Parental diabetes, pubertal stage, and extreme obesity are the main risk factors for prediabetes in children and adolescents: a simple risk score to identify children at risk for prediabetes

Objectives:  The current worldwide increase of prediabetes defined as impaired fasting glucose or impaired glucose tolerance and type 2 diabetes mellitus (T2DM) coincides the increase of obesity. However, it is unclear that which children have an increased risk and should be screened for prediabetes.
Methods:  We studied 437 overweight children and adolescents to identify risk factors for prediabetes. A risk score for prediabetes was calculated using logistic regression. This score was examined in a second, independent cohort of 567 overweight children and adolescents. History of T2DM in parents and grandparents, degree of overweight, age, pubertal stage, birth weight, hypertension, dyslipidemia, acanthosis nigricans, and abdominal obesity were considered as potential risk factors.
Results:  The frequency of prediabetes was 6% in sample 1 and 17% in sample 2. The strongest association was observed for history of parental diabetes with an adjusted odds ratio (aOR) of 9.5 [95% confidence interval (CI) 2.5–36.4] in sample 1 and 6.3 (95% CI 3.7–10.7) in sample 2, followed by pubertal stage with an aOR of 5.5 (95% CI 0.7–45.4) in sample 1 and 6.2 (95% CI 2.4–15.6) in sample 2, and by extreme obesity with an aOR of 5.0 (95% CI 1.7–15.3) in sample 1 and 3.3 (95% CI 2.0–5.4) in sample 2.
Conclusions:  The main risk factors for prediabetes were parental diabetes, pubertal stage, and extreme obesity. Screening for prediabetes seems meaningful in subjects with either a parental history of diabetes or a combination of extreme obesity and pubertal stage and detected nearly 90% of the overweight children and adolescents with prediabetes.     

Very high and increasing incidence of type 1 diabetes mellitus in Newfoundland and Labrador, Canada

Objective:  To determine the incidence of type 1 diabetes mellitus (T1DM) among children aged 0–14 yr inclusive in the Canadian province of Newfoundland and Labrador (NL).
Methods:  Prospective and retrospective cohort study of the incidence of T1DM in children aged 0–14 yr from 1987 to 2005. Identified cases during this time period were ascertained from several sources and verified using the capture–recapture technique.
Results:  Over the study period, 732 children aged 0–14 yr were diagnosed with T1DM. The incidence of T1DM in this population over the period 1987–2005 inclusive was 35.08 per 100 000 (95% confidence interval: 32.54, 37.62). The incidence over this period increased linearly at the rate of 0.78 per 100 000 per year. There was a significant difference between the incidence of 31.61 per 100 000 for boys in the 0–4-yr age-group and 19.05 per 100 000 for girls in the 0–4-yr age-group (p = 0.001). The incidence was very high throughout the entire province.
Conclusions/Interpretation:  The province of NL has one of the highest incidences of T1DM reported worldwide. The incidence is increasing over the 19-yr study period.     

Development of autoantibodies to islet antigens during childhood: implications for preclinical type 1 diabetes screening

Abstract: Objective:  Serum islet antibodies signify increased risk for type 1 diabetes (T1D). Knowledge of the relationship between age and seroconversion would guide screening for at-risk individuals. We aimed to determine the effectiveness of islet antibody screening in early childhood, in particular the proportion of negative children who subsequently seroconverted.
Methods:  We identified 554 children with a first-degree relative with T1D who had tested negative for islet cell antibodies (ICA) and insulin autoantibodies (IAA) when first screened at a mean age of 7.2 yr. Of 423 who were eligible, 350 consented to re-testing for ICA and IAA and antibodies to glutamic acid decarboxylase (GADAb) and tyrosine phosphatase-like insulinoma antigen IA-2 (IA2Ab) at a mean age of 11.1 yr. GADAb and IA2Ab were measured in 239 of the initial stored samples.
Results:  Of the 350 children who tested negative at first screening, 12 (3.4%) subsequently seroconverted, becoming positive for ICA (n = 4), IAA (n = 7), GADAb (n = 6) or IA2Ab (n = 2). Of 239 initially negative for ICA and IAA, 8/239 (3.3%) now tested positive for GADAb (n = 7) or IA2Ab (n = 1). Four of these children were positive for GADAb in both tests; the one child initially positive for IA2Ab only was positive for all four antibodies 4.6 yr later and developed diabetes.
Conclusion:  Screening for ICA and IAA failed to identify 2–3% of genetically at-risk children who subsequently developed islet antibodies. Testing for GADAb and IA2Ab would not have avoided this. Maximizing the sensitivity of detecting risk for T1D requires repeat screening for islet antibodies throughout childhood.     

