Abdominal obesity in adolescents: prevalence and association with physical activity and eating habits.

BACKGROUND: Abdominal obesity in adolescents is associated with cardiovascular and metabolic diseases, but its prevalence and the factors associated with its occurrence are unknown. OBJECTIVES: To determine the prevalence of abdominal obesity in adolescents, and to evaluate whether the indicators of physical activity and dietary habits are associated with the occurrence of abdominal obesity in adolescents. METHODS: The sample included 4138 high school students (14-19 years), selected by cluster sampling in two stages. We obtained data using the Global School-based Health Survey, and anthropometric measurements were taken for determination of overweight and abdominal obesity. Logistic regression was used for analysis of behavioral factors associated with the occurrence of abdominal obesity. The identification of cases of abdominal obesity was performed by waist circumference analysis, using age- and gender-related cutoff points as reference. RESULTS: The mean age was 16.8 years (s = 1.4), and 59.8% of subjects were female. The prevalence of abdominal obesity was 6% (95%CI: 5.3-6.7), and it was significantly higher among girls (6.7%, 95%CI: 5.8-7.8) than among boys (4.9%, 95%CI: 3, 9-6, 0). In the crude analysis, gender and overweight were associated with the occurrence of abdominal obesity. The analysis adjustment by logisic regression allowed us to observe that physical activity was significantly associated with the occurrence of obesity in this group (OR = 0.7; 95% CI: 0.49-0.99), regardless of the presence of overweight. CONCLUSIONS: The prevalence of abdominal obesity was low compared to that observed in international studies, and physical activity was a factor associated with the occurrence of this event in adolescents.

Obesidade abdominal em adolescentes: prevalência e associação com atividade física e hábitos alimentares / Abdominal obesity in adolescents: prevalence and association with physical activity and eating habits

FUNDAMENTO: A obesidade abdominal em adolescentes está associada a doenças cardiovasculares e metabólicas, mas a prevalência e os fatores associados à sua ocorrência são ignorados. OBJETIVOS: Determinar a prevalência e verificar se indicadores de atividade física e hábitos alimentares estão associados à ocorrência de obesidade abdominal em adolescentes. MÉTODOS: A amostra compreendeu 4.138 estudantes do ensino médio (14-19 anos), selecionados mediante amostragem por conglomerados em dois estágios. Obtiveram-se os dados por meio do Global School-based Health Survey, enquanto medidas antropométricas foram aferidas para determinação de excesso de peso e obesidade abdominal. Regressão logística binária foi empregada para análise dos fatores comportamentais associados à ocorrência de obesidade abdominal. Identificação dos casos de obesidade abdominal foi efetuada por análise da circunferência da cintura, tomando-se como referência pontos de corte para idade e sexo. RESULTADOS: A idade média foi de 16,8 anos (s =1,4), e 59,8 por cento dos sujeitos eram do sexo feminino; a prevalência de obesidade abdominal foi de 6 por cento (IC95 por cento:5,3-6,7), significativamente superior entre as moças (6,7 por cento; IC95 por cento: 5,8-7,8) em comparação aos rapazes (4,9 por cento; IC95 por cento:3,9-6,0). As análises brutas evidenciaram que sexo e excesso de peso são fatores associados à ocorrência de obesidade abdominal. O ajustamento das análises por regressão logística permitiu observar que a prática de atividades físicas está significativamente associada à ocorrência de obesidade abdominal nesse grupo (OR = 0,7; IC95 por cento:0,49-0,99), independentemente da presença de excesso de peso. CONCLUSÕES: A Prevalência de obesidade abdominal foi baixa em comparação ao observado em levantamentos internacionais, e a prática de atividades físicas é um fator associado à ocorrência desse evento em adolescentes.

