Influence of parental physical activity on offspring's nutritional status: an intergenerational study in the 1993 Pelotas birth cohort

OBJECTIVE

To investigate the influence of parental physical activity on offspring's nutritional status in the 1993 Pelotas (Brazil) birth cohort.

DESIGN

Birth cohort study.

SETTING

The main outcomes were overweight and obesity status of children. The main exposure was parental physical activity over time, measured during the 11, 15 and 18 years of age follow-ups. The exposure was operationalised as cumulative, and the most recent measure before the birth of child. We adjusted Poisson regression models with robust variance to evaluate crude and adjusted associations between parental physical activity and offspring's nutritional status. All analyses were stratified according to the sex of the parent.

PARTICIPANTS

A total of 874 members from the 1993 Pelotas (Brazil) birth cohort followed-up at 22 years of age with their first-born child were analysed.

RESULTS

Children were, on average, 3·1 years old. Crude analyses showed that the mother's cumulative physical activity measure had an indirect association with the prevalence of children's obesity. The most recent maternal physical activity measure before the birth of the child was associated with 41 % lower prevalence of obesity in children, even after adjustment for confounders.

CONCLUSIONS

The most recent maternal physical activity measure was indirectly associated with the prevalence of obesity in children. No associations were found for fathers, reinforcing the hypothesis of a biological effect of maternal physical activity on offspring's nutritional status.

Early identification of bipolar disorder among young adults - a 22-year community birth cohort

OBJECTIVE

We set forth to build a prediction model of individuals who would develop bipolar disorder (BD) using machine learning techniques in a large birth cohort.

METHODS

A total of 3748 subjects were studied at birth, 11, 15, 18, and 22 years of age in a community birth cohort. We used the elastic net algorithm with 10-fold cross-validation to predict which individuals would develop BD at endpoint (22 years) at each follow-up visit before diagnosis (from birth up to 18 years). Afterward, we used the best model to calculate the subgroups of subjects at higher and lower risk of developing BD and analyzed the clinical differences among them.

RESULTS

A total of 107 (2.8%) individuals within the cohort presented with BD type I, 26 (0.6%) with BD type II, and 87 (2.3%) with BD not otherwise specified. Frequency of female individuals was 58.82% (n = 150) in the BD sample and 53.02% (n = 1868) among the unaffected population. The model with variables assessed at the 18-year follow-up visit achieved the best performance: AUC 0.82 (CI 0.75-0.88), balanced accuracy 0.75, sensitivity 0.72, and specificity 0.77. The most important variables to detect BD at the 18-year follow-up visit were suicide risk, generalized anxiety disorder, parental physical abuse, and financial problems. Additionally, the high-risk subgroup of BD showed a high frequency of drug use and depressive symptoms.

CONCLUSIONS

We developed a risk calculator for BD incorporating both demographic and clinical variables from a 22-year birth cohort. Our findings support previous studies in high-risk samples showing the significance of suicide risk and generalized anxiety disorder prior to the onset of BD, and highlight the role of social factors and adverse life events.

Study on environmental indices and heat tolerance tests in hair sheep

The ability to predict the effects of climatic factors on animals and their adaptability is important for livestock production. The aim of the present study was to analyze whether existing indices are suitable for evaluating heat stress in Santa Ines and Morada Nova sheep, which are locally adapted hair sheep breeds from northeastern Brazil, and if the limits used to classify thermal stress are suitable for these breeds. Therefore, climatic, physiological, and physical parameters, as well as thermographic images, were collected in 26 sheep, 1 1/2 years old, from two genetic groups (Santa Ines 12 males and 4 females; Morada Nov. 7 males and 3 females) for 3 days in both morning (4:00 a.m.) and afternoon (2:00 p.m.) with six repetitions, totalizing 156 repetitions. Statistical analysis included correlations and broken-line regressions. Iberia and Benezra indices were the tolerance tests that best correlated with the assessed parameters. High correlations between environmental indices and rectal or skin surface temperatures was observed, which indicates that these indices can be used for Santa Ines and Morada Nova sheep raised in central Brazil. However, some indicative values of thermal discomfort are different from the existing classification. Therefore, in order to classify appropriately, the model used needs to be carefully studied, because these classifying values can vary according to the species and model. Further research is necessary to establish indicators of thermal stress for sheep breeds raised in the region.

