Twin concordance for a binary trait: III. A bivariate analysis of hay fever and asthma

Self-reported histories of hay fever and asthma were obtained from 3,808 pairs of adult twins 18 years and over registered with the Australian National Health Medical Research Council Twin Registry (1232 MZF, 567 MZM, 751 DZF, 352 DZM, 906 DZO). The prevalence of hay fever and asthma was 0.32 and 0.13, respectively, with little variation with zygosity, sex, and age. The associations between twin pairs for these two traits were analysed, under the assumption of constant prevalences, as a special case of a log-linear model for binary traits in pedigrees using the statistical package GLIM. The model assumption that there are no second- or higher-order interactions was tested in the 2 X 2 X 2 X 2 table of twin by disease outcomes without revealing strong evidence of departure, even in this large data set. The log-linear modelling showed that only three first-order interactions, namely 1) between hay fever in a twin pair, 2) asthma in a twin pair, and 3) hay fever and asthma in the same twin, were necessary to describe the data. The first two interaction terms were significantly larger in identical pairs; the third was independent of zygosity. Under this parsimonious model, there was a significant difference between identical and fraternal pairs in marginal correlation, both in asthma and hay fever, and in the cross-correlation between hay fever in one twin and asthma in the other. This suggests that genetic factors are implicated in both hay fever and asthma and that some of these genetic factors are common (at least among a subgroup of individuals) to both traits.     

Associations between socioeconomic position and asthma: findings from a historical cohort

Understanding the association between asthma and socioeconomic position (SEP) is key to identify preventable exposures to prevent inequalities and lessen overall disease burden. We aim to assess the variation in asthma across SEP groups in a historical cohort before the rise in asthma prevalence. Male students participating in a health survey at Glasgow University from 1948 to 1968 (n?=?11,274) completed medical history of bronchitis, asthma, hay fever, eczema/urticaria, and reported father's occupation. A subsample responded to postal follow-up in adulthood (n?=?4,101) that collected data on respiratory diseases, early life and adult SEP. Lower father's occupational class was associated with higher odds of asthma only (asthma without eczema/urticaria or hay fever) (trend adjusted multinomial odds ratio (aMOR)?=?1.23, 95?% CI 1.03-1.47) but with lower odds of asthma with atopy (asthma with eczema/urticaria or hay fever) (trend aMOR?=?0.66, 95?% CI 0.52-0.83) and atopy alone (trend aMOR?=?0.84, 95?% CI 0.75-0.93). Household amenities (<3), in early life was associated with higher odds of adult-onset asthma (onset?>?30?years) (OR?=?1.48, 95?% CI 1.07-2.05) though this association attenuated after adjusting for age. Adult SEP (household crowding, occupation, income and car ownership) was not associated with adult-onset asthma. Lower father's occupational class in early life was associated with higher odds of asthma alone but lower odds of asthma with atopy in a cohort that preceded the 1960s rise in asthma prevalence. Different environmental exposures and/or disease awareness may explain this opposed socioeconomic patterning, but it is important to highlight that such patterning was already present before rises in the prevalence of asthma and atopy.     

Fertility rates in women with asthma, eczema, and hay fever: a general population-based cohort study

The protective association between having older siblings and the risk of subsequent allergic disease may be due to decreased fertility among women with allergic disease. In this study, the authors compared fertility rates among women with asthma, eczema, or hay fever with those in the general female population. Computerized primary-care data from the United Kingdom were used to conduct a cohort analysis of 491,516 women. General fertility rates and age-specific fertility rates for 1994-2004 were estimated. Using Poisson regression, the authors compared fertility rates among women with asthma, eczema, or hay fever with rates in women without these diagnoses. Fertility rates were 53.0 and 52.3 livebirths per 1,000 person-years in women with and without asthma, respectively. The fertility rate ratio for women with asthma compared with women without asthma was 1.02 (95% confidence interval (CI): 1.00, 1.04) after adjustment for age, smoking, body mass index, and socioeconomic status. Equivalent fertility rate ratios for eczema and hay fever were 1.15 (95% CI: 1.13, 1.17) and 1.08 (95% CI: 1.06, 1.10), respectively. The authors found no evidence that the fertility rates of women with asthma, eczema, or hay fever are lower than those of women in the general population.     

