Características das gestações, partos e recém-nascidos da região metropolitana de Aracaju, Sergipe, Brasil

OBJETIVOS: descrever as características das gestações, partos e nascimentos da região metropolitana de Aracaju. As principais características demográficas e socioeconômicas e de atenção à saúde da população foram avaliadas. MÉTODOS: estudo transversal dos nascimentos ocorridos entre março e julho de 2005, procedentes da região metropolitana de Aracaju, Sergipe, Brasil. Todas as mães que tiveram parto único nascido vivo foram entrevistadas através de um questionário estruturado, com informações sobre as condições demográficas, socioeconômicas, história sexual/reprodutiva. Registros do peso, comprimento e perímetro cefálico das crianças foram transferidos para o questionário. Foi feita comparação com outros estudos brasileiros de características semelhantes. RESULTADOS: foram analisados 4746 nascimentos de parto único de Aracaju, com 69% das mães referindo renda inferior a três salários mínimos. As mães adolescentes representaram 20,6% da amostra. Entre todos os nascimentos, 7,7% tiveram duração inferior a 37 semanas, percentual semelhante ao de baixo peso ao nascer (7,2%). Prevaleceu a assistência pré-natal oferecida pelo Sistema Único de Saúde (SUS) (76,0%), que custeou 85,2% dos partos. Destes, 31,6% foram cesáreas. CONCLUSÕES: o estudo mostrou menores percentuais de partos cesária, prematuridade e baixo peso ao nascer que os encontrados em Ribeirão Preto, São Luís e Pelotas. Estudos como este podem ser muito úteis ao planejamento de saúde perinatal.

alpha1-acid glycoprotein and alpha1-antitrypsin as early markers of treatment response in patients receiving the intensive phase of tuberculosis therapy

The identification of early markers that predict the response to anti-tuberculosis treatment would facilitate evaluation of new drugs and improve patient management. This study aimed to determine whether selected acute phase proteins and micronutrients measured at the time of diagnosis and during the first weeks of treatment could predict treatment responses during the 2-month standard intensive phase of therapy. For this purpose, alpha1-antitrypsin, alpha1-acid glycoprotein, alpha2-macroglobulin, C-reactive protein, C3, C4, zinc, copper and selenium concentrations were measured in Brazilian patients with smear-positive tuberculosis at the time of diagnosis and 1, 3, 5 and 8 weeks after initiation of therapy. Patients were classified into fast (n=29), intermediate (n=18) and slow responders (n=10) if they were smear-negative at 3, 5 or 8 weeks of treatment. alpha1-acid glycoprotein on enrolment and 1 week of treatment, alpha1-antitrypsin at week 1 and C-reactive protein and C3 after 3 weeks of therapy were higher in slow responders than in fast responders. alpha1-antitrypsin and alpha1-acid glycoprotein may be helpful in predicting treatment response at the time of initiation of therapy, and could be used as early markers to identify patients with an increased likelihood of treatment failure.

Significant differences in cesarean section rates between a private and a public hospital in Brazil

This paper evaluates the association of maternal variables and of variables related to prenatal and delivery care with cesarean sections at a public and at a private maternity. A retrospective cross-sectional study was performed at a public maternity clinic (2,889 deliveries) and at a private maternity clinic (2,911 deliveries) in the city of Ribeirão Preto, São Paulo State, Brazil. The prevalence of cesarean sections was 18.9% at the public maternity clinic and 84.3% at the private one. The factors associated with cesarean sections at both hospitals were: mothers from other cities, aged > 25 years and with hypertension. Having more than one child was a protective factor. At the public hospital, cesarean sections were more frequent on Wednesdays and from 12:00 to 23:59 hours of any day of the week, whereas at the private hospital they occurred on any day, though were less common on Sundays, and at any time except in the early morning. At the private hospital, cesarean sections were more frequent when performed by the doctor who had provided the prenatal care. Non-medical factors were more associated with cesarean sections in the private maternity clinic than biological or clinical factors related to pregnancy.

Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adults

BACKGROUND

The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries.

OBJECTIVE

To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings.

METHODS

We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata.

RESULTS

The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma.

CONCLUSION

The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.

