Obesity and dental caries: systematic review

OBJECTIVE Identifying, through a systematic literature review, evidence of a possible association between obesity and dental caries. METHODS A search of articles published between 2005 and January 2012 was performed in the Medline/PubMed, LILACS and Web of Science databases. The quality of scientific evidence of the selected articles was assessed by the items proposed for observational studies in the Downs & Black instrument. RESULTS Initially, 537 references were found; after checking the titles and abstracts by two independent researchers, twenty-eight articles were selected for complete reading. Ten of them that assessed the primary and/or permanent dentition observed a positive association between obesity and dental caries and one study found an inverse association. According to the Downs & Black classification, thirteen articles with good scientific evidence were found. CONCLUSIONS The present review did not find sufficient evidence regarding the association between obesity and dental caries, and it did not clarify the possible role of diet and other possible effect modifiers on this association.

Objectively measured physical activity in the 1993 Pelotas (Brazil) birth cohort

INTRODUCTION

Data on physical activity levels of adolescents are mostly derived from self-reported instruments, and the vast majority of studies using objective measures are from high-income countries. The aim of this study was to describe the patterns of objectively measured physical activity in Brazilian adolescents.

METHODS

In 2004-2005 (mean age of 13.3 yr), a subsample of the 1993 Pelotas (Brazil) Birth Cohort with data on all previous visits was approached. Physical activity was measured using the ActiGraph GT1M accelerometer (ActiGraph Corporation, Pensacola, FL). Demographic and other variables were assessed by self-report.

RESULTS

A total of 486 individuals (51% boys) provided valid data on objectively measured physical activity (response rate = 95.1%). The mean registered time of accelerometer data was 1191 min·d (SD = 112). The mean times (in minutes) spent in sedentary, light, moderate, and vigorous activities were 962 (SD = 114), 176 (SD = 46), 36 (SD = 16), and 17 (SD = 10) min·d, respectively. More than 30% of the adolescents accumulated ≥60 min·d of moderate-to-vigorous physical activity (MVPA). Physical activity intensity (counts per minute) and the prevalence of accumulation ≥60 min·d of MVPA were higher among boys and in those who walked or cycled to school. The prevalence of accumulation >60 min·d of MVPA was 125% higher in those from lower economic levels compared with higher economic levels (P < 0.001).

CONCLUSION

A large proportion of Brazilian adolescents of the 1993 Pelotas Birth Cohort do not achieve the current recommendation for health-related physical activity, and active commuting to school may be a target for interventions aimed at increasing physical activity. Physical activity levels are higher in lower socioeconomic groups than that in higher groups.

Life-course evidence of birth weight effects on bone mass: systematic review and meta-analysis

A systematic review of the literature was performed in July 2011. Original papers based on longitudinal studies measuring spine, femoral neck, or total body bone mass by DXA were included (n = 17). Birth weight was positively associated with bone mass among children. The association was unclear among adolescents and weak among adults. This study aims to evaluate the association between birth weight and bone mass in future ages through a systematic review of literature and meta-analysis. A systematic review of the literature was performed in July 2011 in Medline, Web of Science and LILACS bases using key terms: ("birth size" OR "birth weight" OR birthweight OR prematurity OR premature OR "gestational age") AND (osteoporosis OR "bone mass" OR "bone density" OR "bone mineral density" OR "bone mineral content" OR "bone area") AND (longitudinal OR cohort). Original papers based on longitudinal studies measuring lumbar spine, femoral neck or total body bone mass by dual-emission X-ray absorptiometry (DXA) were included. A meta-analysis was performed using birth weight and bone mass density and/or content as continuous variables and adjusted for current height and/or weight. A total of 218 articles were retrieved from which 17 were selected and grouped into three categories according to age: studies with children; with adolescents and young adults, and studies with adults (older than 25). Five papers were included in the meta-analysis. Positive association between birth weight and bone mass was clear among children, unclear among adolescents, and weak among adults. The effect on bone mass content was stronger than those on body mass density regardless of age. Birth weight influences positively bone health in later life. Preventive health policies dealing with early-life modifiable risk factors, as birth weight, should be encouraged to attain an optimal peak bone mass as an strategy to decrease osteoporosis in the elderly.

Predictors and health consequences of screen-time change during adolescence--1993 Pelotas (Brazil) birth cohort study

PURPOSE

To investigate screen-time change from early to mid adolescence, its predictors, and its influence on body fat, blood pressure, and leisure-time physical activity.

