Should we screen aging physicians for cognitive decline?

OBJECTIVES: To synthesize evidence relevant for informed decisions concerning cognitive testing of older physicians. METHODS: Relevant literature was systematically searched in Medline, EMBASE, PsycInfo, and ERIC, with key findings abstracted and synthesized. RESULTS: Cognitive abilities of physicians may decline in an age range where they are still practicing. Physician competence and clinical performance may also decline with age. Cognitive scores are lower in physicians referred for assessment because of competency or performance concerns. Many physicians do not accurately self-assess and continue to practice despite declining quality of care; however, perceived cognitive decline, although not an accurate indicator of ability, may accelerate physicians' decision to retire. Physicians are reluctant to report colleagues' cognitive problems. Several issues should be considered in implementing cognitive screening. Most cognitive assessment tools lack normative data for physicians. Scientific evidence linking cognitive test results with physician performance is limited. There is no known level of cognitive decline at which a doctor is no longer fit to practice. Finally, relevant domains of cognitive ability vary across medical specialties. CONCLUSION: Physician cognitive decline may impact clinical performance. If cognitive assessment of older physicians is to be implemented, it should consider challenges of cognitive test result interpretation.

Sex-specific characteristics for the coexistence of asthma and COPD in the Canadian population: a cross-sectional analysis of CLSA data.

Objective: The coexistence of asthma and COPD (asthma + COPD) is a condition found among patients who present with clinical features of both asthma and COPD. Epidemiological evidence points to an increasingly disproportionate burden of asthma + COPD and COPD in females. The objective of this cross-sectional study is to identify female and male-specific epidemiological and clinical characteristics associated with asthma + COPD.Methods: Baseline data from the comprehensive cohort of Canadian Longitudinal Study on Aging (CLSA) were used in this cross-sectional study which included 30,097 subjects between the ages of 45- and 85-years Participants were categorized into four mutually exclusive groups: asthma + COPD, COPD-only, asthma-only and neither asthma nor COPD.Results: The prevalence was significantly greater in females than males for asthma + COPD (2.71% vs. 1.41%; p < 0.001), COPD-only (3.22% vs. 2.87%; p < 0.001) and asthma-only (13.31% vs. 10.11%; p < 0.001). The association between smoking and asthma + COPD was modified by age in females. Osteoporosis and underactive thyroid disease were significantly more prevalent in females than in males in asthma + COPD, COPD-only and asthma-only groups. In asthma + COPD group, a greater proportion of respiratory symptoms associated with asthma was observed in females whereas a greater proportion of respiratory symptoms associated with COPD was observed in males. Severity of airway obstruction determined by spirometry measurements was greater in males than females.Conclusions: In the Canadian adult population, several epidemiological and clinical characteristics in asthma + COPD varied between females and males. The findings in this study will help healthcare professional in the recognition and management of coexisting asthma and COPD in females and males.

Ergonomic demands and fetal loss in women in welding and electrical trades: A Canadian cohort study.

OBJECTIVES: To determine the relationship between ergonomic demands of the job at conception and fetal loss (miscarriage or stillbirth). METHODS: Women with a welding or electrical trade apprenticeship were identified across Canada for the Women's Health in Apprenticeship Trades-Metal and Electrical study. They completed a reproductive and employment history at recruitment and every 6 months for up to 5 years to provide details on pregnancies and work demands. Job at conception was identified and fetal loss examined in relation to ergonomic exposures/demands, allowing for potential confounders. RESULTS: A total of 885 women were recruited; 447 in welding and 438 in electrical trades. Of these, 574 reported at least one pregnancy. Analysis of 756 pregnancies since the woman started in her trade suggested no increased risk of fetal loss in those choosing welding rather than electrical work. Among 506 pregnancies conceived during a period working in a trade, 148 (29.2%) ended in fetal loss: 31.2% (73/234) in welding, and 27.6% (75/272) in electrical work. Detailed exposure information was available for 59% (299/506) of these pregnancies. In welders, the risk of fetal loss was increased with whole-body vibration (prevalence ratio [PR] = 2.14; 95% confidence interval [CI] 1.39-3.31) and hand-arm vibration for > 1 hour/day (PR = 2.15; 95% CI 1.33-3.49). In electrical workers risk increased with more than 8 days working without a rest day (PR = 2.29; 95% CI 1.25-4.17). Local exhaust ventilation reduced risk in welders. CONCLUSIONS: There was no significant increase in fetal loss in welding trades compared to electrical work. Vibration, largely from grinding, and extended work rotations appear to be potentially modifiable factors of some importance.