Atopy, home environment and the risk of childhood-onset type 1 diabetes: a population-based case–control study

Background:  The marked increases in the incidence of type 1 diabetes in recent decades strongly suggest the role of environmental influences. These environmental influences remain largely unknown.
Objective:  To investigate atopy and home environment (such as children living at home, sharing a bedroom and house moves) as potential risk factors for type 1 diabetes.
Subjects and method:  In Northern Ireland, 175 children with type 1 diabetes and 4859 control children completed a questionnaire on atopy experience, family composition and home environment. Control children from two age groups (6–8 yr old and 13–14 yr old) were identified from randomly selected primary and secondary schools across Northern Ireland. Cases were identified from a population-based type 1 diabetes register.
Results:  There was little evidence of a difference in the proportion of participants with a history of atopy in the cases compared with controls. There was a significant reduction in the risk of diabetes in children who lived with more siblings {odds ratio (OR) = 0.58 [95% confidence interval (95% CI) 0.39–0.85] in children who lived with three or more siblings compared with one or none} and in children who moved house more often [OR = 0.59 (95% CI 0.40–0.88) in children who moved house twice or more compared with never].
Conclusion:  The reduced risk of type 1 diabetes in children living with siblings, sharing a bedroom and moving house more often could reflect the protection afforded by exposure to infections in early life and consequently may provide support for the hygiene hypothesis.     

Maternal diet during pregnancy and islet autoimmunity in offspring

Background:  Recent studies on the etiology of type 1 diabetes mellitus (T1DM) suggest that the components of the infant diet are associated with islet autoimmunity (IA), a precursor of T1DM. The role of prenatal nutritional exposures has not been thoroughly investigated.
Methods:  The Diabetes Autoimmunity Study in the Young has enrolled newborns from 1993 to 2004 at increased risk for T1DM based on human leukocyte antigen (HLA) genotype and family history of T1DM. The child is tested for islet autoantibodies at 9 and 15 months, 2 yr, and annually thereafter. We conducted a cohort study of 642 subjects for whom a Willett food frequency questionnaire for the mother's third trimester diet was completed. A case is defined as a subject who tests positive for islet autoantibodies at two consecutive blood draws and is still positive (or diabetic) at last follow-up (n = 27).
Maternal consumption frequencies of potatoes, other root vegetables, gluten-containing foods, non-gluten cereal grains, cow's milk and cow's milk products, fruits, vegetables, meat and poultry, and fish were analyzed in a survival analysis.
Results:  Adjusting for breast-feeding duration, age at first cereal introduction, ethnicity, HLA genotype, family history of T1DM, and total caloric intake, higher maternal intake of potatoes (hazard ratio for one standard deviation difference: 0.49, 95% confidence interval: 0.28–0.86) was associated with a delayed time to IA onset. No other food groups ingested during pregnancy were associated with IA in the child.
Conclusions:  The composition of the maternal diet during pregnancy may play a role in the offspring's risk of development of IA and potentially T1DM.     

