Asthma Odds Ratio Research Articles

The Association between Male Asthma and Lower Urinary Tract Symptoms Evaluated by the International Prostate Symptom Score: A Population-Based Study

Objectives: We explored the association between asthma severity and lower urinary tract symptoms (LUTS) using the International Prostate Symptom Score in a population-based study of males (aged ≥19 years) and evaluated voiding and urine storage symptoms. Methods: This was a cross-sectional study of 101,848 males, 2,544 of whom had asthma, who participated in the 2011 Korean Community Health Survey. All subjects were assessed in terms of sociodemographic data, pre-existing conditions, and the presence of LUTS. Logistic regression was used to identify risk factors for LUTS in asthmatics. Results: Urine storage symptoms (frequency, urgency, and nocturia) and voiding symptoms (straining, a weak stream, intermittency, and incomplete emptying) were significantly higher in the asthma group than in the non­asthma group (all p < 0.001). Moderate and severe LUTS were significantly more common in the asthma group (moderate, 24.3%; severe, 22.5%) than in the nonasthma group (moderate, 9.5%; severe, 2.9%). Compared to the mild LUTS group, the odds ratio (OR) for asthma was 2.21 (95% confidence interval [CI] 1.99–2.46) in the moderate LUTS group, and 3.04 (95% CI 2.64–3.51) in the severe LUTS group. In a model evaluating multiple variables, the OR for asthma in the moderate LUTS group was 1.95 (95% CI 1.74–2.16) and that in the severe LUTS group was 2.17 (95% CI 1.87–2.53). Asthma was associated with both voiding and storage symptoms. Conclusions: Male asthma was associated with moderate-to-severe LUTS. More aggressive urological diagnosis and treatment are needed for patients with asthma.

Bladder pain syndrome/interstitial cystitis is associated with asthma: A case-control study.

Although asthma and bladder pain syndrome/interstitial cystitis (BPS/IC) are considered to share similar pathophysiological pathways, the relationship between asthma and BPS/IC is uncertain. This case-control study aimed to investigate the relationship between prior asthma and BPS/IC using a large database in Taiwan. This study used data from the Taiwan Longitudinal Health Insurance Database 2005. We identified 500 female patients with BPS/IC as cases and 500 propensity score-matched females without BPS/IC as controls. We conducted logistic regressions to estimate the odds ratio (OR) and 95% confidence interval (CI) for prior asthma between cases and controls. Results indicated that 143 (14.30%) of the total sampled patients had received a prior diagnosis of asthma. Moreover, prior asthma was found in 86 (17.20%) cases and 57 (11.40%) controls. The OR of prior asthma for cases was 1.61 (95%CI: 1.13-2.32) compared to propensity score-matched controls. Additionally, the ORs of prior asthma for females with BPS/IC aged 18-59 and ≥60 years were 1.72 (95%CI: 1.11-2.69) and 1.40 (95%CI: 0.74-2.62), respectively, compared to controls. We concluded that prior asthma was significantly associated with BPS/IC in a female Taiwanese population.

Patient‐reported signs of dampness at home may be a risk factor for chronic rhinosinusitis: A cross‐sectional study

An association between dampness at home and respiratory conditions has been convincingly demonstrated in children. Fewer studies have been performed in adults, and data are lacking for chronic rhinosinusitis (CRS). With a prevalence of 10.9% in Europe, CRS imposes a significant burden on quality of life, as well as economy. Our aim was to study CRS and other respiratory conditions in relation to dampness at home in a representative sample of adults. The Swedish GA2 LEN questionnaire was answered by 26 577 adults (16-75 years) and included questions on respiratory symptoms, smoking, education and environmental exposure. CRS was defined according to the EP3 OS criteria. Dampness was defined as reporting water damage, floor dampness or visible moulds in the home during the last 12 months. The dampness score was ranked from 0 to 3, counting the number of signs of dampness reported. Dampness at home was reported by 11.3% and was independently related to respiratory conditions after adjustment for demographic and socio-economic factors and smoking: CRS odds ratio (OR) 1.71; allergic rhinitis OR 1.24; current asthma OR 1.21; wheeze OR 1.37; nocturnal dyspnoea OR 1.80; nocturnal coughing OR 1.34; and chronic bronchitis OR 1.64. The risk of CRS and most of the other respiratory conditions was further elevated in subjects reporting multiple signs of dampness. This study demonstrated an independent association between dampness at home and CRS in adults. The high burden of this and the other respiratory conditions studied is a strong argument in favour of countering indoor dampness by improving building standards.