Peso insuficiente ao nascer: estudo de fatores associados em duas coortes de recém-nascidos em Ribeirão Preto, São Paulo

OBJETIVO: Avaliar fatores associados ao aumento das taxas de peso insuficiente (PI) em duas coortes de recém-nascidos (RN) vivos e de parto único de Ribeirão Preto, São Paulo, separadas por 15 anos (1978/79 e 1994). MÉTODOS: Foram estudados 6.223 partos em 1978/79 e 2.522 em 1994, excluindo-se os RN de baixo peso. Associação entre PI e variáveis independentes (idade, trabalho, escolaridade e tabagismo maternos, abortos e natimortos prévios, número de filhos, situação conjugal, visitas de pré-natal, tipo de parto e hospital, categoria de internação, renda familiar, idade gestacional e sexo do RN) foi analisada por cálculo da Odds Ratio (OR) bruto e intervalo de confiança 95%, seguida de regressão logística múltipla. RESULTADOS: Em 1978/79, na análise ajustada, idade materna <20 anos (p=0,014), renda familiar <5 salários-mínimos (p=0,030), menos de quatro consultas de pré-natais (p=0,003), parto vaginal (p<0,001), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001) estiveram associados a PI. Em 1994, os fatores associados ao PI foram: trabalho materno fora do lar (p=0,020), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001). CONCLUSÕES: Variáveis socioeconômicas que atuaram em 1978/79 desapareceram em 1994, restando o sexo do RN, o hábito de fumar e a prematuridade nos dois períodos. Como houve diminuição do tabagismo materno e não houve modificação na proporção de nascimentos do sexo feminino, uma explicação para o aumento do PI seria o aumento nos nascimentos pré-termo entre as duas coortes.

Asthma definitions, relative validity and impact on known risk factors in young Brazilians

BACKGROUND

An asthma score was proposed in the European Community Respiratory Health Survey (ECRHS) framework, as dichotomous definitions could be less appropriate in the study of chronic diseases. The aims of this study were to assess the value of this asthma score in comparison with other definitions of asthma in another population setting, using as criteria bronchial hyperresponsiveness (BHR) to methacholine and diagnosed asthma, and the association of these definitions to known risk factors of asthma.

METHODS

We used the ECRHS questionnaire on 2063 Brazilians, aged 23-25 years, and measured their BHR. We assessed the positive and negative likelihood ratios (PLR and NLR) of the asthma score (0-8), a three question score (ECRHS definition) and single asthma symptoms in relation to BHR and diagnosed asthma.

RESULTS

The PLR were relatively low for all asthma definitions with odd ratios varying from 1.47 for asthma score to 5.50 for wheeze and waking with breathlessness without a cold. The NLR were near 1. The PLR were lower for assessments using the score than for dichotomous assessments or the ECRHS definition. The PLR increased with asthma scores, but the prevalence with higher scores was too low for useful analysis. The asthma score was slightly better for identifying associations from a set of known risk factors than the other two approaches.

CONCLUSION

Our study provided little support for a greater validity of this asthma score over other asthma definitions, and only marginal advantage for identifying risk factors.

Are birth weight and maternal smoking during pregnancy associated with malnutrition and excess weight among school age children?

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5 > or = BMI<P85 to be thin and normal, and children with BMI > or = P85 to be overweight. We evaluated the association of these nutritional disorders with birth factors (infant weight, sex, preterm delivery, number of pregnancies, maternal smoking during pregnancy, marital status, and schooling) and type of school using nominal logistic regression. A total of 2797 schoolchildren were evaluated. There was a significant prevalence of malnutrition (9.5%) and excess weight already tended to increase (15.7%), while 6.4% of the children were obese. Excess weight was more prevalent among children attending private schools (odds ratio, OR = 2.27) and firstborn children (OR = 1.69). Maternal smoking during pregnancy protected against malnutrition (OR = 0.56), while children with lower birth weight were at higher risk for malnutrition (OR = 4.23). We conclude that a nutritional transition was under way while malnutrition was still present, but excess weight and related factors were already emerging.