Heredity of asthma in Saudi population

In a cross-sectional study, the prevalence of asthma, hay fever and eczema was studied in 1150 schoolchildren attending school in Jeddah Western region of Saudi Arabia. The family histories of asthma, hay fever and eczema were examined in first degree relatives. The age range of children studied was 7–12 years, with a mean of 9.3 years (47% boys and 53% girls). A self-administered questionnaire was completed by the parents of the child to collect information concerning bronchial asthma, hay fever, and eczema in the target child and family history of respiratory allergy. A detailed family history and personal histories of asthma were available for 1035 Saudi children aged 7–12 years old. The rate of asthma and hay fever were significantly higher among siblings and offspring (cases) compared to their parents (p < 0.001). The results showed a high positive correlation between the relatives of affected children with respect to asthma and hay fever. These findings support the hypothesis that asthma and hay fever may be inherited in the Saudi population, but the mode of inheritance has yet to be determined.Corresponding author.     

Childhood asthma in the Highlands of Scotland--morbidity and school absence

BACKGROUND: The prevalence of childhood asthma in Scotland is one of the highest in the world. The morbidity secondary to allergic diseases is significant in terms of costs to the nation and effects on the family including the child. AIMS: The aims of this study were to describe the prevalence of asthma, eczema and hay fever in the Highlands of Scotland and in the Shetland Isles and to examine factors in relation to quality of life and social deprivation. METHOD: A total population survey of 12 year old children using a parent completed questionnaire. RESULTS: 86.3% (2658/3080) returned questionnaires. Of the 2549 questionnaires analysed, 476 (18.7%) reported asthma ever, 362 (14.2%) wheeze in last 12 months, 508 (19.9%) reported hay fever ever and 555 (21.8%) reported eczema ever. Of the children reporting asthma or wheeze, 35.4% (229/647) had missed school because of asthma or wheeze, 38.0% (246/647) had missed physical education. 62.5% (354/566) of subjects with wheeze ever reported sleep disturbance. Deprivation measured by DEPCAT scores was associated with maternal smoking and bronchitis in the child but not with allergic diseases. CONCLUSION: Compared with previous studies, the prevalence of asthma was unchanged but eczema has increased in Highland adolescents. Allergic disease has a significant impact on school attendance and physical activity. Deprivation was associated with maternal smoking and bronchitis in the child but not with allergic diseases. The impact of allergic diseases in rural areas may be different from urban areas.     

Different slopes for different folks: socioeconomic and racial/ethnic disparities in asthma and hay fever among 173,859 U.S. men and women

Although allergic diseases such as asthma and hay fever are a major cause of morbidity in industrialized countries, most studies have focused on patterns of prevalence among children and adolescents, with relatively few studies on variations in prevalence by race/ethnicity and socioeconomic position among adults. Our study examined racial/ethnic and socioeconomic patterns in the prevalence of asthma overall, asthma with hay fever, asthma without hay fever, and hay fever overall, in a population of 173,859 women and men in a large prepaid health plan in northern California. Using education as a measure of socioeconomic position, we found evidence of a positive gradient for asthma with hay fever with increasing level of education but an inverse gradient for asthma without hay fever. Hay fever was also strongly associated with education. Compared with their White counterparts, Black women and men were more likely to report asthma without hay fever, and Black women were less likely to have asthma with hay fever. Asian men were also more likely to report asthma with hay fever, and Asian women and men were much more likely to have hay fever. Racial/ethnic disparities in prevalence of allergic diseases were largely independent of education. We discuss implications for understanding these social inequalities in allergic disease risk in relation to possible differences in exposure to allergens and determinants of immunologic susceptibility and suggest directions for future research.     

Not just a spring fever... Information and advice to help families with hay fever sufferers

Hay fever is an allergy to pollen or spores presenting as an allergic inflammatory response in all mucous membranes of the upper airway. The UK has one of the highest rates (it's estimated one in four of us have hay fever) and symptoms are often trivialised, even though the socio-economic and health costs are huge. If left treated, for example, a hay fever sufferer risks developing asthma. Also paediatric allergists now consider the combination of eczema and hay fever to be a significant marker, indicating an atopic child's propensity to develop more serious allergic disease. Unfortunately childhood hay fever is often poorly treated, but a combination of sensible allergen avoidance measures and appropriate medication or treatments is usually sufficient to control symptoms.     