Risk Factors of Acoustic Neuroma: Systematic Review and Meta-Analysis.

PurposeMany epidemiological studies have investigated environmental risk factors for the development of acoustic neuroma. However, these results are controversial. We conducted a meta-analysis of case-control studies to identify any potential relationship between history of noise exposure, smoking, allergic diseases, and risk of acoustic neuroma.Materials and MethodsWe searched PubMed to identify relevant articles. Two researchers evaluated the eligibility and extracted the data independently.ResultsEleven case-control studies were included in our meta-analysis. Acoustic neuroma was found to be associated with leisure noise exposure [odds ratio (OR)=1.33, 95% confidence interval (CI): 1.05–1.68], but not with occupational noise exposure and ever noise exposure (OR=1.20, 95% CI: 0.84–1.72 and OR=1.15, 95% CI: 0.80–1.65). The OR of acoustic neuroma for ever (versus never) smoking was 0.53 (95% CI: 0.30–0.94), while the subgroup analysis indicated ORs of 0.95 (95% CI: 0.81–1.10) and 0.49 (95% CI: 0.41–0.59) for ex-smoker and current smoker respectively. The ORs for asthma, eczema, and seasonal rhinitis were 0.98 (95% CI: 0.80–1.18), 0.91 (95% CI: 0.76–1.09), and 1.52 (95% CI: 0.90–2.54), respectively.ConclusionOur meta-analysis is suggestive of an elevated risk of acoustic neuroma among individuals who were ever exposed to leisure noise, but not to occupational noise. Our study also indicated a lower acoustic neuroma risk among ever and current cigarette smokers than never smokers, while there was no significant relationship for ex-smokers. No significant associations were found between acoustic neuroma and history of any allergic diseases, such as asthma, eczema, and seasonal rhinitis.

Association between asthma and body mass index and socioeconomic status: A cross-sectional study on 849,659 adolescents.

Asthma is associated with body mass index (BMI), but its association with socioeconomic status (SES) is controversial. The combined effect of SES and BMI on asthma prevalence is undetermined. Seventeen-year-old pre-recruits to the Israeli Defense Forces underwent routine physical examinations. SES was determined according to established criteria based on place of residence. The study population was divided according to classic weight groups and three SES groups (low, medium and high). Univariable and multivariable logistic regression models were applied to assess odds ratios (OR) of BMI and SES groups for asthma prevalence. The combined effect of BMI and SES was also calculated. The 849,659 subjects included 480,993 males (9.5% asthma prevalence) and 368,666 females (6.7% asthma prevalence). Increased BMI were associated with increased OR for asthma in females (1.44, 95% CI 1.36-1.52 for obese vs normal weight). Males had a J-shaped curve (OR 1.24 95% CI 1.2-1.29 for obese, 1.12, 95% CI 1.08-1.16 for underweight, both vs normal weight). OR adjusted to SES did not change significantly. All SES groups produced a linear curve (1.59 95% CI 1.53-1.66 for females and 1.79 95% CI 1.74-1.84 for males). Adjustment of SES to BMI produced no significant change in OR. When all groups were compared with the normal weight/lower SES group, the highest OR was for the obese/higher SES group (2.32 95% CI 2.05-2.64 for females and 1.99 95% CI 1.83-2.13 for males). Both BMI and SES are co-independently associated with asthma in adolescent males and females.

P35 Are testicular mixed germ cell tumours associated with hepatitis C(HCV) in HIV infected men who have sex with men?