METHODS

We used data from a longitudinal prospective study, conducted among participants of the 1993 Pelotas (Brazil) Birth Cohort Study. At baseline, adolescents were, on average, 11 years old. They were later visited at age 15 years. Screen time was self-reported, accounting for the time spent watching television, playing video games, and using the computer. Several predictors were examined. The effect of screen-time change on some health outcomes was also analyzed.

RESULTS

Screen time increased on average 60 min/d from 11 to 15 years of age, for the 4,218 adolescents studied. The groups that presented the highest increases in screen time were male, wealthiest, those whose mothers had higher education, and adolescents with a history of school failure. There were positive associations between screen-time change and body mass index, skinfold thickness, waist circumference, and leisure-time physical activity at 15 years of age.

CONCLUSIONS

Screen time increased from early to mid adolescence. This increment was higher among boys and the wealthiest adolescents. Increases in screen time affected body composition, with negative implications on adiposity.

Waist circumference and pulmonary function: a systematic review and meta-analysis

BACKGROUND

Studies have reported an impact of central obesity on people's health. The literature is scarce on the effects of waist circumference (WC) on pulmonary function. Our objective was to review the literature on the association between WC and pulmonary function.

METHODS

A systematic review was carried out in the PubMed, CINAHL, Web of Science and Scopus databases. The search included published, in press and online documents up to December 2011. A meta-analysis was carried out to obtain the pooled effect, and a meta-regression was performed to evaluate sources of heterogeneity.

RESULTS

From the 547 studies identified, 10 were included. The meta-analysis revealed an inverse relationship between WC and pulmonary function parameters, indicating that the effect was greater among men (forced expiratory volume in 1 second (FEV1 β = -15.9 (95% confidence interval = -23.2, -8.5); forced vital capacity (FVC) β = -16.6 (95% confidence interval = -21.0, -12.2)) compared with women (FEV1 β = -5.6 (95% confidence interval = -9.1, -2.1); FVC β = -7.0 (95% confidence interval = -9.1, -4.8)). The meta-regression identified sex as the characteristic that most contributed to the heterogeneity (R2 = 54.8% for FEV1 and R2 = 85.7% for FVC).

CONCLUSIONS

There seems to be an inverse relationship between WC and pulmonary function, mainly in men. More population-based studies should be performed, especially among children and adolescents, to confirm these findings.

Racial inequalities in access to women's health care in southern Brazil

The aim of this population-based cross-sectional study was to investigate access by 20 to 60 year-old women--both black and white--to early detection (pap-smear) exams for breast and cervical cancer in two towns--São Leopoldo and Pelotas--in Rio Grande do Sul State, southern Brazil. Estimates of the association between race/color and access to Pap-smear and breast exams were adjusted for income, education, economic class and age. Of the 2,030 women interviewed, 16.1% were black and 83.9%, white. Black women were significantly less likely to have had a Pap-smear and/or breast exam than white women. Racial inequalities in access to cancer early detection exams persisted after controlling for age and other socioeconomic factors. Racial differentials in access to early detection (Pap-smear) exams for breast and cervical cancers might result from racial and socioeconomic inequalities experienced by black women in access to reproductive health care services and programs.

Insatisfação corporal em adolescentes: um estudo de base populacional

O propósito deste estudo foi avaliar a insatisfação corporal em adolescentes e explorar diferenças conforme sexo, nível econômico e índice de massa corporal. Foram estudados 4.325 indivíduos de 14 a 15 anos da cidade de Pelotas, Brasil. A insatisfação corporal foi avaliada comparando a imagem desejada com a imagem percebida, de acordo com escala de silhuetas de Tiggemann e Wilson-Barret. O estado nutricional foi categorizado conforme proposto pela Organização Mundial da Saúde, enquanto o nível socioeconômico foi avaliado segundo classificação da Associação Brasileira de Empresas de Pesquisas. Verificou-se que 27,6% dos adolescentes estavam acima do peso. A insatisfação corporal, avaliada pela escala de silhuetas, atingiu 51,0% dos meninos e 65,6% das meninas. O nível econômico e o estado nutricional estiveram associados com o desfecho. A maioria dos adolescentes com excesso de peso desejava ter uma silhueta menor do que a percebida. O nível econômico modificou o efeito do estado nutricional sobre a insatisfação corporal. Adolescentes das classes econômicas mais altas fora do peso ideal mostraram maior insatisfação corporal do que os mais pobres e, independente do nível econômico, as meninas estão mais insatisfeitas com o excesso de peso e os meninos com a magreza.

