RESUMO
OBJECTIVE: To study the relationships between nontraditional cardiovascular (CV) risk factors and components of the metabolic syndrome in Native Canadian children, a population at risk of future CV disease. STUDY DESIGN: CV risk factors were evaluated in a population-based study of a Canadian Oji-Cree community, involving 236 children aged 10 to 19 years. RESULTS: Using an age- and sex-specific case definition, 18.6% of the children met criteria for pediatric metabolic syndrome. As the number of metabolic syndrome component criteria increased, C-reactive protein, leptin, and ratio of apolipoprotein B to apolipoprotein A1 levels rose (all P < .0001) and adiponectin concentration decreased (P = .0006). Principal factor analysis using both traditional and nontraditional CV risk factors revealed 5 underlying core traits, defined as follows: adiposity, lipids/adiponectin, inflammation, blood pressure, and glucose. CONCLUSIONS: Nontraditional CV risk factors accompany the accrual of traditional risk factors early in the progression to pediatric metabolic syndrome. Furthermore, inclusion of these factors in factor analysis suggests that 5 core traits underlie the early development of an enhanced CV risk factor profile in Native children.
Assuntos
Doenças Cardiovasculares/sangue , Síndrome Metabólica/sangue , Adiponectina/sangue , Adolescente , Adulto , Apolipoproteína A-I/sangue , Glicemia/análise , Pressão Sanguínea , Constituição Corporal , Proteína C-Reativa/análise , Canadá/epidemiologia , Doenças Cardiovasculares/etiologia , Criança , HDL-Colesterol/sangue , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Análise Fatorial , Jejum , Feminino , Humanos , Interleucina-6/sangue , Leptina/sangue , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Fatores de Risco , Proteína Amiloide A Sérica/análise , Fatores Sexuais , Triglicerídeos/sangueRESUMO
Exercise is frequently recommended in the treatment of diabetes mellitus. Recent studies have improved our understanding of the acute and long-term metabolic and hormonal effects of physical activity in both healthy controls and in people with diabetes. In insulin dependent diabetes mellitus (IDDM), exercise by itself does not have a significant effect on overall glycaemic control and should be encouraged primarily for its nonglycaemic benefits. Hyperglycaemia is the predominant risk associated with exercise in individuals in IDDM and can be reduced by adjusting the insulin and diet prescription in response to information obtained from frequent self-monitoring of blood glucose. In contrast, in non-insulin dependent diabetes mellitus (NIDDM), exercise improves one of the most prominent basic pathophysiologic features of this condition, namely, insulin resistance and, as a consequence, is an important component of management along with diet and/or drug therapy. In addition to the positive effects on overall glycaemic control, exercise in NIDDM also results in non-glycaemic benefits in these patients. The subgroup of NIDDM individuals who have mild moderately impaired glucose tolerance appears most likely to benefit from exercise. However, because people with NIDDM frequently have other concurrent medical conditions, the adverse effects of exercise, particularly in relation to cardiac risks, must be monitored. In both IDDM and NIDDM, appropriate medical screening and patient education before starting on an exercise programme are mandatory to achieve the best quality of life. It is an important component of the management of diabetes, but its role in the therapy for NIDDM and IDDM is clearly distinct. Since exercise programmes have not been shown to have a significant independent beneficial effect on glycaemic control in IDDM subjects, the emphasis must be on developing strategies to allow safe participation in exercise consistent with their lifestyles. Exercise is encouraged in IDDM for its importantly nonglycaemic benefits. Individuals with IDDM should be appropriately screened and educated before starting and exercise have to be individualized, general guidelines regarding frequency of self monitoring of blood glucose, nutrient adjustment, insulin dose regimen modification, and the choice of injection site are appropriate. The majority of diabetic patients have NIDDM.(AU)
Assuntos
Humanos , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Exercício FísicoRESUMO
The transition from the resting state to the exercising state is mediated by several important physiological responses designed primarily to meet the increased energy demands on the muscles. These responses involve the cardiovascular, respiratory, central nervous and endocrine systems, and have been reviewed in detail by other authors. For comparative purposes, we will summarize the metabolic and hormonal changes in this paper. In the resting state, the principal metabolic energy source for skeletal muscle results from oxidation of free fatty acid (FFA). With the initiation of exercise, carbohydrate sources become more prominent as important energy fuels. Plasma glucose remains within a remarkably narrow range when exercise is performed at a low to moderate intensity, 1.e., 30 percent VO (2max). This is achieved by a synchronous matching of glucose production with glucose utilization in concert with mobilization of other energy sources. In the first few seconds to minutes of exercise, when increased oxygen transport from the circulation is just beginning, the anaerobic breakdown of muscle glycogen t form lactate provides an immediate source of high energy phosphate compounds necessary for the contractile process. However, as one might anticipate, muscle glycogen provides a limited energy source and, with continued exercise, blood-borne fuels from liver and the adipose organ must be utilized. The principal blood-borne oxidative fuels for contracting muscles are glucose from the liver and free fatty acids from adipose tissue, while the contribution of amino acids and ketone bodies to energy balance is relatively insignificant. The pattern of fuel utilization and the metabolic response to exercise is determined by several variables including the duration and intensity of exercise, the degree of cardiovascular fitness, and the nutritional hormonal status. The contribution of carbohydrate as the primary energy source for muscle contraction increases as the intensity of exercise increases. However, with increasing duration of exercise, free fatty acids are preferentially utilized as an energy-providing substrate. Exercise training results in an increased ability to utilize blood-borne glucose and, to a greater extent, free fatty acid as an energy source for increasing workloads, sparing muscle glycogen (AU)