RESUMO
BACKGROUND AND AIMS: Although studies have shown association of birth weight (BW) and adult body mass index (BMI) with insulin sensitivity in adults, there is limited evidence that BW is associated with insulin secretion. We assessed the associations between BW and current BMI with insulin sensitivity and secretion in young Latin American adults. METHODS AND RESULTS: Two birth cohorts, one from Ribeirao Preto, Brazil, based on 1984 participants aged 23-25 years, and another from Limache, Chile, based on 965 participants aged 22-28 years were studied. Weight and height at birth, and current fasting plasma glucose and insulin levels were measured. Insulin sensitivity (HOMA%S) and secretion (HOMA%ß) were estimated using the Homeostatic Model Assessment (HOMA2). Multiple linear regression analyses were carried out to test the associations between BW and adult BMI z-scores on log HOMA%S and log HOMA%ß. BW z-score was associated with HOMA%S in the two populations and HOMA%ß in Ribeirao Preto when adult BMI z-score was included in the model. BW z-score was associated with decreasing insulin secretion even without adjusting for adult BMI, but only in Ribeirao Preto. BMI z-score was associated with low HOMA%S and high HOMA%ß. No interactions between BW and BMI z-scores on insulin sensitivity were shown. CONCLUSIONS: This study supports the finding that BW may affect insulin sensitivity and secretion in young adults. The effect size of BW on insulin status is small in comparison to current BMI.
Assuntos
Peso ao Nascer , Composição Corporal , Índice de Massa Corporal , Resistência à Insulina , Insulina/sangue , Insulina/metabolismo , Adulto , Glicemia/análise , Brasil/epidemiologia , Chile/epidemiologia , Estudos de Coortes , Jejum , Feminino , Seguimentos , Humanos , Secreção de Insulina , América Latina/epidemiologia , Masculino , Inquéritos e Questionários , Adulto JovemRESUMO
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.
Assuntos
Asma/etiologia , Hipersensibilidade Imediata/complicações , Hipersensibilidade Imediata/imunologia , Rinite Alérgica Perene/etiologia , Rinite Alérgica Sazonal/etiologia , Adulto , Alérgenos/imunologia , Alternaria/imunologia , Animais , Animais Domésticos/imunologia , Antígenos de Dermatophagoides/imunologia , Antígenos de Plantas/imunologia , Asma/epidemiologia , Brasil , Hiper-Reatividade Brônquica/epidemiologia , Hiper-Reatividade Brônquica/etiologia , Testes de Provocação Brônquica , Gatos , Chile , Conjuntivite Alérgica/epidemiologia , Conjuntivite Alérgica/etiologia , Estudos Transversais , Cães , Feminino , Humanos , Hipersensibilidade Imediata/epidemiologia , Masculino , Sons Respiratórios/etiologia , Rinite Alérgica Perene/epidemiologia , Rinite Alérgica Sazonal/epidemiologia , Testes Cutâneos , Adulto JovemRESUMO
OBJECTIVE: The study assessed the impact of body mass index (BMI) at birth, infancy, and adulthood, and waist circumference on lung function. METHODS: Using a longitudinal design 1221 Chilean young adults were studied. A standardized respiratory questionnaire was used. Forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), height, weight and waist circumference were measured. Data at birth and at 1 year were obtained from clinical notes. RESULTS: Males with a BMI > or = 30 and women with a BMI < 20 had a lower FEV(1) (-230 mL, 95% CI -363 to -98; -106 mL, 95% CI -211 to -0.18, respectively). In both sexes those with a BMI 20-25 had the highest FEV(1) and FVC. In males there was a negative association between waist circumference and FEV(1) and FVC while in women the middle tertile had the highest FEV(1) and FVC. There was an association between birthweight and BMI at birth, and FEV(1) in men, when unadjusted for other measurements. CONCLUSIONS: BMI and waist circumference in adulthood make a greater impact on lung function in adulthood than anthropometric measurements at birth and infancy. Proxy measures of fatness in adulthood reduce lung function, but the pattern between fatness and lung function by sex may be different.
