Activity-related dyspnea in older adults participating in the Canadian Longitudinal Study on Aging.

BACKGROUND: Dyspnea is associated with functional impairment and impaired quality of life. There is limited information on the potential risk factors for dyspnea in an older adult population. OBJECTIVES: Among older adults aged 45 to 85 years of age, what sociodemographic, environmental, and disease related factors are correlated with dyspnea? DESIGN: We used cross-sectional questionnaire data collected on 28,854 participants of the Canadian Longitudinal Study of Aging (CLSA). Multinomial regression was used to assess the independent effect of individual variables adjusting for the other variables of interest. KEY RESULTS: The adjusted odds ratios for dyspnea "walking on flat surfaces" were highest for obesity (OR, 5.71; 95%CI, 4.71-6.93), lung disease (OR, 3.91; 95%CI, 3.41-4.49), and depression (OR, 3.68; 95%CI, 3.15-4.29), and were greater than 2 for lower income, and heart disease. The effect of diabetes remained significant after adjusting for sociodemographics, heart disease and BMI (OR, 1.61; 95%CI, 1.39-1.86). Those with both respiratory disease and depression had a 12.78-fold (95%CI, 10.09-16.19) increased odds of exertional dyspnea, while the corresponding OR for the combination of heart disease and depression was 18.31 (95%CI, 13.4-25.01). CONCLUSIONS: In a community sample of older adults, many correlates of dyspnea exist which have significant independent and combined effects. These factors should be considered in the clinical context where dyspnea is out of proportion to the degree of heart and lung disease. Whether or not diabetes may possibly be a risk factor for dyspnea merits further investigation.

Respiratory Symptoms Are Associated With Frailty in Older Adults With Normal Spirometry, Independent of Smoking, in the Canadian Longitudinal Study of Aging.

BACKGROUND: Recent studies have demonstrated that even in the absence of lung impairment as determined by spirometry, smoking and respiratory symptoms are associated with poor overall health and well-being. However, this relationship is not well defined; and it remains unclear the degree to which symptoms are related to poor health, independent of smoking. This is of particular importance to older adults, as they are more likely to exhibit respiratory symptoms and are, therefore, at risk of not receiving appropriate treatment if they have never smoked and have normal spirometry. METHODS: We performed a cross-sectional analysis of data from the Canadian Longitudinal Study on Aging to delineate the associations of respiratory symptoms and smoking on the health of participants age 45-86 who exhibited normal spirometry. Participant health was estimated using a frailty index, a multidimensional measure of vulnerability to adverse outcomes that has been validated in numerous health settings. RESULTS: Of the 21,293 participants included in our analysis, 87% exhibited a normal FEV1, FVC, and FEV1/FVC; of those, 45% reported at least one respiratory symptom, and 50% were former or current smokers. Both respiratory symptoms and smoking were independently associated with frailty (median interquartile range [IQR] = 0.11 [0.07-0.15]), the most substantial associations observed for those having at least one respiratory symptom (adjusted ß 0.023, 95% CI 0.022-0.025) and current smokers with > 10 pack-year exposure (adjusted ß 0.014, 95% CI [0.010-0.019). Not only was the association between symptoms and frailty evident in never smokers, a significant proportion of the total effect of smoking on frailty was observed to be mediated by symptoms. CONCLUSIONS: Our data show that respiratory symptoms, regardless of smoking history, were a significant correlate of frailty in older adults with normal spirometry. Hence, they should not be simply regarded as a benign by-product of aging.

Associations between air pollution and cardio-respiratory physiological measures in older adults exercising outdoors.

We examined whether exercising indoors vs. outdoors reduced the cardio-respiratory effects of outdoor air pollution. Adults ≥55 were randomly assigned to exercise indoors when the Air Quality Health Index was ≥5 and outdoors on other days (intervention group, n = 37), or outdoors everyday (control group, n = 35). Both groups completed cardio-respiratory measurements before and after exercise for up to 10 weeks. Data were analyzed using linear mixed effect regression models. In the control group, an interquartile range increase in fine particulate matter (PM2.5) was associated with increases of 1.4% in heart rate (standard error (SE) = 0.7%) and 5.6% (SE = 2.6%) in malondialdehyde, and decreases of 5.6% (SE = 2.5%) to 16.5% (SE = 7.5%) in heart rate variability measures. While the hypothesized benefit of indoor vs. outdoor exercise could not be demonstrated due to an insufficient number of intervention days (n = 2), the study provides evidence of short-term effects of air pollution in older adults. ISRCTN #26552763.

