Breastfeeding and the risk of wheeze and asthma in Japanese infants: the Osaka Maternal and Child Health Study

Epidemiological evidence for an effect of breastfeeding on asthma continues to be inconclusive. The present prospective study examined the relationship between breastfeeding and the risk of wheeze and asthma in Japanese infants. A birth cohort of 763 infants was followed. The first survey during pregnancy and the second survey between 2 and 9 months postpartum collected information on potential confounding factors. Data on breastfeeding, wheeze, and asthma were obtained from questionnaires in the third survey from 16 to 24 months postpartum. Adjustment was made for maternal age, maternal and paternal history of asthma, atopic eczema, and allergic rhinitis, indoor domestic pets (cats, dogs, birds, or hamsters), family income, maternal and paternal education, maternal smoking during pregnancy, baby's sex, baby's older siblings, household smoking in the same room as the infant, and time of delivery before the third survey. By the third survey, the cumulative incidence of wheeze and asthma was 22.1% and 4.3%, respectively. Neither exclusive breastfeeding for 4 months or more nor partial breastfeeding for 6 months or more were materially related to the risk of wheeze. No measurable association was observed between exclusive breastfeeding for 4 months or more and the risk of asthma. Partial breastfeeding for 6 months or more was inversely related to the risk of asthma although the adjusted odds ratio (OR) was not statistically significant. When infants were stratified according to whether there was a negative or positive allergic history in at least 1 parent, a nearly 40% and 60% decrease, respectively, in the ORs were found for exclusive and partial breastfeeding only in infants without a parental allergic history, although the ORs were not statistically significant. The present prospective study showed no statistically significant relationship between breastfeeding duration and the risk of wheeze or asthma in Japanese infants.

Fatty acid intake and asthma symptoms in Japanese children: the Ryukyus Child Health Study

BACKGROUND

It has been hypothesized that increased consumption of n-6 polyunsaturated fatty acids and decreased consumption of n-3 polyunsaturated fatty acids have contributed to the recent increased prevalence of asthma.

OBJECTIVES

The present cross-sectional study examined the association of intake of specific types of fatty acids with the prevalence of asthma symptoms using data from the Ryukyus Child Health Study.

METHODS

Study subjects were 25,033 schoolchildren aged 6-15 years in Okinawa, Japan. Symptoms of wheeze and asthma were defined according to diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Information on dietary factors was collected using a self-administered brief diet history questionnaire for children. Adjustment was made for age, sex, number of siblings, smoking in the household, body mass index, paternal and maternal history of allergic diseases, and paternal and maternal educational level.

RESULTS

Intake of polyunsaturated fatty acids, n-3 and n-6 polyunsaturated fatty acids and linoleic acid (18:2 n-6) was independently associated with an increased prevalence of wheeze--the multivariate odds ratios for the highest quintile were 1.19 (95% confidence interval [CI], 1.05-1.35), 1.17 (95% CI, 1.03-1.34), 1.19 (95% CI, 1.04-1.35), and 1.20 (95% CI, 1.06-1.37), respectively. There was no measurable relationship of consumption of alpha-linolenic (18:3 n-3), eicosapentaenoic (20:5 n-3), docosahexaenoic (22:6 n-3) or arachidonic acid (20:4 n-6) or the ratio of n-3 to n-6 polyunsaturated fatty acids with the prevalence of wheeze. Consumption of total fat, saturated fatty acids, monounsaturated fatty acids and cholesterol were not evidently related to wheeze. No material dose-response association was found between the intake of any of the types of fatty acids considered and the prevalence of asthma.

CONCLUSIONS

The findings suggest that consumption of both n-3 and n-6 polyunsaturated fatty acids, especially linoleic acid, may be associated with an increased prevalence of wheeze.

MEFV mutation analysis of familial Mediterranean fever in Japan

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent attacks of fever with serosal inflammation. FMF gene (MEFV) mutations have been identified primarily in patients from Mediterranean populations. Although several clinical cases have been reported in Japan, there have been few reports to date on mutation analysis. We studied FMF patients and their relatives to examine the clinical and genetic features of this disease in the Japanese population.

METHODS

Twelve Japanese FMF patients who met the Tel Hashomer criteria and a total of 17 relatives from 5 of 10 families underwent molecular genetic studies to detect MEFV mutations. The characteristics of these Japanese FMF patients and geno-phenotypical correlations were examined.

