Exertional breathlessness related to medical conditions in middle-aged people: the population-based SCAPIS study of more than 25,000 men and women.

BACKGROUND: Breathlessness is common in the population and can be related to a range of medical conditions. We aimed to evaluate the burden of breathlessness related to different medical conditions in a middle-aged population. METHODS: Cross-sectional analysis of the population-based Swedish CArdioPulmonary bioImage Study of adults aged 50-64 years. Breathlessness (modified Medical Research Council [mMRC] ≥ 2) was evaluated in relation to self-reported symptoms, stress, depression; physician-diagnosed conditions; measured body mass index (BMI), spirometry, venous haemoglobin concentration, coronary artery calcification and stenosis [computer tomography (CT) angiography], and pulmonary emphysema (high-resolution CT). For each condition, the prevalence and breathlessness population attributable fraction (PAF) were calculated, overall and by sex, smoking history, and presence/absence of self-reported cardiorespiratory disease. RESULTS: We included 25,948 people aged 57.5 ± [SD] 4.4; 51% women; 37% former and 12% current smokers; 43% overweight (BMI 25.0-29.9), 21% obese (BMI ≥ 30); 25% with respiratory disease, 14% depression, 9% cardiac disease, and 3% anemia. Breathlessness was present in 3.7%. Medical conditions most strongly related to the breathlessness prevalence were (PAF 95%CI): overweight and obesity (59.6-66.0%), stress (31.6-76.8%), respiratory disease (20.1-37.1%), depression (17.1-26.6%), cardiac disease (6.3-12.7%), anemia (0.8-3.3%), and peripheral arterial disease (0.3-0.8%). Stress was the main factor in women and current smokers. CONCLUSION: Breathlessness mainly relates to overweight/obesity and stress and to a lesser extent to comorbidities like respiratory, depressive, and cardiac disorders among middle-aged people in a high-income setting-supporting the importance of lifestyle interventions to reduce the burden of breathlessness in the population.

Adjusted incidence, remission, and relapse of self-reported physician-diagnosed asthma and asthma medication usage in endurance athletes.

Longitudinal studies are needed to increase our knowledge of the natural history of asthma in athletes. Our aims were to estimate the incidence, remission, and relapse, of self-reported asthma among endurance athletes. A postal questionnaire on self-reported physician-diagnosed asthma, asthma medication, allergy, and respiratory symptoms was sent annually 2011-2015 to 666 Swedish elite athletes competing in cross-country skiing, biathlon, ski orienteering, or orienteering. Athletes at risk for (1) incident asthma were those without previous self-reported asthma, use of asthma medication, or asthma-like symptoms, (2) remission those who discontinued asthma medication usage and (3) relapse those who resumed asthma medication usage during the observation period. The population at risk was used as denominator in the calculations of subsequent event rate. At baseline, 89% responded, the median age was 17 years and 47% were females. Of the 373 athletes with never asthma nor use of asthma medication/asthma-like symptoms at baseline, 31 (8%) reported physician-diagnosed asthma during follow-up, giving an adjusted incidence rate of asthma of 42/1000 person years. Among the 110 athletes with self-reported asthma and use of asthma medication at baseline, 26 (24%) discontinued use of asthma medication during the follow-up, giving a remission rate of 142/1000 person years. Of the 31 athletes with previous asthma and no use of asthma medication at baseline, 9 (29%) resumed use of asthma medication during follow-up, giving a relapse rate was 148/1000 person years. Elite endurance athletes have a high incidence of self-reported physician-diagnosed asthma. The remission and relapse of self-reported asthma medication usage in endurance athletes appear similar to that of the general population.

Influence of exercise duration on respiratory function and systemic immunity among healthy, endurance-trained participants exercising in sub-zero conditions.