The effects of birthweight and breastfeeding on asthma among children aged 1–5 years

Aim:   Asthma is a major cause of morbidity and mortality among children and has steadily increased in prevalence. The combined effect of birthweight and breastfeeding on childhood asthma remains unclear.
Methods:   In this study, we analysed a nationally representative sample of children aged 1–5 years from the National Health and Nutrition Examination Survey 1999–2002. Logistic regression was performed to examine the hypothesis whether birthweight and breastfeeding are independently associated with the prevalence of asthma after accounting for the complex sampling design. In addition, we sought to describe the relationship between birthweight and childhood asthma and to assess the potentially combined effect between birthweight and breastfeeding on asthma among children aged 1–5 years after considering the possible effects of social and environmental factors.
Results:   We found that birthweight (measured continuously) was inversely and linearly associated with the prevalence of childhood asthma (odds ratio (OR) = 0.80 per 1 kg increase in birthweight, 95% confidence interval (CI): 0.65–0.98). Using a categorical variable, low birthweight (LBW) was positively associated with childhood asthma (OR = 1.28, 95% CI: 0.81–2.68). Furthermore, we detected an interaction between birthweight and breastfeeding on childhood asthma. Breastfeeding had a strong protective effect on asthma among children with high birthweight (OR = 0.14, 95% CI: 0.04–0.43) while it had no significant effect on asthma among children with normal birthweight or LBW.
Conclusions:   The mechanisms underlying these relationships remain uncertain and warrant further explanation.     

Altered plasma adipokines and markers of oxidative stress suggest increased risk of cardiovascular disease in First Nation youth with obesity or type 2 diabetes mellitus

Objective:  To evaluate cardiovascular disease risk in First Nation youth with and without type 2 diabetes mellitus (T2DM) or obesity by comparing pro- and anti-inflammatory adipokines, markers of oxidative stress and the plasma phospholipid fatty acid profile.
Method:  Self-declared First Nation youth (12–15 yr) with T2DM (n = 24) as well as age-, gender-, and body mass index-matched controls (obese group; n = 19) and unmatched controls (control group; n = 34) were recruited from a pediatric diabetes clinic.
Results:  Plasma tumor necrosis factor-α, ultrasensitive C-reactive protein, resistin, and total antioxidant status were not different among the three groups. Plasma total leptin, soluble leptin receptor, and free leptin were significantly higher in the T2DM group than the control group (p < 0.001, p = 0.019, p < 0.001, respectively) but did not differ from the obese group. Similarly, oxidized low-density lipoprotein was higher in the T2DM group compared with controls (p = 0.002) but not in the obese group. However, interleukin-6 was significantly higher (p < 0.001) in the T2DM group compared with both the control and the obese groups, suggesting that T2DM, but not an increase in adiposity, was responsible for this elevation. Adiponectin was significantly lower in the T2DM group compared with the control group only (p = 0.035).
Conclusions:  Changes in plasma adipokines and oxidative stress can already be detected in youth with T2DM; however, many of the changes are mirrored in obese youth, suggesting that both these populations are at an increased risk for future cardiovascular complications.     

Effects of prior hypoglycemia and hyperglycemia on cognition in children with type 1 diabetes mellitus

Objective:  Despite the general consensus that youth with type 1 diabetes mellitus (T1DM) can experience modest cognitive impairment, debate continues over the role of severe hypoglycemia (Hypo) and/or hyperglycemia (Hyper) in producing such impairment. Our aim was to determine how Hypo and Hyper experienced during brain development predict patterns of subsequent cognitive performance in youth with T1DM.
Methods:  We tested youth aged 5–16 yr (T1DM, n = 117; non-diabetic sibling controls, n = 58) on cognitive tasks (verbal and spatial intelligence, verbal and spatial memory, and processing speed). T1DM participants were categorized as having experienced 0, 1–2, or 3 or more (3+) Hypo episodes, as having their first Hypo episode before or after 5 yr of age and as having early (before age 5) or late (after age 5) diabetes onset. Hyper exposure was estimated with median hemoglobin A1c, adjusted for diabetes duration for each subject.
Results:  The group with T1DM had lower estimated verbal intelligence than sibling controls. Within the T1DM group, verbal intelligence was reduced with increased exposure to Hyper, not to Hypo. In contrast, spatial intelligence and delayed recall were reduced only with repeated Hypo, particularly when Hypo episodes occurred before the age of 5 yr. Age of onset did not explain these results.
Conclusions:  Hypo and Hyper have qualitatively different effects on cognitive function in T1DM that depend in part on the timing of exposure during development, independent of onset age. This information extends the known benefits of avoiding both Hypo and chronic Hyper during childhood to include preservation of specific cognitive skills.     