Consumo de carnes por adolescentes do Sul do Brasil

OBJETIVO: Descrever a frequência de consumo de diferentes tipos de carnes conforme variáveis sociodemográficas e nutricionais, e analisar o consumo, em adolescentes do Sul do Brasil, de dieta rica em gordura conforme os tipos de carne consumidos. MÉTODOS: Estudo transversal realizado com adolescentes pertencentes à coorte de nascimentos de 1993, em Pelotas (RS). A frequência de consumo de carnes vermelhas, brancas, vísceras e embutidos foi avaliada por um Questionário de Frequência de Consumo Alimentar, adaptado para este estudo. A ingestão de dieta rica em gordura foi avaliada a partir do instrumento proposto por Block. As variáveis independentes foram sexo, cor da pele, nível socioeconômico, escolaridade materna e estado nutricional. Nas análises estatísticas, foram utilizados testes Qui-quadrado de heterogeneidade e de tendência linear. RESULTADOS: Foram avaliados 4.325 adolescentes com idade média de 14,7, DP=0,3 anos, dos quais 51,2% eram do sexo feminino. A frequência de consumo diário de carnes vermelhas foi maior do que a de carnes brancas (43,0% e 9,7%, respectivamente). O consumo de embutidos por mais do que quatro vezes por semana foi referido por 48,5% dos indivíduos, e 81,4% relataram consumir vísceras raramente ou nunca. Adolescentes de maior nível socioeconômico e filhos de mães com maior escolaridade apresentaram maior consumo de carnes vermelhas e embutidos, enquanto aqueles em situação oposta apresentaram maior consumo de carnes brancas. Adolescentes que consomem carnes com maior frequência também consomem dieta rica em gordura. CONCLUSÃO: As carnes consumidas com maior frequência pelos adolescentes foram as vermelhas e os embutidos. No entanto, adolescentes de maior nível socioeconômico consomem carnes vermelhas com maior frequência, enquanto adolescentes menos favorecidos economicamente consomem mais carnes brancas.

Pharmacological treatment of COPD

Approximately seven million Brazilians over 40 years of age have COPD. In recent years, major advances have been made in the pharmacological treatment of this condition. We performed a systematic review including original articles on pharmacological treatments for COPD. We reviewed articles written in English, Spanish, or Portuguese; published between 2005 and 2009; and indexed in national and international databases. Articles with a sample size < 100 individuals were excluded. The outcome measures were symptoms, pulmonary function, quality of life, exacerbations, mortality, and adverse drug effects. Articles were classified in accordance with the Global Initiative for Chronic Obstructive Lung Disease criteria for the determination of the level of scientific evidence (grade of recommendation A, B, or C). Of the 84 articles selected, 40 (47.6%), 18 (21.4%), and 26 (31.0%) were classified as grades A, B, and C, respectively. Of the 420 analyses made in these articles, 236 were regarding the comparison between medications and placebos. Among these 236 analyses, the most commonly studied medications (in 66, 48, and 42 analyses, respectively) were long-acting anticholinergics; the combination of long-acting β(2) agonists and inhaled corticosteroids; and inhaled corticosteroids in isolation. Pulmonary function, adverse effects, and symptoms as outcomes generated 58, 54, and 35 analyses, respectively. The majority of the studies showed that the medications evaluated provided symptom relief; improved the quality of life and pulmonary function of patients; and prevented exacerbations. Few studies analyzed mortality as an outcome, and the role that pharmacological treatment plays in this outcome has yet to be fully defined. The medications studied are safe to use in the management of COPD and have few adverse effects.

Pulmonary rehabilitation programs for patients with COPD

Pulmonary rehabilitation programs are aimed at providing benefits to COPD patients, in various aspects. Our objective was to review the literature on COPD patient rehabilitation. This systematic review involved articles written in English, Spanish, or Portuguese; published between 2005 and 2009; and indexed in national and international databases. Articles were classified in accordance with the Global Initiative for Chronic Obstructive Lung Disease criteria for the determination of the level of scientific evidence (grade of recommendation A, B, or C). The outcome measures were exercise, quality of life, symptoms, exacerbations, mortality, and pulmonary function. Treatments were classified as standard rehabilitation, partial rehabilitation, strength exercises, and resistance exercises. Of the 40 articles selected, 4, 18, and 18 were classified as grades A, B, and C, respectively. Of the 181 analyses made in these articles, 61, 50, 23, 23, 20, and 4, respectively, were related to the outcome measures quality of life, exercise, symptoms, exacerbations, pulmonary function, and mortality. The standard rehabilitation programs showed positive effects on all of the outcomes evaluated, except for mortality (because of the small number of analyses). However, we found no differences among the various rehabilitation programs regarding their effects on the outcomes studied. Rehabilitation programs can be considered important tools for the treatment of COPD. Therefore, health administrators should implement public policies including such programs in the routine of health care facilities.