Food consumption by young adults living in Ribeirão Preto, SP, 2002/2004

There is evidence showing a close relationship between diet and the occurrence of non-communicable chronic diseases. The present study assessed food consumption in a 2002/2004 cohort of young adults born in 1978/79 in Ribeirão Preto, SP, Brazil. The composition of the habitual diet consumed by a sample of 2063 individuals aged 23-25 years was analyzed using a validated semi-quantitative food frequency questionnaire based on studies of prevention of non-communicable chronic diseases. The Dietsys software was used for dietary calculations. In terms of WHO/2003 recommendations, there was a high mean daily consumption of energy from fat (consumption: 35.4%; recommendation: 15-30%), a low mean intake of energy from carbohydrates (47.5%; 55-75%) and a low mean consumption of total fibers (15.2 g; >25 g). Mean intake of energy from fatty acids (10%; <10%) and protein (15.6%; 10-15%) was within recommended limits. When compared to the recommendations of the food pyramid adapted to the Brazilian population, adequate intake was observed only regarding the meat group (consumption: 1.9 portions; recommended: 1-2). There was a low consumption of vegetables (2.9; 4-5), fruits (1.2; 3-5), breads (3.6; 6-9), and dairy products (1.7; 3), with excessive fat and sugar intake (5.7; 1-2). We conclude that the inadequate food consumption observed in this young population may be associated with the development of excess weight and may contribute to the triggering of non-communicable chronic diseases.

Do socioeconomic factors explain why maternal smoking during pregnancy is more frequent in a more developed city of Brazil?

The prevalence of smoking during pregnancy in Ribeirão Preto, a rich Brazilian city, was significantly higher (21.4%) than in São Luís (5.9%), a less developed city. To assess which variables explain the difference in prevalence of smoking during pregnancy, data from two birth cohorts were used, including 2846 puerperae from Ribeirão Preto, in 1994, and 2443 puerperae from São Luís, in 1997/98. In multivariable analysis, risk of maternal smoking during pregnancy was higher in São Luís for mothers living in a household with five or more persons (OR = 1.72, 95%CI = 1.12-2.64), aged 35 years or older (OR = 1.98, 95%CI = 0.99-3.96), who had five or more children (OR = 2.10, 95%CI = 1.16-3.81), and whose companion smoked (OR = 2.20, 95%CI = 1.52-3.18). Age of less than 20 years was a protective factor (OR = 0.55, 95%CI = 0.33-0.92). In Ribeirão Preto there was association with maternal low educational level (OR = 2.18, 95%CI = 1.30-3.65) and with a smoking companion (OR = 3.25, 95%CI = 2.52-4.18). Receiving prenatal care was a protective factor (OR = 0.24, 95%CI = 0.11-0.49). Mothers from Ribeirão Preto who worked outside the home were at a higher risk and those aged 35 years or older or who attended five or more prenatal care visits were at lower risk of smoking during pregnancy as compared to mothers from São Luís. Smoking by the companion reduced the difference between smoking rates in the two cities by 10%. The socioeconomic variables in the model did not explain the higher prevalence of smoking during pregnancy in the more developed city.

Why are the rates of cesarean section in Brazil higher in more developed cities than in less developed ones?

The objective of the present study was to investigate factors associated with cesarean sections in two cities located in different regions of Brazil and to determine factors that explain the higher cesarean section rate in the more developed city, Ribeirão Preto, compared to the less developed one, São Luís. Data from two cohort studies comprising 2846 women in Ribeirão Preto in 1994, and 2443 women in São Luís in 1997/1998 were used. Adjusted and non-adjusted risk estimates were calculated using a Poisson regression model. The cesarean section rate was 33.7% in São Luís and 50.8% in Ribeirão Preto. Adjusted analysis in a joint sequential model revealed a 51% higher risk of cesarean section in Ribeirão Preto compared to São Luís (prevalence rate ratio (PRR) = 1.51). Adjustment for category of hospital admission reduced the PRR to 1.09, i.e., this variable explained 82% of the difference in the cesarean section rate between the two cities. Adjustment for the variable "the same physician for prenatal care and delivery" reduced the PRR to 1.07, with the "physician" factor explaining 86% of the difference between rates. When simultaneously adjusted for the two variables, the PRR decreased to 1.05, with these two variables explaining 90% of the difference in the cesarean section rate between the two cities, and the difference was no longer significant. The difference in the cesarean section rate between the two Brazilian cities, one more and one less developed, was mainly explained by the physician factor and, to a lesser extent, by the category of hospital admission.

