ratio asthma at 18 years, 5.82; 95% CI, 1.59-21.23), whereas exposure to the acidic-predominant profile was associated with a reduced risk of food sensitization (OR at 12 years, 0.08; 95% CI, 0.01-0.67). CONCLUSIONS: In this high-allergy-risk birth cohort, some profiles of HMOs were associated with increased and some with decreased allergic disease risks over childhood. Further studies are needed to confirm these findings and realize the potential for intervention.

Exposure to household air pollution over 10†years is related to asthma and lung function decline.

INTRODUCTION: We investigated if long-term household air pollution (HAP) is associated with asthma and lung function decline in middle-aged adults, and whether these associations were modified by glutathione S-transferase (GST) gene variants, ventilation and atopy. MATERIALS AND METHODS: Prospective data on HAP (heating, cooking, mould and smoking) and asthma were collected in the Tasmanian Longitudinal Health Study (TAHS) at mean ages 43 and 53 years (n=3314). Subsamples had data on lung function (n=897) and GST gene polymorphisms (n=928). Latent class analysis was used to characterise longitudinal patterns of exposure. Regression models assessed associations and interactions. RESULTS: We identified seven longitudinal HAP profiles. Of these, three were associated with persistent asthma, greater lung function decline and % reversibility by age 53 years compared with the "Least exposed" reference profile for those who used reverse-cycle air conditioning, electric cooking and no smoking. The "All gas" (OR 2.64, 95% CI 1.22-5.70), "Wood heating/smoking" (OR 2.71, 95% CI 1.21-6.05) and "Wood heating/gas cooking" (OR 2.60, 95% CI 1.11-6.11) profiles were associated with persistent asthma, as well as greater lung function decline and % reversibility. Participants with the GSTP1 Ile/Ile genotype were at a higher risk of asthma or greater lung function decline when exposed compared with other genotypes. Exhaust fan use and opening windows frequently may reduce the adverse effects of HAP produced by combustion heating and cooking on current asthma, presumably through increasing ventilation. CONCLUSIONS: Exposures to wood heating, gas cooking and heating, and tobacco smoke over 10 years increased the risks of persistent asthma, lung function decline and % reversibility, with evidence of interaction by GST genes and ventilation.

Association between ambient air pollution and development and persistence of atopic and non-atopic eczema in a cohort of adults.

BACKGROUND: There is limited information on risk factors for eczema in adults. Recent evidence suggests that air pollution may be associated with increased incidence of eczema in adults. We aimed to assess this possible association. METHODS: Ambient air pollution exposures (distance from a major road, nitrogen dioxide [NO2 ], fine particulate matter with an aerodynamic diameter ≤2.5 µm [PM2.5 ]) were assessed for the residential address of Tasmanian Longitudinal Health Study participants at ages 43 and 53 years. Eczema incidence (onset after age 43 years), prevalence (at 53 years), and persistence were assessed from surveys, while IgE sensitization was assessed using skin prick tests. The presence or absence of eczema and sensitization was classified into four groups: no atopy or eczema, atopy alone, non-atopic eczema, and atopic eczema. Adjusted logistic and multinomial regression models were fitted to estimate associations between ambient air pollution and eczema, and interaction by sex was assessed. RESULTS: Of 3153 participants in both follow-ups, 2369 had valid skin prick tests. For males, a 2.3 ppb increase in baselineNO2 was associated with increased odds of prevalent eczema (OR = 1.15 [95% CI 0.98-1.36]) and prevalent atopic eczema (OR = 1.26 [1.00-1.59]). These associations were not seen in females (p for interaction = 0.08, <0.01). For both sexes, a 1.6 µg/m3 increase in PM2.5 exposure at follow-up was associated with increased odds of aeroallergen sensitization (OR = 1.15 [1.03-1.30]). CONCLUSION: Increased exposure to residential ambient air pollutants was associated with an increased odds of eczema, only in males, and aeroallergen sensitization in both genders.

Body mass index and weight change are associated with adult lung function trajectories: the prospective ECRHS study.

BACKGROUND: Previous studies have reported an association between weight increase and excess lung function decline in young adults followed for short periods. We aimed to estimate lung function trajectories during adulthood from 20-year weight change profiles using data from the population-based European Community Respiratory Health Survey (ECRHS). METHODS: We included 3673 participants recruited at age 20-44 years with repeated measurements of weight and lung function (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1)) in three study waves (1991-93, 1999-2003, 2010-14) until they were 39-67 years of age. We classified subjects into weight change profiles according to baseline body mass index (BMI) categories and weight change over 20 years. We estimated trajectories of lung function over time as a function of weight change profiles using population-averaged generalised estimating equations. RESULTS: In individuals with normal BMI, overweight and obesity at baseline, moderate (0.25-1 kg/year) and high weight gain (>1 kg/year) during follow-up were associated with accelerated FVC and FEV1 declines. Compared with participants with baseline normal BMI and stable weight (±0.25 kg/year), obese individuals with high weight gain during follow-up had -1011 mL (95% CI -1.259 to -763) lower estimated FVC at 65 years despite similar estimated FVC levels at 25 years. Obese individuals at baseline who lost weight (<-0.25 kg/year) exhibited an attenuation of FVC and FEV1 declines. We found no association between weight change profiles and FEV1/FVC decline. CONCLUSION: Moderate and high weight gain over 20 years was associated with accelerated lung function decline, while weight loss was related to its attenuation. Control of weight gain is important for maintaining good lung function in adult life.