Sports-Related Concussions in Adults Presenting to Canadian Emergency Departments.

OBJECTIVE: To document the occurrence and recovery outcomes of sports-related concussions (SRCs) presenting to the Emergency Department (ED) in a community-based sample. DESIGN: A prospective observational cohort study was conducted in 3 Canadian hospitals. SETTING: Emergency Department. PATIENTS: Adults (≥17 years) presenting with a concussion to participating EDs with a Glasgow Coma Scale score ≥13 were recruited. INTERVENTIONS: Patient demographics (eg, age and sex), clinical characteristics (eg, history of depression or anxiety), injury characteristics (eg, injury mechanisms and loss of consciousness and duration), and ED management and outcomes (eg, imaging, consultations, and ED length of stay) were collected. MAIN OUTCOME MEASURES: Patients' self-reported persistent concussion symptoms, return to physical activity status, and health-related quality of life at 30 and 90 days after ED discharge. RESULTS: Overall, 248 patients were enrolled, and 25% had a SRC. Patients with SRCs were younger and reported more physical activity before the event. Although most of the patients with SRCs returned to their normal physical activities at 30 days, postconcussive symptoms persisted in 40% at 90 days of follow-up. After adjustment, there was no significant association between SRCs and persistent symptoms; however, patients with concussion from motor vehicle collisions were more likely to have persistent symptoms. CONCLUSION: Although physically active individuals may recover faster after a concussion, patients returning to their physical activities before full resolution of symptoms are at higher risk of persistent symptoms and further injury. Patient-clinician communications and tailored recommendations should be encouraged to guide appropriate acute management of concussions.

Effects of tumor necrosis factor (TNF) gene polymorphisms on the association between smoking and lung function among workers in swine operations.

Workers in swine operations may be at increased risk of developing respiratory problems. These respiratory conditions are more prevalent among workers who are smokers. Tumor necrosis factor (TNF) genes play an important role in human immune responses to various respiratory hazards. This study aimed to investigate whether polymorphisms in TNF genes might alter the effects of smoking on lung function among workers in swine operations. Three hundred and seventy-four full-time workers from large swine operations and 411 non-farming rural dwellers in Saskatchewan were included in this study. Information on demographic and lifestyle characteristics, pulmonary function, and blood samples were obtained. Multiple linear regression analyses were used in the statistical analysis. Three promoter polymorphisms (rs1799724, rs361525, and rs1800629) in the TNF gene were investigated. Only the interaction term between smoking status and rs1799724 was significant in the multiple regression models. Among workers with the rs1799724 polymorphism (TT+TC), current smokers exhibited significantly lower lung function than nonsmokers. These associations were not observed among workers with the wild-type (CC). These findings were not observed among non-farming rural dwellers. Data demonstrated the possible involvement of TNF gene in (1) development of adverse respiratory conditions among workers who are smokers, (2) importance of smoking cessation among workers, especially those with polymorphisms in the TNF gene, and (3) potential implications in treatment, screening, and prevention.

The effectiveness of removal from exposure and reduction of exposure for managing occupational asthma: Summary of an updated Cochrane systematic review.