BACKGROUND: Strenuous endurance exercise in sub-zero temperatures can cause airway damage that may lead to EIB. Prolonged exercise can also elicit greater immune perturbations than short-duration exercise. However, the influence of exercise duration on lung function and systemic immunity in sub-zero temperatures has not been established. Additionally, it is currently unknown whether atopic disposition, which is risk factor for EIB, influences respiratory responses in a sub-zero climate. The aim of this study was to compare respiratory and systemic immune responses to two cold air running trials of short and long duration, as well as to examine whether the responses differed between atopic and non-atopic subjects. METHODS: Eighteen healthy, endurance-trained subjects (males/females: 14/4; age: 29.4 ± 5.9 years old; BMI: 23.1 ± 1.7; atopic/non-atopic: 10/8) completed two moderate-intensity climate chamber running trials at - 15 °C, lasting 30 and 90 min, in a randomized, cross-over design. Lung function (spirometry and impulse oscillometry), serum CC16, respiratory symptoms, and blood leukocyte counts were examined before and after the trials. RESULTS: Lung function was not significantly affected by exercise or exercise duration. CC16 concentration increased after both trials (p = 0.027), but the response did not differ between trials. Respiratory symptom intensity was similar after each trial. There was a greater increase in neutrophils (p < 0.001), and a decrease in eosinophils (p < 0.001) after the 90-min bout. The 90-min protocol increased X5 compared to the 30-min protocol only in atopic subjects (p = 0.015) while atopy increased lower airway symptoms immediately after the 90-min session (p = 0.004). CONCLUSIONS: Our results suggest that a 90-min bout of moderate-intensity exercise at - 15 °C does not cause substantial lung function decrements, airway epithelial damage or respiratory symptoms compared to 30 min running in the same environment, despite a heightened redistribution of white blood cells. However, exercise at - 15 °C may cause airway injury and evoke respiratory symptoms, even at moderate intensity. Atopic status may lead to greater peripheral bronchodilation and higher frequency of respiratory symptoms after long-duration exercise in cold. TRIAL REGISTRATION: 01/02/2022 ISRCTN13977758. This trial was retrospectively registered upon submission to satisfy journal guidelines. The authors had not initially registered the study, as the intervention was considered to be a controlled simulation of exercise in a naturally occurring environment (i.e. sub-zero air) for healthy volunteers.

A breathing mask attenuates acute airway responses to exercise in sub-zero environment in healthy subjects.

PURPOSE: Cold air exposure is associated with increased respiratory morbidity and mortality. Repeated inhalation of cold and dry air is considered the cause of the high prevalence of asthma among winter endurance athletes. This study assessed whether a heat- and moisture-exchanging breathing device (HME) attenuates airway responses to high-intensity exercise in sub-zero temperatures among healthy subjects. METHODS: Using a randomized cross-over design, 23 healthy trained participants performed a 30-min warm-up followed by a 4-min maximal, self-paced running time trial in - 15 °C, with and without HME. Lung function was assessed pre- and immediately post-trials. Club cell protein (CC-16), 8-isoprostane, and cytokine concentrations were measured in plasma and urine pre- and 60 min post trials. Symptoms were assessed prior to, during, and immediately after each trial in the chamber. RESULTS: HME use attenuated the decrease in forced expiratory volume in 1 s (FEV1) post trials (∆FEV1: mean (SD) HME - 0.5 (1.9) % vs. no-HME - 2.7 (2.7) %, p = 0.002). HME also substantially attenuated the median relative increase in plasma-CC16 concentrations (with HME + 27% (interquartile range 9-38) vs no-HME + 121% (55-162), p < 0.001) and reduced airway and general symptom intensity, compared to the trial without HME. No significant changes between trials were detected in urine CC16, 8-isoprostane, or cytokine concentrations. CONCLUSION: The HME attenuated acute airway responses induced by moderate-to-maximal-intensity exercise in - 15 °C in healthy subjects. Further studies are needed to examine whether this HMEs could constitute primary prevention against asthma in winter endurance athletes.

Cold air exposure at - 15 °C induces more airway symptoms and epithelial stress during heavy exercise than rest without aggravated airway constriction.

PURPOSE: Exposure to cold air may harm the airways. It is unclear to what extent heavy exercise adds to the cold-induced effects on peripheral airways, airway epithelium, and systemic immunity among healthy individuals. We investigated acute effects of heavy exercise in sub-zero temperatures on the healthy airways. METHODS: Twenty-nine healthy individuals underwent whole body exposures to cold air in an environmental chamber at - 15 °C for 50 min on two occasions; a 35-min exercise protocol consisting of a 5-min warm-up followed by 2 × 15 min of running at 85% of VO2max vs. 50 min at rest. Lung function was measured by impulse oscillometry (IOS) and spirometry before and immediately after exposures. CC16 in plasma and urine, and cytokines in plasma were measured before and 60 min after exposures. Symptoms were surveyed pre-, during and post-trials. RESULTS: FEV1 decreased after rest (- 0.10 ± 0.03 L, p < 0.001) and after exercise (- 0.06 ± 0.02 L, p = 0.012), with no difference between trials. Exercise in - 15 °C induced greater increases in lung reactance (X5; p = 0.023), plasma CC16 (p < 0.001) as well as plasma IL-8 (p < 0.001), compared to rest. Exercise induced more intense symptoms from the lower airways, whereas rest gave rise to more general symptoms. CONCLUSION: Heavy exercise during cold air exposure at - 15 °C induced signs of an airway constriction to a similar extent as rest in the same environment. However, biochemical signs of airway epithelial stress, cytokine responses, and symptoms from the lower airways were more pronounced after the exercise trial.