<h3>OBJECTIVES</h3> To develop a method suitable for estimating exposure risks in population studies of asthma from job titles and international codes, by combining a new job exposure matrix (JEM) with the expert judgement approach. The method was applied in the French epidemiological study of the genetics and environment in asthma (EGEA). <h3>METHODS</h3> The JEM contains 22 exposure groups including 18 high risk groups based on known risk factors for occupational asthma, divided into high molecular weight agents, low molecular weight agents, and mixed environments. After applying the JEM to job codes, exposure estimates for each subject were re-evaluated by examining job title texts. Three high risk exposure estimates for asthma were compared: firstly, applying the JEM to original codes (from different coders in each study centre); secondly, applying the JEM to revised codes (from one experienced coder); and thirdly, after reviewing JEM exposure estimates in the light of job title texts. <h3>RESULTS</h3> The study comprised 173 cases with asthma and 285 controls (age 18–65). Odds ratios (ORs) for asthma for high risk jobs were 1.0 (95% confidence interval (95% CI) 0.6 to 1.7), applying the JEM to original codes; 1.4 (95% CI 0.8 to 2.3), applying the JEM to revised codes; and 1.7 (95% CI 1.1 to 2.7), applying the JEM and subsequently re-evaluating exposure estimates from job title texts. Asthma ORs were 1.4 (95% CI 0.6 to 2.9) for high molecular weight agents, 2.3 (95% CI 1.2 to 4.4) for low molecular weight agents, and 2.1 (95% CI 0.9 to 5.2) for mixed environments. <h3>CONCLUSIONS</h3> This asthma JEM, when enhanced by expert re-evaluation of exposure estimates from job title texts, may be a useful tool in general population studies of asthma. In this study, a 1.7-fold increase in prevalence odds of high risk exposures was found among asthmatic workers compared with controls, with risk magnitude varying for different classes of exposure.

Prevalence of asthma and its association with rhinitis in the elderly

Asthma and rhinitis are frequent respiratory diseases in children and adults. Despite the increase in the aging population, there are few epidemiologic data on both diseases in the elderly. So far, no population-based study has analyzed the association between asthma and rhinitis symptoms and severity in this age group. This study aimed to estimate the prevalence of physician-diagnosed asthma in the population aged ≥65 years in mainland Portugal and to evaluate its association with the presence and classification of rhinitis according to ARIA recommendations, in this age group. A cross-sectional, nationwide, population-based survey of individuals aged ≥65 years, living in mainland Portugal was performed. Data were obtained from 3678 respondents. The prevalence of physician-diagnosed asthma was 10.9% (95% confidence interval (95%CI) 9.9-11.9). The frequency of asthma diagnosis increased with the number of nasal symptoms (p < 0.001). A strong association between asthma and rhinitis was found (odds ratio (OR) 13.86 (95%CI 10.66-18.02)). The strength of this association increased with the persistence and severity of rhinitis, being particularly high in elderly subjects with moderate-severe persistent rhinitis (OR 39.9 (95%CI 27.5-58.0)). Asthma is common in the elderly and strongly associated with rhinitis. The OR for asthma is especially high in persistent and severe ARIA classification rhinitis types. This study strengthens the need for an integrated assessment of asthma together with rhinitis in the elderly.

Slopes and cliffs in health inequalities: comparative morbidity of housed and homeless people

