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Biomedical subjects

S Chinn

Publications and source records attributed to S Chinn.

At least 73 records · Page 4Linked to original sources
PubMed1998

Trends in growth and obesity in ethnic groups in Britain.

AIM: To estimate trends in growth for 5 to 11 year old ethnic minority and inner city children and comparative representative samples from 1983 to 1994. DESIGN: Mixed longitudinal. SUBJECTS: At each of six surveys, more than 2000 inner city white, 1500 Urdu or Punjabi speaking, 5000 English representative white, 3000 Scottish representative white, and around 1000 Afro-Caribbean, 500 falling to 300 Gujarati speaking, and 260 increasing to 300 other Indian children. MAIN OUTCOME MEASUREMENTS: Height, weight for height, and triceps skinfold thickness. RESULTS: Height increased in all inner city groups by approximately 1.5 cm, but group differences were maintained. Trends in triceps skinfold varied, but increased by 4-12% in Indian subcontinent girls. Weight for height increased generally. Inner city white children showed conflicting trends in weight for height and fatness. CONCLUSIONS: Afro-Caribbean children are maintaining their tall, slim build, but other groups emphasise the diversity of obesity patterns in a multi-ethnic society, with a predominant trend towards greater obesity. Monitoring of these groups should continue.

Body Height↗
PubMed1998

Individual allergens as risk factors for bronchial responsiveness in young adults.

BACKGROUND: Bronchial responsiveness is known to be related to atopy, but the relative contribution of sensitisation to individual allergens in the UK, or whether serum total IgE is an independent risk factor, is unknown. METHODS: A random sample of 1864 men and women aged 20-44 years, drawn from family health service registers in Cambridge, Ipswich and Norwich, was invited to answer a detailed questionnaire, undergo skin prick tests and methacholine bronchial challenge, and provide a serum sample for measurement of total and specific IgE. The relation of bronchial responsiveness to risk factors was studied in 749 subjects (40.2%) with complete data. RESULTS: Bronchial responsiveness was increased in those sensitised to cat, D pteronyssinus, Timothy grass and Cladosporium, but decreased in subjects also positive to birch allergen. Additional skin prick tests added little information. Serum total IgE was not significantly related after adjustment for specific IgE to the five allergens. Increasing titres of specific IgE to D pteronyssinus were associated with increasing bronchial responsiveness. Specific IgE to Cladosporium had a prevalence of around 3%, but was associated with greatly increased responsiveness. Decreased baseline lung function was related (p < 0.001) to increased responsiveness. There was an interaction between age and smoking status, with lower responsiveness in older non-smokers. CONCLUSION: Atopy is the most important risk factor for bronchial responsiveness in this age group, but effects are not additive across all allergens. Research in reducing exposure to house dust mite should also address the role of Cladosporium sensitisation and exposure to indoor moulds.

Adult↗
PubMed1998

References values for forced spirometry. Group of the European Community Respiratory Health Survey.

The European Coal and Steel Community (ECSC) prediction equations exemplify a significant effort carried out approximately 15 yrs ago to provide uniform standards for lung function testing, but this set of equations has not been properly validated as yet. The present study evaluates the ECSC reference values and four other sets of prediction equations, using spirometric data collected in 12,900 nonasthmatic subjects (43% lifetime nonsmokers and 36% active smokers) aged 20-44 yrs from the European Community Respiratory Health Survey (ECRHS). Standardized spirometric measurements were obtained using a common protocol in 34 centres in 14 countries. For each prediction equation, the prediction deviations (i.e. observed minus predicted value) for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were examined for the whole study population and for each centre. For the age range included, the errors about the ECSC equations showed the most prominent underestimation of both predicted FVC (+355 and +360 mL on average in males and females, respectively) and predicted FEV1 (+211 and +200 mL, respectively) among the five studies examined. As expected, FVC and FEV1 in active smokers from the ECRHS were significantly lower than in lifetime nonsmokers (each p<0.01). We conclude that the present European recommendations on lung function reference values should be reconsidered, but further data for nonsymptomatic subjects above the age of 44 yrs are needed.

