Alarmingly high prevalence of smoking and symptoms of bronchitis in young women in Sweden: a population-based questionnaire study

Asthma increased in young adults from 2008-2016 despite stable allergic rhinitis and reduced smoking

BACKGROUND

Studies have produced inconsistent results on prevalence trends in asthma and allergic rhinitis (AR). We surveyed young adults about asthma in 2008 and 2016 and examined the impact of gender, AR and smoking.

METHODS

Thirty-thousand randomly selected subjects aged 16-75 years in Western Sweden received postal questionnaires in 2008 and 50,000 in 2016. This study is based on responders aged 16-25 years, 2,143 in 2008 and 2,484 in 2016.

RESULTS

From 2008-2016 current asthma increased from 9.3% to 11.5% (p = 0.014) and was significant in males without AR (aOR 1.83, 95% CI 1.09-3.07) and male smokers (aOR 3.02, 95% CI 1.12-8.13). In both years the risk of current asthma was reduced by growing up on a farm (aOR 0.26, 95% CI 0.81-0.84 and aOR 0.47, 95% CI 0.23-0.996), independent of a family history of asthma or allergy. AR did not differ significantly from 2008-2016 (22.5% vs 24.4%, p = 0.144). Current smoking decreased from 20.3% to 15.2% (p<0.001), especially in females (23.5% to 16.2%, p<0.001). Female smokers started smoking later and smoked fewer cigarettes in 2016 than 2008. In 2016, 4.8% of the cohort reported using electronic cigarettes. Of those, 60.7% also smoked tobacco and more than two-thirds who used both (67.2%) were heavy smokers.

CONCLUSION

Current asthma increased in respondents aged 16-25 from 2008-2016, mainly among males without AR and male smokers. Current AR levelled off in this young population, while current smoking decreased among females.

Association Between Cigarette Smoking and Systemic Lupus Erythematosus: An Updated Multivariate Bayesian Metaanalysis

OBJECTIVE

The association between cigarette smoking and the risk of systemic lupus erythematosus (SLE) remains a matter for debate. Additionally, the effect of the change of smokers' demographics on the risk of development of SLE over time has not been formally addressed. We aimed to examine the association between cigarette smoking and the risk of SLE by performing an updated metaanalysis.

METHODS

A literature search using keywords including "lupus," "smoking," "cigarette," "environmental," "autoimmune," and "connective tissue disease" was performed in computerized databases to identify studies addressing the relationship between cigarette smoking and SLE occurrence. A Bayesian metaanalysis was conducted by computing the log-OR between current and never smokers, and between former and never smokers. The average log-OR (subsequently converted to OR) and their corresponding 95% credible intervals (CrI) were calculated. The effect of publication time, sex, and age of patients with SLE on the effect sizes was examined by multivariate metaregression.

RESULTS

Data aggregation of 12 eligible studies comprising 3234 individuals who developed SLE and 288,336 control subjects revealed a significant association between SLE occurrence and current smoking status (OR 1.54, 95% CrI 1.06-2.25), while only a non-significant trend was demonstrated between SLE occurrence and former smoking status (OR 1.39, 95% CrI 0.95-2.08). Publication time, sex, and the mean age of patients with SLE did not explain the heterogeneity of the effect sizes.

CONCLUSION

Current smoking status is associated with risk of SLE. Sex and age of patients with SLE had no significant effect on the risk of SLE over time.

High prevalence of severe asthma in a large random population study

BACKGROUND

The prevalence of asthma severity is not well described at a population level.

OBJECTIVE

We sought to determine the prevalence of phenotypic signs of asthma severity among asthmatic patients in a general population and to describe risk factors for asthma severity.

METHODS

We performed an epidemiologic study conducted between 2008 and 2012 (West Sweden Asthma Study). A postal questionnaire was sent to a random population (n = 30,000) in west Sweden, with 18,087 responses. A total of 2,006 subjects were carefully phenotyped. Only subjects with "active asthma" (symptoms or medication in the last year, n = 744) were analyzed in this study to determine the degree of severity of the disease within an asthma cohort. Phenotypes of severity were calculated based on (1) multiple symptoms during the day despite ongoing use of asthma medications, (2) FEV₁ of less than 70% of predicted value, (3) daily or almost daily use of rescue medications, (4) nighttime symptoms once a week or more, and (5) oral corticosteroid use/emergency department visits. Asthmatic patients were grouped as having nonsevere disease, 1 sign of severity, or 2 or more signs of severity.

RESULTS

A total of 36.2% of asthmatic patients expressed at least 1 sign of asthma severity, and 13.2% had 2 or more signs. The group with 2 or more signs was older in age and had higher body mass index, a higher rate of tobacco smoking, and lower lung function. Bronchial hyperreactivity, airway inflammation, and sensitization were significantly different among the 3 groups. At a population level, the prevalence of asthma severity was 3.1% for 1 sign and 1.3% for at least 2 signs.