RESULTS

Almost all of our patients had been suffering for a long time from fever of unknown origin and one patient also had systemic amyloidosis. In our 12 FMF patients, we detected the substitutions E84K, L110P, E148Q, R761H and M694I. We also newly diagnosed 2 relatives as having FMF based on clinical symptoms and the existence of FMF mutations. One patient was homozygous for E148Q, the patient with systemic amyloidosis was a homozygote for M694I and 4 patients from 3 families were compound heterozygotes for E148Q and M694I. Three patients in one family were compound heterozygotes for E148Q, L110P and M694I. There were 3 patients who were heterozygous for E84K, L110P-E148Q or M694I and had no other nucleotide changes in the exons of MEFV. On the other hand, 2 relatives who had never experienced symptoms of FMF were homozygous for L110P-E148Q as well as compound heterozygous for E148Q/E148Q-R761H. E148Q and M694I were the most frequently detected substitutions in our study.

CONCLUSIONS

MEFV mutations occur in Japanese FMF patients though FMF is rare in Japan. The identification of MEFV mutations could be a reliable diagnostic test for FMF. The results of genetic analyses on 14 Japanese FMF patients in this study revealed that E148Q and M694I are frequent alleles.

Tuberculin reactivity and allergic disorders in schoolchildren, Okinawa, Japan

BACKGROUND

Bacillus Calmette-Guérin (BCG) vaccination triggers a T-helper type 1 response. Whether BCG vaccination and positive tuberculin reactivity are preventive against allergic disorders remains controversial.

OBJECTIVE

The current cross-sectional study investigated the relationship of BCG vaccination and tuberculin reactivity with the prevalence of allergic disorders using data from the Ryukyus Child Health Study (RYUCHS).

METHODS

Subjects were 5717 schoolchildren aged 8-11 years in Okinawa, Japan. The RYUCHS collected information on symptoms of allergic disorders and potential confounding factors. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Data on BCG vaccination and tuberculin tests were obtained from school records. Allowance was made for grade, sex, sibship size, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level.

RESULTS

No measurable relationship was found between BCG vaccination in infants and the prevalence of allergic disorders. Among 5567 BCG-vaccinated children, positive tuberculin reactivity (induration >/=10 mm) in the first grade was independently associated with a decreased prevalence of wheeze, asthma, and atopic eczema: the multivariate odds ratios for wheeze, asthma, and atopic eczema were 0.80 (95% confidence interval [CI], 0.67-0.94), 0.78 (95% CI, 0.64-0.95), and 0.77 (95% CI, 0.62-0.95), respectively. The inverse associations were more pronounced in children with a negative parental allergic history than in those with a positive parental allergic history. There was no significant relationship between tuberculin reactivity and allergic rhinoconjunctivitis.

CONCLUSIONS

The findings suggest that positive tuberculin reactivity may be inversely associated with the prevalence of wheeze, asthma, and atopic eczema, but not allergic rhinoconjunctivitis, especially among Japanese children without a parental allergic history.

Fat and fish intake and asthma in Japanese women: baseline data from the Osaka Maternal and Child Health Study

OBJECTIVE

It remains controversial whether the intake of n-3 polyunsaturated fatty acids and fish is preventive against asthma. This cross-sectional study investigated the relationship between fat and fish intake and the prevalence of asthma using baseline data from a prospective study.

DESIGN

The subjects were 1002 pregnant Japanese females. A diet history questionnaire was used to assess dietary habits. Current asthma and asthma after age 18 were defined as present if subjects had been treated with medications at some time in the previous 12 months and after reaching the age of 18, respectively.

RESULTS

Fish consumption was independently associated with a decreased prevalence of asthma after age 18 and current asthma. A significant inverse relationship was observed between the ratio of n-3 to n-6 polyunsaturated fatty acid intake and the prevalence of current asthma, but not asthma after age 18. Intake of total fat, saturated, monounsaturated, n-3 polyunsaturated and n-6 polyunsaturated fatty acids, cholesterol, meat, eggs or dairy products was not evidently related to either outcome for asthma.

CONCLUSION

Our results suggest that fish consumption and the high ratio of n-3 to n-6 polyunsaturated fatty acid intake may be associated with a reduced prevalence of asthma in young female Japanese adults.

Magnesium intake is inversely associated with the prevalence of tooth loss in Japanese pregnant women: the Osaka Maternal and Child Health Study

There have only been a few studies on the role of mineral intake in tooth loss. We investigated the association between mineral intake and the prevalence of tooth loss in Japan. We used the baseline data on 1002 pregnant women who were enrolled in the Osaka Maternal and Child Health Study between November 2001 and March 2003. Tooth loss was defined as the previous extraction of one or more teeth. Nutrient intake was assessed by a validated diet history questionnaire. Prevalence odds ratios and confidence intervals were estimated by applying a multiple logistic regression model. The adjusted odds ratio upon comparison of the highest quartile with the lowest quartile of magnesium intake was 0.64 (95% confidence interval, 0.42-0.99), showing a tendency for an inverse dose-response relationship (p for linear trend = 0.05). There were no associations between the level of consumption of calcium, phosphate, iron, zinc, or copper and tooth loss. The present findings suggest that intake of magnesium is related to reduced prevalence of tooth loss among young Japanese women.