Assuntos
Índice de Massa Corporal , Pulmão/fisiologia , Pulmão/fisiopatologia , Estado Nutricional , Gordura Abdominal , Adulto , Fatores Etários , Estatura , Feminino , Idade Gestacional , Humanos , Estudos Longitudinais , Masculino , Fluxo Máximo Médio Expiratório/fisiologia , Estado Nutricional/fisiologia , Sobrepeso/complicações , Gravidez , Transtornos Respiratórios/etiologia , Transtornos Respiratórios/fisiopatologia , Espirometria , Magreza , Capacidade Vital/fisiologia , Relação Cintura-Quadril/efeitos adversosRESUMO
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.
Assuntos
Asma/diagnóstico , Asma/epidemiologia , Inquéritos Epidemiológicos , Cloreto de Metacolina , Índice de Gravidade de Doença , Adulto , Asma/classificação , Brasil/epidemiologia , Hiper-Reatividade Brônquica/diagnóstico , Hiper-Reatividade Brônquica/epidemiologia , Estudos de Coortes , Estudos Transversais , Dispneia/diagnóstico , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Cloreto de Metacolina/efeitos adversos , Prevalência , Sons Respiratórios/diagnóstico , Fatores de Risco , Testes Cutâneos , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To assess the association between smoking and respiratory symptoms, lung function and bronchial hyperresponsiveness (BHR) in young adults in Chile. SETTING: Selected sample of 1232 subjects aged 22-28 years. DESIGN: In this cross-sectional study, the outcome measures were: respiratory symptoms, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% (FEF25-75), FEV1/FVC and BHR. RESULTS: Among the 1232 subjects, 67.7% of the men and 49.4% of the women were smokers; the median cigarettes smoked per day was four for men and three for women. Smoking was associated with wheezing, waking up with a cough, breathlessness following exercise and persistent cough, with odds ratios (OR) between 1.94 (95% CI 1.41-2.66) and 3.12 (95% CI 2.21-4.40) among those smoking > or = 5 cigarettes per day, compared to non-smokers. Smoking < 5 cigarettes was significantly associated with wheezing and waking up with a cough. Smokers had a lower FEV1/FVC than non-smokers by approximately 0.8%. Smoking was not associated with FEV1, FEF25-75 or BHR status. CONCLUSIONS: This study highlights the early effects of smoking on respiratory symptoms. It could help governments in Latin America take vigorous action to deter young people from starting smoking.
Assuntos
Testes de Função Respiratória , Fumar/fisiopatologia , Adulto , Chile , Estudos Transversais , Feminino , Humanos , MasculinoRESUMO
OBJECTIVE: To assess the prevalence of asthma symptoms and their association with sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine. SETTING: A random sample of 1232 adults, aged 22 to 28 years, studied in a Chilean semi-rural area. DESIGN: A cross-sectional design for the purpose of this analysis. RESULTS: The prevalence of wheeze was 27.4% (95%CI 24.9-29.9) and waking with breathlessness 13.7% (95%CI 11.8-15.6), higher than the results of a multi-centre European study. Only 7.8% (95%CI 6.3-9.3) had a positive BHR (< or =8 mg/ml) and 26.3% (95%CI 23.8-28.8) were atopic. The Youden index of asthma symptoms in non-atopic subjects varied from 0.184 to 0.259 when using BHR as gold standard for asthma, and increased from 0.379 to 0.504 among those with positive atopy. Only 4.5% reported asthma, and the Youden index was slightly higher in comparison to the asthma symptom groups. CONCLUSION: The prevalence of asthma symptoms in young adults was high, but only a small proportion of these were sensitised or had a positive BHR. We believe that aetiological studies of asthma should analyse subjects with asthma symptoms separately from those with positive atopic status or positive BHR.