Adult↗
PubMed1998

Individual use of antiasthmatic drugs in the European Community Respiratory Health Survey.

A previous analysis of drug utilization in the European Community Respiratory Health Survey found that only between 8 and 29% of subjects with asthma-related symptoms were using antiasthmatic medication in the different areas studied. The aim of this analysis was to investigate which variables were related to individual use of antiasthmatic medication in different geographical areas. Thirty-three centres in 14 countries were analysed, in which a total of 16,854 people (52.1% females, mean age 33.8 yrs, range 20-48) underwent a structured interview, measurement of specific immunoglobin E, spirometry and methacholine challenge test. The use of antiasthmatic drugs in individuals was, in most countries, independently related to asthma-related respiratory symptoms, bronchial hyperresponsiveness (BHR) and atopy. In all countries smokers with respiratory symptoms were less likely to be using antiasthmatic drugs than nonsmokers and exsmokers. In four of 14 countries females were significantly more likely to use antiasthmatic medication than males, while age and socioeconomic status were unrelated to medication. The use of inhaled anti-inflammatory drugs was positively related to symptoms, BHR and atopy and negatively related to current smoking. In conclusion, in many countries smokers were less likely to be using antiasthmatic drugs than were nonsmokers with comparable levels of symptoms and bronchial hyperresponsiveness. Age and socioeconomic status were unrelated to medication, while in some countries females were more likely than males to use antiasthmatic medication.

Adult↗
PubMed1998

The association of respiratory symptoms and lung function with the use of gas for cooking. European Community Respiratory Health Survey.

The association of respiratory symptoms and lung function with the use of gas for cooking was examined using data collected as part of the European Community Respiratory Health Survey, an international multicentre study. Associations between gas cooking and respiratory symptoms and respiratory function were assessed by logistic and multiple regression models. Tests for interaction were used to examine whether the effect of gas cooking varied between centres and, as there was evidence for this, the average effects were estimated using standard methods for random effects meta-analysis. Data from 5,561 males and 6,029 females living in 23 centres in 11 countries were analysed. There was no significant association found between respiratory symptoms and gas cooking in males. In females the association between some respiratory symptoms and gas cooking varied between centres with an overall positive association with "wheeze in the last 12 months" (odds ratio (OR) 1.24: 95% confidence interval (95% CI) 1.00-1.54) and "wheeze with breathlessness in the last 12 months" (OR 1.33: 95% CI 1.06-1.69). There was no evidence that atopy modified this association. Cooking with gas was associated with airways obstruction in both males and females although the differences failed to reach statistical significance. In some countries the use of gas for cooking is associated with respiratory symptoms suggestive of airways obstruction in females.

Air Pollution, Indoor↗
PubMed1997

The distribution of total and specific serum IgE in the European Community Respiratory Health Survey.

BACKGROUND: Variations in the prevalence of atopy could provide important clues to the etiology of atopy and asthma. Although estimates of prevalence are available from different studies, a lack of standardization makes comparisons difficult. OBJECTIVE: This study was conducted to estimate the variation of geometric mean levels of serum IgE and the prevalence of specific IgE to common allergens between populations as part of the European Community Respiratory Health Survey (ECRHS), a multicenter survey of asthma and risk factors for asthma. METHODS: Random samples of subjects living in 37 centers in 16 countries who had answered a questionnaire about their respiratory symptoms were invited for further assessment including total serum IgE and the presence of specific IgE against house dust mite (Dermatophagoides pteronyssinus), timothy grass, cat, Cladosporium herbarum, and a local allergen. Sera were tested from 13,883 persons. RESULTS: The estimated prevalence of atopy, defined as the presence of at least one positive specific IgE, ranged from 16% in Albacete (Spain) to 45% in Christchurch (New Zealand). The geometric mean total serum IgE varied from 13 kU/L in Reykjavik (Iceland) to 62 kU/L in Bordeaux (France). There was no relation between the geometric mean total serum IgE in a center and the prevalence of atopy. CONCLUSIONS: There are substantial variations in the prevalence of atopy and the level of serum IgE. These variations are independent of each other and likely to be largely environmental in origin.

