The impact of flash glucose monitoring on the clinical practice of healthcare professionals working in diabetes care

AIMS

Research has identified that healthcare professionals' attitudes in clinical consultations impact the efficacy of their communication with service users and the blood glucose monitoring behaviours of their clients. Yet no research has sought to understand the impact of flash glucose monitoring on the experience of undertaking clinical consultations. This qualitative study aimed to explore the impact that flash glucose monitoring has on the clinical practice of healthcare professionals.

METHODS

Semi-structured interviews were conducted with seventeen Healthcare Professionals (female: n = 13; male: n = 4) working with flash glucose monitoring, analysed via Thematic Analysis.

RESULTS

Three themes were identified: (1) Delivering Person-centred Care; (2) Shift in Diabetes Management; and (3) Time Burden. These themes highlight that flash glucose monitoring facilitates person-centred care through the provision of comprehensive data which improves communication between healthcare professionals and service users. However, preparing for consultations which integrate flash glucose monitoring requires a significant, potentially burdensome time investment.

CONCLUSIONS

Flash glucose monitoring enhances the strategic ability of healthcare professionals to provide evidence-based patient-centred care. This facilitates growth in service users' self-efficacy and encourages targeted diabetes self-management. However, further training is needed to optimise the ability of clinicians to rapidly interrogate and present monitoring data to users.

Cough during infancy and subsequent childhood asthma

OBJECTIVES

Wheezing in infancy has been associated with subsequent asthma, but whether cough similarly influences asthma risk has been little studied. We sought to determine whether prolonged cough and cough without cold in the first year of life are associated with childhood asthma.

METHODS

Participants in the Infant Immune Study, a non-selected birth cohort, were surveyed 7 times in the first 9 months of life regarding the presence of wheeze and cough. Cough for more than 28 days was defined as prolonged. Parents were asked at 1 year if the child ever coughed without a cold. Asthma was defined as parental report of physician diagnosis of asthma, with symptoms or medication use between 2 and 9 years. Logistic regression was used to assess adjusted odds for asthma associated with cough characteristics.

RESULTS

A total of 24% (97) of children experienced prolonged cough and 23% (95) cough without cold in the first 9 months, respectively. Prolonged cough was associated with increased risk of asthma relative to brief cough (OR 3.57, CI: 1.88, 6.76), with the risk being particularly high among children of asthmatic mothers. Cough without cold (OR 3.13, 95% CI: 1.76, 5.57) was also independently associated with risk of childhood asthma. Both relations persisted after adjustment for wheeze and total IgE at age 1.

CONCLUSIONS AND CLINICAL RELEVANCE

Prolonged cough in infancy and cough without cold are associated with childhood asthma, independent of infant wheeze. These findings suggest that characteristics of cough in infancy are early markers of asthma susceptibility, particularly among children with maternal asthma.

Relation of early antibiotic use to childhood asthma: confounding by indication?

BACKGROUND

Findings from studies of the relation between early antibiotic use and subsequent asthma have been inconsistent, which may be attributable to methodologic issues.

OBJECTIVE

Our objective was to assess the impact of confounding by indication on the relation of early antibiotic use to childhood asthma through age 5 in a non-selected birth cohort (n=424).

METHODS

Oral antibiotic use was assessed by frequent nurse interviews in the first 9 months of life. Physician-diagnosed active asthma and eczema were assessed by questionnaire at 1, 2, 3, and 5 years, and were considered as ever asthma or ever eczema if positive at any age. Allergen-specific IgE was assessed in plasma at 1, 2, 3, and 5 years. Confounding by indication was investigated by considering the relation of asthma to antibiotic use while controlling for the number of illness visits to a physician in early life.

RESULTS

There was no statistically significant relation of early antibiotic use with physician-diagnosed eczema or allergen-specific IgE. A dose-response relation was evident for antibiotic use with ever asthma (odds ratio [OR]=1.5, P=0.047). Ever asthma also increased significantly with the number of illness visits to a physician (P<0.001). After adjustment for number of illness visits, antibiotic use showed no relation with asthma.

CONCLUSIONS

The relation of asthma to antibiotics in this cohort appears to be an artefact of the strong relation of number of physician visits for illness with both antibiotic use and risk for asthma.

GlaxoSmithKline and Merck: private-sector collaboration for the elimination of lymphatic filariasis

More than 1000 million people in 82 countries are at risk of contracting the tropical disease lymphatic filariasis (LF). Although the disease is wide-spread, transmission of the causative parasites can be stopped through mass drug administrations based on a combination of anti-parasitic medicines. For more than 10 years, the pharmaceutical companies GlaxoSmithKline (GSK) and Merck & Co., Inc., have participated in a unique private-sector collaboration to support the global efforts to eliminate LF, through donations of drugs to prevent the disease. GSK's albendazole and Merck's ivermectin (Mectizan) now reach hundreds of millions of people each year, through national LF-elimination programmes carried out in collaboration with Ministries of Health, the World Health Organization, non-governmental organizations and local communities. Working in support of the Global Programme to Eliminate Lymphatic Filariasis, GSK and Merck not only provide donated medicines but also offer financial, programmatic and management expertise to support LF-elimination efforts worldwide.

The impact of CD14 polymorphisms on the development of soluble CD14 levels during infancy

CD14 is a receptor involved in the recognition of lipopolysaccharide and other bacterial wall components that may be involved in the balance between infectious and allergic disease and the early polarization towards TH1. Our group has shown an association between polymorphisms in the 5' flanking region of the CD14 gene and plasma soluble CD14 (sCD14) levels at 11 years of age. However, whether this association is present at birth and in infancy remains to be determined. In this study, we measured sCD14 levels in plasma from the umbilical cord (n = 387) and at 3 months (n = 357) and 1 year (n = 312) of age in non-selected healthy infants to assess their relationship with CD14 genotypes at -4190, -2838, -1720 and -260 (relative to translation start site). There was no relation of CD14 genotypes with sCD14 at birth. However, there was a significant association between CD14 genotypes and sCD14 as early as 3 months. Longitudinal analysis suggests that CD14 polymorphisms modulate sCD14 levels up to 1 year of age. This association early in life may have an impact on TH1 polarization and subsequent protection against allergic disease.

Eye-hand co-ordination skills in very preterm infants <29 weeks gestation at 3 years: Effects of preterm birth and retinopathy of prematurity

INTRODUCTION

Preterm infants are known to have low gross motor and fine motor skills. We questioned whether poor eye-hand coordination skills are associated with moderate to severe stages of Retinopathy of Prematurity (ROP).

AIMS

The aim of this study was to examine development, with specific reference to eye-hand coordination skills, among preterm infants <29 weeks gestation with different stages of ROP at 3 years of age.

METHODS AND MATERIALS

Fifteen preterm infants (<29 weeks gestation) who developed Stage 3 ROP were matched for gestation, birthweight and gender with infants who developed Stage 2 and Stage 1/no ROP. Developmental (Griffiths Mental Development Scales and Peabody Developmental Motor Scales) and ophthalmic assessments in the 3 matched groups of 15 were performed at 3 years of age.