High incidence rate of asthma among elite endurance athletes: a prospective 4-year survey.

Objective: The prevalence of asthma among elite endurance athletes is high, but less is known about the incidence of asthma among athletes. The aim of this study was to examine the incidence rate of physician-diagnosed asthma among elite endurance athletes.Method: An annual postal questionnaire was sent to an open prospective cohort of elite endurance athletes between 2011 and 2015. Athletes from Swedish National teams, students at universities with elite sport partnership, and pupils at Swedish National elite sport schools, competing in cross-country skiing, biathlon, ski orienteering, or orienteering were invited (n = 666). Incidence rate of physician-diagnosed asthma was calculated among those without asthma at baseline (n = 449). Risk factors for incident physician-diagnosed asthma were identified using a multivariate logistic regression analysis.Results: Response rate was 88.7% (n = 591) at baseline. The median age of participants was 17 (range 15-36) years at inclusion. The study population included 407 (69%) skiers and 184 (31%) orienteers. The prevalence of asthma at baseline was 23.9% (n = 141). Incidence rate (95% confidence interval [CI]) of physician-diagnosed asthma was 61.2 (45.7-80.3) per 1,000 person-years. Risk factors (odds ratio [OR (95% CI)]) for incident physician-diagnosed asthma were family history of asthma (1.97 [1.04-3.68]), being a skier (3.01 [1.42-7.21]), and wheezing without having a cold (4.15 [1.81-9.26]).Conclusion: The incidence rate of physician-diagnosed asthma is high among Swedish elite endurance athletes.

Occupational cold exposure is associated with increased reporting of airway symptoms.

OBJECTIVE: To determine if exposure to cold environments, during work or leisure time, was associated with increased reporting of airway symptoms in the general population of northern Sweden. METHODS: Through a population-based postal survey responded to by 12627 subjects, ages 18-70, living in northern Sweden, the occurrence of airway symptoms was investigated. Cold exposure during work or leisure time was self-reported on numerical rating scales. Binary logistic regression was used to determine the statistical association between cold exposure and airway symptoms. RESULTS: For currently working subjects (N = 8740), reporting any occupational cold exposure was associated to wheeze (OR 1.3; 95% CI 1.1-1.4); chronic cough (OR 1.2; 95% CI 1.1-1.4); and productive cough (OR 1.3; 95% CI 1.1-1.4), after adjusting for gender, age, body mass index, daily smoking, asthma, and chronic obstructive pulmonary disease. Leisure-time cold exposure was not significantly associated to reporting airway symptoms. CONCLUSIONS: Occupational cold exposure was an independent predictor of airway symptoms in northern Sweden. Therefore, a structured risk assessment regarding cold exposure could be considered for inclusion in the Swedish workplace legislation.

A heat and moisture-exchanging mask impairs self-paced maximal running performance in a sub-zero environment.

PURPOSE: Heat-and-moisture-exchanging devices (HME) are commonly used by endurance athletes during training in sub-zero environments, but their effects on performance are unknown. We investigated the influence of HME usage on running performance at - 15 °C. METHODS: Twenty-three healthy adults (15 male, 8 female; age 18-53 years; [Formula: see text] men 56 ± 7, women 50 ± 4 mL·kg-1·min-1) performed two treadmill exercise tests with and without a mask-style HME in a randomised, crossover design. Participants performed a 30-min submaximal warm-up (SUB), followed by a 4-min maximal, self-paced running time-trial (TT). Heart rate (HR), respiratory frequency (fR), and thoracic area skin temperature (Tsk) were monitored using a chest-strap device; muscle oxygenation (SmO2) and deoxyhaemoglobin concentration ([HHb]) were derived from near-infra-red-spectroscopy sensors on m. vastus lateralis; blood lactate was measured 2 min before and after the TT. RESULTS: HME usage reduced distance covered in the TT by 1.4%, despite similar perceived exertion, HR, fR, and lactate accumulation. The magnitude of the negative effect of the HME on performance was positively associated with body mass (r2 = 0.22). SmO2 and [HHb] were 3.1% lower and 0.35 arb. unit higher, respectively, during the TT with HME, and Tsk was 0.66 °C higher during the HME TT in men. HR (+ 2.7 beats·min-1) and Tsk (+ 0.34 °C) were higher during SUB with HME. In the male participants, SmO2 was 3.8% lower and [HHb] 0.42 arb. unit higher during SUB with HME. CONCLUSION: Our findings suggest that HME usage impairs maximal running performance and increases the physiological demands of submaximal exercise.