Sugar Consumption and Changes in Dental Caries from Childhood to Adolescence

There are no prospective studies investigating the effects of sugar-related feeding practices on changes in dental caries from early childhood to young adulthood. The aim of this study was to assess whether sugar-related feeding practices affect dental caries between the ages of 6 and 18 y. This birth cohort study was initiated in 1993 in Pelotas, Brazil. There were 3 dental clinical assessments; at ages 6 y (n = 359), 12 y (n = 339), and 18 y (n = 307). Sugar-related feeding practices were assessed at ages 4, 15, and 18 y. Covariates included sex and life course variables, such as family income, breast-feeding, mother's education, regularity of dental visit, and child's toothbrushing habits. Group-based trajectory analysis was performed to characterize trajectories of time-varying independent variables that had at least 3 time points. We fitted a generalized linear mixed model assuming negative binomial distribution with log link function on 3-time repeated dental caries assessments. One in 5 participants was classified as "high" sugar consumers, and nearly 40% were "upward consumers." "Low consumers" accounted for >40% of the sample. High and upward sugar consumers had higher dental caries prevalence and mean DMFT in all cohort waves when compared with low sugar consumers. Caries occurred at a relatively constant rate over the period of study, but in all sugar consumption groups, the increment of dental caries was slightly higher between ages 6 and 12 y than between 12 and 18 y. Adjusted analysis showed that dental caries increment ratio between ages 6 and 18 y was 20% and 66% higher in upward and high sugar consumer groups as compared with low consumers. The higher the sugar consumption along the life course, the higher the dental caries increment. Even the low level of sugar consumption was related to dental caries, despite the use of fluoride.

Conhecimento sobre a transmissão de HIV/AIDS entre adolescentes com 11 anos de idade do Sul do Brasil

Objetivo: Investigar o efeito de fatores demográficos, socioeconômicos, educacionais e familiares sobre o conhecimento acerca do HIV/AIDS em adolescentes com 11 anos de idade. Métodos: Foram estudados 3.949 adolescentes de Pelotas/RS. O conhecimento acerca do HIV/AIDS foi avaliado por meio de um questionário autoaplicado e mensurado através de cinco perguntas sobre relação heterossexual, relação homossexual, compartilhamento de seringas, beijo na boca e abraçar alguém com AIDS. As análises foram ajustadas com base em um modelo hierárquico, usando regressão de Poisson com ajuste robusto da variância. Resultados: Os percentuais de respostas erradas para as questões examinadas foram: 17,2% para transmissão em relações heterossexuais; 44,1% para relações homossexuais; 34,9% para compartilhar seringas; 25,6% para beijo na boca e 16,2% para abraçar pessoa com AIDS. Na análise ajustada, menor grau de conhecimento foi demonstrado pelos meninos, por adolescentes de menor nível econômico, cujas mães possuíam menor escolaridade, para os adolescentes que não haviam conversado sobre sexo com a mãe e entre os que não tiveram aula sobre educação sexual na escola. O grau de conhecimento não esteve associado com o tipo de escola, cor da pele, tampouco com a conversação com o pai sobre sexo. Conclusão: Fornecer informações aos adolescentes é fundamental para melhorar o conhecimento sobre o risco de transmissão de HIV e de outras infecções sexualmente transmissíveis, principalmente entre jovens do sexo masculino e de menor nível socioeconômico. As políticas públicas devem considerar o rol que a mãe e a escola desempenham no conhecimento sobre este tema por parte dos adolescentes.