Assuntos
Asma/epidemiologia , Hiper-Reatividade Brônquica/epidemiologia , Hipersensibilidade Imediata/epidemiologia , Adulto , Chile/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Prevalência , Saúde da População RuralRESUMO
BACKGROUND: There is uncertainty about the impact of the programming hypothesis in terms of nutritional status at birth, rate of growth in the first year of life, length of gestation, breast feeding, and episodes of illness on asthma. An analysis was therefore carried out to test this hypothesis. METHODS: Data were collected on 1232 children born between 1974 and 1978 in a semi-rural area of Chile. Measurements at birth and growth in the first year of life were obtained from a birth registry and clinical notes. Information on asthma was collected using the European Community Respiratory Health Survey questionnaire. Sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine were determined. All other information was obtained using a questionnaire. Polytomous logistic analyses were carried out to explore the association of factors at birth and during the first year of life with asthma symptoms, atopy, and BHR. RESULTS: Weight and length gain in the first year were positively associated with wheeze (odds ratio (OR) 1.004, 95% CI 1.001 to 1.007 and OR 1.11, 95% CI 0.98 to 1.25, respectively). A higher body mass index (BMI) at birth was protective in subjects reporting both wheeze and waking with breathlessness (OR 0.54, 95% CI 0.35 to 0.84). Length rate in tertiles divided by length at birth in tertiles was related to asthma symptoms (OR 1.68, 95% CI 1.19 to 2.37). Most other assessments were not associated with asthma. CONCLUSION: These results show promising but inconclusive evidence that a rapid rate of growth in length, especially in newborn infants of low length, might be involved in the aetiology of asthma.
Assuntos
Asma/fisiopatologia , Crescimento , Asma/epidemiologia , Estatura/fisiologia , Índice de Massa Corporal , Chile/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Razão de Chances , Estudos Prospectivos , Saúde da População RuralRESUMO
OBJECTIVE: An association between obesity and asthma symptoms has been reported in the literature, but such a relationship is inconsistent if atopic status or bronchial hyper responsiveness (BHR) is considered. The objective was to assess the association between obesity and asthma symptoms or BHR in adults. METHODS: A study was carried out in 1232 people born between 1974 and 1978 in Chile. The participants completed the European Community Health Survey questionnaire, were skin tested and subject to a BHR challenge to methacholine. MEASUREMENTS: Weight, height and waist circumference were measured and body mass index (BMI) was calculated. RESULTS: There was a positive association between wheeze and breathlessness following exercise and BMI (both with an OR 1.03, 95% CI 1.00-1.06), the associations with wheeze tended to disappear in women who did react at least to one allergen, and persisted in those who did not react to any allergens. BMI was negatively associated with BHR (OR 0.93, 95% CI 0.89-0.97). Waist circumference was not associated with asthma symptoms and it was negatively associated with BHR. CONCLUSION: Although there was an association between BMI and asthma symptoms, there were weaknesses in the evidence because waist circumference, a more direct measure of obesity than BMI, was not associated with asthma symptoms, and BMI and waist circumference were negatively associated with BHR.
Assuntos
Asma/etiologia , Obesidade/complicações , Adulto , Asma/imunologia , Hiper-Reatividade Brônquica , Causalidade , Chile , Estudos Transversais , Teste de Esforço , Feminino , Humanos , Modelos Logísticos , Masculino , Obesidade/imunologiaRESUMO
OBJECTIVE: To determine the level of agreement between the American (Chilean) and British food composition tables in estimating intakes of macronutrients and antioxidants. DESIGN, SETTING AND SUBJECTS: Information based on a food-frequency questionnaire with emphasis on antioxidants was collected from 95 Chileans aged 24-28 years. Nutritional composition was analysed using the British table of food composition and the American table of food composition modified by Chilean food items. Mean differences and limits of agreement (LOAs) of estimated intake were assessed. RESULTS: Mean differences between the two tables of food composition ranged from 5.3% to 8.9% higher estimates when using the American (Chilean) table for macronutrients. For micronutrients, a bias towards a higher mean was observed for vitamin E, iron and magnesium when the American (Chilean) table was used, but the opposite was observed for vitamin A and selenium. The intra-class correlation coefficient (ICC) ranged from 0.86 (95% confidence interval (CI) 0.81-0.91) to 0.998 (95% CI 0.995-1.00), indicating high to excellent agreement. LOAs for macronutrients and vitamins A and C were satisfactory, as they were sufficiently narrow. There was more uncertainty for other micronutrients. CONCLUSION: The American table gives relative overestimates of macronutrients in comparison to the British table, but the relative biases for micronutrients are inconsistent. Estimates of agreement between the two food composition tables provide reassurance that results are interchangeable for the majority of nutrients.