BACKGROUND: The objective was to update the 2011 Cochrane systematic review on the effectiveness of workplace interventions for the treatment of occupational asthma. METHODS: A systematic review was conducted with the selection of articles and reports through 2019. The quality of extracted data was evaluated, and meta-analyses were conducted using techniques recommended by the Cochrane Handbook for Systematic Reviews of Interventions. RESULTS: Data were extracted from 26 nonrandomized controlled before-and-after studies. The mean number of participants per study was 62 and the mean follow-up time was 4.5 years. Compared with continued exposure, removal from exposure had an increased likelihood of improved symptoms and change in spirometry. Reduction of exposure also had more favorable results for symptom improvement than continued exposure, but no difference for change in spirometry. Comparing exposure removal to reduction revealed an advantage for removal with both symptom improvement and change in spirometry for the larger group of patients exposed to low-molecular-weight agents. Also, the risk of unemployment was greater for exposure removal versus reduction. CONCLUSIONS: Exposure removal and reduction had better outcomes than continued exposure. Removal from exposure was more likely to improve symptoms and spirometry than reduction among patients exposed to low-molecular-weight agents. The potential benefits associated with exposure removal versus reduction need to be weighed against the potential for unemployment that is more likely with removal from exposure. The findings are based on data graded as very low quality, and additional studies are needed to generate higher quality data.

Characteristics of asthma and COPD overlap syndrome (ACOS) in the Canadian population.

Objective: Asthma is a chronic disease affecting both children and adults, whereas chronic obstructive pulmonary disease (COPD) is a respiratory disease most commonly related to smoking and is usually seen in adults. When the airway disease shares features of both asthma and COPD, the phenotype is referred to as asthma and COPD overlap syndrome (ACOS). The objective of this cross-sectional study is to characterize ACOS in the Canadian population. Methods: Data from the first three cycles of the Canadian Health Measures Survey (CHMS) were used in this study. The study included 9059 subjects aged 30 years and above. The CHMS included a detailed interviewer-administered questionnaire and spirometry measurements. Based on the self-report, subjects were categorized into control, ACOS, COPD only and asthma only groups. Results: The prevalence of ACOS, COPD and asthma groups was 1.59%, 2.21% and 6.65%, respectively. The proportion of females was significantly greater than males in the ACOS group. The proportion of wheeze was highest in the ACOS group (64.93%) whereas the prevalence of shortness of breath was the highest in the COPD group (46.25%). Heart disease, cancer, arthritis and liver disease were more prevalent in the ACOS group than in COPD, asthma and control groups. Severity of airway obstruction was the highest in the ACOS group and was followed by COPD, asthma and control groups, respectively. Conclusions: Characteristics of ACOS in the Canadian population were similar to those observed in the developed countries and longitudinal studies are required to determine the incidence and risk factors of ACOS.

Dental microwear texture analysis of Homo sapiens sapiens: Foragers, farmers, and pastoralists.

OBJECTIVES: The current study seeks to determine if a sample of foragers, farmers, and pastoralists are distinguishable based on their dental microwear texture signatures. MATERIALS AND METHODS: The study included a sample of 719 individuals from 51 archeological sites (450 farmers, 192 foragers, 77 pastoralists). All were over age 12 and sexes were pooled. Using a Sensofar® white-light confocal profiler we collected dental microwear texture analysis (DMTA) data from a single first or second molar from each individual. We leveled and cleaned data clouds following standard procedures and analyzed the data with Sfrax® and Toothfrax® software. The DMTA variables were complexity and anisotropy. Statistics included ANOVA with partial eta squared and Hedges's g. We also performed a follow-up K-means cluster analysis. RESULTS: We found significant differences between foragers and farmers and pastoralists for complexity and anisotropy, with foragers having greater complexity than either the farmers or the pastoralists. The farmers and pastoralists had greater anisotropy than the foragers. The Old World foragers had significantly higher anisotropy values than New World foragers. Old and New World farmers did not differ. Among the Old World farmers, those dating from the Neolithic through the Late Bronze Age had higher complexity values than those from the Iron Age through the medieval period. The cluster analysis discerned foragers and farmers but also indicated similarity between hard food foragers and hard food farmers. DISCUSSION: Our findings reaffirm that DMTA is capable of distinguishing human diets. We found that foragers and farmers, in particular, differ in their microwear signatures across the globe. There are some exceptions, but nothing that would be unexpected given the range of human diets and food preparation techniques. This study indicates that in general DMTA is an efficacious means of paleodietary reconstruction in humans.