DNA methylation changes associated with risk factors in tumors of the upper aerodigestive tract

Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.

The Platino project: methodology of a multicenter prevalence survey of chronic obstructive pulmonary disease in major Latin American cities

BACKGROUND

The prevalence of Chronic Obstructive Pulmonary Disease (COPD) in many developed countries appears to be increasing. There is some evidence from Latin America that COPD is a growing cause of death, but information on prevalence is scant. It is possible that, due to the high frequency of smoking in these countries, this disease may represent a major public health problem that has not yet been recognized as such. The PLATINO study is aimed at measuring COPD prevalence in major cities in Latin America.

METHODS/DESIGN

A multi-country survey is being carried out in major cities in Latin America. In each metropolitan area, a population-based sample of approximately 1,000 individuals aged 40 years or older is being interviewed using standardized questionnaires. Eligible subjects are submitted to pre- and post-bronchodilator spirometry, and classified according to several criteria for COPD. Anthropometric examinations are also performed. Several risk factors are being studied, including smoking, socioeconomic factors, exposure to domestic biomass pollution, occupational exposure to dust and hospital admissions due to respiratory conditions during childhood. Whether or not subjects affected by COPD are aware of their disease, and if so how it is being managed by health services, is also being investigated, as are the consequences of this condition on quality of life and work performance.

RESULTS

At the present time, the study is completed in São Paulo, Mexico City and Montevideo; Chile has started the study in March 2004 and it will be followed by Venezuela; two other metropolitan areas could still join the PLATINO project. Similar sampling procedures, with stratification for socio-economic status, are being used in all sites. Strict coordination, training and standardization procedures have been used to ensure comparability of results across sites. Overall 92% of the pre-bronchodilator spirometry tests fulfilled ATS criteria of quality in the three first sites (97% in Montevideo, 91% in Mexico and 89% in Sao Paulo).

CONCLUSIONS

The PLATINO project will provide a detailed picture of the global distribution of COPD in Latin America. This project shows that studies from Latin America can be carried out with adequate quality and be of scientific value.

Lung cancer in Brazil

Lung cancer is the second leading cause of death in Brazil, after exclusion of external causes. Registries in the country are not reliable because of under-registration and limited coverage. Incidence rates for Brazil are less then half those for selected areas with good registries. Crude and adjusted incidence and mortality rates for lung cancer are rising, particularly among women. The main reason is the acceleration in tobacco consumption and the spread of smoking among women. At present, approximately 40% of men and 25% of women, 15 years of age or older, are current smokers. In the state of Rio Grande do Sul, where registries are reliable, incidence and mortality for males are similar to US data and the figures for women are rapidly approaching those for men. Occupations associated with risks of exposure to respiratory carcinogens show a rise in the incidence of lung cancer in the industrialized area of São Paulo. The main occupational risk in Brazil is exposure to mineral dusts, silica, or asbestos. Although about 15 million Brazilians are exposed to pesticides, agricultural workers were not a risk group for lung cancer in a case-control study. Pesticides containing arsenic and dichlorodiphenyltrichloroethane (DDT) are banned. In recent years, a trend towards a decrease in male smoking has been noted, but there is still a high tobacco exposure burden in both males and females, with a forecast of a further increase in rates of lung cancer incidence and deaths. Control of respiratory carcinogens at work continues to be a problem, particularly in the present scenario of economic and political pressures on Brazil and other developing nations. Semin Oncol 28:143-152.

[Asthmatic children's risk factors for emergency room visits, Brazil]

OBJECTIVES

To study a sample of asthmatic children to get to know how the disease is managed by caretakers and to identify predictive factors associated with attendance in emergency room for asthma.

METHODS

A cross-sectional study nested in a cohort was undertaken in the urban area of Pelotas, Southern Brazil. 981 children aged 4-5 years, who belong to the cohort of 1993, participated in this study.