Atopic diseases in twins born after assisted reproduction

We examined the risk of atopic diseases in twins born after assisted reproduction. Data on atopic diseases and assisted reproduction in 9694 twin pairs, 3-20 years of age, from the Danish Twin Registry were collected via multidisciplinary questionnaires. The risk of atopic diseases in twins born after assisted reproduction was compared with the risk in twins born after spontaneous conception using logistic regression and variance components analysis. Children born after assisted reproduction did not have a different risk of atopic outcomes (adjusted odds ratios [95% confidence intervals] for asthma: 0.95 [0.85, 1.07], P = 0.403; hay fever: 1.01 [0.86, 1.18], P = 0.918; and atopic dermatitis: 1.02 [0.81, 1.11], P = 0.773 respectively) compared with children born after spontaneous conception. Assisted reproduction did not modify the heritability of atopic diseases. This study does not support an association between assisted reproduction and development of atopic diseases. This result must be confirmed in subsequent studies, preferably of singleton populations.     

Prävalenz und Inzidenz von Atemwegserkrankungen und Allergien bei Schulkindern. Ergebnisse einer dreijährigen Kohortenstudie in Südwestdeutschland

Prevalence and incidence of respiratory diseases and allergies in schoolchildren were assessed during a longitudinal study in the years 1990 to 1993 in southwestern Germany. In the beginning of the study, the average age of the children was 7.3 years. In the years 1990 to 1992 each survey involved a questionnaire and a skin prick test with seven inhalative allergens. In spring 1993 the data collection was finished with a final questionnaire. Basically 1 812 subjects took part, from which 1 082 participated in all surveys. Questions regarding asthma, asthmatic symptoms, hay fever and eczema were analyzed, taking local and sex-specific conditions into account. We found a higher prevalence of asthma, asthmatic symptoms, hay fever and hay fever associated symptoms among males, and a higher prevalence of eczema among females. Male subjects more often reacted positively in the skin prick tests. A not significantly higher prevalence of asthma and most of the asthmatic symptoms occured in Kehl. Consistent local differences regarding hay fever, eczema or positive skin prick test results could not be demonstrated. During the three surveys the prevalence of positive skin prick test reactions to the aeroallergens increased. Incidences of asthma and positive skin prick test results were higher in male than in female subjects     

Does a higher number of siblings protect against the development of allergy and asthma? A review

STUDY OBJECTIVE: To review the "protective" effects of having a higher number of siblings for the risk of atopic eczema, asthma wheezing, hay fever, and allergic sensitisation. METHOD: Review of the literature (Medline since 1965 and references). MAIN RESULTS: 53 different studies were identified. For eczema, 9 of 11 studies reported an inverse relation with number of siblings; for asthma and wheezing, 21 of 31 reported the inverse association; for hay fever, all 17 studies showed the effect; for allergic sensitisation or immunoglobulin E reactivity 14 of 16 studies supported the "protective" effect of a higher number of siblings. The studies emphasise a "theory" that is based exclusively on epidemiological associations. CONCLUSIONS: Research has not yet answered the question of which causal factors explain the sibling effect. Causal factors must meet two criteria; they must vary with sibship size and they must protect against atopic manifestations. The prevailing "hygiene hypothesis" failed to explain the findings adequately. Alternative explanations include in utero programming or endocrine explanatory models. The epidemiology research into siblings and atopic disorders has entered an intellectually challenging phase. Possessing sufficient knowledge about the causal factors might prevent at least 30% of all cases of asthma, eczema, and hay fever.     

Undue influence of weight on self-evaluation: a population-based twin study of gender differences

OBJECTIVE: To explore the extent to which genetic and environmental factors contribute to liability to placing undue importance on weight as an indicator of self-evaluation and to determine whether differences exist across genders in the nature and magnitude of these effects. METHOD: Self-report data were collected on 8,045 same-sex and opposite-sex twins, aged 18-31 years, from a population-based registry of Norwegian twins. Structural equation modeling was utilized to estimate the relative contribution of genetic and environmental factors to liability for undue influence of weight on self-evaluation, allowing for gender-specific effects. RESULTS: Individual variation in undue influence of weight on self-evaluation was best explained by shared and individual environmental influences. No significant gender differences were found. Shared environmental factors accounted for 31% of the variance. DISCUSSION: These results raise the possibility that there may be distinct sources of familial resemblance for different symptoms of bulimia nervosa as codified in the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994).     