BackgroundMarginalised groups are not only excluded from health services but also from routine health statistics. A key challenge for public health is measurement of the health of marginalised groups to make their needs visible and focus prevention and treatment activities. Internationally, there has been much research into the health inequalities slope, whereby almost all important health problems gradually rise in frequency with increasing social deprivation. Geographical measures of deprivation based on people's postcodes are often used to assess the effect of inequalities on health (eg, dividing the population into deprivation quintiles on the basis of indices of multiple deprivation [IMD-5]). However, this notion of inequality does not adequately capture the experience of many marginalised groups who have more extreme deprivation. Furthermore, marginalised groups are often deemed too difficult to engage to allow collection of meaningful health data. In this study, we aim to compare the prevalence of chronic disease across population quintiles of social deprivation (housed population) and in homeless people; and develop a generalisable methodology for health surveys in marginalised groups by use of peer interviewers to achieve engagement and high uptake. MethodsWe undertook a cross-sectional health survey of homeless people attending 27 low-threshold services in London (eg, hostels, day centres, soup runs). Questions asked were directly comparable with key questions within the national Health Survey for England (HSE) and health-related quality of life (EQ-5D), allowing direct comparison across quintiles of deprivation in the housed population and in homeless people. Peers with personal experience of homelessness were used to engage participants and undertake the surveys to achieve high uptake and provide as representative a sample as possible. Data were merged with HSE 2010 data on a representative housed population. We calculated age-adjusted and sex-adjusted odds ratios (ORs) of chronic disease, multiple morbidities, and quality of life scores as measured by the EQ-5D to compare homeless participants with housed people living in areas in the poorest quintile of the IMD-5. Findings455 (77%) of 592 people responded. Reasons for non-response were not obtained, but this is a high response rate for a population survey. Most respondents were men (365 of 455 [80%]) and most were aged 16–44 years (261 of 455 [57%]) and were born in the UK (277 of 455 [61%]). Nearly three-quarters were registered with a local general practice (329 of 455 [72%]). Missing data was less than 1% across all variables. There was a gradual increase in risk of chronic disease across the quintiles of multiple deprivation in HSE. However, compared with housed people living in the most socially deprived areas, homeless people had higher risks of asthma, heart disease, stroke, and epilepsy. The adjusted OR for asthma was 2·46 (95% CI 1·78–3·39; p<0·0001), for heart disease was 5·87 (3·63–9·49; p<0·0001); for stroke was 4·93 (2·15–11·28; p<0·0001), and for epilepsy was 12·40 (5·10–30·16; p<0·0001). Conversely, the likelihood of diagnosed diabetes was lower in the homeless than in those living in deprived areas (adjusted OR 0·59, 95% CI 0·35–0·99; p=0·046). The adjusted OR for having two or more of these disorders was 5·12 (3·06–8·57; p<0·0001). Quality of life measures showed similar disparities. InterpretationOur data show that in comparison with the slope in health inequalities, the health experience of the homeless is more akin to a cliff, with homeless people experiencing a significantly disproportionate burden of morbidity. This method could act as a template for surveys in other marginalised groups. FundingThis study was possible as a result of funding from Knowledge Into Action (Registered Charity No. 1123566), with data management and analytical support provided through a National Institute for Health Research Programme Grant For Applied Research (PGfAR RP-PG-0407-10340). The study funders had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.

Prenatal or Early-Life Exposure to Antibiotics and Risk of Childhood Asthma: A Systematic Review

The increasing prevalence of childhood asthma has been associated with low microbial exposure as described by the hygiene hypothesis. We sought to evaluate the evidence of association between antibiotic exposure during pregnancy or in the first year of life and risk of childhood asthma. PubMed was systematically searched for studies published between 1950 and July 1, 2010. Those that assessed associations between antibiotic exposure during pregnancy or in the first year of life and asthma at ages 0 to 18 years (for pregnancy exposures) or ages 3 to 18 years (for first-year-of-life exposures) were included. Validity was assessed according to study design, age at asthma diagnosis, adjustment for respiratory infections, and consultation rates. For exposure in the first year of life, the pooled odds ratio (OR) for all studies (N = 20) was 1.52 (95% confidence interval [CI]: 1.30-1.77). Retrospective studies had the highest pooled risk estimate for asthma (OR: 2.04 [95% CI: 1.83-2.27]; n = 8) compared with database and prospective studies (OR: 1.25 [95% CI: 1.08-1.45]; n = 12). Risk estimates for studies that adjusted for respiratory infections (pooled OR: 1.16 [95% CI: 1.08-1.25]; n = 5) or later asthma onset (pooled OR for asthma at or after 2 years: OR: 1.16 [95% CI: 1.06-1.25]; n = 3) were weaker but remained significant. For exposure during pregnancy (n = 3 studies), the pooled OR was 1.24 (95% CI: 1.02-1.50). Antibiotics seem to slightly increase the risk of childhood asthma. Reverse causality and protopathic bias seem to be possible confounders for this relationship.