Airflow obstruction in never smokers in five Latin American cities: the PLATINO study

BACKGROUND

Although chronic obstructive pulmonary disease (COPD) is mostly related to tobacco smoking, a variable proportion of COPD occurs in never smokers. We investigated differences between COPD in never smokers compared with smokers and subjects without COPD.

METHODS

PLATINO is a cross-sectional population-based study of five Latin American cities. COPD was defined as postbronchodilator FEV(1)/FVC <0.70 and FEV(1) <80% of predicted values.

RESULTS

Among 5,315 subjects studied, 2278 were never smokers and 3036 were ever smokers. COPD was observed in 3.5% of never smokers and in 7.5% of ever smokers. Never smokers with COPD were most likely older and reported a medical diagnosis of asthma or previous tuberculosis. Underdiagnosis was as common in obstructed patients who never smoked as in ever smokers.

CONCLUSIONS

Never smokers comprised 26% of all individuals with airflow obstruction. Obstruction was associated with female gender, older age and a diagnosis of asthma or tuberculosis.

Time trend of asthma in children and adolescents in Brazil, 1998-2008

OBJECTIVE

To analyze the trends in asthma prevalence in children and adolescents between 1998 and 2008 in Brazil.

METHODS

Data on asthma prevalence from the 1998, 2003 and 2008 National Household Sample Surveys were analyzed. The sample was comprised of 141,402, 144,443 and 134,032 individuals in 1998, 2003 and 2008, respectively, and the analysis was adjusted for the sample design. Trends in asthma prevalence were described for sex, Brazilian regions and place of residence of children (zero to nine years of age) and adolescents (ten to 19 years of age).

RESULTS

The prevalence of asthma in children was 7.7% in 1998, 8.1% in 2003 and 8.5% in 2008, with an annual increase of 1%. The highest annual increase was observed in the Southeast and North regions (1.4%). Among adolescents, the prevalence of asthma was 4.4% in 1998, 5.0% in 2003 and 5.5% in 2008, with an increase of 2.2% per year. In the Northeast region, the annual increase in the prevalence of asthma was 3.5%. The greatest increases were observed in boys and in residents of rural areas.

CONCLUSIONS

Although asthma has decreased in some developing countries, the results found in Brazil point to an increase in this disease in children and adolescents between 1998 and 2008, especially in rural areas.

Association of socioeconomic position with maternal pregnancy and infant health outcomes in birth cohort studies from Brazil and the UK

BACKGROUND

Socioeconomic inequalities in health outcomes are dynamic and vary over time. Differences between countries can provide useful insights into the causes of health inequalities. The study aims to compare the associations between two measures of socioeconomic position (SEP)-maternal education and family income-and maternal and infant health outcomes between ALSPAC and Pelotas cohorts.

METHODS

Birth cohort studies were started in Avon, UK, in 1991 (ALSPAC) and in the city of Pelotas, Brazil, in 1982, 1993 and 2004. Maternal outcomes included smoking during pregnancy, caesarean section and delivery not attended by a doctor. Infant outcomes were preterm birth, intra-uterine growth restriction (IUGR) and breast feeding for <3 months. The relative index of inequality was used for each measure of SEP so that results were comparable between cohorts.

RESULTS

An inverse association (higher prevalence among the poorest and less educated) was observed for almost all outcomes, with the exception of caesarean sections where a positive association was found. Stronger income-related inequalities for smoking and education-related inequalities for breast feeding were found in the ALSPAC study. However, greater inequalities in caesarean section and education-related inequalities in preterm birth were observed in the Pelotas cohorts.

CONCLUSIONS

Mothers and infants have more adverse health outcomes if they are from poorer and less well-educated socioeconomic backgrounds in both Brazil and the UK. However, our findings demonstrate the dynamic nature of the association between SEP and health outcomes. Examining differential socioeconomic patterning of maternal and infant health outcomes might help understanding of mechanisms underlying such inequalities.

Paid employment in subjects with and without chronic obstructive pulmonary disease in five Latin American cities: the PLATINO study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a costly condition that frequently causes permanent work disabilities. Little information exists regarding the impact of COPD on work force participation and the indirect costs of the disease in developing countries.

OBJECTIVE

To examine the frequency of paid employment and factors influencing it in a Latin-American population-based study.

