Objective The aim of this study was to analyze the effect of exercise on the pattern of muscle myostatin (MSTN) protein expression in two important metabolic disorders, i.e., obesity and diabetes mellitus. Materials and methods MSTN, is a negative regulator of skeletal muscle mass. We evaluated the effect of exercise on MSTN protein expression in diabetes mellitus and high fat diet-induced obesity. MSTN protein expression in gastrocnemius muscle was analyzed by Western Blot. P < 0.05 was assumed. Exercise induced a significant decrease in glycemia in both diabetic and obese animals. Results The expression of precursor and processed protein forms of MSTN and the weight of gastrocnemius muscle did not vary in sedentary or exercised obese animals. Diabetes reduced gastrocnemius muscle weight in sedentary animals. However, gastrocnemius muscle weight increased in diabetic exercised animals. Both the precursor and processed forms of muscle MSTN protein were significantly higher in sedentary diabetic rats than in control rats. The precursor form was significantly lower in diabetic exercised animals than in diabetic sedentary animals. However, the processed form did not change. Conclusion These results demonstrate that exercise can modulate the muscle expression of MSTN protein in diabetic rats and suggest that MSTN may be involved in energy homeostasis.

OBJETIVO: Estimar a prevalência de diabetes melito (DM) e tolerância à glicose diminuída (TGD) na população urbana de 30 a 79 anos da cidade de São Carlos, São Paulo. MÉTODOS: Foi realizado estudo de base populacional entre agosto de 2007 e junho de 2008. Todos os indivíduos, exceto mulheres grávidas, não diabéticos e aqueles com glicemia capilar em jejum < 199 mg/dl foram submetidos a teste oral de tolerância à glicose e classificados em diabéticos, com TGD ou com tolerância normal à glicose. RESULTADOS: Participaram da pesquisa 1.116 voluntários. As prevalências gerais de DM e TGD foram 13,5% e 5%, respectivamente. Houve associação entre DM e TGD e as variáveis "idade", "escolaridade", "índice de massa corpórea" e "circunferência abdominal". Não houve associação entre DM ou TGD e as variáveis "gênero", "cor da pele" e "rendimento mensal". CONCLUSÕES: Houve aumento na prevalência de DM em comparação a estudos anteriores no Brasil e na região. Embora tenha havido avanços no diagnóstico, o tratamento do DM requer otimização.

OBJECTIVE: To assess the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in the urban population aged 30-79 years of the city of São Carlos, São Paulo, Brazil. METHODS: It was performed a population survey, from August 2007 to June 2008. Non diabetic individuals, excluding pregnant women, and those with fasting capillary glycemia < 199 mg/dl were administered oral glucose tolerance test and classified as diabetic, with IGT or with normal glucose tolerance. RESULTS: The number of individuals who participated in the study was 1,116. The overall rates of DM and IGT were 13.5% and 5%, respectively. DM and IGT were associated with age, education, body mass index and waist. They were not associated with gender, race or income. CONCLUSIONS: The prevalence of DM has increased when compared with previous studies in Brazil and in the state. Improvement in the diagnosis has occurred, however, treatment requires optimization.