Self-reported physician-diagnosed asthma among Swedish adolescent, adult and former elite endurance athletes.

OBJECTIVE: Asthma is common among elite endurance athletes. Since the first published Swedish studies in 1993, awareness of "skiers' asthma" has increased. The current prevalence of asthma among Swedish skiers is unknown. This paper aims to present the design of a 5-year prospective annual questionnaire study on asthma among Swedish current and former elite endurance athletes, the first cross-sectional results on prevalence, age of onset, and predictors of self-reported physician-diagnosed asthma in the study population. METHODS: An annual postal questionnaire is sent to Swedish elite skiers and orienteers during 2011-2015. In 2013, former Swedish Olympic skiers were similarly invited. We present cross-sectional data obtained in 2011 from the adolescents and adults and in 2013 from former skiers. A total of 491 athletes were invited. The results are presented by age, sex and sport. Chi-square test was used for group comparisons. Predictors of asthma were identified using logistic regression. RESULTS: Response rate was 82%. Among athletes aged 15-19, 29% of the skiers (38% of the female skiers), and 17% of the orienteers reported asthma (p = 0.071). Among the athletes aged 20-34, 35% of the skiers and 16% of the orienteers reported asthma (p = 0.029). Among the former skiers aged 40-94, 22% reported asthma. Among the active athletes, the onset of asthma was in early adolescence. Logistic regression found increasing age, female sex, allergy, family history of allergy/asthma and being skier predictors of self-reported physician-diagnosed asthma. CONCLUSIONS: The prevalence of physician-diagnosed asthma is high among Swedish endurance athletes, especially female adolescent skiers.

Effects of controlled diesel exhaust exposure on apoptosis and proliferation markers in bronchial epithelium - an in vivo bronchoscopy study on asthmatics, rhinitics and healthy subjects.

BACKGROUND: Epidemiological evidence demonstrates that exposure to traffic-derived pollution worsens respiratory symptoms in asthmatics, but controlled human exposure studies have failed to provide a mechanism for this effect. Here we investigated whether diesel exhaust (DE) would induce apoptosis or proliferation in the bronchial epithelium in vivo and thus contribute to respiratory symptoms. METHODS: Moderate (n = 16) and mild (n = 16) asthmatics, atopic non-asthmatic controls (rhinitics) (n = 13) and healthy controls (n = 21) were exposed to filtered air or DE (100 µg/m(3)) for 2 h, on two separate occasions. Bronchial biopsies were taken 18 h post-exposure and immunohistochemically analysed for pro-apoptotic and anti-apoptotic proteins (Bad, Bak, p85 PARP, Fas, Bcl-2) and a marker of proliferation (Ki67). Positive staining was assessed within the epithelium using computerized image analysis. RESULTS: No evidence of epithelial apoptosis or proliferation was observed in healthy, allergic or asthmatic airways following DE challenge. CONCLUSION: In the present study, we investigated whether DE exposure would affect markers of proliferation and apoptosis in the bronchial epithelium of asthmatics, rhinitics and healthy controls, providing a mechanistic basis for the reported increased airway sensitivity in asthmatics to air pollutants. In this first in vivo exposure investigation, we found no evidence of diesel exhaust-induced effects on these processes in the subject groups investigated.

The Prevalence of COPD in Individuals with Acute Coronary Syndrome: A Spirometry-Based Screening Study.