Paracetamol in early infancy: the risk of childhood allergy and asthma

We investigated whether paracetamol exposure in pregnancy and until 6 months of age was associated with allergic disease in school children. In a prospective birth cohort study in Oslo, 1016 children included at birth were re-investigated at 10 years. Paracetamol exposure in pregnancy and until 6 months of age was registered. Outcomes at 10 years included current asthma, a history of asthma, allergic sensitization and allergic rhinitis. Maternal paracetamol use in the first trimester increased the risk for allergic rhinitis at 10 years OR (odds ratio) (95%CI) 2.30 (1.06, 4.97) in boys and girls. Paracetamol use until 6 months in girls increased the risk for allergic sensitization OR 2.20 (1.15, 4.22) and a history of asthma OR 2.20 (1.13, 4.30). The ORs for allergic sensitization and history of asthma in girls remained unchanged adjusting for upper or lower airway infections during the first 6 months of life. Paracetamol exposure in pregnancy was associated with allergic rhinitis, but not with asthma or allergic sensitization at 10 years of age. Paracetamol used until 6 months of age was associated with allergic sensitization and having a history of asthma in girls at 10 years of age, even considering concomitant airway infections.

The New Zealand Workforce Survey II: Occupational Risk Factors for Asthma

We conducted a cross-sectional population-based survey in New Zealand that collected information on work history, current workplace exposures, and selected health outcomes. We report here the findings on occupational risk factors for asthma symptoms. A random sample of men and women aged 20-64 years were selected from the New Zealand Electoral Roll and invited to take part in a telephone survey. Current asthma was defined as: (i) woken up by shortness of breath in the past 12 months; or (ii) an attack of asthma in the past 12 months; or (iii) currently taking asthma medication. Adult-onset asthma was defined as first attack of asthma at age 18 or over. Prevalence odds ratios (ORs) for all occupations were calculated using logistic regression adjusting for sex, age, smoking, and deprivation. Totally, 2903 participants were included in the analyses. The prevalence of current asthma was 17% and the prevalence of adult-onset asthma was 9%. Prevalence ORs for current asthma were elevated for ever working as a printer [OR = 2.26; 95% confidence interval (CI) = 1.09-4.66], baker (OR = 1.98; 95% CI = 1.02-3.85), sawmill labourer (OR = 3.26; 95% CI = 1.05-10.16), metal processing plant operator (OR = 2.48; 95% CI = 1.22-5.05), and cleaner (OR = 1.60; 95% CI = 1.09-2.35). Excess risks of adult-onset asthma were also found for ever working as a printer, baker, and sawmill labourer as well as ever-working as a market-oriented animal producer (OR = 1.66; 95% CI = 1.14-2.41), and other agricultural worker (OR = 2.08; 95% CI = 1.03-4.20). A number of occupations not previously considered at high risk for asthma were also identified, including teachers and certain sales professionals. This population-based study has confirmed findings of previous international studies showing elevated risks in a number of high-risk occupations. The strongest risks were consistently observed for printers, bakers, and sawmill labourers. Several occupations were also identified that have not been previously associated with asthma, suggesting that the risk of occupational asthma may be more widely spread across the workforce than previously assumed.

Trauma, Posttraumatic Stress Disorder, and Physical Illness: Findings from the General Population