Racial inequalities and perinatal health in the southeast region of Brazil

Few studies are available about racial inequalities in perinatal health in Brazil and little is known about whether the existing inequality is due to socioeconomic factors or to racial discrimination per se. Data regarding the Ribeirão Preto birth cohort, Brazil, whose mothers were interviewed from June 1, 1978 to May 31, 1979 were used to answer these questions. The perinatal factors were obtained from the birth questionnaire and the ethnic data were obtained from 2063 participants asked about self-reported skin color at early adulthood (23-25 years of age) in 2002/2004. Mothers of mulatto and black children had higher rates of low schooling (< or = 4 years, 27.2 and 38.0%) and lower family income (< or = 1 minimum wage, 28.6 and 30.4%). Mothers aged less than 20 years old predominated among mulattos (17.0%) and blacks (14.0%). Higher rates of low birth weight and smoking during pregnancy were observed among mulatto individuals (9.6 and 28.8%). Preterm birth rate was higher among mulattos (9.5%) and blacks (9.7%) than whites (5.5%). White individuals had higher rates of cesarean delivery (34.9%). Skin color remained as an independent risk factor for low birth weight (P < 0.001), preterm birth (P = 0.01), small for gestational age (P = 0.01), and lack of prenatal care (P = 0.02) after adjustment for family income and maternal schooling, suggesting that the racial inequalities regarding these indicators are explained by the socioeconomic disadvantage experienced by mulattos and blacks but are also influenced by other factors, possibly by racial discrimination and/or genetics.

Do intrauterine growth restriction and overweight at primary school age increase the risk of elevated body mass index in young adults?

Obesity is one of the rising public health problems characterized as a risk factor for many chronic diseases in adulthood. Early life events such as intrauterine growth restriction, as well as life style, are associated with an increased prevalence of this disease. The present study was performed to determine if intrauterine growth restriction interacts with overweight at primary school age to affect body mass index (BMI) in young adults. From June 1, 1978 to May 31, 1979, 6827 singleton liveborns from Ribeirão Preto, São Paulo State, Brazil, corresponding to 98% of all births at the 8 maternity hospitals, were examined and their mothers were interviewed. Samples from the initial cohort were examined again at primary school age (8 to 11 years of age) and at the time of military service (18 years of age). There were 519 male individuals with complete measurements taken in the three surveys. Intrauterine growth-restricted individuals had a BMI 0.68 kg/m(2) lower than that of individuals who were not restricted (95%CI = -1.34 to -0.03) and overweight at primary school age showed a positive and strong effect on BMI at 18 years of age (coefficient 5.03, 95%CI = 4.27 to 5.79). However, the increase in BMI was much higher--6.90 kg/m(2)--when the conscript had been born with intrauterine growth restriction and presented overweight at primary school age (95%CI = 4.55 to 9.26). These findings indicate that the effect of intrauterine growth restriction on BMI at 18 years of age is modified by later weight gain during school age.

Social inequality and perinatal health: comparison of three Brazilian cohorts

The objective of the present study was to estimate and compare social inequality in terms of three indicators, i.e., low birth weight (LBW), preterm birth (PTB) and small for gestational age (SGA) birth, in three birth cohorts. Two cohorts were from the city of Ribeirão Preto, where data were collected for all 6748 live born singletons in 1978/79 and for one third of live born singletons (2846) in 1994. The third cohort consisted of 2443 singletons born in São Luís over a period of one year (1997/98). In Ribeirão Preto, LBW and PTB rates increased in all social strata from 1978/79 to 1994. Social inequalities regarding LBW and PTB disappeared since the increase in these rates was more accelerated in the groups with higher educational level. The percentage of SGA infants increased over the study period. Social inequality regarding SGA birth increased due to a more intense increase in SGA births in the strata with lower schooling. In São Luís, in 1997/98 there was no social inequality in LBW or PTB rates, whereas SGA birth rate was higher in mothers with less schooling. We speculate that the more accelerated increase in medical intervention, especially due to the increase in cesarean sections in the more privileged groups, could be the main factor explaining the unexpected increase in LBW and PTB rates in Ribeirão Preto and the decrease or disappearance of social inequality regarding these perinatal indicators in the two cities.