A comprehensive analysis of factors related to lung function in older adults: Cross-sectional findings from the Canadian Longitudinal Study on Aging.

Maintenance of lung function is an often underappreciated, yet critical component of healthy aging. Given the unprecedented shift in the average age of Canadians over the next half century, it will be important to investigate the determinants of lung function in the elderly. In the following study, we estimated the association between lung function and a broad array of factors related to sociodemographics, lifestyle, chronic medical conditions and psychosocial factors in older adults aged 45-86 years old using cross-sectional data from the Canadian Longitudinal Study of Aging (n = 21,338). In addition to examining the entire cohort, we also performed stratified analyses within men/women, adults aged 45-64/65+, and healthy/comorbid. In multivariable regression, our explanatory factors (excluding age, sex, height and ethnicity) were able to explain 17% and 11% of the total variance in FEV1 and FEV1/FVC, respectively. Notable and significant contributions were observed for respiratory disease, smoking, obesity, income, and physical activity, while psychosocial factors mainly exhibited non-significant associations. Generally, these associations were stronger for males than females, and adults 65 and older as compared to those aged 45-64. Our findings indicate that there are pervasive and generally under-recognized sociodemographic and lifestyle factors that exhibit significant associations with FEV1 and FEV1/FVC in older adults. While implication of causality in these relationships is not possible due to the cross-sectional nature of the study, future work aiming to investigate determinants of lung health in older adults may choose to target these factors, given that many are modifiable.

Is residential ambient air limonene associated with asthma? Findings from the Canadian Health Measures Survey.

Asthma is a common chronic disease. Exposure to limonene is commonplace because it may be used in the manufacture of personal care products and household cleaners. We investigated the influence of limonene on asthma in a population-based sample of approximately 3000 Canadians. During the Canada Health Measures Survey, carried out between 2012 and 2013, participants were asked if they wheezed or had a diagnosis of asthma, and underwent spirometry and measurement of the fraction of exhaled nitric oxide (FeNO). These variables were tested for an association with limonene concentrations measured in their household air samples, using linear regression analysis A 100% increase in air limonene concentration was associated with an approximate 17% adjusted relative increase wheezing with an odds ratio of 1.17 (95%CI 1.16, 1.18). The percent change in FeNO for a 100% increase in limonene was twice as large for children, 2.89% (95% CI 1.88, 4.43) compared to adults, 1.44% (95%CI 1.16, 1.79). Among boys, the odds ratio was 1.50 (95%CI 1.48, 1.52) between a 100% increase in limonene and a diagnosis of asthma. This study provides evidence that household exposure to limonene may increase the prevalence of asthma in the general population.

Cardiorespiratory Effects of Air Pollution in a Panel Study of Winter Outdoor Physical Activity in Older Adults.

OBJECTIVE: The aim of this study was to assess cardiorespiratory effects of air pollution in older adults exercising outdoors in winter. METHODS: Adults 55 years of age and older completed daily measurements of blood pressure, peak expiratory flow and oximetry, and weekly measurements of heart rate variability, endothelial function, spirometry, fraction of exhaled nitric oxide and urinary oxidative stress markers, before and after outdoor exercise, for 10 weeks. Data were analyzed using linear mixed effect models. RESULTS: Pooled estimates combining 2014 (n = 36 participants) and 2015 (n = 34) indicated that an interquartile increase in the Air Quality Health Index was associated with a significant (P < 0.05) increase in heart rate (0.33%) and significant decreases in forced expiratory volume (0.30%), and systolic (0.28%) and diastolic blood pressure (0.39%). CONCLUSION: Acute subclinical effects of air pollution were observed in older adults exercising outdoors in winter.

Cardio-Respiratory Effects of Air Pollution in a Panel Study of Outdoor Physical Activity and Health in Rural Older Adults.