METHODS

Post-bronchodilator FEV(1)/FVC < 0.70 (forced expiratory volume in 1 s/forced vital capacity) was used to define COPD. Information regarding paid work was assessed by the question 'At any time in the past year, have you worked for payment?'

RESULTS

Interviews were conducted with 5571 subjects; 5314 (759 COPD and 4554 non-COPD) subjects underwent spirometry. Among the COPD subjects, 41.8% reported having paid work vs. 57.1% of non-COPD (P < 0.0001). The number of months with paid work was reduced in COPD patients (10.5 ± 0.17 vs. 10.9 ± 0.06, P < 0.05). The main factors associated with having paid work in COPD patients were male sex (OR 0.33, 95%CI 0.23-0.47), higher education level (OR 1.05, 95%CI 1.01-1.09) and younger age (OR 0.90, 95%CI 0.88-0.92). COPD was not a significant contributor to employment (OR 0.83, 95%CI 0.69-1.00, P = 0.054) in the entire population.

CONCLUSIONS

Although the proportion of persons with paid work is lower in COPD, having COPD appears not to have a significant impact on obtaining paid employment in the overall population of developing countries.

Tabagismo no Brasil: desigualdades regionais e prevalência segundo características ocupacionais

O estudo descreveu a prevalência do tabagismo diário segundo sexo, idade, renda domiciliar e ocupação dos moradores de 15 anos ou mais, no Brasil e regiões, baseado nos dados da Pesquisa Nacional por Amostra Domiciliar 2008 (PNAD/IBGE). A análise considerou o desenho da amostra e incluiu 252.768 indivíduos. A prevalência de fumo diário no Brasil foi 15,1%, variando de 12,8% na região Norte a 17,4% na região Sul, sendo 62% maior nos homens que mulheres. A prevalência de fumo foi inversamente proporcional à renda domiciliar, sendo 18,6% entre os 20% mais pobres e 11,5% entre os 20% mais ricos. As mesmas tendências para sexo, idade e renda foram observadas nas diferentes regiões do país. O consumo diário de cigarros foi 3% maior entre os trabalhadores comparados com não trabalhadores. Trabalhadores não manuais apresentaram prevalências de fumo abaixo de 10%, enquanto trabalhadores manuais relataram frequências acima de 20%. A associação entre tabagismo e ocupação permaneceu após ajuste para sexo, idade e renda. As desigualdades encontradas devem ser consideradas no planejamento e direcionamento de ações efetivas para redução do tabagismo. Os grupos ocupacionais mais expostos deveriam ter prioridade nas intervenções.

Childhood body mass index and risk of asthma in adolescence: a systematic review

Asthma and obesity, both of which are considered global health issues, affect approximately 300 million individuals worldwide. The observation that asthma and obesity tend to increase in parallel may indicate a potential link between these two conditions. The aim of this systematic review of the literature was to investigate the relationship between childhood nutritional status and incidence or persistence of asthma during adolescence. The principal eligibility criteria for selection of articles were including longitudinal analysis, and which measured of exposure during childhood or adolescence and outcome during adolescence. The systematic search initially returned 1563 unique articles. After inspection of titles and reading the abstracts of these articles, we chose 27 for full reading. Of these, 10 were selected to be included in the present review. Of the 10 selected studies, eight showed positive associations between overweight/obesity and asthma. Of these, two were independent of sex, three were found only among men and another three only among women. The present study shows strong evidence that, although the role of sex is not clear, obesity precedes, and is associated with, the persistence and intensity of symptoms of asthma.

Caesarean sections and risk of wheezing in childhood and adolescence: data from two birth cohort studies in Brazil

Background

There is evidence from two meta-analyses that children born through caesarean section (C-section) may have an increased risk of developing asthma compared with those born through vaginal delivery.

Objective

To evaluate the association between mode of delivery and wheezing (current and persistent) in childhood and adolescence, in two birth cohort studies in Brazil.

Methods

The outcome variable was based on the International Study of Allergy and Asthma questionnaire, which collects information about wheezing within the 12 months before the interview. Persistent wheezing was defined when it was present in more than one follow-up at different ages, in the 1993 cohort. The questions were asked to mothers when children were aged 4 years (1993 and 2004 cohorts) and directly to cohort participants at 11 and 15 years (1993 cohort). Mode of delivery was collected by the research team of each cohort when children were born.