To determine in a general population sample the differential impact on physical health of exposure to traumatic experiences and posttraumatic stress disorder (PTSD). Trauma exposure and PTSD have been associated with physical illness in specific populations, such as veterans. Medical histories including cardiovascular, endocrine, pulmonary, and other chronic diseases were obtained from 3171 adults living in the community. They were administered the PTSD module of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), and were assigned to three groups: no trauma (n = 1440); trauma, but no PTSD (n = 1669); and trauma with subsequent PTSD (n = 62). After adjustments for sociodemographic factors, smoking, body mass index, blood pressure, depression, and alcohol use disorders, subjects with trauma history had higher odds ratios (ORs) for angina pectoris and heart failure (OR = 1.2; 95% Confidence Interval [CI] = 1.1-1.3), stroke (OR = 1.2; 95 CI = 1.0-1.5), bronchitis, asthma, renal disease, and polyarthritis (ORs between 1.1 and 1.3) compared with nontraumatized participants. The PTSD positive subsample had increased ORs for angina (OR = 2.4; 95% CI = 1.3-4.5), heart failure (OR = 3.4; 95% CI = 1.9-6.0), bronchitis, asthma, liver, and peripheral arterial disease (ORs, range = 2.5-3.1). Our findings suggest a strong association between PTSD and cardiovascular and pulmonary diseases. Particular diagnostic and treatment attention should be paid to physical illness in PTSD positive patients in primary care, medical, and mental health settings.

Obesity, waist size and prevalence of current asthma in the California Teachers Study cohort

Background:Obesity is a risk factor for asthma, particularly in women, but few cohort studies have evaluated abdominal obesity which reflects metabolic differences in visceral fat known to influence systemic inflammation....

Ethnic variation in childhood asthma and wheezing illnesses: findings from the Millennium Cohort Study

It is not clear how respiratory morbidity during early childhood varies across ethnic groups in the UK. This article seeks to determine whether asthma and wheeze illnesses during early childhood differ across ethnic groups and what factors explain observed differences. Data from the UK Millennium Cohort Study on 14,630 children were analyzed from the second sweep of interviews. Parental interviews were conducted when the cohort member was aged approximately 3(1/2) years. Data collected included the occurrence of asthma and wheezing symptoms, biological and socio-economic factors and markers of cultural tradition. At age 3, 12.3% (n = 1,902) of children had ever had asthma and 20.0% (n = 3,030) had wheezed in the last 12 months. 18.2% of Black Caribbean children and 5.0% of Bangladeshi children reported ever asthma compared with 11.6% of White children. 25.5% of Black Caribbean children and 8.7% of Bangladeshi reported recent wheeze compared with 19.4% of White children. After adjustments, the disadvantage in asthma and recent wheeze for Black Caribbeans was mostly explained by socio-economic factors (adjusted odds ratios (OR) for asthma 1.42, 95% confidence interval (CI) 0.96-2.09; recent wheeze 1.18, 0.85-1.64). The Bangladeshi advantage lost statistical significance, mostly due to adjustment for markers of cultural tradition (adjusted OR for asthma 0.40, 95% CI 0.15-1.09; recent wheeze 0.44, 0.18-1.19). Our results point to the need to locate child health within the unique context of each ethnic group and to recognize that potential explanations for observed differences do not necessarily hold for all groups.

Overweight, Obesity, and Incident Asthma

Although obesity has been implicated as an asthma risk factor, there is heterogeneity in the published literature regarding its role in asthma incidence, particularly in men. To quantify the relationship between categories of body mass index (BMI) and incident asthma in adults and to evaluate the impact of sex on this relationship. Online bibliographic databases were searched for prospective studies evaluating BMI and incident asthma in adults. Independent observers extracted data regarding annualized asthma incidence from studies meeting predetermined criteria, within defined categories of normal weight (BMI < 25), overweight (BMI, 25-29.9), and obesity (BMI >or= 30). Data were analyzed by inverse-variance-weighted, random-effects meta-analysis. Stratified analysis between BMI categories and within sex was performed. Seven studies (n=333,102 subjects) met inclusion criteria. Compared with normal weight, overweight and obesity (BMI >or= 25) conferred increased odds of incident asthma, with an odds ratio (OR) of 1.51 (95% confidence interval [CI], 1.27-1.80). A dose-response effect of elevated BMI on asthma incidence was observed; the OR for incident asthma for normal-weight versus overweight subjects was 1.38 (95% CI, 1.17-1.62) and was further elevated for normal weight versus obesity (OR, 1.92; 95% CI, 1.43-2.59; p<0.0001 for the trend). A similar increase in the OR of incident asthma due to overweight and obesity was observed in men (OR, 1.46; 95% CI, 1.05-2.02) and women (OR, 1.68; 95% CI, 1.45-1.94; p=0.232 for the comparison). Overweight and obesity are associated with a dose-dependent increase in the odds of incident asthma in men and women, suggesting asthma incidence could be reduced by interventions targeting overweight and obesity.