RESULTS

1) Whilst the eye-hand coordination scores and Peabody fine motor scores were lower in the Stage 3 ROP group, they were not significantly lower than the other ROP groups. 2) Locomotor, Peabody gross motor skills and hearing and speech were significantly lower in the infants with Stage 3 ROP. The other developmental domains were not significantly different to the severe ROP group. 3) All 3 groups (of preterm infants) had lower eye-hand coordination and Peabody fine motor scores compared to test norms. 4) There were 8 of 15 infants with Stage 3 ROP who developed moderate visual problems by 3 years of age.

CONCLUSION

In preterm infants, low eye-hand coordination/fine motor scores are likely to be due to their extreme prematurity.

Postnatal development of a large auditory nerve terminal: the endbulb of Held in cats

The endbulbs of Held are formed by the ascending branches of myelinated auditory nerve fibers and represent one of the largest synaptic endings in the brain. Most of the developmental changes in structure occur during the first 30 postnatal days of age. The neonatal endbulb begins as a flattened expansion with many filopodia, resembling a growth cone and characterized by numerous puncta adherentia and synapses associated with small postsynaptic densities; the most impressive feature of the ending at this age is its highly irregular plasma membrane that interdigitates with that of the postsynaptic spherical bushy cell. During these first 30 days, the number of puncta adherentia diminishes, postsynaptic densities nearly double in size, intermembraneous cisternae emerge, and plasma membranes flatten. These features endow the endbulb with an adult-like appearance. On the other hand, synaptic vesicle density increases progressively from approximately 50/microm2 at birth to 100/microm2 at adulthood. Mitochondria size remains constant over this developmental period but mitochondrial volume fraction increases until 60 days postnatal. Although many features of endbulb morphology stabilize by 30 days, other features suggest that endbulb development continues into the third month of age. Many of these observations correlate with the maturation of physiological response properties and suggest issues for further study.

Dynamic changes in sensitization to specific aeroallergens in children raised in a desert environment

BACKGROUND

Allergen skin test reactivity and total serum IgE are objective measures used to characterize and help diagnose allergic diseases. Cross-sectional studies have shown that overall aeroallergen skin test reactivity increases throughout childhood. However, little attention has been paid to whether individual aeroallergen remittance occurs, which could distort or mask relationships to disease.

OBJECTIVE

To access the incidence and remittance of skin test reactions to individual allergens in children aged 6-11 years.

METHODS

Longitudinal sensitization to six aeroallergens and total IgE were assessed in 828 children raised in the semi-arid US southwest at ages 6 and 11 years.

RESULTS

New sensitization (to any allergen) between 6 and 11 years occurred in 30.2% of children compared with 39.7% before age 6 years. The rate of complete remittance from positive to negative between ages 6 and 11 years was 8.2%, and total IgE at age 6 years was not predictive. Remittance rates for individual allergens were high and variable (19-49%). The perennial allergens Bermuda and Alternaria were early sensitizers and had low remittance rates. Early sensitization to the four seasonal allergens was less common and more subject to remittance with the bulk of sensitization occurring between 6 and 11 years.

CONCLUSION

This study shows that sensitization to individual aeroallergens in childhood is dynamic and indicates the limitation of single point assessment of skin test reactivity.

A case of childhood dermatofibrosarcoma protuberans without detected cytogenetic abnormality

Dermatofibrosarcoma protuberans (DFSP) is a rare, infiltrative skin tumour of intermediate malignancy, with a limited potential for metastasis but a high rate of recurrence; specific cytogenetic abnormalities are now known. Childhood DFSP has been considered a rarity in the past, but it is now recognized that many cases of childhood DFSP are diagnosed only in adulthood. Despite advances in the understanding of its pathogenesis as well as the development of valuable immunohistochemical and cytogenetic diagnostic techniques, there often remains a significant delay between the initial presentation and diagnosis of DFSP. We report a case of childhood DFSP in which the diagnosis was reached only after a nodular lesion developed in a plaque that was initially present. Causes for delay between initial presentation and diagnosis in childhood DFSP are discussed. Histology and immunostaining in our patient showed the typical features of DFSP, but the G-banded cytogenetic analysis of short-term tissue culture was negative. However, this technique offers only a detection rate between 50% and 80%. Clinicians should be aware of the limitations of newer diagnostic techniques. Increasing recognition amongst paediatricians and paediatric dermatologists that childhood DFSP is not as rare as once believed will probably lead to the use of newer diagnostic methods at an earlier stage, and so reduce the delay between the onset of symptoms and diagnosis.

The association of allergic sensitization in mother and child in breast-fed and formula-fed infants

Human milk contains immunologically active substances potentially capable of altering infant immune response. As part of the prospective Children's Respiratory Study, we assessed whether the association between maternal allergic status and allergic status of the child was altered by breast-feeding. Skin-prick tests for 7 common allergens were administered to 702 6-year-old children and their mothers. The percentage of children sensitized to specific allergens, maternal skin test response to that allergen, and whether or not the child was ever breast-fed was determined. Findings indicated that specific sensitization in the mother was associated with specific sensitization in the child only if the child was breast-fed. This indirectly supports the hypothesis that contents of milk differ with maternal allergic status, and appear to affect allergic status in the child. These results suggest that milk from allergic mothers either promotes a Th2 type immune response or suppresses Th1 immune response in the child.

The association between persistent eosinophilia and asthma in childhood is independent of atopic status

BACKGROUND

Although peripheral blood eosinophilia is associated with risk of asthma, the relation with atopy has not been established.

OBJECTIVE

To assess the relationship between eosinophils and chronic asthma in childhood, and to determine the factors associated with eosinophil levels over time.

METHODS

Percent eosinophils/300 white blood cell (WBC) count ('eos') was measured at 9 months, 6 years and 11 years in subjects participating in the prospective Tucson Children's Respiratory Study. Children were classified based on the number of measurements in which they had low (< or = 2%) or high (>5%) eosinophils, as follows: (1) Persistently low eos (n = 130); (2) Low eos (intermittently low or consistently moderate, but never high, n = 317); (3) Intermittently high eos (n = 192); and (4) Persistently high eos (n = 17). Only children with > or = 2 eos measurements were included in the analysis. Chronic asthma was defined as medical doctor (MD)-diagnosed asthma with reports of wheezing during the previous year, on > or = 3 questionnaires completed between 2 and 13 years of age. Children with at least one positive skin prick test (SPT; > or = 3 mm) at age 6 or 11 were considered 'atopic'.

RESULTS

Chronic asthma was linearly related to longitudinally ascertained eosinophils (trend chi2 P<0.001) with prevalence ranging from 5.8% among children with persistently low eos to 37.5% among children with persistently high eos. This relation was independent of atopy. Parental history of asthma was associated with both chronic asthma (P <0.001) and with longitudinal eosinophil status (P < 0.001). After adjusting for atopy and gender, there was a 70% increase in asthma risk with each increase in longitudinal eosinophil level. This stepwise increase was reduced to 48% when parental asthma was added to the model.

CONCLUSION

Longitudinal eosinophil levels are linearly associated with chronic asthma in childhood, independent of atopy. The strong association between parental asthma and eosinophil status suggests that genetic background may be an important determinant of eosinophilic response.