Results

Response rates in the last follow-up visit of the 1993 and 2004 cohorts were 85% and 92%, respectively. The prevalence of current wheezing increased from 20% to 28% at 4 years from 1993 to 2004; at 11 and 15 years, the prevalence was around 14% and 12%, in the 1993 cohort. The proportion of C-sections increased from 30.5% to 45% between 1993 and 2004. In each cohort, the prevalence of current wheezing was similar among children born through vaginal and C-section. The risk for persistent wheezing in the 1993 cohort was higher among girls born through C-section than boys.

Conclusion

Despite the increase in the proportion of C-section in two cohorts in Southern Brazil, we found no evidence of an association between mode of delivery and the subsequent risk of wheezing. Among girls, although there was no statistical significance, the risk was higher for those born by C-section, especially regarding persistent wheezing.

Hábitos alimentares de escolares adolescentes de Pelotas, Brasil

OBJETIVO: Descrever a frequência com que escolares adolescentes de Pelotas (RS) estão seguindo as recomendações nacionais para uma alimentação saudável. MÉTODOS: Estudo transversal aninhado a um estudo longitudinal em 2004, incluindo adolescentes de 13 e 14 anos matriculados em 32 escolas públicas de Pelotas (RS). A amostra incluiu 2.209 adolescentes. Para avaliação da frequência de consumo alimentar, foi utilizado questionário proposto pelo Instituto Nacional do Câncer. Foram construídos desfechos baseados nos dez passos para a alimentação saudável propostos pelo Ministério da Saúde do Brasil. RESULTADOS: Os hábitos alimentares saudáveis mais frequentes foram o consumo diário de feijão e leite, relatado por cerca de metade dos adolescentes. Quase metade dos jovens referiu ingerir batata frita e salgadinhos no máximo uma vez por semana. Verificou-se consumo adequado de alimentos conservados e enlatados em 44,6% dos adolescentes. Pouco menos da metade dos jovens (43,6%) nunca colocava sal adicional na comida. Quanto ao consumo de doces e outros alimentos ricos em açúcar, constatou-se que aproximadamente um terço deles consumia bolos ou biscoitos no máximo duas vezes por semana. CONCLUSÃO: Verificou-se baixa frequência de hábitos alimentares saudáveis em todos os subgrupos estudados, sendo a frequência mais baixa entre jovens de maior nível socioeconômico e entre as meninas. O hábito alimentar que apresentou mais baixa frequência - 5,3% dos adolescentes - foi o consumo de frutas e verduras cinco ou mais vezes por dia. Políticas públicas de promoção da saúde voltadas à melhoria da alimentação e nutrição dos adolescentes são necessárias e urgentes.

Sintomas articulares crônicos em adultos de Pelotas, Rio Grande do Sul, Brasil: prevalência e determinantes

Com o objetivo de estimar a prevalência de sintomas articulares crônicos e seus determinantes, foi realizado um estudo transversal, com 2.953 adultos com 20 anos ou mais, residentes em Pelotas, Rio Grande do Sul, Brasil. Foram investigadas a presença de dor, edema ou rigidez articular, além de informações demográficas, sócio-econômicas e sobre problemas de saúde. A análise multivariável foi realizada pela regressão de Poisson. A prevalência geral de sintomas articulares crônicos foi de 36,5% (42,4% nas mulheres e 28,7% nos homens). A presença da tríade - dor, edema e rigidez articulares - foi de 14,1% e 5,5% nas mulheres e homens, respectivamente. Sintomas articulares crônicos se mostraram linearmente associados ao aumento da idade (RP: 2,9; IC95%: 2,4-3,5), do índice de massa corporal (RP: 1,6; IC95%: 1,3-2,0) e à menor escolaridade (RP: 1,5; IC95%: 1,3-1,8). Somente 6% dos homens e 18% das mulheres relataram diagnóstico médico de artrite. As prevalências gerais de limitações para atividades de vida diária e para atividades laborais, secundárias a sintomas articulares crônicos, foi de 15% e 21%, respectivamente. Os jovens e homens representam a maioria dos indivíduos com sintomas articulares crônicos subdiagnosticados.

Infant feeding and obesity at 11 years: prospective birth cohort study

OBJECTIVE

To evaluate the association between breastfeeding duration, introduction of solid or semi-solid foods before four months of age and overweight/obesity at 11 years.

METHODS

Prospective population-based birth cohort study, including 1 204 adolescents aged 11 years who were born in Pelotas (Brazil), in 1993, and were previously interviewed at birth, six and 12 months of age. Five explanatory variables were used: duration of any breastfeeding, duration of exclusive or predominant breastfeeding, ever breastfeeding, introduction of solid or semi-solid foods before four months of age, and feeding pattern at four months of age. Risk of overweight was defined as body mass index (BMI) > or = 85(th) percentile, and obesity was defined as BMI > or = 85(th) percentile plus triceps and subscapular skinfolds > or = 90(th) percentile, using the National Center for Health Statistics curves.