Epidemiology of eczema among Lebanese adolescents

OBJECTIVE: The study aims to determine the prevalence of eczema among Lebanese adolescents and identify demographic, nutritional and environmental characteristics associated with eczema. METHODS: A cross-sectional study conducted on a convenient sample of 3 153 students (13-14 years) selected from five different provinces in Lebanon. Significant unadjusted demographic, nutritional and environmental variables were considered in a stepwise regression model. RESULTS: Ever having an itchy rash that lasted for a period more than six months was reported by 788 (25.0%) adolescents, while 404 (12.8%) reported ever having eczema. Females and passive smokers were at 1.5 increased risk of having eczema than their counterparts. Exercising regularly, living near a busy area, and frequent eating of eggs were positively associated with eczema. Finally, adolescents who suffered from allergic diseases, asthma (Odds ratio (OR): 1.64, 95% CI: 1.16-2.32), rhinitis (OR: 1.35, 95% CI: 1.07-1.70) and hay fever (OR: 2.77; 95% CI: 2.12-3.62) also reported having had eczema. CONCLUSION: Environmental factors were found to play an important role in the prevalence of eczema among adolescents.     

Atopic manifestations,breast-feeding protection and the adverse effect of DDE

Despite the numerous studies on the possible protective effect of breast feeding against the onset of atopic manifestations during childhood, this issue remains controversial. As part of an environmental epidemiological study, we investigated whether different blood concentrations of dichlorodiphenyl-dichloroethylene (DDE) modified the protective effect of breast feeding against atopic manifestations in 338 children. DDE concentration, duration of breast feeding and manifestation of atopic disorders were measured in 1994-95 at age 7-8 years. Information gathered on asthma, atopic eczema and hay fever was based on questionnaire data. We measured the total serum concentration of immunoglobulin E (IgE) and specific IgE levels against inhalant allergens. In 1997, we also determined bronchial hyper-reactivity with a hypertonic saline challenge test. To estimate odds ratios from our cross-sectional analysis, we applied logistic regressions, controlling for confounders. Breast feeding had a protective effect on the two asthma variables (e.g.> 12 weeks breast feeding for doctor-diagnosed asthma, OR = 0.32 [95% CI 0.11, 0.87]; for 'ever' asthma, OR = 0.13 [95% CI 0.02, 0.68]), but not on bronchial hyper-reactivity, hay fever, atopic eczema or the two IgE variables. The protective effect became stronger in children with DDE blood levels below the median of 0.29 micro g/L (e.g. doctor-diagnosed asthma,> 12 weeks breast feeding, OR = 0.24 [95% CI 0.06, 0.95]). Also, for specific IgE against inhalant allergens, the association gained statistical significance. For children with a DDE concentration of 0.29 micro g/L and higher, breast feeding did not show a significant protective effect. Our results suggest that contaminants such as DDE may modify the protective effect and may have contributed to inconsistent findings on the protective effect of breast feeding in previous studies. We recommend determining levels of breast milk contaminants in children when assessing the impact of breast feeding on atopic manifestations.     

Allergic conditions and brain tumor risk

An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway, Finland, Sweden, and southeast England between 2000 and 2004. Detailed information on self-reported physician-diagnosed allergic conditions was collected from 1,527 glioma cases, 1,210 meningioma cases, and 3,309 randomly selected controls. Logistic regression showed an odds ratio of 0.70 (95% confidence interval: 0.61, 0.80) for glioma associated with a diagnosis of any of asthma, hay fever, eczema, or other type of allergy. The risk estimates for glioma were around 0.65 for each allergic condition (asthma, eczema, hay fever, and food allergy), and the 95% confidence intervals were equally consistent, at around 0.55, 0.80. The reduced risks of glioma related to eczema, hay fever, and allergy overall, but not asthma, were confined to current rather than past conditions. Meningioma risk was not associated with allergic conditions, except for eczema (odds ratio = 0.74, 95% confidence interval: 0.60, 0.91). Our results show a reduced risk for glioma associated primarily with current allergic conditions. If this is etiologic, it has implications for the understanding of how allergic conditions might reduce the tumor risk.     