Prevalence of allergic symptoms among children with diabetes mellitus type 1 of different socioeconomic status

Abstract:  The aim of the study was to assess the possible associations between allergies and type 1 diabetes mellitus (DM1), stratified by social class. We studied 127 children with DM1 with a median age of 10.8 yr and 150 controls of comparable age and sex distribution. The parents completed questionnaires on their education and occupation and on their children's history of allergic symptoms, breast-feeding, viral infections, and measles–mumps–rubella (MMR) vaccination. Lower family's social class was more frequently encountered among the DM1 families than in the controls (OR = 0.56, 95% CI: 0.35–0.92). The occurrence of any allergic symptoms among children with DM1 (35.45%) was not significantly different from the controls (38.78%), neither in the total group (OR = 0.87, 95% CI: 0.52–1.45) nor in the stratified analysis by social class. Similar findings were observed regarding the different types of allergic symptoms. In the univariate analysis, breast-feeding, the experience of viral infections, and MMR vaccination were found to be protective of DM1 presentation in both upper and lower social classes. In the multiple logistic regression analysis, the experience of more than 2 infections/yr (OR = 0.12, 95% CI: 0.04–0.34), the origin from middle and upper social classes (OR = 0.42, 95% CI: 0.22–0.80) and breast-feeding (OR = 0.58, 95% CI: 0.31–1.07) were protective of DM1 occurrence. In children with DM1, the presence of allergic symptoms was not associated with the development of DM1. Among the environmental factors, the origin from middle or upper social classes, breast-feeding, the experience of viral infections, and MMR vaccination were found to have a protective effect on DM1 presentation.     

Association of cord blood cytokine levels with wheezy infants in the first year of life

As antenatal environment may influence the development of atopy-predisposing immune response, cord blood cytokine productions may be an important predictor for wheezing. We investigated cord blood cytokines in a prospective birth cohort, intensively monitored for wheezy infant outcome at 1 yr. Cord blood serum samples from 269 children were assayed for interleukin (IL)-1β, -2, -4 to -8, -10, -12 (p70), -13, and -17, interferon-γ, tumor necrosis factor-α, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein-1, and macrophage inflammatory protein-1β. Associations between family histories, antenatal and perinatal factors, cord blood cytokine concentrations, and wheezy infant outcomes (wheezing more than two times) were analyzed. In cord blood sera from 269 children, there were associations between high levels of IL-6, -8 and G-CSF concentrations, and cesarean section. Data at 1 yr were obtained from 213 infants, including 33 wheezy infants. Risk of wheezing was related to gestational age, birth weight, cesarean section, and maternal eczema, but not to bacterial/viral infection during pregnancy, maternal asthma, maternal smoking, or paternal history. High level of cord blood IL-8 concentration had a significant association with wheezy infant outcomes at 1 yr (p = 0.025). By using multivariate logistic regression analysis, birth weight [odds ratio(OR) = 0.998, 95% confidence interval (CI) = 0.997–1.000] and maternal eczema (OR = 5.356, 95% CI = 1.340–21.41), but no other factors, were significant predictors of wheezy infants. Birth weight, gestational age, and maternal history were important risk factors for wheezing in the first year of life. Several cord blood cytokine productions were influenced by cesarean section, and IL-8 may be a predictor for recurrent wheezing at 1 yr.     

Type 1 diabetes: increased height and weight gains in early childhood

Objective:  The accelerator/beta-cell stress hypothesis regards insulin resistance as one common basis for type 1 and type 2 diabetes and weight increase as an important trigger of type 1 diabetes. To test this hypothesis, we examined children's height and weight gain from birth to the time of diagnosis of type 1 diabetes.
Method:  Growth charts (n = 316) from children 0–16 yr old up to the time of diagnosis of type 1 diabetes were compared with growth charts from age- and sex-matched controls.
Results:  Compared with their controls, children who developed diabetes had experienced more pronounced gain in both weight and height. In the year of diagnosis, they were taller [0.5 vs. 0.36 standard deviation score (SDS), p < 0.03] and heavier (0.7 vs. 0.45 SDS, p < 0.01). Children who developed diabetes aged 5 yr or less gained more weight during the period between their third month and third year of life (p < 0.01). Children who were diagnosed between 6 and 10 yr of age had gained more in height before they were 5 yr old (p < 0.05). Regression analysis showed that a high weight or a high body mass index (BMI) at 5 yr of age indicated, more than the other measurements, a high risk for diabetes later during childhood, while height and weight at ages less than 5 yr did not add any further information on diabetes risk.
Conclusions:  Rapid growth before 7 yr of age and increased BMI in childhood are risk factors for later type 1 diabetes. These findings support the accelerator/beta-cell stress hypothesis.     