RESULTS

The prevalence of risk of overweight and obesity at 11 years were 23.2% and 11.6%, respectively. The lowest prevalence of both outcomes was found among subjects who were breastfed for one to three months. However, tests for linear trend or heterogeneity did not result in a significant association between breastfeeding indicators and anthropometry at 11 years. Adjustment for sex, skin color, birth weight, maternal schooling, smoking during pregnancy and maternal pre-pregnancy BMI did not alter the findings.

CONCLUSIONS

Our results do not support the hypothesis that breastfeeding has a long-term lasting effect on anthropometry in this population.

Asthma and lung function in a birth cohort at 6-7 years of age in southern Brazil

OBJECTIVE

Asthma and respiratory symptoms are common in children, and many studies have shown associations between childhood symptoms and impaired lung function in adult life. The aim of the present study was to investigate the association of various respiratory symptoms with wheezing patterns (persistent, early, and late-onset) and lung function, as well as to determine whether lung function was associated with atopy or with demographic, socioeconomic, environmental, and gestational factors, in a birth cohort at 6-7 years of age.

METHODS

The target population consisted of children aged 6-7 years from a birth cohort of 5,304 children born in southern Brazil in 1993. For this follow-up evaluation, 532 of those children were randomly selected, and a sub-sample was submitted to spirometry and skin prick tests. A questionnaire was administered to the parent(s) or legal guardian(s) of each child.

RESULTS

Spirometric values were lower in the children with respiratory symptoms or asthma. Mean forced expiratory volume in one second/forced vital capacity ratio (FEV1/FVC ratio) was lower in children with any of the following: current wheezing and asthma; asthma ever; four or more episodes of wheezing within the preceding 12 months; sleep disturbance due to wheezing; and exercise-induced wheezing. Persistent wheezing was associated with lower FEV1/FVC ratio. After multiple linear regression, exercise-induced wheezing was also associated with reduced FEV1/FVC ratio. Nonwhite skin color and wheezing severe enough to limit speech were associated with lower FEV1.

CONCLUSIONS

Children with persistent wheezing and symptoms of severe asthma have impaired lung function at 6-7 years of age.

Physical activity as a predictor of adolescent body fatness: a systematic review

Adolescent obesity has increased dramatically in several countries in recent decades; however, the contribution of physical activity level to adolescent adiposity requires clarification. This article investigates the effect of physical activity on subsequent levels of adiposity in adolescence. The methodological aspects of the studies included in this article, particularly in terms of measurement accuracy for both exposure (physical activity) and outcome (adiposity) variables, are also evaluated. Systematic searches of the literature were undertaken using online databases, including PubMed/MEDLINE, examination of citations and contacting of authors. The online databases were searched from their earliest records until 2007. Only longitudinal studies with 50 or more adolescents were included. Two independent reviewers assessed the quality of the studies using the Downs and Black checklist. Thirteen observational, five experimental and six quasi-experimental studies (without a control group) were identified. Almost all studies were carried out in high-income settings and showed protective effects of physical activity for both prevention and treatment of adolescent obesity. However, experimental studies undertaken with obese adolescents at baseline usually combined physical activity with dietary changes, making it difficult to assess the effect of physical activity itself on the treatment of obesity. Physical activity estimated from questionnaires and body mass index (BMI) were the most frequently used measures. Despite the feasibility of using these approaches in epidemiological studies, significant limitations are evident. Questionnaires are subjective and adolescents may not report physical activity level accurately. Furthermore, BMI is not an accurate measure of fatness for adolescents, as it is also associated with lean mass, hence bias may arise from its longitudinal association with physical activity level. Despite the majority of studies reviewed showing protective effects of physical activity on adiposity, particularly in individuals who are obese at baseline, the current literature on this issue is sparse and several methodological drawbacks are evident. The main limitations relate to a lack of validity in the measurements of both physical activity and body composition. Further studies are needed in order to generate evidence-based recommendations for the quantity and quality of adolescent physical activity required to prevent or treat adolescent obesity.

[Wheezing phenotypes from birth to adolescence: a cohort study in Pelotas, Brazil, 1993-2004]

OBJECTIVE

To study the prevalence of wheezing patterns and their associations with independent variables.