OBJECTIVE: To examine cardio-respiratory effects of air pollution in rural older adults exercising outdoors. METHODS: Adults 55 and over completed measurements of blood pressure, peak expiratory flow and oximetry daily, and of heart rate variability, endothelial function, spirometry, fraction of exhaled nitric oxide and urinary oxidative stress markers weekly, before and after outdoor exercise, for 10 weeks. Data were analyzed using linear mixed effect models. RESULTS: Pooled estimates combining 2013 (n = 36 participants) and 2014 (n = 41) indicated that an interquartile increase in the air quality health index (AQHI) was associated with a significant (P < 0.05) increase in heart rate (2.1%) and significant decreases in high frequency power (-19.1%), root mean square of successive differences (-9.5%), and reactive hyperemia index (-6.5%). CONCLUSIONS: We observed acute subclinical adverse effects of air pollution in rural older adults exercising outdoors.

The influence of polycyclic aromatic hydrocarbons on lung function in a representative sample of the Canadian population.

We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV1), forced vital capacity (FVC), and the ratio between the two (FEV1/FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV1 and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population.

Does Mental Health Status Influence Susceptibility to the Physiologic Effects of Air Pollution? A Population Based Study of Canadian Children.

BACKGROUND: Both air pollution exposure and the presence of mental illness are associated with an increased risk of physical illness. OBJECTIVE: To determine whether or not children with less favourable mental health are more susceptible to pulmonary and cardiovascular effects of ambient air pollution, compared to those who are mentally healthy. METHODS: We carried out a cross-sectional study of 1,883 children between the ages of 6 and 17 years of age who participated in the Canadian Health Measures population survey between 2007 and 2009. Subjects were assigned the air pollution values obtained from the National Air Pollution monitor closest to their neighborhood. Lung function, heart rate and blood pressure were stratified by indicators of mental health. The latter were ascertained by questions about feelings of happiness, a diagnosed mood disorder, and the emotional symptom subscale of the Strengths and Difficulties Questionnaire. RESULTS: Among those who reported a mood disorder, an interquartile increase in ozone was associated with increases in systolic and diastolic pressures of 3.8 mmHg (95% CI 1.6, 5.9) and 3.0mmHg (95%CI 0.9, 5.2) respectively, and a decreases in FVC of 7.6% (95% CI 2.9, 12.3). No significant changes in these variables were observed in those who did not report a mood disorder. Among those with unfavourable emotional symptoms, ozone was associated with a 6.4% (95% CI 1.7, 11.3) increase in heart rate, a 4.1% (95%CI 1.2, 7.1) increase in systolic blood pressure, and a 6.0% (95% CI 1.4, 10.6) decrease in FEVl. No significant effect was seen in these variables among those with no emotional symptoms. CONCLUSIONS: In the Canadian population, children who report mood disorders or unfavourable emotional symptoms appear to be more vulnerable to the adverse physiologic effects of air pollution.

Residential exposure to volatile organic compounds and lung function: results from a population-based cross-sectional survey.

Exposure to residential volatile organic compounds (VOCs) is ubiquitous in homes, and may influence respiratory health with important public health implications. To investigate the association between VOCs measured in residential indoor air and lung function in the Canadian population Cycle 2 of the Canadian Health Measures Survey - a population based cross-sectional survey designed to be representative of the Canadian population - was carried out between 2009 and 2011. Of the 84 VOCs measured, 47 were detectable in at least 50% of homes and ten were negatively associated with lung function: decanal, 2-furancarboxaldehyde, hexanal, nonanal, octanal, benzene, styrene, α-pinene, 2-methyl-1,2-butadiene and naphthalene. Differences were observed between males and females, as well as by age, and significant associations were most frequent in those under 17 years. These results provide evidence that some VOCs measured indoors are negatively associated with lung function in the Canadian population.

The association between urinary phthalates and lung function.