Maternal asthma status alters relation of infant feeding to asthma in childhood

The relation of infant feeding to childhood asthma is controversial. This study tested the hypothesis that maternal asthma alters the relation of breastfeeding to childhood asthma. Questionnaires were completed at age 6, 9 or 11 years by parents of 1043 children enrolled at birth. Active MD asthma was defined as a physician diagnosis of asthma plus asthma symptoms reported on one of the questionnaires. Duration of exclusive breastfeeding, categorized as never, < 4 months, or > or = 4 months, was based on prospective physician reports or questionnaires completed at 18 months. The relationship between breastfeeding and asthma differed by maternal asthma status. For children with maternal asthma, the percent developing active MD asthma increased significantly with longer duration of exclusive breastfeeding. Odds of developing asthma among these children were significantly elevated (OR: 5.7,CI: 2.8-11.5), after adjusting for confounders. This association of longer exclusive breastfeeding with increased risk of reported asthma among children with asthmatic mothers may be biologically based, or may reflect reporting biases.

Relation between infantile colic and asthma/atopy: a prospective study in an unselected population

OBJECTIVE

To assess whether children with history of infantile colic may be at increased risk of subsequently developing asthma and/or atopy.

METHODS

We used data collected in a large, prospective study from an unselected population. Infantile colic and concurrent feeding method were determined from the 2-month well-infant visit form completed by the physician for 983 children who were enrolled at birth. Markers of atopy (total serum immunoglobulin E and allergy skin prick test), allergic rhinitis, asthma, wheezing, and peak flow variability were the main outcome measures studied at different ages between infancy and 11 years.

RESULTS

Ninety (9.2%) children had infantile colic. Prevalence of colic was similar among children fed either breast milk or formula. There was no association between infantile colic and markers of atopy, asthma, allergic rhinitis, wheezing, or peak flow variability at any age.

CONCLUSION

Our data cannot support the hypothesis that infantile colic provides increased risk for subsequent allergic disease or atopy.

Dog exposure in infancy decreases the subsequent risk of frequent wheeze but not of atopy

BACKGROUND

Influence of household pets in the development of childhood asthma or atopy has been controversial.

OBJECTIVE

The purpose of this study was to investigate whether pet exposure in early life decreases the subsequent risk of frequent wheezing and/or allergic sensitization.

METHODS

This was a prospective observational birth cohort study. The setting was a large health maintenance organization in Tucson, Ariz; the subjects were a population sample of 1246 newborns enrolled at birth and followed prospectively to age 13 years. The main outcome measures were as follows: time to first report of frequent wheezing (>3 episodes in the past year), skin prick test reactivity at 6 years and 11 years of age, and total serum IgE at 9 months, 6 years, and 11 years of age.

RESULTS

Children living in households with > or =1 indoor dogs at birth were less likely to develop frequent wheeze than those not having indoor dogs (P =.004). This inverse association was confined to children without parental asthma (hazard ratio = 0.47; P <.001 [Cox regression]) and was not evident for children with parental asthma (hazard ratio = 0.96; P =.87). Adjustment by potential confounders did not change the results. Indoor cat exposure was not significantly associated with the risk of frequent wheezing. Neither cat exposure in early life nor dog exposure in early life was associated with skin prick test reactivity or total serum IgE at any age.

CONCLUSION

Dog exposure in early life might prevent the development of asthma-like symptoms, at least in low-risk children with no family history of asthma. Nevertheless, early pet exposure does not seem to significantly influence the development of allergic sensitization.

Navajo perceptions of asthma and asthma medications: clinical implications

BACKGROUND

Despite the large number of asthma patients, relatively little is known about the beliefs of asthmatic children and their parent(s), or the extent to which these beliefs influence management of the disease.

OBJECTIVE

The purpose of this study was to examine how medication-taking and the use of health care services were influenced by perceptions of the disease and beliefs about medications among Navajo families.

METHODS

Ethnographic interviews were used to investigate the disease and medication beliefs of 22 Navajo families with 29 asthmatic children.

RESULTS

Most respondents perceived asthma as the transient experience of symptoms in someone who was chronically vulnerable to breathing problems. The majority (97%) of these asthmatics reported using bronchodilators, although only 34% reported current use of antiinflammatory medications. Although controller medications were distinguished from rescue medications, they were thought to have the same effect on the lungs. Many families were concerned about becoming dependent on the medicines and attempted to "wean" the asthmatic from the drugs. A large proportion (80%) of children had assumed responsibility for their own medication taking. Parents often referred to previous attacks requiring treatment in the emergency department when deciding whether to initiate medication or seek medical attention, often resulting in a delay of treatment. Nebulized treatments delivered in the emergency department were perceived to be the strongest therapy available. As a result, visits to the emergency department were common (79%), as were hospital admissions (57%).

CONCLUSION

This study provides evidence that, among pediatric Navajo asthma patients, perceptions of asthma and beliefs about the activity of asthma medications influence when and how often asthma medicines are taken, as well as the use of health care services. In addition, excessive reliance on emergency treatments and the high rates of hospital admissions suggest that asthma is undertreated in this group of Navajo patients.

A survey of trainee obstetricians preferences for childbirth

OBJECTIVE

To determine trainee obstetricians personal preferences regarding mode and place of delivery given various scenarios.

STUDY DESIGN

An anonymous nationwide postal survey of 365 specialist registrars.

RESULTS

The response rate was 76%. About 2.5% preferred a home birth. And 16% of men and 15% of women opted for elective cesarean section (CS). When faced with a proposed trial of instrumental delivery in theatre, 60% accepted and a further 12% accepted only if they could choose the obstetrician performing the delivery. Regarding a breech presentation at term, 78% would accept external cephalic version (ECV).

CONCLUSIONS

The percentage of obstetricians who preferred vaginal delivery and ECV were considerably higher than previously reported, and there were no significant gender differences. This study shows a more balanced attitude from obstetricians and refutes the previously held view that they necessarily advocate high levels of intervention for themselves.

Increased incidence of asthmalike symptoms in girls who become overweight or obese during the school years

The possibility of a causal relationship is suggested by recent concomitant increases in the prevalence of obesity and asthma. In a general population sample, prevalence and incidence of asthma symptoms, skin tests, and body mass index (BMI) were ascertained at mean ages of 6.3 (n = 688) and 10.9 (n = 600) yr. Lung function, bronchodilator responsiveness, and daily peak flow variability were measured at 11 yr of age. There was no association between BMI at age 6 and wheezing prevalence at any age. Females, but not males, who were overweight or obese at 11 yr of age were more likely to have current wheezing at ages 11 and 13 but not at ages 6 or 8. This effect was strongest among females beginning puberty before the age of 11. Females who became overweight or obese between 6 and 11 yr of age were 7 times more likely to develop new asthma symptoms at age 11 or 13 (p = 0.0002); at age 11 their peak flow variability and bronchodilator responsiveness were significantly more likely to be increased. In females, becoming overweight or obese between 6 and 11 yr of age increases the risk of developing new asthma symptoms and increased bronchial responsiveness during the early adolescent period.

Factors influencing the relation of infant feeding to asthma and recurrent wheeze in childhood

BACKGROUND

The relationship between infant feeding and childhood asthma is controversial. This study tested the hypothesis that the relation between breast feeding and childhood asthma is altered by the presence of maternal asthma.

METHODS

Healthy non-selected newborn infants (n = 1246) were enrolled at birth. Asthma was defined as a physician diagnosis of asthma plus asthma symptoms reported on > or = 2 questionnaires at 6, 9, 11 or 13 years. Recurrent wheeze (> or = 4 episodes in the past year) was reported by questionnaire at seven ages in the first 13 years of life. Duration of exclusive breast feeding was based on prospective physician reports or parental questionnaires completed at 18 months. Atopy was assessed by skin test responses at the age of 6 years.