Continuous subcutaneous insulin infusion vs. multiple daily injections in children with type 1 diabetes: a systematic review and meta-analysis of randomized control trials

Objective:  To investigate potential effects of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) on glycemic control in children with type 1 diabetes mellitus (T1DM).
Study design:  Meta-analysis and systematic review of randomized control studies (RCTs). The electronic databases MEDLINE, Cochrane Library, and EMBASE were searched through October 2007.
Results:  Six RCTs involving 165 participants with T1DM met our predefined inclusion criteria. Combined data from all trials showed that the CSII group compared with the MDI group experienced a significant reduction in the level of glycosylated hemoglobin. The pooled weighted mean difference (WMD) was −0.24% [95% confidence interval (95% CI) −0.41 to −0.07, p < 0.001] with a fixed model and remained significant in the random effect model. This effect was reached by slightly decreasing insulin requirement [three RCTs, n = 74, WMD −0.22 IU/kg/d (95% CI −0.31 to −0.14, p < 0.001)]. No differences in the incidences of ketoacidosis and severe hypoglycemic events were found.
Conclusions:  In short-term insulin therapy, CSII compared with MDI is a more effective form of metabolic control and allows reducing the daily insulin requirement. Yet, no conclusions have been made so far whether this effect holds in later years. These results should be approached with caution because of the methodological limitations of the analyzed studies.     

Mild fasting hyperglycemia in children: high rate of glucokinase mutations and some risk of developing type 1 diabetes mellitus

Background:  Incidental hyperglycemia in children generates concern about the presence of preclinical type 1 diabetes mellitus (T1DM).
Objective:  To genetically evaluate two common forms of maturity-onset diabetes of youth (MODY), the short-term prognosis in children with mild hyperglycemia, and a positive family history of diabetes mellitus.
Subjects:  Asymptomatic children and adolescents (n = 14), younger than 15 yr, with fasting hyperglycemia, a positive family history of mild non-progressive hyperglycemia, and negative pancreatic autoantibodies were studied.
Patients and methods:  Glucokinase gene ( GCK ) and hepatocyte nuclear factor 1 alpha gene ( HNF1A ) causing two common forms of MODY were sequenced. The clinical outcome was evaluated after a follow-up period of 2.8 ± 1.3 yr.
Results:  GCK mutations were present in seven children. The confirmation of this diagnosis allowed discontinuation of insulin in two families and oral medications in three families. Mutations of HNF1A were not detected in any of the families. During the follow-up period, all the GCK mutation carrier children remained asymptomatic without medication and the last hemoglobin A1c levels were 6.4 ± 0.7%. In the GCK -negative children (n = 7), one developed T1DM, corresponding to 7.2% of the total group. Mild fasting hyperglycemia persisted during follow-up in four GCK -negative children and normalized in the remaining two.
Conclusions:  The presence of mild persistent hyperglycemia in any patient without autoantibodies should lead to genetic analysis of GCK , particularly if there is a positive family history. Furthermore, those without GCK mutations should be followed with repeat autoantibody testing, and other genetic types of diabetes should be considered if hyperglycemia worsens.     