BACKGROUND: The prevalence of COPD among individuals with acute coronary syndrome (ACS) is estimated at 5% to 18%, and COPD appears to be a predictor of poor outcome. Diagnosis of COPD has mostly been based on medical records without spirometry. As COPD is largely undiagnosed and misdiagnosed, the prevalence and clinical significance of COPD in the ACS population has not been reliably assessed. The present study aimed to estimate the prevalence of COPD in patients with ACS and evaluate the accuracy of medical record-based COPD diagnoses. METHODS: This was a single-centre spirometry screening study for COPD in patients admitted for ACS in the county of Jämtland, Sweden. Patient medical records were reviewed to register previous medical history. Spirometry was performed prior to discharge or at the first follow-up outpatient visit after discharge. COPD was defined as a post-bronchodilator FEV1/FVC of <0.7 or below lower limit of normal. RESULTS: Of 743 eligible patients, 407 performed spirometry. Five percent had COPD according to medical records; 11% and 5% fulfilled spirometric criteria of COPD according to FEV1/FVC of < 0.7 (p = 0.002) and below lower limit of normal definitions, respectively. "COPD according to medical history" had a sensitivity of 23%, specificity of 98%, positive predictive value of 53%, and negative predictive value of 91% compared with spirometric COPD FEV1/FVC of < 0.7 CONCLUSIONS: In patients with ACS, COPD is underdiagnosed and misdiagnosed. We raise concerns regarding the validity of medical record-based COPD in evaluating the biological and clinical association between COPD and coronary disease. CLINICAL TRIAL REGISTRATION: ISRCTN number 05697808 (www. controlled-trials.com).

All-cause and cause-specific mortality by spirometric pattern and sex - a population-based cohort study.

BACKGROUND: Chronic airway obstruction (CAO) and restrictive spirometry pattern (RSP) are associated with mortality, but sex-specific patterns of all-cause and specific causes of death have hardly been evaluated. OBJECTIVES: To study the possible sex-dependent differences of all-cause mortality and patterns of cause-specific mortality among men and women with CAO and RSP, respectively, to that of normal lung function (NLF). DESIGN: Population-based prospective cohort study. METHODS: Individuals with CAO [FEV1/vital capacity (VC) < 0.70], RSP [FEV1/VC ⩾ 0.70 and forced vital capacity (FVC) < 80% predicted] and NLF (FEV1/VC ⩾ 0.70 and FVC ⩾ 80% predicted) were identified within the Obstructive Lung Disease in Northern Sweden (OLIN) studies in 2002-2004. Mortality data were collected through April 2016, totally covering 19,000 patient-years. Cox regression and Fine-Gray regression accounting for competing risks were utilized to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for age, body mass index, sex, smoking habits and pack-years. RESULTS: The adjusted hazard for all-cause mortality was higher in CAO and RSP than in NLF (HR, 95% CI; 1.69, 1.31-2.02 and 1.24, 1.06-1.71), and the higher hazards were driven by males. CAO had a higher hazard of respiratory and cardiovascular death than NLF (2.68, 1.05-6.82 and 1.40, 1.04-1.90). The hazard of respiratory death was significant in women (3.41, 1.05-11.07) while the hazard of cardiovascular death was significant in men (1.49, 1.01-2.22). In RSP, the higher hazard for respiratory death remained after adjustment (2.68, 1.05-6.82) but not for cardiovascular death (1.11, 0.74-1.66), with a similar pattern in both sexes. CONCLUSION: The higher hazard for all-cause mortality in CAO and RSP than in NLF was male driven. CAO was associated with respiratory death in women and cardiovascular death in men, while RSP is associated with respiratory death, similarly in both sexes.

All-cause and cause specific mortality in relation to different lung function patterns and sex; normal, obstructive and restricted lung functionChronic airway obstruction and restrictive spirometry pattern are associated with mortality, but sex specific patterns have hardly been evaluated.Aim: To study possible sex-dependent differences of all-cause and cause-specific mortality among men and women with chronic airway obstruction and restrictive spirometry pattern, respectively, compared to that of normal lung function.Methods: Individuals with chronic airway obstruction, restrictive spirometry pattern and normal lung function were identified within the Obstructive Lung Disease in Northern Sweden (OLIN) studies in 2002-04. Mortality data were collected through April 2016, totally covering 19,000 patient-years of observation time. We analyzed the Hazard Ratios for all-cause and cause-specific death comparing chronic airway obstruction and restrictive spirometry pattern to that of normal lung function, adjusting for age, body mass index, sex, smoking habits and pack-years. Similar analyses were conducted separately for men and women.Results: The hazard for all-cause mortality was higher in both chronic airway obstruction and restrictive spirometry pattern than in normal lung function and, the higher hazards were male-driven. In chronic airway obstruction the hazard of respiratory and cardiovascular deaths higher than in those with normal lung function. The increased hazard of respiratory death was significant in women while the increased hazard of cardiovascular death was significant in men. In restrictive spirometry pattern, the higher hazard for respiratory but not cardiovascular death persisted after adjustment, similarly in both sexes.Conclusions: The higher hazard for all-cause mortality in chronic airway obstruction and restrictive spirometry pattern than in normal lung function was male-driven. Chronic airway obstruction associated with respiratory death in women and cardiovascular death in men, while restrictive pattern associated with respiratory death, similarly in both sexes.