Early life, current socioeconomic position and serum lipids in young adulthood of participants in a cohort study initiated in 1978/1979

The association between socioeconomic position (SEP) and serum lipids has been little studied and the results have been controversial. A total of 2063 young adults born in 1978/79 were evaluated at 23-25 years of age in the fourth follow-up of a cohort study carried out in Ribeirão Preto, SP, Brazil, corresponding to 31.8% of the original sample. Total serum cholesterol (TC), triglycerides, high-density cholesterol (HDL cholesterol) and low-density cholesterol (LDL cholesterol) were analyzed according to SEP at birth and during young adulthood. SEP was classified into tertiles of family income and a cumulative score of socioeconomic disadvantage was created. TC was 11.85 mg/100 mL lower among men of lower SEP in childhood (P < 0.01) but no difference was found in women, whereas it was 8.46 lower among men (P < 0.01) and 8.21 lower among women of lower SEP in adulthood (P < 0.05). Individuals of lower SEP had lower LDL and HDL cholesterol, with small differences between sexes and between the two times in life. There was no association between SEP and triglyceride levels. After adjustment of income at one time point in relation to the other, some associations lost significance. The greater the socioeconomic disadvantage accumulated along life, the lower the levels of TC, LDL and HDL cholesterol (P < 0.05). The socioeconomic gradient of TC and LDL cholesterol was inverse, representing a lower cardiovascular risk for individuals of lower SEP, while the socioeconomic gradient of HDL cholesterol indicated a lower cardiovascular risk for individuals of higher SEP.

Profile of three Brazilian birth cohort studies in Ribeirão Preto, SP and São Luís, MA

We describe three birth cohort studies, respectively carried out in 1978/79 and 1994 in Ribeirão Preto, a city located in the most developed region of Brazil, and in 1997/98 in São Luís, a city located in a less developed region. The objective of the present report was to describe the methods used in these three studies, presenting their history, methodological design, objectives, developments, and difficulties faced along 28 years of research. The first Ribeirão Preto study, initially perinatal, later encompassed questions regarding the repercussions of intrauterine development on future growth and chronic adult diseases. The subjects were evaluated at birth (N = 6827), at school age (N = 2861), at the time of recruitment for military service (N = 2048), and at 23/25 years of age (N = 2063). The study of the second cohort, which started in 1994 (N = 2846), permitted comparison of aspects of perinatal health between the two groups in the same region, such as birth weight, mortality and health care use. In 1997/98, a new birth cohort study was started in São Luís (N = 2443), capital of the State of Maranhão. The 1994 Ribeirão Preto cohort and the São Luís cohort are in the second phase of joint follow-up. These studies permit comparative temporal analyses in the same place (Ribeirão Preto 1978/79 and 1994) and comparisons of two contrasting populations regarding cultural, economic and sociodemographic conditions (Ribeirão Preto and São Luís).

Factors associated with infant and adolescent mortality

Few studies have described factors associated with infant and adolescent mortality since birth. We report here mortality during a 20-year period in a birth cohort from Ribeirão Preto in order to identify birth variables that influenced mortality among infants and children between 10 and 19 years of age, the main causes of death, and the influence of social inequality at birth on death. Mothers were interviewed shortly after delivery. Social, biological and demographic information was collected, and mortality up to 19 years of age was investigated in registry systems. Of the 6748 liveborn singletons born in the municipality from 1978 to 1979, 343 died before or when 19 years of age were completed. Most of the cohort mortality (74.9%) occurred during the first year of life and 19.6% occurred from 10 to 19 years. Mortality was higher among boys. Preterm birth (hazard ratio, HR = 7.94) and low birth weight (HR = 10.15) were strongly associated with infant mortality. Other risk factors for infant mortality were: maternal age (3)35 years (HR = 1.74), unskilled manual occupation of family head (HR = 2.47), and for adolescent mortality: unskilled manual occupation of family head (HR = 9.98) and male sex (HR = 6.58). "Perinatal conditions" were the main causes of deaths among infants and "external causes" among adolescents, especially boys. Socioeconomic factors at birth, represented by occupation, influenced adolescent mortality due to external causes, which was higher among boys (7:1). The influence of social inequality at birth on death, measured by occupation, was greater in adolescence than in infancy.

Do early life factors influence body mass index in adolescents?