Caesarean section delivery and the risk of allergic disorders in childhood

The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C-sections). To determine whether children born by C-section have a different risk of allergic disorders compared with those delivered vaginally. We also tested the hypothesis that the risk of allergic disorders is highest for children born after 'repeat C-sections'. A retrospective cohort study of 8,953 children aged 3-10 years. Children diagnosed with allergic rhinoconjunctivitis (AR), asthma, atopic dermatitis (AD), or food allergies were identified from the Kaiser Permanente Northwest Region electronic records. The children's sex, birth weight, birth order, postnatal exposure to antibiotics as well as the mothers' age, ethnicity, education, marital status, smoking status during pregnancy, and use of asthma or hayfever medications were identified through the mothers' medical records or through the Oregon Birth Registry. The risk of being diagnosed with AR was significantly higher in the children born by C-section than in those delivered vaginally: adjusted odds ratio (OR)=1.37%, 95% confidence interval (CI)=1.14-1.63. Delivery by C-section was also associated with the subsequent diagnosis of asthma (OR=1.24%, 95% CI=1.01-1.53); this association was gender specific, with a positive association restricted to girls (OR for asthma in girls: OR=1.53%, 95% CI=1.11-2.10; in boys: OR=1.08%, 95% CI=0.81-1.43). There was no significant association between mode of delivery and AD. If children born in a 'repeat C-section' were considered separately the risk of being diagnosed with AR increased further (OR=1.78%, 95% CI=1.34-2.37). The same increase was noted for asthma in girls (OR=1.83%, 95% CI=1.13-2.97) but not in boys. Caesarean sections may be associated with an increased risk of developing AR in childhood.

Low socioeconomic status as a risk factor for asthma, rhinitis and sensitization at 4 years in a birth cohort

The relation between socioeconomic status and allergic diseases in childhood is controversial. Some studies have proposed childhood asthma to be more common in families with low socioeconomic status, while sensitization to airborne allergens seems to be more frequent in individuals with higher socioeconomic status in childhood. To assess the relation between socioeconomic status and asthma, rhinitis and sensitization in an unselected prospective birth cohort. Four thousand and eighty-nine families with children born 1994-1996 in predefined areas of Stockholm answered questionnaires on environmental factors, socioeconomic status (parental occupation), and symptoms of allergic disease at birth, 1, 2 and 4 years of age. Blood samples taken at 4 years from 2614 children were analysed for specific IgE to common airborne and food allergens. Odds ratios (OR) and 95% confidence intervals (CI) for various outcomes in relation to socioeconomic status were estimated with a multiple logistic regression model, adjusting for potential confounders such as heredity for allergic diseases, maternal smoking, short duration of breastfeeding and house construction. There was a decreasing risk of asthma and rhinitis with increasing socioeconomic status. The OR for asthma was 0.33 (95% CI 0.17-0.66) and for rhinitis 0.50 (0.32-0.79) comparing the highest and the lowest socioeconomic groups, with a tendency to stronger effects in those with heredity for allergic disease. The risk of sensitization to food allergens also decreased with increasing socioeconomic status; OR 0.65 (0.41-1.02) in the highest socioeconomic group (Ptrend=0.03), which was not clearly seen for airborne allergens. Asthma, rhinitis and sensitization is more common in lower than in higher socioeconomic groups after adjustment for traditional risk factors. This may be related to additional uncontrolled differences in life style and environmental exposures between the groups, and calls for further studies.