Airway inflammatory responses to diesel exhaust in allergic rhinitics.

CONTEXT: Proximity to traffic, particularly to diesel-powered vehicles, has been associated with inducing and enhancing allergies. To investigate the basis for this association, we performed controlled exposures of allergic rhinitics to diesel exhaust (DE) at a dose known to be pro-inflammatory in healthy individuals. OBJECTIVE: We hypothesized that diesel-exhaust exposure would augment lower airway inflammation in allergic rhinitics. MATERIALS AND METHODS: Fourteen allergic rhinitics were exposed in a double-blinded, randomized trial to DE (100 µg/m³ PM10) and filtered air for 2 h on separate occasions. Bronchoscopy with endobronchial mucosal biopsies and airway lavage was performed 18 h post-exposure, and inflammatory markers were assessed. RESULTS: No evidence of neutrophilic airway inflammation was observed post-diesel, however, a small increase in myeloperoxidase was found in bronchoalveolar lavage (p = 0.032). We found no increases in allergic inflammatory cells. Reduced mast cell immunoreactivity for tryptase was observed in the epithelium (p = 0.013) parallel to a small decrease in bronchial wash stem cell factor (p = 0.033). DISCUSSION AND CONCLUSION: DE, at a dose previously shown to cause neutrophilic inflammation in healthy individuals, induced no neutrophilic inflammation in the lower airways of allergic rhinitics, consistent with previous reports in asthmatics. Although there was no increase in allergic inflammatory cell numbers, the reduction in tryptase in the epithelium may indicate mast cell degranulation. However, this occurred in the absence of allergic symptoms. These data do not provide a simplistic explanation of the sensitivity in rhinitics to traffic-related air pollution. The role of mast cells requires further investigation.

Elite skiers' experiences of heat- and moisture-exchanging devices and training and competition in the cold: A qualitative survey.

Background and Aims: Winter endurance athletes have a high prevalence of exercise-induced bronchoconstriction (EIB) and asthma, probably due to repeated and prolonged inhalation of cold and dry air. Heat- and moisture-exchanging devices (HME) warm and humidify inhaled air and prevent EIB. The aim of this study was to share cross-country skiers and biathletes' experiences of training and competition in low temperatures, views on temperature limits, usage of HME, and consequences of cold exposure on their health. Methods: Eleven Swedish World Championship or Olympic medalists in cross-country skiing and biathlon were interviewed and transcripts were analyzed using qualitative content analysis. Results: Participants described how cold temperatures predominantly affected the airways, face, and extremities. During training, extreme cold was managed by choosing warmer clothing, modification of planned sessions, use of HME, delaying training, or changing location. In competition, participants described limited possibility for such choices and would prefer adjustment of existing rules (i.e., more conservative temperature limits), especially since they understood elite skiing in low temperatures to present an occupational hazard to their health. Participants had at times used HMEs during training in cold environments but described mixed motives for their use-that HMEs warm and humidify cold inhaled air but introduce additional resistance to breathing and can cause problems due to mucus and ice build-up. Skiers also perceived that they had become more sensitive to cold during the latter part of their careers. Conclusions: The present study gives a unique insight into the "cold" reality of being an elite athlete in skiing and biathlon. Cold exposure results in negative health consequences that are preventable, which means that rules must be followed, and organizers should acknowledge responsibility in protecting athletes from occupational hazards. Development of evidence-based guidelines for protection of athletes' respiratory health should be a focus for future translational research.

A longitudinal follow-up of continuous laryngoscopy during exercise test scores in athletes irrespective of laryngeal obstruction, respiratory symptoms, and intervention.