The association between early life factors and body mass index (BMI) in adulthood has been demonstrated in developed countries. The aim of the present study was to assess the influence of early life factors (birth weight, gestational age, maternal smoking, and social class) on BMI in young adulthood with adjustment for adult socioeconomic position. A cohort study was carried out in 1978/79 with 6827 mother-child pairs from Ribeirão Preto city, located in the most developed economic area of the country. Biological, economic and social variables and newborn anthropometric measurements were obtained shortly after delivery. In 1996, 1189 males from this cohort, 34.3% of the original male population, were submitted to anthropometric measurements and were asked about their current schooling on the occasion of army recruitment. A multiple linear regression model was applied to determine variables associated with BMI. Mean BMI was 22.7 (95%CI = 22.5-23.0). After adjustment, BMI was 1.22 kg/m(2) higher among infants born with high birth weight ( > or = 4000 g), 1.21 kg/m(2) higher among individuals of low social class at birth and 0.69 kg/m(2) higher among individuals whose mothers smoked during pregnancy (P < 0.05). The association between social class at birth and BMI remained statistically significant (P < 0.05) even after adjustment for adult schooling. These findings suggest that early life social influences on BMI were more important and were not reversed by late socioeconomic position. Therefore, prevention of overweight and obesity should focus not only on changes in adult life styles but also on factors such as high birth weight.

Inadequate utilization of prenatal care in two Brazilian birth cohorts

Data for two birth cohorts from two Brazilian municipalities, Ribeirão Preto in 1994 and São Luís in 1997/1998, were used to identify and compare factors associated with inadequate utilization of prenatal care and to identify factors capable of explaining the differences observed between the two cities. Prenatal care was defined as adequate or inadequate according to the recommendations of the Brazilian Ministry of Health. The chi-square test and Poisson regression were used to compare differences in the inadequacy of prenatal care utilization. The percentage of inadequacy was higher in São Luís (34.6%) than in Ribeirão Preto (16.9%). Practically the same variables were associated with inadequacy in both cities. Puerperae with lower educational level, without a companion or cohabiting, who delivered in public health units, younger than 20 years, multiparae and smokers, with low family income presented higher percentages of inadequate prenatal care utilization. However, the effects of some variables differed between the two cities. The risk for inadequate use of prenatal care was higher for women attended in the public health sector in São Luís and for cohabiting women in Ribeirão Preto. The effect of the remaining factors studied did not differ between cities. The category of admission accounted for 57.0% of the difference in the inadequate use of prenatal care between cities and marital status accounted for 45.3% of the difference. Even after adjustment for all variables, part of the difference in the inadequacy of prenatal care utilization remained unexplained.

Health in early adulthood: the contribution of the 1978/79 Ribeirão Preto birth cohort

The increase in non-communicable chronic diseases of adults is due to demographic changes and changes in the risk factors related to physical activity, smoking habits and nutrition. We describe the methodology for the evaluation of persons at 23/25 years of age of a cohort of individuals born in Ribeirão Preto in 1978/79. We present their socioeconomic characteristics and the profile of some risk factors for chronic diseases. A total of 2063 participants were evaluated by means of blood collection, standardized questionnaires, anthropometric and blood pressure measurements, and methacholine bronchoprovocation tests. The sexes were compared by the chi-square test, with alpha = 0.05. Obesity was similar among men and women (12.8 and 11.1%); overweight was almost double in men (30.3 vs 17.7%). Weight deficit was higher among women than among men (8.6 and 2.6%). Women were more sedentary and consumed less alcohol and tobacco. Dietary fat consumption was similar between sexes, with 63% consuming large amounts (30 to 39.9 g/day). Metabolic syndrome was twice more frequent among men than women (10.7 vs 4.8%), hypertension was six times more frequent (40.9 vs 6.4%); altered triglyceride (16.1 vs 9.8%) and LDL proportions (5.4 vs 2.7%) were also higher in men, while women had a higher percentage of low HDL (44.7 vs 39.5%). Asthma and bronchial hyper-responsiveness were 1.7 and 1.5 times more frequent, respectively, among women. The high prevalence of some risk factors for chronic diseases among young adults supports the need for investments in their prevention.

Does child labour affect final height?

BACKGROUND

Although the negative effects of child labour on health are well known, the impact of child labour on final height is still controversial.

AIMS

To assess the effect of child labour on the final height of young adults.

METHODS

The study included 2063 adults aged 23-25 years from a cohort study of all live births (6827) in Ribeirão Preto, Brazil (1978-79). Height was measured in centimetres. Information on work, physical activity and smoking was obtained retrospectively and the other variables were obtained at cohort baseline. Work was classified according to age at first job: <14 (child labour), 14-16 and >or=17 years. Analyses were performed separately for males and females. Multiple linear regression analysis followed bivariate and stratified analysis.