Workplace interventions for treatment of occupational asthma.

BACKGROUND: The impact of workplace interventions on the outcome of occupational asthma is not well understood. OBJECTIVES: To evaluate the effectiveness of workplace interventions on occupational asthma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (PubMed); EMBASE(Ovid); NIOSHTIC-2; and CISILO (CCOHS) up to July 31, 2019. SELECTION CRITERIA: We included all eligible randomized controlled trials, controlled before and after studies and interrupted time-series of workplace interventions for occupational asthma. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study eligibility and risk of bias, and extracted data. MAIN RESULTS: We included 26 non-randomized controlled before and after studies with 1,695 participants that reported on three comparisons: complete removal from exposure and reduced exposure compared to continued exposure, and complete removal from exposure compared to reduced exposure. Reduction of exposure was achieved by limiting use of the agent, improving ventilation, or using protective equipment in the same job; by changing to another job with intermittent exposure; or by implementing education programs. For continued exposure, 56 per 1000 workers reported absence of symptoms at follow-up, the decrease in forced expiratory volume in one second as a percentage of a reference value (FEV1 %) was 5.4% during follow-up, and the standardized change in non-specific bronchial hyperreactivity (NSBH) was -0.18.In 18 studies, authors compared removal from exposure to continued exposure. Removal may increase the likelihood of reporting absence of asthma symptoms, with risk ratio (RR) 4.80 (95% confidence interval (CI) 1.67 to 13.86), and it may improve asthma symptoms, with RR 2.47 (95% CI 1.26 to 4.84), compared to continued exposure. Change in FEV1 % may be better with removal from exposure, with a mean difference (MD) of 4.23 % (95% CI 1.14 to 7.31) compared to continued exposure. NSBH may improve with removal from exposure, with standardized mean difference (SMD) 0.43 (95% CI 0.03 to 0.82).In seven studies, authors compared reduction of exposure to continued exposure. Reduction of exposure may increase the likelihood of reporting absence of symptoms, with RR 2.65 (95% CI 1.24 to 5.68). There may be no considerable difference in FEV1 % between reduction and continued exposure, with MD 2.76 % (95% CI -1.53 to 7.04) . No studies reported or enabled calculation of change in NSBH.In ten studies, authors compared removal from exposure to reduction of exposure. Following removal from exposure there may be no increase in the likelihood of reporting absence of symptoms, with RR 6.05 (95% CI 0.86 to 42.34), and improvement in symptoms, with RR 1.11 (95% CI 0.84 to 1.47), as well as no considerable change in FEV1 %, with MD 2.58 % (95% CI -3.02 to 8.17). However, with all three outcomes, there may be improved results for removal from exposure in the subset of patients exposed to low molecular weight agents. No studies reported or enabled calculation of change in NSBH.In two studies, authors reported that the risk of unemployment after removal from exposure may increase compared with reduction of exposure, with RR 14.28 (95% CI 2.06 to 99.16). Four studies reported a decrease in income of 20% to 50% after removal from exposure.The quality of the evidence is very low for all outcomes. AUTHORS' CONCLUSIONS: Both removal from exposure and reduction of exposure may improve asthma symptoms compared with continued exposure. Removal from exposure, but not reduction of exposure, may improve lung function compared to continued exposure. When we compared removal from exposure directly to reduction of exposure, the former may improve symptoms and lung function more among patients exposed to low molecular weight agents. Removal from exposure may also increase the risk of unemployment. Care providers should balance the potential clinical benefits of removal from exposure or reduction of exposure with potential detrimental effects of unemployment. Additional high-quality studies are needed to evaluate the effectiveness of workplace interventions for occupational asthma.

Psychiatric co-morbidity and asthma: A pilot study utilizing a free use tool to improve asthma care.

