Asthma and bronchitis in Sydney school children. I. Prevalence during a six-year study.

During a study to document the effects of childhood respiratory disease and smoking on the lung function of Sydney schoolchildren, the prevalence of children with asthma was documented. Two groups of children aged 12.6 (6590) and 8.9 years (4893) were studied in schools selected at random from the Sydney metropolitan area. Initially parents filled out a questionnaire recording whether the child had ever been treated for asthma or bronchitis by a physician. The children were seen yearly between 1971 and 1976 and a history of asthma and/or bronchitis present duirng the preceding year -as recorded. The cumulative prevalence of asthma until 1976 was significantly higher in boys than in girls in both age groups. Bronchitis was more prevalent than asthma but the difference between girls and boys was less obvious in the younger age group.

Asthma and bronchitis in Sydney schoolchildren. II. The effect of social factors and smoking on prevalence.

During a study of the prevalence of asthma and bronchitis in Sydney schoolchildren, some social and environmental factors were documented to ascertain if these affected the prevalence of either of these diseases. Socioeconomic status obtained from father's occupation, area of residence, family size, nationality, country of birth and smoking habits were examined. Although small differences were found between groups, no consistent relationship was found between social class and lung disease with the exception of increased prevalence of asthma in boys in social class I and girls in social class II. There were no major associations with area of residence or with family size. Children who were born outside Australia tended to have less asthma and bronchitis than children born inside Australia and migrant children tended to first develop asthma several years after arriving in Australia. Bronchitis was found to be more common in children with an earlier history of bronchitis in infancy and early childhood. The prevalence of recent bronchitis in the group of children who smoked 20 or more cigarettes per week was higher than that in the nonsmoking group of children.

The influence of lower respiratory illness in infancy and childhood and subsequent cigarette smoking on lung function in Sydney schoolchildren.

A prospective study of respiratory illness history and lung function of 10,898 school children in Sydney was begun in 1971. At the first visit, a history of previous asthma and of bronchitis before and after the first 2 years of life was obtained from a parental questionnaire, and maximal expiratory flow-volume curves were recorded. These lung function studies were repeated yearly between 1972 and 1974, at which time a history of respiratory illness during the previous 12 months and a personal smoking history were recorded, Two groups of children from a random selection of primary and secondary schools in Sydney were studied. Their respective mean ages were 8.9 yr (primary group) and 12.6 yr (high school group) in 1971. Mean values for the maximal flow at 50 percent of the forced vital capacity were lower in children with a history of bronchitis and/or asthma than those in the control group. This was true in both age groups in both sexes. No differences were found in the 0.5-s forced expiratory volume or forced vital capacity. The differences in maximal flow at 50 per cent of the forced vital capacity were present again in 1974. In 1974, the data from smokers were compared with those from nonsmokers; small differences were found. The results suggest that bronchitis in infancy and childhood as well as asthma may affect lung function as children grow, that the abnormality may not be detected by the forced expiratory volume, that the abnormality persists, and that it is possible that the abnormality is further affected by smoking.

Cigarette smoking in a cohort of Sydney schoolchildren: 1971--1974.

Cigarette smoking habits of a cohort of Sydney schoolchildren aged 12--13 years in 1971 have been recorded for four years. Smoking prevalence increases steadily over those years, 2.3% of boys and 0.5% of girls smoking 20 or more cigarettes a week at age 12.7 years in 1971, rising to 23.6% of boys and 17.6% of girls by age 15.6 years in 1974. A substantial increase in smoking prevalence in children aged 15.6 years was found in 1974 compared with a similarly aged group studied by the National Health and Medical Research Council (Australia) Subcommittee on Smoking in 1968. Quite a few children changed their smoking habits during the study. Children who changed or left schools smoked more than children who remained at the one school. Attacks of asthma or bronchitis were not related to smoking except that girls who were very heavy smokers reported more of these illnesses in 1974. No changes in lung function could be attributed to smoking by age 14.6 years. New approaches to smoking need to be evaluated in view of its rising prevalence, especially among older schoolchildren.

CNS lesions in cystinuria.

A man with cystinuria developed, at the age of 23, a neurological disorder with relapses and remissions similar to multiple sclerosis. This is the third documented case of cystinuria with central neuraxis lesions, and it is suggested that neurological complications may occur in cystinuria more frequently than is generally recognized.

Maximum expiratory flow-volume curves in children: changes with growth and individual variability.

Environmental factors may affect the lungs of children by retarding growth of ventilatory capacity. To detect retarded growth, we recorded maximum expiratory flow-volume (MEFV) curves in boys and girls aged 8-14 years observing the normal patterns of growth. The accuracy with which deviations from the normal patterns of growth may be measured was also determined. Expiratory flow rates and timed expiratory volumes were less reproducible in the same child than was forced vital capacity. At all ages the shape of girls' MEFV curves was different from that of boys curves in that girls had greater maximum expiratory flow rates (Vmax.) when differences in forced vital capacity (FVC) had been taken into account. The ratio of Vmax. 50% FVC to FVC decreased in both boys and girls as they grew older. The rates of growth of the MEFV curve measurements and estimates of their reproducibility were used to calculate minimum sample sizes required to detect retarded growth of ventilatory capacity. To detect a change of 10% in the normal growth rate in Vmax. 50% FVC between ages 8 and 14 years, nearly 2,000 children would need to be studied annually. Smaller samples could be used if changes in FVC growth rates were of primary concern.

Levels of reduced glutathione in red cells of New Guinea western Highlanders.

Reduced glutathione levels in erythrocytes of 14 Enga New Guinea Highlanders had a mean value of 50.1 mg/100 ml (S 5.9) which was significantly lower than the mean value of 67.9 mg/100 ml (S 9.7) found in 16 normal Caucasian Australians (P less than .001).