OBJECTIVE: To investigate the influence of phthalate exposure on lung function in the Canadian population. METHODS: We tested the association between 1-second forced expiratory volume (FEVl), forced vital capacity (FVC), and urinary phthalate metabolite levels in a nationally representative sample of 3147, from 6 to 49 years old. RESULTS: An interquartile increase in mono-n-butyl phthalate was associated with decreases in percent predicted FEV1 of 0.8% (95% confidence interval = 0.3 to 1.4) and in FVC of 0.9% (95% confidence interval = 0.3 to 1.5). Results were similar for mono-3-carboxypropyl phthalate, mono-benzyl phthalate, and di(2-ethylhexyl) phthalate metabolites, but significant effects of the latter were only seen in males and those at least 17 years old. CONCLUSIONS: These results provide evidence that phthalate exposure may adversely affect lung function in the Canadian population. Given that these chemicals are ubiquitous, the population health burden may be significant if the associations were causal.

The association between personal care products and lung function.

PURPOSE: Chemical exposures are important determinants of respiratory health. The objective of the present study was to determine the association between the use of personal care products, which may contain respirable components, and lung function. METHODS: Using questionnaire and spirometry data collected during the Canadian Health Measures population survey, the association was tested between 1-second forced expiratory volume (FEV(l)) and forced vital capacity (FVC) expressed as a percentage of predicted, and the frequency of use of personal care products categorized as eye makeup, fragrances, hairstyle products, lipstick, and scented body products. RESULTS: Five thousand sixteen of the 5604 participants in the survey reported using at least one personal care product in the past 3 months. Among men and women, an interquartile increase in hairstyle products was associated with an approximate 2% decrease in both FEV(1) and FVC (P < .05). Among women, each product category was associated with a significant decrease in lung function with the largest observed effect being a 4.08% (95% confidence interval, 7.71-0.45) decrease in FVC associated with an interquartile range increase in the frequency of use of scented body products. CONCLUSIONS: This study provides data suggesting that using personal care products may have a small adverse effect on lung function. Further research is warranted to investigate this possibility.

Air pollution and hospitalization for acute complications of diabetes in Chile.

Exposure to air pollution has been shown to cause insulin resistance in mice. To determine the relevance to humans, we tested the association between daily air pollution concentrations and daily hospitalization for acute serious complications of diabetes, coma and ketoacidosis, in Santiago between 2001 and 2008, using generalized linear models with natural splines to control for long term trends. For an interquartile range (IQR) increase in air pollutant, the relative risks (95% CI) of hospitalization for diabetes were: 1.15 (1.10, 1.20) for carbon monoxide (IQR=1.00); 1.07 (0.98, 1.16) for ozone (IQR=63.50); 1.14 (1.06, 1.22) for sulfur dioxide (IQR=5.88); 1.12(1.05, 1.20) for nitrogen dioxide (IQR=27.94); 1.11 (1.07, 1.15) for particulate matter≤10 µm diameter(IQR=34.00); and 1.11 (1.06, 1.16) for fine particulate matter ≤2.5 µm diameter (IQR=18.50). Results were similar when stratified by age, sex and season. Air pollution appears to increase the risk of acute complications of diabetes requiring hospitalization, suggesting that improvements in air quality may reduce morbidity from diabetes.

The influence of neighborhood traffic density on the respiratory health of elementary schoolchildren.

BACKGROUND: Several studies have found that living near major roadways is associated with an increase in respiratory illness but few studies have measured the volume and type of traffic. OBJECTIVE: We investigated the relation between traffic volume and respiratory health of 2328 children 9 to 11 years old in the city of Windsor, Canada. METHODS: We identified the roadways within a 200 meter radius of the child's neighborhood using the latitude and longitude of the residential postal code. Traffic exposure was defined as the sum of the annual volume of vehicles on all of these roadways. Volume was calculated using sensors to detect passing vehicles (simple traffic counts), and by counts and direction of traffic at intersections (turning movement counts). Ventilatory lung function was measured by spirometry and airway inflammation by exhaled nitric oxide (eNO). RESULTS: The odds ratio between an interquartile increase in truck turning movement counts and chest congestion was 1.20 (1.06-1.35). The percentage of predicted FVC declined 0.68%, (95% CI 1.32, 0.03) for an interquartile increase in simple traffic counts (33,787 vehicles daily). Among those with self-reported asthma, effect sizes were larger. Percentage predicted FEV(1) declined 1.84% (95% CI 0.07, 3.61) associated with an interquartile range increase in turning movement counts. No statistically significant change was detected between traffic measures and exhaled nitric oxide. CONCLUSIONS: Our findings provide further support for the hypothesis that neighborhood exposure to traffic-related air pollution increases respiratory symptoms and reduces ventilatory function in children, especially those with self-reported asthma.