Odor sensitivity and respiratory complaint profiles in a community-based sample with asthma, hay fever, and chemical odor intolerance.

This is a community-based study of odor sensitivity and respiratory complaints for persons reporting asthma (n = 14/141), hay fever (n = 72/140), and chemical odor intolerance (CI) (n = 41/181). CI, a symptom of multiple chemical sensitivity (MCS), was determined from self-ratings of feeling 'moderately' to 'severely' ill using the Chemical Odor Intolerance Index (CII). Index odors included perfume, pesticide, drying paint, new carpet odor, and car exhaust. Six additional odors [natural gas, disinfectants, chlorinated water, room deodorizers, and environmental tobacco smoke (ETS)] were also assessed in the health and environment survey. Asthmatics reported feeling 'frequently' to 'almost always' ill from the CII index odors of drying paint, new carpet odor, perfume, and cleaning agents compared to nonasthmatics. People with hay fever documented feeling 'frequently' to 'almost always' ill from pesticides, drying paint, and car exhaust compared to individuals without hay fever. The CI cited illness from air freshener, natural gas and chlorinated water, in addition to the index odors of perfume, paint, pesticides, new carpeting and auto exhaust. All three groups were significantly more likely to report feeling ill from ETS. People with asthma were significantly more likely to report lower lung complaints, such as wheeze and dyspnea. People with hay fever cited more chest tightness. The CI were significantly more likely to report upper and lower respiratory symptoms. Given this overlap in respiratory complaints, it could be that CI may serve to amplify these traditional immune-related disorders and/or suggest that having asthma or hay fever could make one more vulnerable to CI.     

Diphtheria tetanus pertussis poliomyelitis vaccination and reported atopic disorders in 8-12-year-old children

BACKGROUND: Evidence for the relationship between the diphtheria tetanus pertussis (DTP) vaccination and atopic disorders is inconclusive, because the available studies that constitute the evidence are liable to confounding by indication. STUDY OBJECTIVE: To assess the relationship between diphtheria-tetanus-pertussis-(inactivated) poliomyelitis vaccination (DTP-IPV) in the first year of life and reported atopic disorders at primary school age. METHOD: 1875 children attending Orthodox Reformed (Protestant) primary schools in the Netherlands returned questionnaires with data on vaccination status, atopic symptoms and lifetime atopic disorders (asthma, hay fever, eczema and food allergy), and possible confounders. RESULTS: The adjusted odds ratio of any atopic disorder (vaccinated/unvaccinated) was 1.00 (CI95%: 0.80-1.24). For asthma, hay fever, eczema and food allergy the results were respectively: 1.04 (CI95%: 0.76-1.42), 0.79 (CI95%: 0.55-1.12), 0.87 (CI95%: 0.66-1.14) and 1.13 (CI95%: 0.71-1.81). CONCLUSION: The DTP-IPV vaccination was not related to reported atopic disorders at primary school age.     

Early childhood predictors of asthma

To investigate potential risk factors for the development of childhood asthma, the authors undertook a longitudinal study using a cohort of 770 children aged 5-9 years from East Boston, Massachusetts, that has been under study since 1975. The disease outcome considered was age at first onset of asthma, as determined by parental or self-reporting of a physician's diagnosis. Potential risk factors were evaluated specifically in relation to their presence antecedent to a diagnosis of asthma. Standardized questionnaires were used to obtain childhood illness histories, environmental exposures, and the asthmatic and atopic statuses of first-degree relatives. Ninety-one cases of asthma were identified from 1975 to 1988 (57 males and 34 females). Significant sex-adjusted relative risk estimates were seen for antecedent pneumonia, bronchitis, hay fever, sinusitis, parental asthma, and parental atopy. Neither bronchiolitis, eczema, croup, personal cigarette smoking, maternal smoking, paternal smoking, nor delivery complications bore an apparent relation to the development of asthma. A history of parental asthma or parental atopy did not significantly alter the sex-adjusted relative risk estimates for pneumonia, bronchitis, hay fever, or sinusitis. These results support the hypothesis that asthma is a multifactor disease whose expression is dependent on both familial and environmental influences.     