Allergens↗
PubMed1997

Family size, atopic disorders in parents, asthma in children, and ethnicity.

BACKGROUND: Several studies have reported an association between family size and atopic conditions, but few have found an association between asthma and family size. OBJECTIVE: This study was designed to assess the effect of familial aggregation and sibling number on asthma in children. METHODS: Children from 5 to 11 years of age in England and Scotland participated in a study in 1990 or 1991 in which responses to questions on asthma and wheezing in children and atopic conditions in parents were ascertained. Data on 11,924 complete family sets of child, mother, and father in three samples (the "representative" samples of England and Scotland and the English "inner city" sample) were analyzed. RESULTS: The following factors were highly associated with child's asthma or wheezing: mother's or father's asthma or wheezing (with the same odds ratio [OR], 2.4; 95% confidence interval [CI], 2.0 to 2.9), other atopic condition in mothers and fathers (OR, 1.5; 95% CI, 1.3 to 1.8 and OR, 1.4; 95% CI, 1.2 to 1.7, respectively), and three or more siblings compared with no siblings (OR, 0.5; 95% CI, 0.4 to 0.6). CONCLUSION: The negative relation between family size and wheezing or asthma indicates a protective effect of number of children sharing an environment at a young age. The level of association of asthma or wheezing in the parents and the child and the association between the child's asthma or wheezing and other atopic conditions in parents suggest that a general susceptibility and a lung-specific susceptibility are important in the etiology of asthma.

Adolescent↗
PubMed1997

The use of nutritional supplements by 4-12 year olds in England and Scotland.

OBJECTIVE: To determine the levels of and factors associated with the use of nutritional supplements by children participating in the National Study of Health and Growth (NSHG). DESIGN: Cross-sectional study. SETTING: Fifty-six study areas in England and Scotland. SUBJECTS: Fifteen thousand, two hundred and seventy five children aged between 4 and 12 y. INTERVENTIONS: Parental completion of a self-administered questionnaire on the child's health, social background and supplement use. Height, weight and skinfold measurements. RESULTS: An 88% response rate to the supplement question, 15.9% of responders reported using a supplement. Multivitamins were the most commonly consumed supplement (84%) with 52% taking a supplement daily. Younger children, those whose mothers reached further education, whose fathers were in non-manual occupations or who lived in the Midlands or South were significantly more likely to use a supplement, as were children from smaller families or whose parents were non-smokers. There was no significant association between supplement use and sex, height, birthweight, length of gestation, father's education, number of parents in the home or vegetarianism. Significant differences were found in the use of supplements between the ethnic origin groups. Children of Afro-Caribbean, Asian or other origin were more likely to take a supplement compared to white English and Scottish groups. There were differences in the type of supplements used with Afro-Caribbean and other origin children using more cod liver oil. CONCLUSION: We support the findings of other studies which show that children with the least need for supplements as defined by socio-economic variables are more likely to receive them and suggest that cultural background is also an important factor in influencing supplement use. SPONSORSHIP: This study was supported by grants from the Department of Health in England and the Scottish Home and Health Department.

Africa↗
PubMed1997

Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT.

Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation. Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients. Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete. Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP.

Adult↗
PubMed1997

The accuracy of a new system for estimating organ volume using ultrasound.