RESULTS

The relationship between breast feeding, asthma, and wheeze differed with the presence or absence of maternal asthma and atopy in the child. After adjusting for confounders, children with asthmatic mothers were significantly more likely to have asthma if they had been exclusively breast fed (OR 8.7, 95% CI 3.4 to 22.2). This relationship was only evident for atopic children and persisted after adjusting for confounders. In contrast, the relation between recurrent wheeze and breast feeding was age dependent. In the first 2 years of life exclusive breast feeding was associated with significantly lower rates of recurrent wheeze (OR 0.45, 95% CI 0.2 to 0.9), regardless of the presence or absence of maternal asthma or atopy in the child. Beginning at the age of 6 years, exclusive breast feeding was unrelated to prevalence of recurrent wheeze, except for children with asthmatic mothers in whom it was associated with a higher odds ratio for wheeze (OR 5.7, 95% CI 2.3 to 14.1), especially if the child was atopic.

CONCLUSION

The relationship between breast feeding and asthma or recurrent wheeze varies with the age of the child and the presence or absence of maternal asthma and atopy in the child. While associated with protection against recurrent wheeze early in life, breast feeding is associated with an increased risk of asthma and recurrent wheeze beginning at the age of 6 years, but only for atopic children with asthmatic mothers.

Relation of two different subtypes of croup before age three to wheezing, atopy, and pulmonary function during childhood: a prospective study

OBJECTIVE

Some retrospective evidence suggests that children with a history of croup may be at increased risk of subsequently developing asthma, atopy, and diminished pulmonary function. The objective of this study was to determine the long-term outcome of croup (as diagnosed by a physician) in early life.

METHODS

Lower respiratory illnesses (LRIs) in the first 3 years of life were assessed in 884 children who were enrolled in a large longitudinal study of airway diseases at birth. Pulmonary function tests, markers of atopy, and wheezing episodes were studied at different ages between birth and 13 years.

RESULTS

Ten percent of children had croup with wheeze (Croup/Wheeze), 5% had croup without wheeze (Croup/No Wheeze), 36% had another LRI (Other LRI), and 48% had no LRI. Respiratory syncytial virus was more frequently isolated in children with Croup/Wheeze and Other LRI than in those with Croup/No Wheeze. There was no association between croup in early life and markers of atopy measured during the school years. Only children with Croup/Wheeze and with Other LRI had a significant risk of subsequent persistent wheeze later in life. Significantly lower levels of indices of intrapulmonary airway function were observed at ages <1 (before any LRI), 6, and 11 years in children with Croup/Wheeze and Other LRI compared with children with No LRI. Conversely, inspiratory resistance before any LRI episode was significantly higher in infants who later developed Croup/No Wheeze than in the other 3 groups.

CONCLUSIONS

We distinguish 2 manifestations of croup with and without wheezing. Children who present with croup may or may not be at increased risk of subsequent recurrent lower airway obstruction, depending on the initial lower airway involvement, and preillness and postillness abnormalities in lung function associated with this condition.

The rise of breastfeeding in the United States

What factors influenced the resurgence of breastfeeding in the last decades of the twentieth century? This article has considered several explanations. Demographic trends, particularly the increased birth rate among black and Hispanic women, coupled with the resurgence of breastfeeding in these groups, may have contributed to the increase in the breastfeeding rate during the 1990s but likely played a minimal role in the earlier, more dramatic increase. The decrease in breastfeeding in the earlier part of the twentieth century may be partly attributable to increased maternal employment, but the resurgence of breastfeeding occurred during the late twentieth century--a period of unprecedented influx of new mothers into the workforce. There is no evidence that health care practitioners are providing more support for breastfeeding, and most international and US policies postdated the resurgence of breastfeeding, although they may have influenced the increase in the 1990s. A more plausible explanation of the resurgence of breastfeeding in all major segments of society is the pervasive influence of the natural-childbirth movement of the 1960s and 1970s, with its effects on the standard management of childbirth. Also, the increase in breastfeeding among low-income women may be attributable partly to programmatic changes in the provision of supplemental food through the WIC program and the targeting of breastfeeding-promotion efforts to the specific concerns of these women. Although breastfeeding increased at the end of the twentieth century relative to earlier decades, the disparity between the recommended rates and those achieved by US women is great. Thus, efforts to increase breastfeeding initiation and duration should continue, particularly for the groups that are at greatest risk for illness, such as minority and low-income infants. This article suggests that the strategies likely to have a lasting effect on future breastfeeding rates will be social pressures that affect existing barriers to breastfeeding. Such pressures may come from health maintenance organizations, insurance companies, and the US government, which are likely to increasingly recognize the costs of not breastfeeding to their institutions. The provision of flexible work hours and paid maternity leave, either by the US government or family-friendly workplaces, could increase the ability of employed women to optimally feed their infants. As Retsinas noted in an article on the cultural context of breastfeeding, "While it is 'known' that breastfeeding is better, our society is not structured to facilitate that choice." Efforts to improve breastfeeding rates need to make visible the wider cultural context in which infant-feeding choices are made and alter components that make it difficult for US women to feed their infants optimally.

A clinical index to define risk of asthma in young children with recurrent wheezing

Because most cases of asthma begin during the first years of life, identification of young children at high risk of developing the disease is an important public health priority. We used data from the Tucson Children's Respiratory Study to develop two indices for the prediction of asthma. A stringent index included frequent wheezing during the first 3 yr of life and either one major risk factor (parental history of asthma or eczema) or two of three minor risk factors (eosinophilia, wheezing without colds, and allergic rhinitis). A loose index required any wheezing during the first 3 yr of life plus the same combination of risk factors described previously. Children with a positive loose index were 2.6 to 5.5 times more likely to have active asthma between ages 6 and 13 than children with a negative loose index. Risk of having subsequent asthma increased to 4.3 to 9.8 times when a stringent index was used. We found that 59% of children with a positive loose index and 76% of those with a positive stringent index had active asthma in at least one survey during the school years. Over 95% of children with a negative stringent index never had active asthma between ages 6 and 13. We conclude that the subsequent development of asthma can be predicted with reasonable accuracy using simple, clinically based parameters.

Siblings, day-care attendance, and the risk of asthma and wheezing during childhood

BACKGROUND

Young children with older siblings and those who attend day care are at increased risk for infections, which in turn may protect against the development of allergic diseases, including asthma. However, the results of studies examining the relation between exposure to other children and the subsequent development of asthma have been conflicting.

METHODS

In a study involving 1035 children followed since birth as part of the Tucson Children's Respiratory Study, we determined the incidence of asthma (defined as at least one episode of asthma diagnosed by a physician when the child was 6 to 13 years old) and the prevalence of frequent wheezing (more than three wheezing episodes during the preceding year) in relation to the number of siblings at home and in relation to attendance at day care during infancy.