METHODS

Cohort study of live births in 1993 in Pelotas, Brazil. A systematic subsample (20%) of the original cohort was evaluated at 6 months, 12 months and 4 years. At 10-12 years, 87.5% of the original cohort was contacted. Wheezing was categorized: transient, wheezing at 4 years but not at 10-12; persistent, wheezing at all evaluations; late-onset, wheezing at 10-12 years. Independent variables were analyzed: gender; skin color; family income; smoking/asthma during pregnancy; breastfeeding; respiratory infection/diarrhea (during the 1st year); family members with asthma/allergy (at 4 years and at 10-12); physician-diagnosed rhinitis/eczema (at 10-12 years).

RESULTS

The subsample comprised 897 adolescents. Wheezing patterns were expressed as prevalence (95% CI): transient, 43.9% (40.7-47.2); persistent, 6.4% (4.8-8.0); and late-onset, 3.3% (2.2-4.5). The transient pattern was more common in children from low-income families, children breastfed for less time, children with a history of respiratory infections (during the 1st year) and children with asthma in the family (at 4 years). The persistent pattern was almost twice as common in males, in children whose mothers had asthma during pregnancy, in children with respiratory infections (during the 1st year) and in children with asthma in the family (at 4 and 10-12 years). The late-onset pattern was more prevalent among those with asthma in the family (at 10-12 years) and those diagnosed with rhinitis (at 10-12 years), being less prevalent among those reporting respiratory infections (during the 1st year) and those diagnosed with eczema (at 10-12 years).

CONCLUSIONS

Knowledge of the associations of wheezing patterns allows us to adopt preventive and therapeutic measures.

Can a normal peak expiratory flow exclude severe chronic obstructive pulmonary disease?

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is underdiagnosed. One barrier to diagnosis is the limited availability of spirometry testing, but in adults at risk for COPD, a normal pre-bronchodilator (pre-BD) peak expiratory flow (PEF) may rule out clinically significant COPD.

OBJECTIVE

To identify post-BD airway obstruction using data from 13 708 individuals aged >or=40 years from the PLATINO and BOLD studies.

METHODS

We evaluated different cut-off points of pre-BD. The PEF was obtained from a diagnostic-quality spirometer (not a mechanical PEF meter). At least one of the following COPD risk factors was present in 77% of the subjects: chronic respiratory symptoms; exposure to tobacco smoke, biomass smoke or dust in the workplace; or a previous diagnosis of asthma, COPD, emphysema or chronic bronchitis.

RESULTS

Although the positive predictive value was low as expected, a pre-BD PEF of >or=70% predicted effectively ruled out Stages III and IV COPD of the Global Initiative for Chronic Obstructive Lung Disease. Among those with at least one risk factor, only 12% would require confirmatory spirometry using this criterion.

CONCLUSIONS

Adding PEF measurement to a screening questionnaire may rule out severe to very severe COPD without the need for pre- and post-BD spirometry testing. Confirmation is needed from a study using inexpensive PEF meters or pocket spirometers with a staged screening protocol.

Occupational exposures and COPD: an ecological analysis of international data

The occupational contribution to chronic obstructive pulmonary disease (COPD) has yet to be put in a global perspective. In the present study, an ecological approach to this question was used, analysing group-level data from 90 sex-specific strata from 45 sites of the Burden of Obstructive Lung Disease study, the Latin American Project for the Investigation of Obstructive Lung Disease and the European Community Respiratory Health Survey follow-up. These data were used to study the association between occupational exposures and COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II or above. Regression analysis of the sex-specific group-level prevalence rates of COPD at each site against the prevalence of occupational exposure and ever-smoking was performed, taking into account mean smoking pack-yrs and mean age by site, sex, study cohort and sample size. For the entire data set, the prevalence of exposures predicted COPD prevalence (0.8% increase in COPD prevalence per 10% increase in exposure prevalence). By comparison, for every 10% increase in the proportion of the ever-smoking population, the prevalence of COPD GOLD stage II or above increased by 1.3%. Given the observed median population COPD prevalence of 3.4%, the model predicted that a 20% relative reduction in the disease burden (i.e. to a COPD prevalence of 2.7%) could be achieved by a 5.4% reduction in overall smoking rates or an 8.8% reduction in the prevalence of occupational exposures. When the data set was analysed by sex-specific site data, among males, the occupational effect was a 0.8% COPD prevalence increase per 10% change in exposure prevalence; among females, a 1.0% increase in COPD per 10% change in exposure prevalence was observed. Within the limitations of an ecological analysis, these findings support a worldwide association between dusty trades and chronic obstructive pulmonary disease for both females and males, placing this within the context of the dominant role of cigarette smoking in chronic obstructive pulmonary disease causation.