A new system is described for estimating volume from a series of multiplanar 2D ultrasound images. Ultrasound images are captured using a personal computer video digitizing card and an electromagnetic localization system is used to record the pose of the ultrasound images. The accuracy of the system was assessed by scanning four groups of ten cadaveric kidneys on four different ultrasound machines. Scan image planes were oriented either radially, in parallel or slanted at 30 degrees to the vertical. The cross-sectional images of the kidneys were traced using a mouse and the outline points transformed to 3D space using the Fastrak position and orientation data. Points on adjacent region of interest outlines were connected to form a triangle mesh and the volume of the kidneys estimated using the ellipsoid, planimetry, tetrahedral and ray tracing methods. There was little difference between the results for the different scan techniques or volume estimation alogorithms, although, perhaps as expected, the ellipsoid results were the least precise. For radial scanning and ray tracing, the mean and standard deviation of the percentage errors for the four different machines were as follows: Hitachi EUB-240, -3.0 +/- 2.7%; Tosbee RM3, -0.1 +/- 2.3%; Hitachi EUB-415, 0.2 +/- 2.3%; Acuson, 2.7 +/- 2.3%.

Animals↗
PubMed1997

Determinants of nocturnal enuresis in England and Scotland in the '90s.

The aim of this study was to assess whether changes have occurred in the determinants of nocturnal enuresis in Scotland and England in comparison with previous studies. The study was based on 22 study areas from a representative English sample, 14 areas from a representative Scottish sample, and 20 areas from an English inner-city sample. A total of 14,674 subjects was included in the analysis from 16,835 eligible children in the age range 5 to 11 years. For the main analysis, an enuretic child was one who wet the bed at least once a week. As expected, the frequency of enuresis was higher in boys and decreased markedly with age in both sexes. Bedwetting was more frequent in: Afro-Caribbean children compared with white children in the representative samples (OR 1.72 95% CI 1.22 to 2.42); those whose mothers smoked at least 10 cigarettes at home compared with non-smokers (OR 1.58 95% CI 1.26 to 1.98); children who had disturbed sleep compared with those who slept well (OR 1.96 95% CI 1.53 to 2.51); those with mothers aged less than 20 years at the child's birth compared with mothers in the age range 25 to 34 (OR 1.63 95% CI 1.20 to 2.22); and in the second- or third-born in the family in comparison with the first-born (OR 1.42 95% CI 1.17 to 1.72). Father's social class was associated with enuresis only in girls. Only 50% of the parents consulted a doctor for enuresis in their child. The percentage was even lower in Afro-Caribbean families (33%). Enuresis continues to be a highly prevalent problem and has not decreased over the last 45 years. We confirm that environmental factors are still important in the aetiology of enuresis. It is surprising that despite the availability of effective treatment only half of parents consult a doctor about the problem.

Black or African American↗
PubMed1997

Trends in growth in England and Scotland, 1972 to 1994.

AIM: To monitor the growth of 5 to 11 year old English and Scottish children from 1972 to 1994. No similar data are available from any other study. DESIGN: Mixed longitudinal. SUBJECTS: In England 7000 children were sampled in the first year, falling to 5000. In Scotland the original sample was 2000 but this was enlarged later to 3500. MAIN OUTCOME MEASUREMENTS: Height, weight, weight for height index, and triceps skinfold thickness. RESULTS: Height of English children in most age groups increased by more than 1 cm and by more than 2 cm in Scotland during the period 1972 to 1994. Triceps skinfold measurement increased by almost 8% in 7 year old English boys and by 7% in 7 year old girls. In Scotland triceps skinfold measurement increased by nearly 10% in 7 year old boys and by 11% in 7 year old girls. Weight for height index followed a similar pattern. CONCLUSION: Children in England and Scotland are becoming taller for a given age. The increases in fatness indicate an urgent need for realistic interventions for reductions in obesity in the whole population. As weight for height index is less sensitive than skinfold thickness we recommend triceps and subscapular skinfold thickness measurements for monitoring obesity in children.

Body Height↗
PubMed1997

Variation in nebulizer aerosol output and weight output from the Mefar dosimeter: implications for multicentre studies.