RESULTS

The presence of one or more older siblings at home protected against the development of asthma (adjusted relative risk for each additional older sibling, 0.8; 95 percent confidence interval, 0.7 to 1.0; P=0.04), as did attendance at day care during the first six months of life (adjusted relative risk, 0.4; 95 percent confidence interval, 0.2 to 1.0; P=0.04). Children with more exposure to other children at home or at day care were more likely to have frequent wheezing at the age of 2 years than children with little or no exposure (adjusted relative risk, 1.4; 95 percent confidence interval, 1.1 to 1.8; P=0.01) but were less likely to have frequent wheezing from the age of 6 (adjusted relative risk, 0.8; 95 percent confidence interval, 0.6 to 1.0; P=0.03) through the age of 13 (adjusted relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.5; P<0.001).

CONCLUSIONS

Exposure of young children to older children at home or to other children at day care protects against the development of asthma and frequent wheezing later in childhood.

Prostate cancer and other xenografts from cells in peripheral blood of patients

Good models for the investigation of human prostate cancer are few. Cells from approximately 9.2-21 ml of peripheral blood from patients with metastatic prostate cancer or metastatic colon cancer were injected s.c. into nude mice. Prostate cancer from 2 of 11 patients and colon cancer from 1 of 3 patients were found to be growing as metastases in the lungs of the nude mice. To our knowledge, this is the first report of the formation of xenografts from carcinoma cells taken directly from the peripheral blood of patients. Expanding circulating cancer cells with this approach may have important translational applications including: (a) development of models of human cancers; and (b) sampling of cancers from specific patients for novel molecular and therapeutic approaches.

Urticaria and hidden salicylates

A 23-month-old girl had a chronic urticaria resistant to antihistamine therapy. She was found to be using large quantities of a topical salicylate preparation which was being regularly applied to her pacifier. Once this habit was stopped, her urticaria cleared and has not recurred.

Familial aggregation and segregation analysis of eosinophil levels

The number of circulating eosinophils is associated with the risk of asthma in population samples. Therefore, eosinophil levels may be an intermediate phenotype for asthma amenable to genetic analysis. We examined familial aggregation of the number of eosinophils x 10(6) L(-1) and the percentage of eosinophils based on a 300 count differential in 644 Hispanic and non-Hispanic white families, with 2, 097 subjects, enrolled in the Tucson Children's Respiratory Study. Both measures were adjusted for age, season and year at the time blood was drawn, sex, and ethnicity. Segregation analysis was conducted in the 458 non-Hispanic white families, as there were no significant familial correlations in the Hispanic families, and there was significant heterogeneity by ethnic group. Familial correlations (rho) in the non-Hispanic white families were as follows: mother-father, 0.05; mother-child, 0.18 (p < 0.001); father-child, 0.07; sibling-sibling, 0.31 (p < 0.001). Without covariates analyses indicated a polygenic/multifactorial mode of inheritance. After adjusting for current and past asthma an oligogenic mode of inheritance was suggested, plus additional residual familial components that were mainly maternally mediated. This study supports the notion of multiple, relatively common genes interacting to determine genetic susceptibility to asthma. Holberg CJ, Halonen M, Wright AL, Martinez FD. Familial aggregation and segregation analysis of eosinophil levels.

Breast-feeding, maternal IgE, and total serum IgE in childhood

BACKGROUND

There is controversy regarding the relationship of the effect of breast-feeding on markers of allergy such as total serum IgE in childhood.

OBJECTIVE

This study, using longitudinal data, tested the hypothesis that the relation of breast-feeding to IgE in childhood differs depending on maternal total IgE level.

METHODS

Total serum IgE was assessed with the paper radioimmunosorbent test at 4 ages in nonselected children enrolled at birth into the prospective Tucson Children's Respiratory Study. Children were classified as never breast-fed, breast-fed less than 4 months, or breast-fed 4 months or longer, on the basis of physician report or questionnaires completed by parents by the time the child was 18 months old. A longitudinal random effects model was used to test for group differences and temporal trends in IgE for children classified with reference to maternal IgE (high tertile vs all others) and breast-feeding history. A total of 664 children with 1457 observations were included.

RESULTS

Among children whose mothers were in the 2 lower tertiles of IgE, breast-feeding was associated with lower total serum IgE at age 6 years (24.2 vs 44.3 IU/mL for never breast-fed children; P <.02); similar trends existed at age 11 years. In contrast, for children whose mothers were in the highest tertile of IgE, breast-feeding of 4 months or longer was associated with higher IgE levels in the child compared with those never breast-fed or breast-fed less than 4 months (97.0 vs 38.9 IU/mL; P <. 005). These cross-sectional analyses were confirmed with the longitudinal random effects model, which also showed no effect of confounders. Paternal IgE showed no similar relation with child IgE.

CONCLUSION

Breast-feeding appears to have paradoxic relations with IgE in childhood, depending on maternal IgE level. These findings may help explain the contradictory results found in other investigations of the relation of breast-feeding to allergic symptoms and markers.

Respiratory syncytial virus in early life and risk of wheeze and allergy by age 13 years

BACKGROUND

The relation between lower respiratory tract illnesses in early life caused by the respiratory syncytial virus (RSV) and the subsequent development of wheezing and atopy in childhood is not well understood. We studied this relation in children who had lower respiratory tract illnesses that occurred before 3 years of age.

METHODS

Children were enrolled at birth and cases of lower respiratory tract illness were ascertained by a physician. Viral tests were done for specimens collected at the time of the illness. Children were classified into five groups according to type and cause of lower respiratory tract illness. Children were then followed prospectively up to age 13, and we measured frequency of wheezing, pulmonary function, and atopic status (allergy skin-prick tests, serum IgE concentrations).

FINDINGS

RSV lower respiratory tract illnesses were associated with an increased risk of infrequent wheeze (odds ratio 3.2 [95% CI 2.0-5.0], p < 0.001), and an increased risk of frequent wheeze (4.3 [2.2-8.7], p < or = 0.001) by age 6. Risk decreased markedly with age and was not significant by age 13. There was no association between RSV lower respiratory tract illnesses and subsequent atopic status. RSV lower respiratory tract illnesses were associated with significantly lower measurements of forced expiratory volume (2.11 [2.05-2.15], p < or = 0.001) when compared with those of children with no lower respiratory tract illnesses, but there was no difference in forced expiratory volume after inhalation of salbutamol.

INTERPRETATION

RSV lower respiratory tract illnesses in early childhood are an independent risk factor for the subsequent development of wheezing up to age 11 years but not at age 13. This association is not caused by an increased risk of allergic sensitisation.

Two subphenotypes of childhood asthma that differ in maternal and paternal influences on asthma risk

Asthma is a phenotypically heterogeneous disease. Two subgroups are defined here based initially on skin test reactivity to the allergen Alternaria at age 6 from among a large population of children born and raised in the Southwestern desert environment of Tucson, Arizona. When compared with asthma among Alternaria-positive subjects, asthma among Alternaria-negative subjects was associated with lower levels of total serum IgE, no relation to local aeroallergen skin tests, a younger age at diagnosis, greater remittance by age 11, and more frequent wheezing lower respiratory illnesses (LRIs) in the first year of life. Despite the difference in total serum IgE, however, IgE concentrations were significantly higher in each asthma group compared with its respective control group. Asthma in each parent contributed approximately equivalent risk for Alternaria-positive asthma in the child. However, neither parental skin test sensitization nor total serum IgE levels provided risk for asthma in the child. Inheritance patterns for Alternaria-negative asthma revealed a contribution from maternal but not paternal asthma. Thus, dividing asthma in children at age 6 into Alternaria-positive and Alternaria-negative groups identifies subphenotypes that are further distinguished by differences in phenotypic markers and parental influences.