RESULTS

The asthma prevalence in the children sample was 25.4%. Morbidity for asthma was quite high: 31% of the children were seen in emergency rooms in the last year, 57% attended medical clinics and 26% were hospitalized in the first 4 years of life. The crude analysis identified the following predictive factors for emergency room visits: low educational level (RO=4.1), low family income (RO=6. 5), 3 or more children sleeping in the same room (RO=2.2), severity of asthma attacks (RO=2.7), use of asthma medicines in the last year (RO=1.9) and hospitalizations due to asthma (RO=3.0). Multivariate analyses using logistic regression were used to adjust each variable for the effect of the remainder.

CONCLUSIONS

The asthma prevalence among preschool children in Pelotas is high, resulting therefore in high morbidity. The predictor factors for emergency room visits due to asthma found, after multivariate analysis, were mother's low educational level, severity of the asthma attacks and hospitalization.

[Hospitalization for bronchiolitis: a risk factor for recurrent wheezing]

This longitudinal study evaluated the role of hospitalization for acute bronchiolitis as a risk factor for recurrent wheezing. Participants were children from a 1993 cohort in a southern Brazilian city. Hierarchical multivariate analysis showed that previous hospitalization for bronchiolitis was the most important risk factor for recurrent wheezing, with an odds ratio of 4.9. This strong association is consistent with a casual relationship hypothesis.

[Tuberculosis treatment adherence in Pelotas, Brazil, from the patient's perspective]

This study deals with adherence to tuberculosis treatment among men and women as well as the disease's links and consequences vis-à-vis life styles and treatment outcomes. The ethnographic study was a component of the Tuberculosis Epidemiological Control Project in the city of Pelotas and aimed to identify the reasons patients failed to complete treatment. Direct ethnographic observations and semi-structured interviews were used. Use of the term "adherence" is justified by the concern for extending to other fundamental factors in addition to the patient's own individual responsibility. This approach fostered an understanding of views towards disease, social dynamics among the various protagonists involved in the disease process, and treatment. Some of the factors considered in adherence to treatment were: socio-demographic characteristics, cultural factors, popular beliefs, the cost-benefit relationship, physical and chemical aspects of the drugs, the physician-patient relationship, and level of family participation in treatment.

Severe brain injury after cardiac surgery in children: consequences for the family and the need for assistance

OBJECTIVE

To identify the short and longer term needs of parents whose children sustain severe brain injury after cardiac surgery and to determine what further measures could be of use to the family after such a catastrophe.

DESIGN

Qualitative analysis of data generated by semistructured interviews and a series of self report questionnaires.

SETTING

Tertiary cardiothoracic referral centre.

SUBJECTS

Group 1: four sets of parents (eight individuals) whose children had suffered severe brain injury after heart surgery; group 2: four sets of parents (seven individuals) caring for children with acute brain injury from other causes.

RESULTS

The data provide evidence of social, emotional, physical, practical, and financial difficulties. After the children suffered brain injury following cardiac surgery their parents did not receive information, support, and practical assistance as early as they needed it.

CONCLUSIONS

Although a small population was studied, it would seem that a structured, planned health care service response to this devastating event is not established; therefore, the needs of these parents are not well met. The parents and our inquiries suggest that a coordinator who is not attached to the hospital where brain injury occurred might optimally fulfil this role.

[Risk factors for perinatal mortality in Pelotas, a southern city of Brazil, 1993]

INTRODUCTION

Although there was a considerable reduction in infant mortality in Pelotas, Rio Grande do Sul in the last decade, its perinatal causes were reduced only by 28%. The associated factors of these causes were analysed.

MATERIAL AND METHOD

All hospital births and perinatal deaths were assessed by daily visits to all the maternity hospitals in the city, throughout 1993 and including the first week of 1994.