CONCLUSION

More than 1 in 3 asthmatic patients show at least 1 sign of asthma severity. The phenotypes of asthma severity are highly diverse, which is important to consider when implementing personalized medicine in asthmatic patients.

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.

High risk of adult asthma following severe wheezing in early life

BACKGROUND

Severe wheezing in early life is associated with an increased risk of asthma during childhood and adolescence. The aim of the present follow-up was to investigate the asthma prevalence and risk factors for asthma in adulthood.

METHODS

We have prospectively studied asthma development in 101 children hospitalized due to severe wheezing before the age of 24 months. The cohort was re-investigated at a mean age of 27 years and tested for bronchial hyper-responsiveness and allergic sensitization. The response rate in adulthood was 81% (82/101). The results were compared with a population-based, age-matched control group (n = 1,210) recruited from the West Sweden Asthma Study.

RESULTS

Current doctor-diagnosed asthma was found in 37% (30/82) compared with 7% (82/1,210) in the control group. The risk of adult asthma in the cohort compared with the control group was increased 10-fold (adjusted OR 10.0, 95% CI 5.3-18.7), independently of allergic rhinitis, gender, smoking and heredity. Within the cohort, current allergy (aOR 9.6, 95% CI 3.0-31.2) and female gender (aOR 3.2, 95% CI 1.1-9.3) independently increased the risk of adult asthma. Females with current allergy had the highest risk of adult asthma (OR 29.4, 95% CI 5.0-173.3), compared with males without allergy. When separately adjusting for factors present at admission in early life within the cohort, a family history of asthma was a significant risk factor for asthma in adulthood (aOR 4.0, 95% CI 1.3-12.5).

CONCLUSION

Subjects with severe early wheezing have a 10-fold increase in the risk of adult asthma compared to an age-matched control group, adjusted for allergic rhinitis, gender, smoking and heredity.

Age-related macular degeneration patients’ awareness of nutritional factors

Age-related macular degeneration (AMD) is the leading cause of visual impairment in older adults in the United Kingdom. This study sought to characterise AMD patients who seek the services of the Macular Society, and determine the level and source of their dietary knowledge. A questionnaire was designed, validated, and administered to 158 participants. The questions covered demographic data and knowledge of nutrition and supplementation. The mean age of participants was 79 years; 61% of them were female, and 27% were registered visually impaired. Only 55% of the participants thought diet was important for eye health, 63% felt that they had not received enough information about AMD. The participants reported that their information mainly came from non-professional support groups. Most participants identified healthy food, but could not say why, and were not able to identify carotenoid rich foods. The results of the study will inform design of education and dissemination methods regarding dietary information.

Prevalence trends in respiratory symptoms and asthma in relation to smoking - two cross-sectional studies ten years apart among adults in northern Sweden

Background

Smoking is considered to be the single most important preventable risk factor for respiratory symptoms. Estimating prevalence of respiratory symptoms is important since they most often precede a diagnosis of an obstructive airway disease, which places a major burden on the society. The aim of this study was to estimate prevalence trends of respiratory symptoms and asthma among Swedish adults, in relation to smoking habits. A further aim was to estimate the proportion of respiratory symptom and asthma prevalence attributable to smoking.

Methods

Data from two large-scale cross-sectional surveys among adults performed in northern Sweden in 1996 and 2006 were analysed. Identical methods and the same questionnaire were used in both surveys. The association between smoking, respiratory symptoms and asthma was analysed with multiple logistic regression analyses. Changes in prevalence of respiratory symptoms and asthma from 1996 to 2006 were expressed as odds ratios. Additionally, the population attributable risks of smoking were estimated.

Results

The prevalence of most respiratory symptoms decreased significantly from 1996 to 2006. Longstanding cough decreased from 12.4 to 10.1%, sputum production from 19.0 to 15.0%, chronic productive cough from 7.3 to 6.2%, and recurrent wheeze from 13.4 to 12.0%. Any wheeze and asthmatic wheeze remained unchanged. This parallels to a decrease in smoking from 27.4 to 19.1%. In contrast, physician-diagnosed asthma increased from 9.4 to 11.6%. The patterns were similar after correction for confounders. All respiratory symptoms were highly associated with smoking, and the proportion of respiratory symptoms in the population attributed to smoking (PAR) ranged from 9.8 to 25.5%. In 2006, PAR of smoking was highest for recurrent wheeze (20.6%).

Conclusions

In conclusion, we found that respiratory symptoms, in particular symptoms common in bronchitis, decreased among adults in northern Sweden, parallel to a decrease in smoking from 1996 to 2006. In contrast, the prevalence of physician-diagnosed asthma increased during the same time-period. Up to one fourth of the respiratory symptom prevalence in the population was attributable to smoking.