Influence of parental smoking on respiratory symptoms during the first decade of life: the Tucson Children's Respiratory Study

Compelling evidence suggests a causal relation between exposure to parental cigarette smoking and respiratory symptoms during childhood. Still, the roles of prenatal versus postnatal parental smoking need clarification. In this study, the authors assessed the effects of passive smoking on respiratory symptoms in a cohort of over 1,000 children born during 1980-1984. The children were enrolled in the Tucson Children's Respiratory Study in Tucson, Arizona, and were followed from birth to age 11 years. The population was generally middle class and consisted of two main ethnic groups, non-Hispanic Whites (75%) and Hispanics (20%), reflecting Tucson's population. Information on parental smoking and on wheeze and cough in their children was elicited from parents by using questionnaires at five different surveys. Data were analyzed both cross-sectionally and by using the generalized estimation equation approach, a longitudinal mixed-effects model. The best-fitting model indicated that maternal prenatal but not postnatal smoking was associated with current wheeze (odds ratio = 2.3, 95% confidence interval 1.4-3.8) independently of a family history of asthma, socioeconomic factors, and birth weight. This effect was time dependent and significant only below age 3 years; although independent of gender, the association was stronger for girls (odds ratio = 3.6, 95% confidence interval 1.6-8.0). Cough was not associated with parental smoking during the first decade of life. This transitory effect of maternal prenatal smoking on wheezing could be due to changes that affect the early stages of lung development.

Association of radiologically ascertained pneumonia before age 3 yr with asthmalike symptoms and pulmonary function during childhood: a prospective study

Epidemiologic evidence suggests an association between reports of pneumonia in early life and the subsequent development of diminished lung function. However, no studies are available in which the diagnosis of pneumonia was based on radiologic evidence. Lower respiratory illnesses with or without a radiologically confirmed diagnosis of pneumonia were assessed in a study of 888 children enrolled at birth. Pulmonary function tests, markers of atopy, asthma diagnosis, and prevalence of respiratory symptoms were assessed at different ages between birth and 11 yr. Incidence of pneumonia during the first 3 yr of life was 7.4%. Respiratory syncytial virus was the most frequent agent identified both in children with pneumonia and in those with lower respiratory tract illness (LRI) without pneumonia (36.4% versus 35.6%, respectively). Children with a diagnosis of pneumonia were more likely to have physician-diagnosed asthma and current wheezing at ages 6 and 11 yr than were those who had no LRIs. When compared with children without LRIs, those with a diagnosis of pneumonia had lower levels of maximal flows at FRC at mean age of 2 mo (albeit not significantly) and at age 6 yr, and lower levels of FEV1 and FEF25-75 at age 11 yr. These deficits were independent of known confounders, including wheezing at the time of study, and were partly and significantly reversed after administration of a bronchodilator. We conclude that children with radiologically confirmed pneumonia have diminished airway function that is probably present shortly after birth. These deficits are at least in part due to alterations in the regulation of airway muscle tone.

Health care costs of formula-feeding in the first year of life

OBJECTIVE

To determine the excess cost of health care services for three illnesses in formula-fed infants in the first year of life, after adjusting for potential confounders.

METHODS

Frequency of health service utilization for three illnesses (lower respiratory tract illnesses, otitis media, and gastrointestinal illness) in the first year of life was assessed in relation to duration of exclusive breastfeeding in the Tucson Children's Respiratory Study (n = 944) and the Dundee Community Study (Scottish study, n = 644). Infants in both studies were healthy at birth and represented nonselected, population-based samples. Children were classified as never breastfed, partially breastfed, or exclusively breastfed, based on their feeding status during the first 3 months of life. Frequency of office visits and hospitalizations for the three illnesses was adjusted for maternal education and maternal smoking, using analysis of variance. Cost estimates, from the perspective of the health care provider/payer, were based on the direct medical costs during 1995 within a large managed care health care system.

RESULTS

In the first year of life, after adjusting for confounders, there were 2033 excess office visits, 212 excess days of hospitalization, and 609 excess prescriptions for these three illnesses per 1000 never-breastfed infants compared with 1000 infants exclusively breastfed for at least 3 months. These additional health care services cost the managed care health system between $331 and $475 per never-breastfed infant during the first year of life.

CONCLUSIONS

In addition to having more illnesses, formula-fed infants cost the health care system money. Health care plans will likely realize substantial savings, as well as providing improved care, by supporting and promoting exclusive breastfeeding.

Differential immune responses to acute lower respiratory illness in early life and subsequent development of persistent wheezing and asthma

BACKGROUND

Recent epidemiologic evidence suggests that 2 wheezing syndromes coexist in early life: transient wheezing, limited to early childhood, and persistent wheezing, which starts in early childhood and persists beyond that age.

OBJECTIVE

Whether the nature of the immune response occurring during acute lower respiratory illnesses (LRIs) in infancy differs between these 2 groups of wheezers has yet to be determined.

METHODS

We compared total serum IgE levels and peripheral blood eosinophil counts obtained during the acute phase of the first LRI with those obtained during the convalescent phase or with well-baby samples in persistent (n = 49) and transient early wheezers (n = 88), as well as in children who had only nonwheezing LRIs (n = 43) during the first 3 years of life.

RESULTS

Total serum IgE levels were significantly higher (P =.008) during the acute phase compared with the convalescent phase of the LRI in persistent wheezers, a response not observed in transient early wheezers (P =.7). Peripheral blood eosinophil counts were significantly reduced during the acute phase of the LRI (P =.009) in transient early wheezers, a response not observed among persistent wheezers (P =.7). Acute responses in children who had nonwheezing LRIs only were similar to those seen in transient early wheezers.

CONCLUSION

Alterations in acute immune response to viral infection may be detected at the time of the first wheezing episode in subjects who will go on to have persistent wheezing symptoms.

Differences in familial segregation of FEV1 between asthmatic and nonasthmatic families. Role of a maternal component

Studies have demonstrated familial aggregation of lung function. This study employed segregation analysis to investigate the mode of inheritance of FEV1 using regressive models for continuous traits. The study population comprised 309 families (1,163 individuals) enrolled in the Tucson Children's Respiratory Study who had both parents and at least one child with FEV1 data. Results showed significant genetic heterogeneity among the 87 families (328 individuals) with at least one member with asthma and the 222 families (835 individuals) with no asthmatic members. In families with no asthmatic members, all statistical models were rejected, indicating the absence of a major gene controlling lung function. However, a significant familial component indicated a strong polygenic/multifactorial mode of inheritance. In families with asthmatic member(s), results suggested polygenic/multifactorial inheritance with weak evidence for a Mendelian component expressed in a recessive fashion. However, while both father-offspring and mother-offspring correlations were statistically significant in families with no asthmatic members, only the mother-offspring correlation was significant in families with asthmatic members. The data suggest that lung function is inherited as a polygenic/multifactorial trait, but in asthmatic families a major element of intergenerational correlation is associated with a maternal influence, which may be genetically or environmentally mediated.