Early menarche is associated with lower adult lung function: A longitudinal cohort study from the first to sixth decade of life.

BACKGROUND AND OBJECTIVE: Early menarche is increasing in prevalence worldwide, prompting clinical and public health interest on its links with pulmonary function. We aimed to investigate the relationship between early menarche and lung function in middle age. METHODS: The population-based Tasmanian Longitudinal Health Study (born 1961; n = 8583), was initiated in 1968. The 5th Decade follow-up data (mean age: 45 years) included age at menarche and complex lung function testing. The 6th Decade follow-up (age: 53 years) repeated spirometry and gas transfer factor. Multiple linear regression and mediation analyses were performed to determine the association between age at menarche and adult lung function and investigate biological pathways, including the proportion mediated by adult-attained height. RESULTS: Girls reporting an early menarche (<12 years) were measured to be taller with greater lung function at age 7 years compared with those reporting menarche ≥12 years. By 45 years of age, they were shorter and had lower post-bronchodilator (BD) forced expiratory volume in 1 s (adjusted mean difference: -133 mL; 95% CI: -233, -33), forced vital capacity (-183 mL; 95% CI: -300, -65) and functional residual capacity (-168 mL; 95% CI: -315, -21). Magnitudes of spirometric deficits were similar at age 53 years. Forty percent of these total effects were mediated through adult-attained height. CONCLUSION: Early menarche was associated with reduced adult lung function. This is the first study to investigate post-BD outcomes and quantify the partial role of adult height in this association.

Comparison of apnoea-hypopnoea index and oxygen desaturation index when identifying obstructive sleep apnoea using type-4 sleep studies.

The concordance of different indices from type-4 sleep studies in diagnosing and categorising the severity of obstructive sleep apnoea is not known. This is a critical gap as type-4 sleep studies are used to diagnose obstructive sleep apnoea in some settings. Therefore, we aimed to determine the concordance between flow-based apnoea-hypopnoea index (AHIflow50% ) and oxygen desaturation index (ODI3% ) by measuring them concurrently. Using a random sub-sample of 296 from a population-based cohort who underwent two-channel type-4 sleep studies, we assessed the concordance between AHIflow50% and ODI3% . We compared the prevalence of obstructive sleep apnoea of various severities as identified by the two methods, and determined their concordance using coefficient Kappa(κ). Participants were aged (mean ±â€…SD) 53 ±â€…0.9 years (48% male). The body mass index was 28.8 ±â€…5.2 kg m-2 and neck circumference was 37.4 ±â€…3.9 cm. The median AHIflow50% was 5 (inter-quartile range 2, 10) and median ODI3% was 9 (inter-quartile range 4, 15). The obstructive sleep apnoea prevalence reported using AHIflow50% was significantly lower than that reported using ODI3% at all severity thresholds. Although 90% of those with moderate-severe obstructive sleep apnoea classified using AHIflow50% were identified by using ODI3% , only 46% of those with moderate-severe obstructive sleep apnoea classified using ODI3% were identified by AHIflow50% . The overall concordance between AHIflow50% and ODI3% in diagnosing and classifying the severity of obstructive sleep apnoea was only fair (κ = 0.32), better for males (κ = 0.42 [95% confidence interval 0.32-0.57] versus 0.22 [95% confidence interval 0.09-0.31]), and lowest for those with a body mass index ≥ 35 (κ = 0.11). In conclusion, ODI3% and AHIflow50% from type-4 sleep studies are at least moderately discordant. Until further evidence is available, the use of ODI3% as the measure of choice for type-4 sleep studies is recommended cautiously.

Detecting sleep apnoea syndrome in primary care with screening questionnaires and the Epworth sleepiness scale.

OBJECTIVE: To examine the utility of apnoea screening questionnaires, alone and in combination with the Epworth sleepiness scale (ESS), for detecting obstructive sleep apnoea (OSA) in primary care. DESIGN, SETTING: Prospective validation study in an Australian general population cohort. PARTICIPANTS: 424 of 772 randomly invited Tasmanian Longitudinal Health Study, 6th decade follow-up participants with OSA symptoms (mean age, 52.9 years; SD, 0.9 year) who completed OSA screening questionnaires and underwent type 4 sleep studies. MAIN OUTCOME MEASURES: Clinically relevant OSA, defined as moderate to severe OSA (15 or more oxygen desaturation events/hour), or mild OSA (5-14 events/hour) and excessive daytime sleepiness (ESS ≥ 8); diagnostic test properties of the Berlin (BQ), STOP-Bang and OSA-50 questionnaires, alone or combined with an ESS ≥ 8. RESULTS: STOP-Bang and OSA-50 correctly identified most participants with clinically relevant OSA (sensitivity, 81% and 86% respectively), but with poor specificity (36% and 21% respectively); the specificity (59%) and sensitivity of the BQ (65%) were both low. When combined with the criterion ESS ≥ 8, the specificity of each questionnaire was high (94-96%), but sensitivity was low (36-51%). Sensitivity and specificity could be adjusted according to specific needs by varying the STOP-Bang cut-off score when combined with the ESS ≥ 8 criterion. CONCLUSIONS: For people likely to trigger OSA assessment in primary care, the STOP-Bang, BQ, and OSA-50 questionnaires, combined with the ESS, can be used to rule in, but not to rule out clinically relevant OSA. Combined use of the STOP-Bang with different cut-off scores and the ESS facilitates a flexible balance between sensitivity and specificity.