PURPOSE: To assess the prevalence of co-morbid psychiatric disorders in asthmatic patients in a Western Canadian Regional Severe Asthma Center. METHODS: A prospective study was completed of patients evaluated through the Edmonton Regional Severe Asthma Clinic (ERSAC). A standardised evaluation, the Mini International Neuropsychiatric Interview (MINI) screen was used to identify possible psychiatric disorders. RESULTS: Twenty-four individuals with moderate to severe asthma, who presented for treatment at ERSAC, were recruited and underwent assessment with the MINI screen. The average patient age was 48 years (range 18-81 years). Nine patients were male and fifteen were female. Twenty subjects (83%) screened positive for a possible psychiatric co-morbidity using the MINI screen. The most common psychiatric co-morbidities identified were post-traumatic stress disorder (50% of the sampled population), depressive episode or persistent depressive disorder (42%), substance/alcohol abuse (33%), generalized anxiety disorder (335), manic episode (25%), agoraphobia (21%), panic disorder (21%) and obsessive-compulsive disorder (17%). Some individuals had more than one concomitant possible psychiatric co-morbidity identified by the MINI screen. CONCLUSIONS: Psychiatric co-morbidity was confirmed to be common in patients with moderate-severe asthma. In individuals with asthma, the MINI screen appeared to be a simple and useful clinical tool to screen for untreated/sub-optimally-managed psychiatric co-morbidities that may impact management.

Gender-specific associations between polymorphisms in the Toll-like receptor (TLR) genes and lung function among workers in swine operations.

Workers in swine operations are exposed to dust, bacteria, and virus, and are at increased risk of respiratory problems. Toll-like receptors (TLR) play an important role in human immune responses to respiratory hazards. Worker gender and age may significantly modify the involvement of TLR in the etiology of these respiratory outcomes. The aim of this study was to investigate whether modification effects of worker gender and age altered associations between polymorphisms in the TLR genes and lung function. This study included 374 full-time workers from large swine operations from Saskatchewan. Information on demography, lifestyle, pulmonary function,  and blood samples were obtained. Multiple linear regression and decision tree model were used in the analysis. Among females aged <45.8 years, workers with polymorphisms of rs4696480 in the TLR2 gene exhibited markedly better lung function than workers with wild-type. These associations were not observed among female workers aged ≥45.8 years and males. Among males, workers with polymorphisms of rs187084 in the TLR9 gene displayed significantly lower lung function than those with wild-type. This male-specific association was not dependent on worker age. This is the first study to report gender-specific correlations between lung function and polymorphisms of TLR genes, and modification effects of worker age on these associations, suggesting the importance of considering gender and age in genetic association studies of airway diseases due to exposure of high concentration of respiratory hazards.

Concussion diagnoses among adults presenting to three Canadian emergency departments: Missed opportunities.

OBJECTIVES: Patients with concussion commonly present to the emergency department (ED) for assessment. Misdiagnosis of concussion has been documented in children and likely impacts treatment and discharge instructions. This study aimed to examine diagnosis of concussion in a general adult population. METHODS: Patients >17years old presenting meeting the World Health Organization's definition of concussion were recruited in one academic (Hospital 1) and two community (Hospitals 2 and 3) EDs in a Canadian city. A physician questionnaire and patient interviews documented recommendations given by emergency physicians. Bi-variable comparisons are reported using chi-square tests, t-tests or Mann-Whitney tests, as appropriate. Multivariate analyses were performed using logistic regression methods. RESULTS: Overall, the study enrolled 250 patients. The median age was 35 (IQR: 23 to 49) and 52% were female. A variety of concussion causes were documented. Forty-one (16%) patients were not diagnosed with a concussion despite meeting criteria. Concussion diagnosis was less likely with a longer ED length of stay (OR=0.71; 95% CI: 0.60 to 0.83), presenting to the non-academic centers (Hospital 2: OR=0.21, 95% CI: 0.08 to 0.58; Hospital 3: OR=0.07, 95% CI: 0.02 to 0.24), or involvement in a motor vehicle collision (OR=0.11; 95% CI: 0.03 to 0.46). CONCLUSION: One in six patients with concussion signs and symptoms were misdiagnosed in the ED. Misdiagnosis was related to injury mechanism, length of stay, and enrolment site. Closer examination of institutional factors is needed to identify effective strategies to promote accurate diagnosis of concussion.

