A associação entre a adiposidade corporal e a aptidão musculoesquelética em meninos é mediada pelo nível econômico? Does socioeconomic status mediate the association between adiposity and musculoskeletal fitness in boys?

1 Resumo - Objetivou-se estimar a prevalencia de adiposidade corporal elevada e sua associacao com a aptidao musculoesqueletica, por nivel economico, em criancas e adolescentes do sexo masculino. Estudo epidemiologico transversal realizado em 1.531 escolares (6-17 anos) da rede de ensino publica do municipio de Cascavel, PR, Brasil. A adiposidade corporal foi estimada pela tecnica de dobras cutâneas. Foram coletadas informacoes referentes a idade, nivel economico e estagio maturacional, bem como ao desempenho nos testes de sentar e alcancar, abdominal em 1 minuto, impulsao horizontal e Shuttle run. As analises (teste t de student nao pareado e regressao de Poisson) foram realizadas por nivel economico alto e baixo (baixo+medio), com nivel de significância de 5%. A prevalencia de adiposidade corporal elevada foi de 30,4%, sendo maior (p<0,05) naqueles de nivel economico alto (33,3% vs 28,3%). Apos ajuste para todas as variaveis, no nivel economico baixo, a adiposidade corporal elevada se associou a baixa resistencia abdominal (RP=1,44; IC95%=1,05-1,99) e potencia de membros inferiores (RP=2,09; IC95%=1,46-1,98). No nivel economico alto, o desfecho foi associado a baixa resistencia abdominal (RP=1,72; IC95%=1,17-2,51) e, a media (RP=2,83; IC95%=1,76-4,55) e baixa (RP=3,90; IC95%=2,38-6,38) potencia de membros inferiores. Em ambos os estratos sociais, o menor desempenho muscular (resistencia abdominal e potencia de membros inferiores) conferiu maior probabilidade de ter adiposidade corporal elevada. Porem, a magnitude das valencias musculares associadas a adiposidade corporal elevada parece diferir de acordo com o nivel economico. Palavras-chave: Adolescente; Crianca; Forca muscular; Obesidade. Abstract - We aimed to estimate the prevalence of high body adiposity and its association with musculoskeletal fitness in male children and adolescents according to socioeconomic status. A cross-sectional epidemiological study was carried out with 1,531 school children (6- 17 years old) attending public schools in Cascavel, state of Parana, Brazil. Body adiposity was estimated based on skinfold thickness. Information was also collected on chronological age, socioeconomic status, sexual maturation, performance in physical tests such as sit and reach, 1-minute sit-up, stationary long jump and Shuttle run. Statistical analyses were performed (Student's unpaired t test and Poisson regression) taking into consideration socioeconomic status (high and low+middle), with p<0.05. High body adiposity was observed in 30.4% of the sample, and was greater (p<0.05) among those of high socioeconomic status (33.3% vs 28.3%). After adjustment for all variables, high body adiposity was associated with low abdominal resistance (PR=1.44; CI95%=1.05-1.99) and lower limb power (PR=2.09; CI95%=1.46- 1.98) in the low socioeconomic status group. In the high socioeconomic status group, the outcome was associated with low abdominal resistance (PR=1.72; CI95%=1.17-2.51) and with intermediate (PR=2.83; CI95%=1.76-4.55) and low (PR=3.90; CI95%=2.38-6.38) lower limb power. In both socioeconomic levels, lower musculoskeletal fitness (abdominal resistance and lower limb power) was associated with high body adiposity. However, the magnitude of the association between muscular capacity and high body adiposity seems to differ according to socioeconomic status.