Do Glutathione S-Transferase Genes Modify the Link between Indoor Air Pollution and Asthma, Allergies, and Lung Function? A Systematic Review.

PURPOSE OF REVIEW: Glutathione S-transferase (GST) genes are involved in oxidative stress management and may modify the impact of indoor air pollution. We aimed to assess the influence of GST genes on the relationship between indoor air pollution and allergy/lung function. RECENT FINDINGS: Our systematic review identified 22 eligible studies, with 15 supporting a gene-environment interaction. Carriers of GSTM1/T1 null and GSTP1 val genotypes were more susceptible to indoor air pollution exposures, having a higher risk of asthma and lung function deficits. However, findings differed in terms of risk alleles and specific exposures. High-exposure heterogeneity precluded meta-analysis. We found evidence that respiratory effects of indoor air pollution depend on the individual's GST profile. This may help explain the inconsistent associations found when gene-environment interactions are not considered. Future studies should aim to improve the accuracy of pollution assessment and investigate this finding in different populations.

Traffic-related air pollution exposure is associated with allergic sensitization, asthma, and poor lung function in middle age.

BACKGROUND: Traffic-related air pollution (TRAP) exposure is associated with allergic airway diseases and reduced lung function in children, but evidence concerning adults, especially in low-pollution settings, is scarce and inconsistent. OBJECTIVES: We sought to determine whether exposure to TRAP in middle age is associated with allergic sensitization, current asthma, and reduced lung function in adults, and whether these associations are modified by variants in Glutathione S-Transferase genes. METHODS: The study sample comprised the proband 2002 laboratory study of the Tasmanian Longitudinal Health Study. Mean annual residential nitrogen dioxide (NO2) exposure was estimated for current residential addresses using a validated land-use regression model. Associations between TRAP exposure and allergic sensitization, lung function, current wheeze, and asthma (n = 1405) were investigated using regression models. RESULTS: Increased mean annual NO2 exposure was associated with increased risk of atopy (adjusted odds ratio [aOR], 1.14; 95% CI, 1.02-1.28 per 1 interquartile range increase in NO2 [2.2 ppb]) and current wheeze (aOR, 1.14; 1.02-1.28). Similarly, living less than 200 m from a major road was associated with current wheeze (aOR, 1.38; 95% CI, 1.06-1.80) and atopy (aOR, 1.26; 95% CI, 0.99-1.62), and was also associated with having significantly lower prebronchodilator and postbronchodilator FEV1 and prebronchodilator forced expiratory flow at 25% to 75% of forced vital capacity. We found evidence of interactions between living less than 200 m from a major road and GSTT1 polymorphism for atopy, asthma, and atopic asthma. Overall, carriers of the GSTT1 null genotype had an increased risk of asthma and allergic outcomes if exposed to TRAP. CONCLUSIONS: Even relatively low TRAP exposures confer an increased risk of adverse respiratory and allergic outcomes in genetically susceptible individuals.

Traffic-related air pollution exposure over a 5-year period is associated with increased risk of asthma and poor lung function in middle age.

Current evidence concerning the impact of exposure to traffic-related air pollution (TRAP) on adult respiratory morbidity mainly comes from cross-sectional studies. We sought to establish more robust measures of this association and potential gene-environment interactions using longitudinal data from an established cohort study.Associations between measures of TRAP (nitrogen dioxide (NO2) and distance to major roads) and wheeze, asthma prevalence and lung function were investigated in participants of the Tasmanian Longitudinal Health Study at 45- and 50-year follow-ups. Generalised estimating equations were used to quantify associations and the potential modifying effect of glutathione S-transferase gene variants.Living <200 m from a major road was associated with increased prevalence of current asthma and wheeze, and lower lung function. The association between living <200 m from a major road and current asthma and wheeze was more marked for carriers of the GSTT1 null and GSTP1 val/val or ile/val genotypes. Over the 5-year period, higher NO2 exposures were associated with increased current asthma prevalence. Higher NO2 exposure was associated with lower forced vital capacity for carriers of the GSTT1 null genotype.TRAP exposures were associated with increased risk of asthma, wheeze and lower lung function in middle-aged adults. The interaction with the GSTT1 genotype suggests that deficient antioxidant mechanisms may play a role in these adverse health effects.