BACKGROUND: Abdominal obesity in adolescents is associated with cardiovascular and metabolic diseases, but its prevalence and the factors associated with its occurrence are unknown. OBJECTIVES: To determine the prevalence of abdominal obesity in adolescents, and to evaluate whether the indicators of physical activity and dietary habits are associated with the occurrence of abdominal obesity in adolescents. METHODS: The sample included 4138 high school students (14-19 years), selected by cluster sampling in two stages. We obtained data using the Global School-based Health Survey, and anthropometric measurements were taken for determination of overweight and abdominal obesity. Logistic regression was used for analysis of behavioral factors associated with the occurrence of abdominal obesity. The identification of cases of abdominal obesity was performed by waist circumference analysis, using age- and gender-related cutoff points as reference. RESULTS: The mean age was 16.8 years (s = 1.4), and 59.8 percent of subjects were female. The prevalence of abdominal obesity was 6 percent (95 percentCI: 5.3-6.7), and it was significantly higher among girls (6.7 percent, 95 percentCI: 5.8-7.8) than among boys (4.9 percent, 95 percentCI: 3, 9-6, 0). In the crude analysis, gender and overweight were associated with the occurrence of abdominal obesity. The analysis adjustment by logisic regression allowed us to observe that physical activity was significantly associated with the occurrence of obesity in this group (OR = 0.7; 95 percent CI: 0.49-0.99), regardless of the presence of overweight. CONCLUSIONS: The prevalence of abdominal obesity was low compared to that observed in international studies, and physical activity was a factor associated with the occurrence of this event in adolescents.

Indicadores antropométricos de obesidade abdominal: revisão dos artigos indexados na biblioteca SciELO / Anthropometric indicators of abdominal obesity: review of the papers indexed on SciELO electronic library

Recorreu-se à revisão sistemática de artigos originais publicados no período de 1993 a 2007 e indexados na Scientific Electronic Library Online - SCIELO, a fim de identificar os indicadores antropométricos utilizados na detecção da obesidade abdominal em diferentes subgrupos populacionais e sintetizar os resultados observados quanto à relação entre estes indicadores e comorbidades associadas à obesidade. Na análise dos manuscritos, observou-se: ano de publicação; tamanho/faixa etária da amostra; indicador antropométrico empregado para detecção dos casos de obesidade abdominal; e, resultados principais. Foram localizados 47 artigos que atendiam aos critérios de inclusão, 34 dos quais publicados nos últimos cinco anos. A medida da relação cintura-quadril e da circunferência da cintura foram utilizadas como indicador de obesidade abdominal, respectivamente, em 34 e em 11 dos estudos. Na maioria, a amostra foi constituída por grupos heterogêneos em relação à idade (27), sendo que dez incluíam também adolescentes. Das investigações com amostras mais homogêneas em relação à faixa etária, quatro foram com idosos e três com crianças, mas nenhum com amostra exclusiva de adolescentes. Em 26 manuscritos, o tamanho da amostra foi superior a 500 sujeitos. Apesar de diferenças quanto à magnitude, de uma maneira geral, os estudos evidenciaram que os indicadores antropométricos de obesidade abdominal estão correlacionadosà ocorrência de hipertensão, diabetes, dislipidemias e risco coronariano elevado. Resultados desta revisão sugerem que a obesidade abdominal está associada à morbidade por doenças metabólicas, mas há escassez de estudos com crianças e adolescentes, fato que denota a necessidade de intensificação da investigação na área.

A systematic review of original articles published between 1993 and 2007 and indexed in SciELO (Scientific Electronic Library Online) was carried out to identify the anthropometric indicators used to assess abdominal obesity in different target subgroups, and to provide an overviewof available evidence regarding the relationship between these anthropometric indicators and obesity-associated comorbidities. The articles were analyzed and the following data were collected:year of publication, sample size and age, anthropometric measure used to detect abdominal obesity, and main results of the study. The review comprised 47 articles which met all inclusion criteria, most of them published over the last 5 years. Waist-hip ratio and waist circumference were used as indicators of abdominal obesity in 34 and 11 of the articles reviewed, respectively. With respect to age range, the samples were heterogeneous in most of the studies (n=27) and ten included adolescents. Four studies were conducted on elderly subjects and three included children, but none exclusively involved adolescents as the target population. The sample size was larger than 500 in 26 studies. Despite disagreement in terms of the degree of correlation, the studies generally showed that the anthropometric indicators of abdominal obesity were correlated with hypertension, diabetes, dyslipidemias, and coronary heart risk. The results of this review suggest that abdominal obesity is associated with metabolic diseases. However, there is a lack of studies involving the adolescent population, suggesting the need for further research in this area.