High birth weight, asthma and atopy at the age of 16 yr

The association between high birth weight and asthma has been suggested. The Northern Finland Birth Cohort 1986, a longitudinal cohort originally including 9479 participants, has been followed up since birth until the age of 16 yr. Using the data of this study, we analyzed the association of high birth weight with asthma and atopic sensitization at the age of 16 yr. The analysis included the 5995 subjects with complete skin prick test data and the 5500 subjects with data on doctor-diagnosed asthma (written questionnaire) at the age of 16 yr. Atopy was defined as at least one positive skin prick test reaction, which definition was also used to separate atopic and non-atopic asthma. There was a significant association between high birth weight (>4510 g) and asthma among the atopic subjects (OR 2.40, 95% CI 1.33–4.32). When looking at atopy, the highest risk was observed among the subjects with highest birth weight category (>4510 g) (OR 1.44, 95% CI 1.05–1.97) and the adjacent (4200–4500 g) birth weight category (OR 1.24, 95% CI 1.01–1.53), when compared with the reference category (2500–3340 g). Our results support the notion that high birth weight is associated with an increased risk of asthma and suggest that the association is mostly explained by an increased risk of atopy. The biological mechanisms behind the associations are unknown, but they could be related to obesity.     

Young children (<5 yr) and adolescents (>12 yr) with type 1 diabetes mellitus have low rate of partial remission: diabetic ketoacidosis is an important risk factor

Objective:  To determine whether there are different rates of partial remission in preschool, school-age children, and adolescents with type 1 diabetes mellitus (T1DM) and to identify clinical characteristics that are associated with increased rate of partial remission.
Design/methods:  A total of 152 consecutive patients with newly diagnosed T1DM in 2004 were studied. Clinical characteristics at diagnosis, hemoglobin A1C (HbA1C), and total daily insulin dose (TDD) at 3-month interval follow-up for 1 yr were analyzed in each age-group (group 1, aged <5 yr; group 2, aged 5–12 yr; and group 3, aged >12 yr). Partial remission was defined as TDD <0.5 units/kg/d with HbA1C <8% assessed at 6 months after diagnosis.
Results:  Young children (group 1, 26.8%) and adolescents (group 3, 29%) had low rates of partial remission compared with school-age children (group 2, 56%, p = 0.002). There were no differences in the rates of diabetic ketoacidosis (DKA), autoantibody frequency, and HbA1C at diagnosis between age-groups. DKA at diagnosis was associated with less likelihood of having partial remission (p < 0.001). There were no associations between gender, autoantibodies, and HbA1C at diagnosis and the rate of partial remission.
Conclusions:  Young children and adolescent children with T1DM had a low rate of partial remission. Metabolic control was poorest in young children, whereas higher dose insulin in adolescents because of insulin resistance contributes to less likelihood of having partial remission. DKA at diagnosis was associated with low rate of partial remission. It is possible that the low frequency of honeymoon phase in young children reflects more aggressive beta-cell destruction in young children.     

Urinary tract infections in pediatric renal transplant recipients – a two center risk factors study

Abstract:  UTI are common in renal Tx recipients and may significantly impact on the graft function. The aim of our study was to evaluate the prevalence, risk factors, and significance of UTI in Tx children. We performed a retrospective cross-sectional study of 76 Tx patients, median age at Tx was 13.4 yr. Twenty-one of 76 (28%) patients developed at least one UTI during the mean follow-up time of 3.3 ± 2.0 yr post-Tx. The first UTI occurred at a median of 160 days post-Tx. The RR of having UTI was significantly higher in patients with the primary diagnosis of obstructive uropathy (RR = 2.6, 95th CI = 1.1–6.0, p = 0.032), history of PN pre Tx (RR = 2.7, 95th CI = 1.3–5.4, p = 0.009) and pre Tx VUR (RR = 2.2, 95th CI = 1.1–4.5, p = 0.045). These three factors also significantly decreased the infection-free survival time to the first UTI. Most UTI caused reversible acute allograft dysfunction, but the long-term graft function could not be reliably assessed with SCr. In conclusion, UTI occurred in 28% of pediatric Tx recipients, mostly during the first year post-Tx despite antibiotic prophylaxis. The diagnosis of obstructive uropathy, history of UTI and VUR prior to Tx were significant risk factors.     