Agricultural injuries among farm and non-farm children and adolescents in Alberta, Canada.

BACKGROUND: Understanding of the specific risk of agricultural injury sustained by different populations of children and adolescents is needed for effective safety intervention. OBJECTIVE: To compare the rates and patterns of agricultural injury incidence (fatal and non-fatal injury) between farm and non-farm children less than 18 years of age in Alberta, Canada. METHODS: A total of 115 378 children (five subgroups: two groups of farm children and three groups of non-farm children) in Alberta were followed from 1999 to 2010 to examine injury incidence using the linkage of three administrative health databases. A recurrent event survival analysis using Cox proportional hazards regression was carried out. RESULTS: A total of 1 849 agricultural injury episodes (1 616 emergency department visits, 225 hospitalizations, and 8 deaths) were identified from 1999 to 2010. The age- and gender-adjusted rate (per 100 000 person years) of agricultural injury was 672.3 for rural-living farm children, 369.4 for urban-living farm children, 180.2 for rural non-First Nations (FN) children, 64.4 for rural FN children, and 23.7 for urban children in descending order. CONCLUSION: Specific strategies for different children's populations to prevent agricultural injuries and to extend agricultural injury controls to non-farming populations are needed.

A Prospective Evaluation of the Influence of an Electronic Clinical Practice Guidelines on Concussion Patients' Future Activities and Outcomes.

BACKGROUND: Patients with mild traumatic brain injury or concussion commonly present to the emergency department for assessment; providing patients with information on usual symptoms and their progression may encourage faster recovery. OBJECTIVES: This study aimed to document the role of an electronic clinical practice guideline (eCPG) patient handout on concussion recovery in adult patients discharged from the hospital. METHODS: A prospective cohort study was carried out in 3 Canadian urban emergency departments. Adults (≥17 years of age) with a Glasgow Coma Scale score of 13 to 15 who sustained a concussion were recruited by on-site research assistants. Physician use of a concussion-specific eCPG was documented from physician and patient reports. Patient follow-up calls at 30 and 90 days documented return to work/school activities and patient symptoms. Multivariate analyses were performed using logistic regression methods. RESULTS: Overall, 250 patients were enrolled; the median age was 35 (interquartile range 23-49) and 52% were female. Approximately half (n = 119, 48%) of patients received the eCPG handout, and return to work/school recommendations varied. Symptoms persisted in 60% of patients at 30 days; patients in the eCPG group had fewer symptoms (odds ratio 0.57, 95% confidence interval 0.33-0.99). At 90 days, 40% of patients reported persistent symptoms, with no significant difference between groups. CONCLUSION: An eCPG handout improved patients' short-term outcomes; however, physician use and adherence to guideline recommendations was low. To further facilitate physician compliance and therefore patient recovery, barriers to use of the eCPG handout need to be identified and addressed.

Social, obstetric and environmental determinants of low Apgar score among infants born in four selected hospitals in Ibadan, Nigeria.

Little information exists about socio-economic, environmental or occupational determinants of low Apgar scores among Nigerian neonates. Mothers in lying-in wards of four hospitals in Ibadan were interviewed on socio-demographic characteristics, obstetric history and work activities during index pregnancy. Apgar scores and clinical data were extracted from case notes. Of the 1349 respondents, 20% had Apgar score <7 at one minute, 4% at five minutes. Lower education, cooking with kerosene, physical exertion at work, nulliparity, hypertension in pregnancy, prolonged rupture of membranes, breech presentation and caesarean section were predictors for low Apgar scores at one minute; nulliparity, male infant and breech presentation at five minutes. Occupations with lower socio-economic status or those requiring physical exertion; tailoring, catering and hairdressing recorded higher rates of low Apgar scores at one minute (p = .08). Physical exertion at work and cooking with kerosene may be predictive of low Apgar scores and require further study.