Maternal Fish Consumption During Pregnancy and Risk of Early Childhood Asthma

Maternal fish consumption during pregnancy may affect children's asthma risk by modulating early-life immune development. Type of fish intake may be important because of differences in fatty acid content. To test this hypothesis, we conducted a nested case-control study, selecting subjects from the Children's Health Study, a population-based study of school-aged children in southern California. Cases had physician-diagnosed asthma and controls were asthma-free by age 5 years. Mothers or guardians provided information on fish consumption during pregnancy in telephone interviews. We computed odds ratio (OR) and 95% confidence interval (CI) by using conditional logistic regression models that accounted for the sampling. In children born to mothers with a history of asthma, the OR of asthma was 0.20 (95% CI = 0.06–0.65) when mothers ate oily fish at least monthly during pregnancy compared with no consumption (ptrend = 0.006). Maternal oily fish consumption during pregnancy did not benefit children of non-asthmatic mothers. In contrast, fish stick (a source of trans-fats) consumption during pregnancy increased asthma risk in children (OR = 2.04; 95% CI = 1.18–3.51). Our results suggest that maternal oily fish intake during pregnancy may protect offspring from asthma; however, eating fish sticks during pregnancy may increase asthma risk in children.

Exposure-response relationships between lifetime exposure to residential coal smoke and respiratory symptoms and illnesses in Chinese children.

Data collected in a large epidemiologic study were analyzed to examine respiratory health effects of residential coal use in 7058 school children living in the four Chinese cities of Chongqing, Guangzhou, Lanzhou, and Wuhan. A Scenario Evaluation Approach was used to develop two exposure variables, heating coal smoke and cooking coal smoke. Estimated lifetime exposures to heating coal smoke and cooking coal smoke were both classified into four-level ordinal scales, as follows: no reported exposure (control); lightly exposed; moderately exposed; and heavily exposed. Zero-one dummy variables were constructed for each exposure level other than the control level (total six variables). These variables were entered into the analytical model. We tested for exposure-response relationships using logistic regression models, while controlling for other relevant covariates, including an indicator variable of ambient air pollution levels. We observed monotonic and positive exposure-response relationships of exposure to heating coal smoke with modeled odds ratios (ORs) of phlegm, cough with phlegm, and bronchitis. Other health outcomes were not associated with such exposure in a monotonic exposure-response pattern. However, ORs for cough, wheeze, and asthma were all higher in the exposed groups than in the control group. We observed no consistent associations between cooking coal smoke and the examined health outcomes. We conclude that exposure to heating coal smoke could have adverse effects on children's respiratory symptoms and illnesses in these four Chinese cities.

Caesarean section increases the risk of hospital care in childhood for asthma and gastroenteritis.

To investigate if caesarean section (CS) increases the risk for childhood asthma and gastroenteritis with reference made to children born with vaginal delivery (VD). Retrospective study of data from linked Swedish medical service registers--Medical Birth Registry (MBR) and Hospital Discharge Registry (HDR). Data were obtained from women without any background/perinatal morbidity noted, and from children without any neonatal complications. Children that had reached at least 1 year of age and were found in the HDR were considered as cases, whereas children not found in the HDR or hospitalized for other causes than asthma or gastroenteritis were defined as controls. Odds ratios (OR) stratified for year of birth, maternal age, parity and smoking in early pregnancy were calculated. Investigations were made comparing the risk for in hospital treatment for asthma or gastroenteritis in CS children and in VD siblings of CS children. The overall inpatient morbidity in CS and VD children were also investigated. The OR for asthma in CS children was 1.31 [95% confidence interval (CI) 1.23-1.40]. The same OR, 1.31, was found for gastroenteritis (95% CI 1.24-1.38). The OR for CS children having experienced both asthma and gastroenteritis was further increased (1.74, 95% CI 1.36-2.23). The risk for asthma in VD siblings of CS children was not significantly increased, whereas VD siblings experienced a slightly increased risk for gastroenteritis. CS children had an increased overall in hospital morbidity when compared to VD children. There is a significant increase of the risk for developing symptoms of asthma and/or gastroenteritis that motivates admission for hospital care in CS children older than 1 year. It is speculated that a disturbed intestinal colonization pattern in CS children may be a common pathogenic factor.