Does air pollution increase the effect of aeroallergens on hospitalization for asthma?

BACKGROUND: Clinical experiments demonstrate that the asthmatic response to an aeroallergen can be enhanced by prior exposure to an air pollutant. OBJECTIVE: We sought to compare the effects of ambient aeroallergens on hospitalization for asthma between high and low air pollution days in 11 large Canadian cities. METHODS: Daily time-series analysis was used, and results were adjusted for day of the week, temperature, barometric pressure, and relative humidity. RESULTS: The relative risk of admission for an interquartile increase in tree pollen levels was 1.124 (95% CI, 1.101-1.147) on days of lower values of fine particulate matter with a median aerodynamic diameter less than or equal to 2.5 µm (PM(2.5)) compared with 1.179 (95% CI, 1.149-1.21) on days of higher PM(2.5) values. Significant (P ≤ .05) differences in the relative risks of admission between lower versus higher values of particulate matter with a median aerodynamic diameter less than or equal to 10 µm in diameter were 1.149 (95% CI, 1.118-1.181) versus 1.210 (95% CI, 1.161-1.261) for ascomycetes, 1.112 (95% CI, 1.085-1.14) versus 1.302 (95% CI, 1.242-1.364) for basidiomycetes, 1.159 (95% CI, 1.125-1.195) versus 1.149 (95% CI, 1.129-1.169) for deuteromycetes, and 1.061 (95% CI, 1.016-1.107) versus 1.117 (95% CI, 1.092-1.143) for weeds. CONCLUSION: We identified an association between aeroallergens and hospitalizations for asthma, which was enhanced on days of higher air pollution. Minimizing exposure to air pollution might reduce allergic exacerbations of asthma.

The risk of dying on days of higher air pollution among the socially disadvantaged elderly.

RATIONALE: The estimated mortality rate associated with ambient air pollution based on general population studies may not be applicable to certain subgroups. OBJECTIVE: The objective of the present study was to determine the influence of age, education, employment status and income on the risk of mortality associated with ambient air pollution. METHODS: Daily time-series analyses tested the association between daily air pollution and daily mortality in seven Chilean urban centers during the period January 1997-December 2007. Results were adjusted for long-term trends, day-of-the week and humidex. RESULTS: Interquartile increases in particulate matter (PM(10) and PM(2.5)), sulphur dioxide, nitrogen dioxide, carbon monoxide, and elemental and organic carbon were associated with a 4-7% increase in mortality among those who did not complete primary school (p<0.05) vs. 0.5-1.5% among university graduates (p>0.05). Among those at least 85 years of age respective estimates were 2-7%. However, among the elderly who did not complete primary school, respective estimates were 11-19% (p<0.05). The degree of effect modification was less for income and employment status than education, and sex did not modify the results. CONCLUSION: The socially disadvantaged, especially if elderly appear to be especially susceptible to dying on days of higher air pollution. Concentrations deemed acceptable for the general population would not appear to protect this susceptible subgroup.

Air pollution and hospitalization for epilepsy in Chile.

OBJECTIVE: To determine the association between gaseous and fine particulate air pollution (PM(2.5)) and epilepsy in a general population sample. METHOD: A daily time-series analyses tested the association between daily hospitalization for epilepsy in seven Chilean urban centers during the period 2001 and 2005. Results were adjusted for long term trends, day-of-the-week, and average humidex on the day of hospitalization and the day before. RESULTS: Pooled city estimates of relative risk (95% CI) of hospitalization for epilepsy associated with changes in pollutant concentrations equivalent to their interquartile range were: 1.098(1.045, 1.155) for carbon monoxide (CO); 1.100 (1.025, 1.181) for ozone O(3); 1.085 (1.03, 1.144) for sulfur dioxide (SO(2)); 1.108 (1.021, 1.204) for nitrogen dioxide (NO(2)); 1.083(1.038, 1.13) for particulate matter

A comparison of obese and nonobese people with asthma: exploring an asthma-obesity interaction.