BACKGROUND: Exercise-induced laryngeal obstruction (EILO) is diagnosed by the continuous laryngoscopy during exercise (CLE) test. Whether or how much CLE test scores vary over time is unknown. This study aimed to compare CLE test scores in athletes over time, irrespective of respiratory symptoms and grade of laryngeal obstruction. METHODS: Ninety-eight athletes previously screened for EILO were invited for a follow-up CLE test irrespective of CLE scores and respiratory symptoms. Twenty-nine athletes aged 16-27 did a follow-up CLE test 3-23 months after the baseline test. Laryngeal obstruction at the glottic and supraglottic levels was graded by the observer during exercise, at baseline and follow-up, using a visual grade score (0-3 points). RESULTS: At baseline, 11 (38%) of the 29 athletes had moderate laryngeal obstruction and received advice on breathing technique; among them, 8 (73%) reported exercise-induced dyspnea during the last 12 months. At follow-up, 8 (73%) of the athletes receiving advice on breathing technique had an unchanged supraglottic score. Three (17%) of the 18 athletes with no or mild laryngeal obstruction at baseline had moderate supraglottic obstruction at follow-up, and none of the 3 reported exercise-induced dyspnea. CONCLUSIONS: In athletes with repeated testing, CLE scores remain mostly stable over 3-24 months even with advice on breathing technique to those with EILO. However, there is some intraindividual variability in CLE scores over time. TRIAL REGISTRATION: ISRCTN, ISRCTN60543467, 2020/08/23, retrospectively registered, ISRCTN - ISRCTN60543467: Investigating conditions causing breathlessness in athletes.

Severity of adult-onset asthma - a matter of blood neutrophils and severe obesity.

BACKGROUND: Adult-onset asthma is associated with a poor treatment response. The aim was to study associations between clinical characteristics, asthma control and treatment in adult-onset asthma. METHODS: Previous participants within the population-based Obstructive Lung Disease in Northern Sweden studies (OLIN) were in 2019-2020 invited to clinical examinations including structured interviews, spirometry, fractional exhaled nitric oxide (FeNO), skin prick test and blood sampling. In total, n = 251 individuals with adult-onset asthma (debut >15 years of age) were identified. Uncontrolled asthma was defined according to ERS/ATS and treatment step according to GINA (2019). RESULTS: Among individuals with uncontrolled asthma (34%), severe obesity (16.3% vs 7.9%, p = 0.041) and elevated levels of blood neutrophils, both regarding mean level of blood neutrophils (4.25*109/L vs 3.67*109/L, p = 0.003), and proportions with ≥4*109/L (49.4% vs 33.3%, p = 0.017) and ≥5*109/L (32.1% vs 13.7%, p < 0.001) were more common than among those with controlled asthma. Adding the dimension of GINA treatment step 1-5, individuals with uncontrolled asthma on step 4-5 treatment had the highest proportions of blood neutrophils ≥5*109/L (45.5%), severe obesity (BMI≥35, 26.1%), dyspnea (mMRC≥2) (34.8%), and most impaired lung function in terms of FEV1%<80% of predicted (42.9%), FEV1

High prevalence of interstitial lung abnormalities in middle-aged never-smokers.

Background: Interstitial lung abnormalities (ILA) are incidental findings on chest computed tomography (CT). These patterns can present at an early stage of fibrotic lung disease. Our aim was to estimate the prevalence of ILA in the Swedish population, in particular in never-smokers, and find out its association with demographics, comorbidities and symptoms. Methods: Participants were recruited to the Swedish CArdioPulmonary BioImage Study (SCAPIS), a population-based survey including men and women aged 50-64 years performed at six university hospitals in Sweden. CT scan, spirometry and questionnaires were performed. ILA were defined as cysts, ground-glass opacities, reticular abnormality, bronchiectasis and honeycombing. Findings: Out of 29 521 participants, 14 487 were never-smokers and 14 380 were men. In the whole population, 2870 (9.7%) had ILA of which 134 (0.5%) were fibrotic. In never-smokers, the prevalence was 7.9% of which 0.3% were fibrotic. In the whole population, age, smoking history, chronic bronchitis, cancer, coronary artery calcium score and high-sensitive C-reactive protein were associated with ILA. Both ILA and fibrotic ILA were associated with restrictive spirometric pattern and impaired diffusing capacity of the lung for carbon monoxide. However, individuals with ILA did not report more symptoms compared with individuals without ILA. Interpretation: ILA are common in a middle-aged Swedish population including never-smokers. ILA may be at risk of being underdiagnosed among never-smokers since they are not a target for screening.

Proinflammatory doses of diesel exhaust in healthy subjects fail to elicit equivalent or augmented airway inflammation in subjects with asthma.