Cumulative incidence of asthma and allergy in north-Norwegian schoolchildren in 1985 and 1995

The prevalence of asthma and allergy in children is increasing. In order to investigate time trends, follow-up studies conducted several years apart and with identical study designs are essential. We compared two identical, cross-sectional and questionnaire-based studies of asthma and allergy in north-Norwegian schoolchildren (7–13 years of age). The first study was conducted in 1985 (n = 10,093) and the second in 1995 (n = 8,676). The cumulative incidence was as follows: diagnosed asthma, 8.6% in 1995 vs. 5.1% in 1985, relative risk (RR) = 1.71 (95% CI: 1.53–1.90); allergic rhinoconjunctivitis, 22.1% in 1995 vs. 16.4% in 1985, RR = 1.39 (95% CI: 1.31–1.47); and atopic dermatitis, 19.7% in 1995 vs. 13.2% in 1985, RR = 1.48 (95% CI: 1.39–1.58). The cumulative incidence of allergic rhinoconjunctivitis and atopic dermatitis was higher in children of Sami ethnicity than Norse ethnicity in the 1985 study. Furthermore, although not statistically significant, there was a trend towards a greater increase in the cumulative incidence of diagnosed asthma, symptoms of asthma, allergic rhinoconjunctivitis, and atopic dermatitis from 1985 to 1995 in children of Sami ethnicity than Norse ethnicity. We conclude that there has been a marked increase in the cumulative incidence of asthma and allergy prevalence among schoolchildren in northern Norway from 1985 to 1995.     

Exposure to maternal smoking in the first year of life interferes in breast-feeding protective effect against the onset of respiratory allergy from birth to 5 yr

The aim of this study was to evaluate the interaction between the exclusive breast-feeding protective effect and the exposure to tobacco smoke at domicile in the first year of life, on the onset of respiratory allergy (asthma and rhinitis) in children until 5 yr of age. This is prospective cohort study, observational, institutional based. Three hundred children born in a public hospital of Salvador-Bahia (Brazil) were followed from birth to 5 yr of age. Data from 268 children at 60 months of life were analyzed. Occurrence of allergic symptoms were studied and correlated with gender, allergic relatives in first degree, exclusive breast-feeding duration, smoking mother, and presence of other smoker at home, considering the first year of life. Exclusive breast-feeding for at least 6 months showed a protection effect against the onset of respiratory allergy in children from birth to 5 yr (p < 0.05); odds ratio (OR): 0.33 (95% CI: 0.18–0.59). Breast-fed children for less then 6 months compared with those breast-fed for 6 months or more, presented a higher risk (OR: 2.34–95% CI: 1.4–3.74) for developing allergic respiratory symptoms just to 5 yr. The protective effect of exclusive prolonged breast-feeding on the onset of respiratory allergy in children from birth until 5 yr was lost when their mothers were smokers (OR: 2.50–95% CI 1.19–5.19). Therefore, the protective effect of breast-feeding in the first year of life on the onset of allergic symptoms until the age of 5 yr was confirmed. This study proposes a confounding effect of maternal smoking on this protection, exposed by a higher risk for present allergic symptoms until the age of 5 yr, in children exclusively breast-fed for 6 months or more, when their mothers smoked.     

Cross-sectional survey of risk factors for asthma in 6–7-year-old children in New Zealand: International Study of Asthma and Allergy in Childhood Phase Three

Aim:   To identify risk factors for asthma in primary school-aged children in New Zealand.
Methods:   A cross-sectional survey of 10 873 6–7-year-old children in Auckland, Bay of Plenty, Nelson and Christchurch (a response rate of 85.2%). A questionnaire was completed by the parent or care giver.
Results:   22.2% of children wheezed in the last 12 months (current wheeze). Maori children were at greater risk of current wheeze compared with European children (adjusted odds ratio (adjOR) = 1.37; 95% confidence interval = 1.18–1.59). Antibiotics and paracetamol used in the first year of life were associated with an increased risk of current wheeze (adjOR = 1.78 (1.56–2.04) and adjOR = 1.31 (1.06–1.61), respectively). Watching television for 5 or more hours per day was associated with an increased risk of current wheeze (adjOR = 1.44 (1.13–1.83)). Milk and egg consumption in the last 12 months was associated with a reduced risk of current wheeze.
Conclusions:   This study has identified risk factors for asthma in children aged 6–7 years, although causal pathways cannot be established. These associations have important public health implications if causal.