Allergies in adults

Only few epidemiological studies have assessed allergic diseases in adults. In a follow-up study of the MONICA survey S3 (1994/95), which was performed 1997-1999, a total of 1,537 persons were interviewed and tested by skin prick and patch test. Furthermore data of the MONICA survey (RAST, cholesterol, food diaries) could be used. Within survey S4 (1999/2001) a total of 4,261 subjects were interviewed concerning their personal history of atopic diseases and the corresponding history of their partners. In survey S3 the prevalence of allergic sensitisation was 20.5 % for persons without formal graduation from school and 48.1 % for those with a university degree. 20.8 % reported a hypersensitivity to food and about one quarter exhibited a positive reaction in skin prick test. Atopic eczema and hay fever increased over quartiles of HDL cholesterol. Similar, allergic sensitisation (RAST) increased over quartiles of uptake of unsaturated fatty acids in men. 40 % of those who were patch tested exhibited a positive reaction, with perfume mix, nickel, thimerosal and balsam of Peru being the most prominent allergens. Inhabitants of the City of Augsburg were sensitised more often (34.0 % overall, 23.9 % pollen) than inhabitants of villages with (29.4 %, 17.0 %). Full time farmers were sensitised less frequently (22.0 %, 8.4 %). In survey S4 the lifetime prevalence of atopic diseases diagnosed by doctors was 5.1 % for atopic eczema, 6.1 % for asthma and 13.7 % for hay fever. Subjects who lived together with a partner who suffered from hay fever were affected in 19.6 % whereas 13.1 % had hay fever when the partner was not affected. Future studies will offer an unique opportunity to analyse the incidence and remission of manifestations of atopy in adults.     

Food hypersensitivity and allergic diseases

Allergic disease is a common cause of morbidity, particularly in young children. The prevalence of allergic disease has increased in the last 20 y in most countries. The sequential order of occurrence of allergy is food hypersensitivity, gastrointestinal manifestations, atopic eczema, asthma and hay fever. A variety of factors increase the risk of allergic disease, for example hereditary predisposition, exposure to 'allergenic' foods and environmental triggers such as house dust mites and tobacco in early life. Prolonged breast feeding, the use of a partial whey hydrolysed formula, delayed introduction of certain 'allergenic foods', and avoidance of inhalant allergens reduces the incidence of eczema and asthma, especially in high-risk infants. These preventive measures are extremely cost-effective and should be adopted widely at the community level.     

The associations between childhood asthma and atopy, and parental asthma, hay fever and smoking

Summary. The aim of this analysis was to examine the degree to which a life time prevalence of asthma in a 7-year-old child is statistically associated with atopic conditions of the child, and with parental asthma, hay fever and smoking. In 1968, 8585 children who were born in 1961 and who were attending school in Tasmania were surveyed. This comprised 99% of the eligible population. The prevalence of a history of asthma in the 7-year-olds was 16.2% (males 19.0%, females 13.2%). Multiple logistic regression analysis showed that a history of asthma in a 7-year-old was associated with the child being male (odds ratio [OR] 1.56; 99% confidence interval 1.30–1.86), having a history of hay fever (3.86; 3.12–4.78), eczema (2.04; 1.63–2.55), hives (1.34; 1.09–1.65) or allergy to foods or medicines (1.70; 1.26–2.30), the child's mother or father having a history of asthma (2.63; 2.08–3.31 or 2.52; 1.99–3.19, respectively), and the mother being a smoker (1.26; 1.05–1.51). Parental hay fever and paternal smoking were not independently associated with childhood asthma. The strength of association between childhood asthma and parental asthma was independent of the sex of either the parent or the child, and of atopic conditions in the child. In the 133 children for whom both parents were asthmatic, 65 (49%) had a history of asthma. These findings, based on a population survey, are consistent, not only with a childhood history of asthma being strongly associated with atopy, but also with the existence of strong unmeasured determinants common to family members, the effects of which are not mediated via atopy. The risk for asthma being independent of both the sex of the child and of the parent, is consistent with a genetic aetiology for susceptibility to asthma.