OBJECTIVE: The objectives of our study were to compare patient characteristics and severity of disease in obese and normal-weight-confirmed people with asthma and to explore reasons for misdiagnosis of asthma, including potential interactions with obesity. METHODS: We randomly selected patients with physician-diagnosed asthma from eight Canadian cities. Asthma diagnosis was confirmed via a sequential lung function testing algorithm. Logistic analysis was conducted to compare obese and normal-weight-confirmed people with asthma and to assess characteristics associated with misdiagnosis of asthma. Interaction with obesity was investigated. RESULTS: Complete assessments were obtained on 496 subjects who reported physician-diagnosed asthma (242 obese and 254 normal-weight subjects); 346 had asthma confirmed with sequential lung testing, and in 150 subjects a diagnosis of asthma was ruled out. Obese subjects with asthma were significantly more likely to be men, have a history of hypertension and gastroesophageal reflux disease, and have a lower FEV(1) compared with normal-weight subjects with asthma. Older subjects, men, and subjects with higher FEV(1) were more likely to have received misdiagnoses of asthma. Obesity was not an independent predictor of misdiagnosis, however there was an interaction between obesity and urgent visits for respiratory symptoms. The odds ratio for receiving a misdiagnosis of asthma for obese individuals as compared with normal-weight individuals was 4.08 (95% CI, 1.23-13.5) for those with urgent visits in the past 12 months. CONCLUSIONS: Obese people with asthma have lower lung function and more comorbidities compared with normal-weight people with asthma. Obese individuals who make urgent visits for respiratory symptoms are more likely to receive a misdiagnosis of asthma.

Components of particulate air pollution and emergency department visits in Chile.

The objective of the present study was to determine the association between several elements of particulates and Emergency Department (ED) visits in a general population sample. Daily time-series analyses tested the association between daily ED visit and air pollutants and components of particulates measured in Santiago Centro, a municipality, which includes downtown Santiago during the period from 2001 to 2006. The strongest individual effect was seen for elemental carbon. A 4.76 microg/m3 increase was associated with a relative risk (RR) of 1.12 (95% confidence interval [CI] = 1.10-1.14) increase in total ED visits, and a RR of 1.18 (95% CI = 1.16-1.21) for respiratory ED visit. Using factor analysis, the authors determined that traffic combustion-related particulates were significantly associated with ED visits. Among all the sources identified, traffic combustion-related particulates had the strongest association with ED visits. A factor indicating soil-sourced particles had a weaker but statistically significant observed morbidity effect. Of the many components of particulate air pollution, those from motor vehicle exhaust had the greatest observed effect on morbidity.

Air pollution and hospitalization for headache in Chile.

The authors performed a time-series analysis to test the association between air pollution and daily numbers of hospitalizations for headache in 7 Chilean urban centers during the period 2001-2005. Results were adjusted for day of the week and humidex. Three categories of headache-migraine, headache with cause specified, and headache not otherwise specified-were all associated with air pollution. Relative risks for migraine associated with interquartile-range increases in specific air pollutants were as follows: 1.11 (95% confidence interval (CI): 1.06, 1.17) for a 1.15-ppm increase in carbon monoxide; 1.11 (95% CI: 1.06, 1.17) for a 28.97-microg/m(3) increase in nitrogen dioxide; 1.10 (95% CI: 1.04, 1.17) for a 6.20-ppb increase in sulfur dioxide; 1.17 (95% CI: 1.08, 1.26) for a 69.51-ppb increase in ozone; 1.11 (95% CI: 1.00, 1.19) for a 21.51-microg/m(3) increase in particulate matter less than 2.5 mum in aerodynamic diameter (PM(2.5)); and 1.10 (95% CI: 1.04, 1.15) for a 37.79-microg/m(3) increase in particulate matter less than 10 mum in aerodynamic diameter (PM(10)). There was no significant effect modification by age, sex, or season. The authors conclude that air pollution appears to increase the risk of headache in Santiago Province. If the relation is causal, the morbidity associated with headache should be considered when estimating the burden of illness and costs associated with poor air quality.