Lessons from long-term cohort studies. Childhood asthma

Cohort studies, which are longitudinal studies that follow a group of people with reference to the development of disease, have been a cornerstone of research on childhood asthma. These studies are uniquely suited to address questions concerning the incidence of illness, the natural history of disease, and the sequence of events linking exposures with outcomes. Three findings from on-going cohort studies are particularly relevant for the design of future intervention studies. First, most childhood asthma begins in infancy, with 80% of children who develop asthma having their first episode of wheeze before the age of 3 yrs. Second, events in early life, possibly including allergen exposure, infant feeding practices and viral infections, may be critical to the development of asthma in childhood. Finally, wheezing presents as separate phenotypes at different ages, with each phenotype having distinct characteristics, risk factors and prognoses. Additional cohort studies are required to determine to what extent events occurring in infancy, both viral and allergic, trigger expression of asthma, what are the mechanisms whereby they foster development of the disease, and whether their effect can be prevented.

Increasing breastfeeding rates to reduce infant illness at the community level

OBJECTIVE

Although breastfeeding is associated with lower rates of a variety of infant illnesses, skeptics have suggested that much of the association is attributable to confounding, even after appropriate statistical adjustment. This article utilizes a novel design to investigate changes in infant illness at the community level after a successful breastfeeding promotion program.

METHODS

In this population-based cohort study, the medical records of all infants born in one Navajo community the year before a breastfeeding promotion program (n = 977) and the year during the intervention (n = 858) were reviewed. Outcomes assessed include changes after the intervention in: proportion breastfeeding and/or breastfeeding exclusively; incidence of common infant illnesses in the first year of life; and feeding-group specific incidence of illness.

RESULTS

The proportion of women breastfeeding exclusively for any period of time increased from 16.4% to 54.6% after the intervention. The percent of children having pneumonia and gastroenteritis declined 32. 2% and 14.6%, respectively, after the intervention. Feeding-group specific rates of these illnesses were unchanged, indicating that the decline observed was attributable to the increased proportion of infants breastfeeding. In contrast, rates of croup and bronchiolitis increased after the intervention among those fed formula from birth, suggesting a viral epidemic which was limited to those never exclusively breastfed. Finally, sepsis declined in both formula-fed and breastfed infants after the intervention, suggesting that other factors affected this illness outcome after the intervention.

CONCLUSIONS

Increasing the proportion of exclusively breastfed infants seems to be an effective means of reducing infant illness at the community level. The experimental design suggests that the increased incidence of illness among minimally breastfed infants is causally related to lack of breast milk, rather than being attributable to confounding.

Cold air challenge at age 6 and subsequent incidence of asthma. A longitudinal study

The aim of this study was to assess the relation between bronchial hyperresponsiveness to dry, cold air at age 6 and the subsequent incidence of asthma. The cumulative incidence of newly diagnosed asthma between ages 6 and 11 among 360 children included in this study was 12.0%. Survival analysis showed that hyperresponsiveness to cold air at age 6 was associated with an increased risk of developing subsequent asthma (hazard ratio = 2.6, 95% CI = 1.2-5.4; p = 0.01). However, after adjusting for potential confounders, only mild wheezing at age 6 (adjusted hazard ratio 7.5, 95% CI = 3.6-15.9; p < 0.001) and skin test reactivity to allergens at age 6 (adjusted hazard ratio 3.6, 95% CI = 1.5-8.5; p < 0.01), but not hyperresponsiveness to cold air (adjusted hazard ratio = 0.9, 95% CI = 0.4-2.2; p = 0.8), remained significant predictors of subsequent development of asthma. These findings were substantially confirmed after stratifying for wheezing illnesses before age 3. We conclude that hyperresponsiveness to cold air at age 6 was associated with subsequent development of a diagnosis of asthma but this effect was not independent of atopy and mild wheezing at age 6.

Peak flow variability, methacholine responsiveness and atopy as markers for detecting different wheezing phenotypes in childhood

BACKGROUND

There is increasing evidence that wheezing during childhood may be a heterogeneous condition, and that different forms of wheezing may be associated with different risk factors and prognosis. The aim of this study was to determine if measures of airway lability and of atopy could identify distinct wheezing phenotypes during childhood.

METHOD

In a cohort of children followed from birth peak flow variability (n = 600) was evaluated and methacholine challenge responsiveness (n = 397) was measured at age 11 in relation to wheezing before the age of three, and at age six and 11 years total serum IgE and skin test reactivity to allergens were determined.

RESULTS

Neither positive peak flow variability nor methacholine hyperresponsiveness measured at age 11 were associated with wheezing occurring only during the first three years of life. Both methacholine hyperresponsiveness and positive peak flow variability were associated with wheezing at both ages six and 11 (OR 5.1 (95% CI 2.4 to 10.6) and 2.3 (1.2 to 4.5), respectively). In addition, positive peak flow variability was associated with wheezing up to the age of six but not at age 11 in non-atopic children (OR 2.9 (95% CI 1.0 to 8.8)). Methacholine hyperresponsiveness measured at age 11 was more frequently observed in boys (OR 2.1 (95% CI 1.2 to 3.5)) and was strongly associated with serum IgE levels measured at ages six and 11 (p < 0.001) and with positive skin test reactivity (OR 4.5 (95% CI 2.0 to 10.1)). Peak flow variability was unrelated to sex or markers of atopy (IgE and skin test reactivity).

CONCLUSIONS

Methacholine responsiveness and peak flow variability assessed at age 11, together with markers of atopy (IgE and skin test reactivity to allergens) identify three different wheezing phenotypes in childhood: "transient early wheezing" limited to the first three years of life and unrelated to increased airway lability; "non-atopic wheezing" of the toddler and early school years associated with positive peak flow variability but not with methacholine hyperresponsiveness; and "IgE-associated wheeze/asthma" associated with persistent wheezing at any age and with methacholine hyperresponsiveness, peak flow variability, and markers of atopy.

Using cultural knowledge in health promotion: breastfeeding among the Navajo

Although many attempts have been made to promote breastfeeding in a variety of contexts, few programs have explicitly incorporated cultural beliefs in these efforts. This article describes a breastfeeding promotion program conducted on the Navajo reservation. This program was designed to be culturally appropriate. Background information regarding beliefs and factors affecting infant feeding practices in this setting is provided, followed by a description of the intervention. The intervention, which incorporated both social marketing and community participation techniques, consisted of three components: an intervention in the health care system, a community intervention, and an individual intervention. Based on medical records review of feeding practices of all the infants born the year before (n = 988) and the year after (n = 870) the intervention, the program was extremely successful. This combination of techniques, including qualitative and quantitative research into local definitions of the problem, collaboration with local institutions and individuals, reinforcement of traditional understandings about infant feeding, and institutional change in the health care system, is an effective way of facilitating behavioral change.

Alternaria as a major allergen for asthma in children raised in a desert environment

The relationships of asthma and allergic rhinitis with individual immediate skin test responses were examined for preferential associations and for changes with age in children raised in a semiarid environment. Prevalence of physician-diagnosed asthma was 9.8% at age 6 (n = 948) and 15.5% at age 11 (n = 895). Immediate skin test responses to Bermuda grass were the most prevalent among children with allergic rhinitis and control subjects, whereas responses to the mold, Altenaria alternata, were the most prevalent among asthmatics. Skin test responses for crude house dust, Dermatophagoides farinae, and cat had low prevalences in all groups. By logistic regression, Alternaria was the only allergen independently associated with increased risk for asthma at both ages 6 and 11. Allergic rhinitis showed independent association with sensitization to Bermuda grass and mulberry tree pollen at age 11 but did not show an independent relation to any single allergen at age 6. Logistic regression further revealed that persistent asthma (diagnosed before age 6) was independently associated with Alternaria skin tests at both ages 6 and 11, whereas new asthma (diagnosed after age 6) was associated with Alternaria skin tests at age 6 but not at age 11. We conclude that Alternaria is the major allergen associated with the development of asthma in children raised in a semiarid environment and that skin test responses at age 6 are more closely linked to asthma than those at age 11.