RESULTS

The perinatal mortality rate was 22.1 per thousand births. The multivariate analysis showed the following risk factors: low socioeconomic level, male sex and maternal age above 35 years. Among multigravidae women, the fetal mortality rate was significantly increased for mothers with a previously low birthweight and a previous stillbirth. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.

CONCLUSIONS

Main risk factors for perinatal mortality: low socioeconomic level, maternal age above 35 years and male sex. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.

Length and ponderal index at birth: associations with mortality, hospitalizations, development and post-natal growth in Brazilian infants

BACKGROUND

Low birthweight infants suffer greater mortality and neonatal morbidity, grow less well in infancy and show poorer psycho-motor development. However, this simple categorization may obscure important differences in aetiology and prognosis between infants born stunted, thin, or both.

METHODS

In 1993, all births in Pelotas, Brazil, were enrolled into a prospective study of health and development in infancy. Of 5249 live births, 5160 had length and weight measures at birth, and were classified into tertiles of length and ponderal index. All deaths and hospitalizations were monitored, and suspected developmental delay and attained growth at 12 months were assessed on a subsample of 1364 infants. Logistic regression was used to control for gestational age and socioeconomic status.

RESULTS

There was no association between birth length and ponderal index tertiles. After adjusting for gestational age, infants in the lower tertiles of both length and ponderal index presented a 3.8-times higher risk of mortality from day 8 to day 365, and a 2.5-times higher risk of hospitalization compared to infants with greater birth lengths and/or ponderal indices. Suspected developmental delay was associated with length and, less strongly, with ponderal index, but there was no synergism between the two. Infants in the middle and upper tertiles of ponderal index at birth became thinner.

CONCLUSIONS

Birth length was strongly associated with development at 12 months, but only infants born both short and thin were at increased risk of mortality and hospitalizations. The combination of the two measures provides a useful classification of the anthropometric status of the newborn.

[Populational study of investigation of perinatal and infant deaths: methodology, validity of diagnosis and under-registration]

OBJECTIVE

The main objectives of the present study were to evaluate the percentage of under-registration of infant mortality in 1993 and compare it with the ones found 1982; to analyze the agreement between the official death certificates and the ones made by the referees.

METHODS

The infant mortality of all children born in Pelotas, in 1993, was monitored through daily visits to hospitals, as it was done in 1982; monthly, cemeteries and public registration offices were visited to detect any deaths outside the hospitals. Besides the official death certificates, two independent referees established the underlying cause of death based on information from pediatricians, case-notes, autopsies and through a home visit to the parents of the children.

RESULTS

The percentage of under-registration fell substantially from 24%, in 1982, to 5.4%, in 1993. The agreement between the official death certificates and the ones made by the referees showed satisfactory Kappas, unless for ill defined diseases such as sudden infant death, where the agreement was null.

CONCLUSIONS

The authors conclude that there was a significant fell of the under-registration for infant death in Pelotas, and the ill defined causes such as sudden infant death have been hidden by the diagnosis of pneumonia.

Environmental tobacco smoke and breastfeeding duration

The effect of smoking on breastfeeding duration was investigated in a population-based birth cohort study of 1,098 Brazilian infants. There were few losses to follow-up (3.2%) in the first 6 months. Maternal smoking was strongly associated with breastfeeding duration, even after adjustment for confounding. Compared with nonsmokers, mothers smoking 20 or more cigarettes daily presented an odds ratio of 1.94 for breastfeeding for less than 6 months. Environmental tobacco smoke was also an independent risk factor. After adjustment for maternal smoking and other confounders, households where more than 10 cigarettes were smoked daily by persons other than the mother presented an odds ratio of 1.48 compared with those without smokers. These results remained unchanged after stratification for maternal smoking. This is the first report of a possible effect of environmental tobacco smoke on breastfeeding duration.

[Tobacco smoking among pregnant women in an urban area in southern Brazil, 1982-93]

OBJECTIVE

A comparison between on the prevalence of smoking during pregnancy in 1982 and that in 1993 in Pelotas, Southern Brazil.