RESULTS

The average height for males and females were respectively 176.0 cm [95% confidence interval (CI) 175.6-176.4] and 162.7 cm (95% CI 162.3-163.0). Labour before the age of 14 years was performed by 20% of males and 12% of females. In the bivariate analysis, child labour was statistically associated with final height for both males (P < 0.01) and females (P < 0.01). However, the association was not maintained after adjusting for confounders.

CONCLUSION

We were not able to demonstrate significant height differences between those previously employed or not employed as a child, other than differences explained by other social and biological factors.

Which factors could explain the low birth weight paradox?

OBJECTIVE: Low birth weight children are unusual among well-off families. However, in Brazil, low birth weight rate was higher in a more developed city than in a less developed one. The study objective was to find out the reasons to explain this paradox. METHODS: A study was carried out in two municipalities, Ribeirão Preto (Southeastern Brazil) and São Luís (Northeastern Brazil), which low birth weight rates were 10.7% and 7.6% respectively. Data from two birth cohorts were analyzed: 2,839 newborns in Ribeirão Preto in 1994 and 2,439 births in São Luís in 1997-1998. Multiple logistic regression analysis was performed, adjusted for confounders. RESULTS: Low birth weight risk factors in São Luís were primiparity, maternal smoking and maternal age less than 18 years. In Ribeirão Preto, the associated variables were family income between one and three minimum wages, maternal age less than 18 and equal to or more than 35 years, maternal smoking and cesarean section. In a combined model including both cohorts, Ribeirão Preto presented a 45% higher risk of low birth weight than São Luís. When adjusted for maternal smoking habit, the excess risk for low birth weight in Ribeirão Preto compared to São Luís was reduced by 49%, but the confidence interval was marginally significant. Differences in cesarean section rates between both cities contributed to partially explain the paradox. CONCLUSIONS: Maternal smoking was the most important risk factor for explaining the difference in low birth weight between both cities. The other factors contributed little to explain the difference in low birth weight rates.

Prevalence and risk factors for work related asthma in young adults

OBJECTIVES

To investigate the prevalence and predictors of work related asthma in young adults from the general population.

METHODS

A total of 1922 subjects randomly selected from a birth cohort 1978/79 in Brazil, aged 23-25 years, completed a respiratory symptoms questionnaire based on the European Community Respiratory Health Survey, and underwent spirometry, bronchial challenge test with methacholine, and skin prick test. For subjects presenting with bronchial hyperresponsiveness, workplace exposure and its relationship with symptoms were assessed by a specific questionnaire and individualised job description to define cases of work related asthma.

RESULTS

The prevalence of work related asthma was 4.2% (81 cases): 1.5% (29 cases) were classified as aggravated asthma and 2.7% (52 cases) as occupational asthma. Work related asthma was associated with atopy and education. Lower educational level (1-8 years of schooling) was associated with work related asthma (odds ratio 7.06, 95% CI 3.25 to 15.33). There was no association between work related asthma and smoking, gender, or symptoms of rhinitis.

CONCLUSION

The prevalence of work related asthma was high (4.2%), and was associated with low schooling, probably because of low socioeconomic level. The disease may therefore be a consequence of poverty.

Role of Rab5 in insulin receptor-mediated endocytosis and signaling

Activated insulin receptors recruit various intracellular proteins leading to signal generation and endocytic trafficking. Although activated receptors are rapidly internalized into the endocytic compartment and subsequently degraded in lysosomes, the linkage between insulin receptor signaling and endocytosis is not well understood. This study utilizes both overexpression and depletion of Rab5 proteins to show that they play a critical role in both insulin-stimulated fluid phase and receptor-mediated endocytosis. Specifically, Rab5:WT and Rab5:Q79L (a GTP-hydrolysis defective mutant) enhance both types of endocytosis in response to insulin, while Rab5:S34N (a GTP-binding defective mutant) has the opposite effect. Morphological analysis indicates that both Rab5 and insulin receptor are found on early endosomes, but not at the plasma membrane. In addition, expression of Rab5:WT and Rab5:Q79L enhance both Erk1/2 and Akt activation without affecting JN- and p38-kinase activities, while the expression of Rab5:S34N blocks both Erk1/2 and Akt activation. Consistent with these observations, DNA synthesis is also altered by the expression of Rab5:S34N. Taken together, these results demonstrate that Rab5 is required for insulin receptor membrane trafficking and signaling.