Association of living in a farming environment with asthma incidence in Canadian children.

OBJECTIVE: The objective of this population-based 14-year follow-up study was to examine the effect of living in a farm environment on asthma incidence in children. METHODS: A total of 10,941 children of ages 0 to 11 years who were free of asthma and wheeze at the baseline (1994-1995) in the National Longitudinal Survey of Children and Youth were considered in the study. Children's living environment was classified, based on interviewer's observation, into three categories: non-rural, rural non-farming, and farming. An incidence of asthma was obtained from health-professional diagnosed asthma reported either by the person most knowledgeable for children under 15 years or by the children themselves if they were of ages 16 years and over. RESULTS: The 14-year cumulative incidence of asthma among children living in farming environments was 10.18%, which was significantly lower than that observed for children living in rural non-farming (13.12%) and non-rural environments (16.50%). After adjusting for age group, number of older siblings, allergy, parental history of asthma, dwelling in need of repairs and SES index, a dose-response relationship was observed with children living in rural non-farming and farming environments having significantly reduced risk of asthma [hazard ratio (HR): 0.77; 95% confidence interval (CI): (0.60, 1.00); p = 0.047 and HR: 0.56; 95% CI: (0.41,0.77); p < 0.001] in comparison to those living in non-rural environments. CONCLUSION: This cohort study provides further evidence that living in a farming environment during childhood is protective of asthma incidence in adolescence and adulthood and this finding provides further support for the hygiene hypothesis.

Pesticide exposures and respiratory health in general populations.

Human exposures to pesticides can occur in the workplace, in the household and through the ambient environment. While several articles have reviewed the impact of pesticide exposures on human respiratory health in occupational settings, to the best of our knowledge, this article is the first one to review published studies on the association between pesticide exposures and human respiratory health in the general populations. In this article, we critically reviewed evidences up to date studying the associations between non-occupational pesticide exposures and respiratory health in general populations. This article also highlighted questions arising from these studies, including our recent analyses using the data from the Canadian Health Measures Survey (CHMS), for future research. We found few studies have addressed the impact of environmental pesticide exposures on respiratory health, especially on lung function, in general populations. In the studies using the data from CHMS Cycle 1, exposures to OP insecticides, pyrethroid insecticides, and the organochlorine pesticide DDT were associated with impaired lung function in the Canadian general population, but no significant associations were observed for the herbicide 2,4-D. Future research should focus on the potential age-specific and pesticide-specific effect on respiratory health in the general population, and repeated longitudinal study design is critical for assessing the temporal variations in pesticide exposures. Research findings from current studies of non-occupational pesticide exposures and their health impact in general population will help to improve the role of regulatory policies in mitigating pesticide-related public health problems, and thereafter providing greater benefit to the general population.

Urinary concentrations of pyrethroid metabolites and its association with lung function in a Canadian general population.

OBJECTIVES: While there is increasing concern about the health impact of pyrethroid insecticides, little is known about their effect on lung function. In this cross-sectional study, urinary concentrations of pyrethroid (PYR) metabolites and their associations with lung function were examined among a Canadian general population using data from the Canadian Health Measures Survey (CHMS). METHODS: Urinary concentrations of 5 pyrethroid metabolites (3-PBA, 4-F-3-PBA, cis-DCCA, trans-DCCA and cis-DBCA) were available for 5436 CHMS participants aged 6-79 years. Lung function parameters considered were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio and forced expiratory flow between 25% and 75% of FVC. Multiple linear regression analyses were used to examine associations between PYR concentrations and lung function in children (6-11 years), adolescents (12-19 years) and adults (20-79 years), respectively. RESULTS: Almost all CHMS participants (99.8%) had PYR metabolites detectable in urine. In multiple linear regression analyses, 1 unit increase in log transformed urinary concentration (nmol/g creatinine) of total pyrethorid metabolites (ΣPYR) was associated with a 17.4 mL reduction in FEV1 (p=0.045) in children, a 37.1 mL reduction in FVC (p=0.05) in adolescents and a 0.3% (p=0.01) increase in FEV1/FVC ratio in adults. CONCLUSIONS: These results show evidence of widespread exposures to pyrethroid insecticides among the Canadian general population. Pyrethroid exposures were associated with lower FEV1 in children, lower FVC in adolescents and relatively higher FEV1/FVC ratio in adults. Further research is necessary to confirm the potential effect of pyrethroid insecticides on lung function reported in this study.