METHODOLOGY

Cross-sectional study. All hospital deliveries in 1982 and 1993--corresponding to over 99% of all births in those years--were studied. A total of 6,011 and 5,304 mothers were interviewed, respectively.

RESULTS

The prevalence of smoking during pregnancy showed a small decrease from 35.7% in 1982 to 33.5% in 1993 (p < 0.05). In the two years under study, family income and number of antenatal care visits were inversely associated with the prevalence of maternal smoking. The rate of stopping smoking during pregnancy was 20.6%.

Low birthweight, preterm births and intrauterine growth retardation in relation to maternal smoking

The association between the intensity and duration of cigarette smoking during pregnancy and the frequency of low birthweight, preterm births and intrauterine growth retardation was investigated in a historical cohort. All 5166 livebirths occurring in the city of Pelotas, Brazil, during 1993 were identified and mothers interviewed soon after delivery. Children whose mothers smoked during pregnancy had a birthweight 142 g lower than those of non-smoking mothers. The odds ratio for low birthweight among children of smokers was 1.59 [95% CI 1.30-1.95]. There was no association between smoking and preterm delivery assessed by the Dubowitz score. In relation to intrauterine growth retardation, smoking was associated with an odds ratio of 2.07 [95% CI 1.69-2.53]. There was a direct dose-response association between the number of cigarettes smoked and the risk of growth retardation. Women whose partner smoked were also at higher risk of having a child with growth retardation. All the above results were adjusted for confounding factors. The effect of maternal smoking on low birthweight seems to be attributable to intrauterine growth retardation rather than preterm delivery.

[Longitudinal study of the mother and child population in an urban region of southern Brazil, 1993: methodological aspects and preliminary results]

All babies born in the hospitals of the city of Pelotas, Brazil, in 1982 were studied soon after delivery and followed up prospectively during the first years of their lives. In 1993, this study was repeated with a similar methodology, with the aim of assessing eventual changes in the level of maternal and child health. All five maternity hospitals in the city were visited daily and the 5,304 babies born included in the study. They were weighed and measured, and their gestational age was assessed using the Dubowitz method. Their mothers were examined and interviewed regarding a large number of risk factors. The mortality of these children was studied through the surveillance of all hospitals, cemeteries and death registries, and all hospital admissions were also recorded. Two nested case-control studies were carried out to assess risk factors for mortality and hospital morbidity. A systematic sample of 655 children were examined at home at one and three months of age, and these infants, as well as another sample of 805 children including all low-birthweight babies were also examined at the ages of six and twelve months. Their psychomotor development was also assessed. Losses to follow-up were only 6.6% at twelve months. Relative to the 1982 indicators, perinatal mortality fell by about 30% and infant mortality by almost 50%. The median duration of breastfeeding increased from 3.1 to 4.0 months. On the other hand, there was little change in the prevalences of low birthweight or of length for age at twelve months. The article that refers this abstract describes the methodology of the study and forthcoming publications will present detailed results.

Chronic bronchitis and the type of cigarette smoked

BACKGROUND

Smoking is a well known primary risk factor for chronic bronchitis. However, little is known about the relationship between different types of cigarettes smoked and chronic bronchitis.

OBJECTIVE

To determine the association between chronic bronchitis and the type of cigarette smoked.

METHODS

A cross-sectional prevalence study was conducted in an urban area (Pelotas) of Southern Brazil. A total of 1053 subjects aged > or = 40 years were interviewed about respiratory symptoms and some risk factors for chronic bronchitis.

RESULTS

After adjustment for confounding factors, the number of daily cigarettes smoked was strongly associated with the risk of chronic bronchitis (odds ratio [OR] = 8.10, 95% CI: 4.46-14.71 for smokers of > or = 20 cigarettes per day compared to non-smokers). Among smokers, maize leaf cigarettes showed the highest risk (OR = 5.43 compared to non-smokers, 95% CI: 2.65-11.13) and filter cigarettes the lowest (OR = 2.19, 95% CI: 1.19-4.03).