The active aerosol component of nebulizers is less than 100% of output by weight, and may vary between nebulizers in different batches from the same manufacturer. A measure of bronchial responsiveness to methacholine, which can overcome this problem, is required. One hundred and sixty nebulizers from 21 centres in the European Community Respiratory Health Survey (ECRHS) were calibrated for aerosol and weight output. Methacholine challenge data were obtained for 1,021 subjects in three English centres of the ECRHS. The dose producing a 20% fall in forced expiratory volume in one second (PD20), and log-slope, the regression slope of percentage decline in FEV1 with log (dose), were calculated, with and without calibration of nebulizers by weight. Within-centre variation in nebulizer percentage aerosol output had a coefficient of variation of less than 10%. Unlike PD20, log-slope is unaffected by constant percentage overestimation of nebulizer output. Variation in output by weight of nebulizers of 10% had little affect on log-slope. It is, however, affected by the scheduled range of doses. Log-slope shows advantages in analysis, and is less affected by variation in nebulizer output. It can be used for multicentre comparisons, with restriction to a common dose protocol.

Aerosols↗
PubMed1997

Physician-diagnosed asthma and drug utilization in the European Community Respiratory Health Survey.

The aim of this analysis was to estimate the geographical variation in the prevalence of physician-diagnosed asthma and treatment practice for asthma in young adults. The results are based on an ecological analysis of 34 centres in 14 countries, in which a total of 17,029 randomly selected subjects (52% females, age 20-48 yrs) underwent a structured interview and spirometry as part of the European Community Respiratory Health Survey. The sample was enriched with 2,903 symptomatic subjects when investigating treatment in subjects with physician-diagnosed asthma. The prevalence of physician-diagnosed asthma was highest in New Zealand and Australia (11-13%) and lowest in Erfurt, Germany (1.2%) and Spain (1.5-3.0%). The reported use of antiasthma medication in the last 12 months was also highest in New Zealand and Australia (12-16%) and correlated closely with the prevalence of diagnosed asthma (r=0.89, p<0.001). Herbal remedies against breathing problems had been used by 13% of subjects in Hamburg but the reported use of alternative remedies for breathing problems was low in most other centres. The use of inhaled anti-inflammatory drugs in subjects with physician-diagnosed asthma ranged from 49% in the UK to 17% in Italy and correlated with the prevalence of doctors' consultations within the last 12 months (r=0.66, p<0.05). The prevalence of anti-inflammatory treatment was positively related to the prevalence of nocturnal asthma symptoms (p<0.05). We conclude that there is a wide geographical variation in the prevalence of physician-diagnosed asthma and use of antiasthma medication. The geographical variation in the use of anti-inflammatory drugs among individuals with diagnosed asthma may be related to variations in asthma severity, as well as differences in treatment practices between countries.

Adult↗
PubMed1997

Variation in bronchial responsiveness in the European Community Respiratory Health Survey (ECRHS).

Attempts to compare bronchial responsiveness between populations have been hampered by between-study differences in the pharmacological agent of provocation, the method of administration and the summary statistic employed. The European Community Respiratory Health Survey used methacholine challenge delivered by Mefar dosimeter according to a standardized protocol used in 35 centres in 16 countries. Data were obtained from 13,161 men and women, aged 20-44 yrs at the start of the study. The dose of methacholine producing a 20% fall in forced expiratory volume in one second (FEV1) (PD20) and the regression coefficient of percentage decline in FEV1 with log dose, were calculated ("slope", after transformation), with and without calibration of nebulizers by weight and adjustment for nonresponse bias. Standardization for baseline lung function and variation in smoking prevalence was applied to slope. Results were robust to whichever summary measure was used, and to the various adjustments. Responsiveness was low in Iceland and Switzerland, and in most centres in Sweden, Italy and Spain, and high in New Zealand, Australia, the USA, Britain, France, Denmark and Germany. Bronchial responsiveness varies considerably in Europe, and high levels are not confined to the English-speaking world.

Adult↗
PubMed1997

The association of family size with atopy and atopic disease.