Association between vitamin D and respiratory outcomes in Canadian adolescents and adults.

BACKGROUND: Asthma is one of the most prevalent chronic diseases worldwide, affecting more than 200 million people. Vitamin D deficiency has been reported among individuals with asthma and might play a role in asthma exacerbations. In this cross-sectional study, we investigated the association of serum 25-hydroxy vitamin D [25(OH)D] levels and current asthma, ever asthma, and lung function. METHODS: Data from 3937 subjects aged 13-69 years who participated in the Canadian Health Measures Survey - Cycle 1 were considered in this study. Serum 25(OH)D levels were categorized into ≤49 nmol/L (low), 50-74 nmol/L (moderate) and ≥75 nmol/L (high). RESULTS: The proportion of subjects with current and ever asthma was greater in the lower 25(OH)D category than in moderate and high categories. After adjusting for potential confounders, subjects in the low 25(OH)D levels were more likely to have current asthma than those in the moderate levels (OR: 1.54, 95% CI: 1.01-2.36). Low 25(OH)D levels were also associated with ever asthma (OR: 2.12, 95% CI: 1.40-3.21) among those with a family history of asthma and this association was stronger in those with asthma onset before 20 years of age. High 25(OH)D levels were associated with lower mean value of FEV1/FVC ratio. No significant association was observed between 25(OH)D levels and other lung function measurements. CONCLUSION: In this study, 25(OH)D levels below 50 nmol/L were associated with an increased risk of current and ever asthma. Further exploration of this relationship is needed to determine the optimal level of vitamin D in the management of asthma in adolescents and adults.

Genetic susceptibility to beryllium: a case-referent study of men and women of working age with sarcoidosis or other chronic lung disease.

OBJECTIVE: The study was designed to investigate whether beryllium exposure was related to illness diagnosed as sarcoidosis. Chronic beryllium disease (CBD) and sarcoidosis are clinically and pathologically indistinguishable, with only the presence of beryllium-specific T-lymphocytes identifying CBD. Testing for such cells is not feasible in community studies of sarcoidosis but a second characteristic of CBD, its much greater incidence in those with a glutamic acid residue at position 69 of the HLA-DPB1 gene (Glu69), provides an alternative approach to answering this question. METHODS: Cases of sarcoidosis aged 18-60 years diagnosed in Alberta, Canada, from 1999 to 2005 were approached through their specialist physician, together with age-matched and sex-matched referents with other chronic lung disease. Referents were grouped into chronic obstructive pulmonary disease (COPD), asthma and other lung disease. Participants completed a telephone questionnaire, including industry-specific questionnaires. DNA was extracted from mailed-in mouthwash samples and genotyped for Glu69. Duration of employment in types of work with independently documented beryllium exposure was calculated. RESULTS: DNA was extracted for 655 cases (270 Glu69 positive) and 1382 referents (561 positive). No increase in sarcoidosis was seen with either Glu69 or beryllium exposure (none, <10, ≥10 years) as main effects: longer duration in possible beryllium jobs was related to COPD. In Glu69 positive men with exposure ≥10 years, the trend towards increasing rate of COPD was reversed, and a significant interaction of duration of exposure and Glu69 was detected (OR=4.51 95% CI 1.17 to 17.48). CONCLUSIONS: The gene-environment interaction supports the hypothesis that some cases diagnosed as sarcoidosis result from occupational beryllium exposure.