CONCLUSIONS

In addition to the number of cigarettes smoked, the use of maize leaf cigarettes was shown to have an important independent association with chronic bronchitis.

Prevalence and risk factors for chronic bronchitis in Pelotas, RS, Brazil: a population-based study

BACKGROUND

Chronic bronchitis causes high morbidity and mortality throughout the world. It is basically a preventable disease. However, few population based studies of chronic bronchitis have been carried out in less developed countries.

METHODS

A population based cross sectional survey was conducted to determine the prevalence of chronic bronchitis and associated risk factors in an urban area (Pelotas) of southern Brazil. 1053 subjects aged 40 years and over (90.3% of eligible subjects) were interviewed using the ATS-DLD-78 questionnaire.

RESULTS

Of the subjects interviewed 12.7% were classified as having chronic bronchitis. In univariate analyses a significant increase in the relative odds of chronic bronchitis was seen in men (OR = 2.17, 95% CI 1.50 to 3.13), low family income (OR = 2.60, 95% CI 1.47 to 4.47 for lowest quartile), low schooling (OR = 4.65, 95% CI 2.36 to 9.18 for those with no schooling), smoking habits (OR = 6.92, 95% CI 4.22 to 11.36 for smokers of 20 or more cigarettes per day), high occupational exposure to dust (OR = 2.48, 95% CI 1.56 to 3.94), inadequate housing (OR = 2.09, 95% CI 1.22 to 3.58), high level of indoor air pollution (OR = 1.86, 95% CI 1.16 to 2.99), and reported childhood respiratory illnesses (OR = 2.08, 95% CI 1.25 to 3.49). Multiple logistic regression resulted in the identification of the following independent risk factors: family income (OR = 1.99, 95% CI 1.04 to 3.81 for subjects in the lowest quartile compared with those in the highest quartile), schooling (OR = 5.60, 95% CI 2.52 to 12.45 for subjects with no schooling compared with those with nine or more years), smoking (OR = 8.10, 95% CI 4.46 to 14.71 for smokers of 20 or more cigarettes per day compared with non-smokers), and history of major respiratory illnesses in childhood (OR = 2.16, 95% CI 1.20 to 3.85).

CONCLUSIONS

Low family income, poor schooling, smoking, and childhood respiratory illnesses were significantly associated with chronic bronchitis.

[Smoking habits among students at the Pelotas Medical School: prevalence in 1986 and 1991]

A cross-sectional survey of smoking habits was carried out among students at the School of Medicine in Pelotas, State of Rio Grande do Sul, Brazil, in 1986 and 1991. The overall participation rate for the originally selected sample was 96% and 98% respectively. In 1986, regular smokers comprised 21.6% of the students and 14.6% in 1991; former smokers were 7.3% and 10.9%, respectively. There was no association between sex, parental smoking, and smoking habits of the students. Students in their last two years of medical training showed an increased prevalence in smoking habits (1991). Respiratory symptoms were associated with smoking habits. It was concluded that the prevalence of smoking is decreasing among students of the School of Medicine in Pelotas.

Effect of myrcene on nociception in mice

Myrcene, a monoterpene isolated from lemon grass oil (Cymbopogon citratus) has been investigated for antinociception in mice by a low temperature (51.5 +/- 0.5 degrees C) hot plate method and by the acetic acid-induced writhing test. Significant inhibition of nociception was seen in the tests with myrcene at doses of 10 and 20 mg kg-1 (i.p.) or at 20 and 40 mg kg-1 (s.c.), respectively. The antinociceptive effect was significantly antagonized by naloxone (1 mg kg-1) or yohimbine (2 mg kg-1). The results suggest that myrcene is capable of inducing antinociception in mice, probably mediated by alpha 2-adrenoceptor stimulated release of endogenous opioids.