BACKGROUND: Studies in children have shown that family size is negatively associated with atopy and atopic disease. OBJECTIVE: To describe the association of family size with atopy and atopic disease in young adults. METHODS: A randomly selected sample of 1159 men and women aged 20-44 years provided information on respiratory symptoms, hay fever and eczema. Blood samples were taken for assessment of total IgE and specific IgE to house dust mite, grass, cat, Cladosporium and birch. The association of family size and birth order with respiratory symptoms, atopy and total IgE was assessed by multiple logistic and linear regression. RESULTS: There was a negative association between family size and the reporting of 'wheeze with breathlessness' (adjusted odds ratio for an increase of one sibling 0.85; 95% confidence interval 0.75-0.98), 'wheeze without a cold' (adjusted odds ratio for an increase of one sibling 0.85; 95% confidence interval 0.75-0.98) and 'asthma attacks' in the last 12 months (adjusted odds ratio for an increase of one sibling 0.77; 95% confidence interval 0.61-0.97), current 'hayfever and nasal allergies' (adjusted odds ratio for an increase of one sibling 0.84; 95% confidence interval 0.75-0.94) and sensitization to grass (adjusted odds ratio for an increase of one sibling 0.87; 95% confidence interval 0.76-0.99). Birth order was negatively associated with 'hayfever and nasal allergies' only. A decreased risk of sensitization to grass in those from large families did not fully explain the negative association between family size and hayfever. No statistically significant (P > 0.05) association of family size or birth order with the reporting of other respiratory symptoms, eczema, sensitization to the other allergens or total IgE was observed. CONCLUSION: There is a negative association between family size and some symptoms suggestive of asthma, 'hayfever and nasal allergies' and sensitization to grass in young adults. There is no consistent, significant association between family size and eczema, total IgE or sensitization to other allergens.

Adult↗
PubMed1996

Influence of ethnic group on asthma treatment in children in 1990-1: national cross sectional study.

OBJECTIVE: To examine the extent to which the prescription of drugs for asthma adhered to recommended guidelines in 1990-1 and to assess the influence of ethnic group on prescription. DESIGN: Cross sectional. SETTING: Primary schools in England and Scotland in 1990-1. SUBJECTS: Children aged mainly 5-11 years. The representative samples included 10628 children. The inner city sample included 7049 children, 4866 (69%) from ethnic minority groups. For the prevalence estimation 14490 children were included in the analysis (82% of the eligible children). For the treatment analysis a subgroup of 5494 children with respiratory symptoms was selected. MAIN OUTCOME MEASURES: Prevalence of respiratory symptoms and drugs commonly prescribed for asthma, method of administration, inappropriate treatment, and odds ratios to assess the effect of ethnic group on rate of prescription and method of administration. RESULTS: Children with respiratory symptoms in the inner city sample were less likely to be diagnosed as having asthma. Of children with reported asthma attacks, those in inner city areas had a higher risk of not having been prescribed any drug for asthma (odds ratio 1.87 (95% confidence interval 1.26 to 2.77). Overall, 773 (75%) of these children had received a beta 2 agonist, 259 (25%) had received steroids, 148 (14%) had received sodium cromoglycate, and 194 (19%) had received no drug treatment in the previous year. When prescribed, beta 2 agonists were inhaled in 534 (69%) of cases, and this percentage was even lower in ethnic minority groups. Children of Afro-Caribbean and Indian subcontinent origin who had asthma were less likely to receive beta 2 agonists, and those from the Indian subcontinent were less likely to receive anti-inflammatory drugs. Antibiotics were less prescribed and antitussives more prescribed in children from ethnic minority groups than in white children. CONCLUSION: In 1990-1 the risk of underdiagnosis and undertreatment of asthma was higher in children from ethnic minority groups. The implementation of indicators and targets to monitor inequalities in the treatment of asthma in ethnic groups could improve equity and effectiveness in the NHS.

Adrenergic beta-Agonists↗