BACKGROUND: Exposure to traffic-derived air pollutants, particularly diesel emissions, has been associated with adverse health effects, predominantly in individuals with pre-existing respiratory disease. Here the hypothesis that this heightened sensitivity reflects an augmentation of the transient inflammatory response previously reported in healthy adults exposed to diesel exhaust is examined. METHODS: 32 subjects with asthma (mild to moderate severity) and 23 healthy controls were exposed in a double-blinded crossover control fashion to both filtered air and diesel exhaust (100 µg/m(3) PM(10)) for 2 h. Airway inflammation was assessed by bronchoscopy 18 h postexposure. In addition, lung function, fraction of exhaled nitric oxide and bronchial reactivity to metacholine were examined in the subjects with asthma. RESULTS: In healthy control subjects a significant increase in submucosal neutrophils (p=0.004) was observed following the diesel challenge. Significant increases in neutrophil numbers (p=0.01), and in the concentrations of interleukin 6 (p=0.03) and myeloperoxidase (p=0.04), were also seen in bronchial wash after diesel, relative to the control air challenge. No evidence of enhanced airway inflammation was observed in the subjects with asthma following the diesel exposure. CONCLUSIONS: Exposure to diesel exhaust at concentrations consistent with roadside levels elicited an acute and active neutrophilic inflammation in the airways of healthy subjects. This response was absent in subjects with asthma, as was evidence supporting a worsening of allergic airway inflammation.

High Prevalence of Exercise-induced Laryngeal Obstruction in a Cohort of Elite Cross-country Skiers.

INTRODUCTION: Exercise-induced laryngeal obstruction (EILO) is a differential diagnosis for asthma and prevalent in athletes referred for exercise-induced dyspnea. The aim of this study was to estimate the prevalence of EILO in elite cross-country skiers, known for a high prevalence of asthma. METHOD: Elite cross-country skiers were invited for screening of EILO. Screening consisted of clinical assessment, questionnaires, skin prick test, spirometry, eucapnic voluntary hyperventilation test, and continuous laryngoscopy during exercise test. Current asthma was defined as physician-diagnosed asthma and use of asthma medication during the last 12 months. EILO was defined as ≥2 points at the supraglottic or glottic level during exercise at maximal effort, using a visual grade score system. RESULT: A total of 89 (51% female) cross-country skiers completed the study. EILO was identified in 27% of the skiers, 83% of whom were female. All skiers with EILO had supraglottic EILO, and there was no glottic EILO. Current asthma was present in 34 (38%) of the skiers, 10 (29%) of whom had concomitant EILO. In the skiers with EILO, a higher proportion reported wheeze or shortness of breath after exercise, compared with skiers without EILO. In skiers with EILO and current asthma, compared with skiers with asthma only, a higher proportion reported wheeze or shortness of breath after exercise. Asthma medication usage did not differ between these groups. CONCLUSION: EILO is common in elite cross-country skiers, especially females. Asthma and EILO may coexist, and the prevalence of respiratory symptoms is higher in skiers with both. Testing for EILO should be considered in cross-country skiers with respiratory symptoms.

Respiratory Health Effects of Wildfire Smoke during Summer of 2018 in the Jämtland Härjedalen Region, Sweden.

During the summer of 2018 Sweden experienced a high occurrence of wildfires, most intense in the low-densely populated Jämtland Härjedalen region. The aim of this study was to investigate any short-term respiratory health effects due to deteriorated air quality generated by the smoke from wildfires. For each municipality in the region Jämtland Härjedalen, daily population-weighted concentrations of fine particulate matter (PM2.5) were calculated through the application of the MATCH chemistry transport model. Modelled levels of PM2.5 were obtained for two summer periods (2017, 2018). Potential health effects of wildfire related levels of PM2.5 were examined by studying daily health care contacts concerning respiratory problems in each municipality in a quasi-Poisson regression model, adjusting for long-term trends, weekday patterns and weather conditions. In the municipality most exposed to wildfire smoke, having 9 days with daily maximum 1-h mean of PM2.5 > 20 µg/m3, smoke days resulted in a significant increase in daily asthma visits the same and two following days (relative risk (RR) = 2.64, 95% confidence interval (CI): 1.28-5.47). Meta-estimates for all eight municipalities revealed statistically significant increase in asthma visits (RR = 1.68, 95% CI: 1.09-2.57) and also when grouping all disorders of the lower airways (RR = 1.40, 95% CI: 1.01-1.92).