The relation between physician-diagnosed sinusitis, asthma, and skin test reactivity to allergens in 8-year-old children

The purpose of this study was to assess the prevalence of sinusitis in a nonselected sample of children, and the relation of sinusitis to allergic rhinitis (AR), atopy, asthma, and cough in the same population sample. Of 1246 children enrolled at birth in the Tucson Children's Respiratory Study, 835 were studied at a mean age +/-SD of 8.6 +/- 0.7 years. Questionnaires asking about MD-Sinusitis, MD-AR, MD-Asthma, and cough were completed by parents. Skin tests for seven common aeroallergens in the Tucson area had been performed in 630 of the participating children at the mean age +/-SD of 6.3 +/- 0.9 years. Prevalence of MD-Sinusitis was 13.1%; 78% of subjects with MD-Sinusitis also had MD-AR. Detailed analysis of the relation between MD-Sinusitis and individual environmental allergens tested for showed that only a response to Bermuda grass pollen was significantly associated with MD-Sinusitis after controlling for MD-AR [adjusted odds ratio 2.3 (95% CI 1.2-4.3)]. Having MD-Sinusitis was also significantly associated with MD-Asthma and cough [odds ratios 3.0 (95% CI 1.8-5.2)] and 2.5 (95% CI 1.6-3.8), respectively]. However, logistic regression demonstrated that, after controlling for MD-AR and skin test reactivity, MD-Sinusitis was no longer significantly associated with MD-Asthma or cough. We conclude that MD-Sinusitis is a common condition in childhood. The main independent risk factors in our community for MD-Sinusitis were grass pollen and current MD-AR. MD-Sinusitis was not associated with MD-Asthma or with cough after controlling for skin test reactivity and for MD-AR.

Segregation analysis of physician-diagnosed asthma in Hispanic and non-Hispanic white families. A recessive component?

The inheritance of asthma, evident from its high family concordance, is not well understood. To investigate whether asthma may be inherited through a major gene with two alleles, segregation analyses were conducted in 3,369 individuals from 906 nuclear families enrolled, without selection, in a longitudinal study of respiratory health in Tucson, Arizona. Physician-diagnosed asthma and its age of onset were ascertained for each family member when children were at a mean age of 7 yr. Age of asthma diagnosis was allowed for in analyses, and the impact of the covariate total serum IgE level on age of onset was examined. Segregation analyses were conducted with and without residual family effects, with and without the covariate IgE. The hypothesis of a single two-allele locus for asthma was rejected. However, depending on the method of assessment of the residual familial effects, either a polygenic/multifactorial mode of inheritance alone, or an oligogenic model with some evidence of a recessive component present in the population with the high frequency of 0.67, were compatible with the data. Results were unchanged with the addition of the covariate IgE.

Serum levels of the soluble low affinity receptor for IgE and soluble interleukin-2 receptor in childhood, and their relation to age, gender, atopy and allergic disease

Identifying immune factors associated with the development of atopy can enhance our understanding of the in vivo mechanisms involved and may have utility in paradigms designed to prevent disease. Two candidates suggested for such roles are the soluble low affinity receptor for IgE (sCD23) and the soluble interleukin-2 receptor (sCD25). To assess serum levels of these factors blood samples were collected at birth and at age 6 in a large nonselected population from Tucson, AZ. Log mean sCD23 and sCD25 levels decreased from birth to age 6, (for sCD23 0.60 ffi 0.26pg/l, n = 340 and 0.53 + 0.28pg/l, n = 333 and for sCD25 1.95 i 0.14pM, n = 304 and 1.86 ffi 0.20pM, n = 327, for the two ages respectively. Anglo children had lower sCD23 levels at birth compared to Hispanic children (p < 0.01); no effect of gender was observed. Skin test reactivity at age 6 was directly related to sCD25 levels at age 6 (p = 0.007) and even levels at birth showed a similar trend (p = 0.06). These relations were distinct from any relation to total serum IgE. No relation was observed with sCD23 levels for either skin test reactivity or serum IgE. The prevalences of asthma, rhinitis and eczema by age 6 were unrelated to sCD25 or sCD23 levels. The results indicate that soluble CD23 and CD25 have higher levels at birth than later in childhood and that the development of skin test reactivity may be associated with regulatory mechanisms involving sCD25, whereas sCD23 was not similarly implicated.

Recurrent cough in childhood and its relation to asthma

Risk factors for recurrent cough (RC) in childhood, and its relation to asthma were investigated as part of the prospective, longitudinal Tucson Children's Respiratory Study. RC, defined as > or = 2 episodes of cough without a cold in the past year, was assessed by questionnaire in 987 children at age 6. Children having RC without wheeze (n = 154) did not differ from children with neither symptom (n = 610) in serum IgE levels, skin test response, size-corrected forced expiratory flow, or percentage of decline following cold air challenge. In contrast, children with both RC and wheeze (n = 116) had significantly more respiratory illness, more atopy, lower flow at end-tidal expiration (V'maxFRC), and greater declines in lung function following cold air challenge than children with neither symptom. Current parental smoking was a risk for RC without wheeze, whereas male gender, maternal allergy, wheezing lower respiratory tract illness (LRI) in early life, and high IgE were significant risks for RC with wheeze, compared with children having neither symptom. RC early in life resolved in the majority of children, between ages 2-3 yr and age 6, and between age 6 and age 11. High IgE and positive skin prick test were associated with persistence of RC to age 6 among children who wheezed, and markers of allergy were associated with persistence of RC between 6 and 11 yr. These findings suggest that recurrent cough in the absence of wheeze differs in important respects from classic asthma, and using the same label to refer to these distinct syndromes may obscure their diverse pathophysiologies.

Evaporative cooling and other home factors and lower respiratory tract illness during the first year of life. Group Health Medical Associates

Lower respiratory tract illness (LRI) is associated with exposure to various environmental factors. The relation between home environment and LRI in infants was studied with the use of data from the Children's Respiratory Study in Tucson, Arizona. Healthy infants from a health maintenance organization were recruited at birth (1980-1984). Analysis was restricted to one infant per family, and to those followed through the first year (n=936). Environmental data were collected at enrollment, and clinicians diagnosed LRI according to predetermined criteria. During the first year of life, 196 infants (21%) had wheezing LRI, and 60 (6%) had nonwheezing LRI. The risk of wheezing LRI was higher in infants with evaporative home cooling (24%) than in those without evaporative home cooling (15%) (odds ratio = 1.8, 95% confidence interval 1.1-3.0); this association was stronger among infants who lived with other children in the home. The risk of nonwheezing LRI was associated with parents' rating of neighborhood dustiness, ranging from 5% in the least dusty environments to 12% in the dustiest (p for trend = 0.002). Neither association could be explained by confounding factors. LRI was not related to the type of home heating, cooking fuel, or the numbers of indoor dogs or cats.