Creatine as an ergogenic supplement for athletes

Several researches on creatine have been done due to its potential effects on the physical performance of athletes involved in high intensity, short duration and intermittent exercises with short periods of recovery. Phosphorylated creatine is an energy reserve in the muscle cells. During an intense exercise, its breakdown liberates energy used to regenerate adenosine triphosphate. Approximately 95% of the creatine pool is found in the skeletal muscle, and the regenerating process after exercise is oxygen dependent. Studies show that supplementation with this compound may procedure an increase of 10% to 20% in the organic pool, and this percentage is higher in vegetarian athletes (up to 60%). There is still controversy regarding the benefits and risks of supplementation with this substance. This paper reviews some aspects related to the creatine metabolism and its use as an ergogenic substance in sports practice.A creatina vem sendo muito pesquisada devido ao seu potencial efeito no rendimento físico de atletas envolvidos em exercícios de alta intensidade e curta duração, intermitentes e com curtos períodos de recuperação. A creatina fosforilada é uma reserva de energia nas células musculares. Durante um exercício intenso, a sua quebra libera energia é usada para regenerar o trifosfato de adenosina. Aproximadamente 95% do pool de creatina encontra-se na musculatura esquelética e sua regeneração após o exercício é um processo dependente de oxigênio. Estudos mostram que a suplementação com este composto pode aumentar o pool orgânico em 10 a 20%, e este percentual é maior em atletas vegetarianos (até 60%). Ainda existe controvérsia com relação aos benefícios e riscos da suplementação com esta substância. Este estudo revisa alguns dos aspectos relacionados com o metabolismo da creatina e seu uso como substância ergogênica na prática desportiva.Universidade Federal de São Paulo (UNIFESP) Departamento de Pediatria Escola Paulista de MedicinaUNIFESP, Depto. de Pediatria Escola Paulista de MedicinaSciEL

Dietas para perda de peso anunciadas na imprensa leiga

Weight-loss diets advertised in mainstream non-scientific publications and targeting the adult female public were evaluated in relation to total energy value, macronutrients, calcium, iron, vitamins A and E, and cholesterol content, as well as the presence of information regarding the duration of diets, fluid intake, physical activity, and maintenance diets. Two publications were selected, considering periodicity, circulation, readership, and years in publication. The Virtual Nutri software was used to evaluate the nutrients of 112 diets. Micronutrient content was compared to the Dietary Reference Intakes. All diets were inadequate in at least one of the evaluated items. Less than 25.0% of the diets presented adequate macronutrient distribution. Calcium, iron, and vitamin E were also predominantly inadequate (85.7, 97.3, and 91.9%, respectively). Non-scientific publications should not be allowed to advertise weight-loss diets. In addition, their chemical composition is inadequate and they are not accompanied by important instructions for such therapy.Diversas dietas para redução de peso, anunciadas em periódicos não-científicos de grande circulação, foram avaliadas em relação ao teor energético e de macronutrientes, cálcio, ferro, vitaminas A e E, colesterol e presença de informações sobre a duração da dieta, ingestão de fluidos, atividade física e dieta de manutenção. Duas publicações foram selecionadas em função da periodicidade, tiragem, número de leitores e anos de publicação. Foi utilizado o programa Virtual Nutri para medir os nutrientes de 112 dietas. Os teores de micronutrientes foram comparados com as Dietary Reference Intakes. Todas as dietas eram inadequadas em relação a uma ou mais substâncias avaliadas. Menos de 25,0% das dietas apresentaram distribuição adequada de macronutrientes. Predominavam os níveis inadequados de cálcio, ferro e vitamina E (85,7, 97,3, e 91,9%, respectivamente). Não deveria ser permitido que publicações não-científicas anunciassem dietas para perda de peso que não apresentassem também uma composição química adequada.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

Amenorrhea and osteosporosis in adolescents athletes

The female participation in sports has been increasing over the years. Scientific studies have shown the benefits this practice brings to women's health, but, when it comes to competitive sports, problems may arise. The most common complication described by the literature is the Female Athlete Triad, which involves three processes: the eating disorder, the amenorrhea, and the osteoporosis. In the United States, the amenorrhea afflicts up to 66% of the competition athletes, and some of its possible causes of are: weight loss, excessive training, insufficient quantity of body fat, loss of specific stores of body fat, and inadequate diet. As a consequence of the amenorrhea, the sportswoman may develop precocious osteoporosis. It is not known for sure the percentage of athletes with osteopenia, but there are indications that the lack of estrogen, the inadequate diet, and the insufficient consumption of calcium are factors predisposing them to develop the disease.A participação feminina no esporte foi crescendo ao longo dos anos. Trabalhos científicos têm mostrado os benefícios trazidos por esta prática para a saúde da mulher, mas quando se trata de esporte competitivo podem surgir problemas. A complicação mais comum descrita pela literatura é a tríade da atleta, a qual envolve três processos: o distúrbio alimentar, a amenorréia e a osteoporose. A amenorréia atinge, nos Estados Unidos, até 66% das atletas de competição, e algumas de suas possíveis causas são: perda de peso, excesso de treino, quantidade insuficiente de gordura corporal, perda de estoques específicos de gordura corporal e dieta inadequada. Como conseqüência da amenorréia, a esportista pode desenvolver osteoporose precoce. Não se sabe ao certo a porcentagem de atletas com osteopenia, mas há indícios de que a falta de estrógeno, a dieta inadequada e o consumo insuficiente de cálcio serem fatores que as predispõem a desenvolver a doença.Universidade Federal de São Paulo (UNIFESP) EPM Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL

Nutritional status, hematological and serum levels of iron in preschool children from cities with different child development indexes

OBJECTIVE: To evaluate nutritional status and iron hematological and serum levels of preschool children from cities with different child development indexes (CDI). METHODS: This cross-sectional study enrolled 34 preschool children aged between three to six years from two municipalities of Brazil: Laranjal, Paraná, with a low CDI, and Presidente Prudente, São Paulo, with a medium CDI. Children of both cities were matched by age and gender. The nutritional status was evaluated by Z score for weight/height and height/age. The biochemical evaluation included hemoglobin, hematocrit, seric iron and ferritin levels. The following tests were used for statistical analysis: t test, Mann-Whitney, chi-square and Fisher's exact test. RESULTS: The weight, height and Z score of the anthropometric relationships were significantly lower in the group of Laranjal children. Anemia was present in 8.8% of the children studied in both cities, without significant differences in the prevalence of iron deficiency or in the ferritin levels. CONCLUSIONS: The preschool children from the city with low CDI presented mainly malnutrition, while overweight and obesity were more prevalent on preschool children from the city with a medium CDI. Hematimetric values, iron and ferritin levels were similar between the preschool children of both cities.OBJETIVO: Avaliar o estado nutricional e os níveis hematológicos e séricos de ferro em pré-escolares de municípios com diferentes índices de desenvolvimento infantil (IDI). MÉTODOS: Estudo transversal de 34 pré-escolares com idade de três a seis anos do município de Laranjal, Paraná, com IDI baixo e com o mesmo número de crianças pareadas por idade e gênero, provenientes de Presidente Prudente, São Paulo, município com IDI médio. Avaliou-se o estado nutricional por meio do escore Z das relações peso/estatura e estatura/idade. A avaliação bioquímica constou de dosagens de hemoglobina, hematócrito, ferro sérico e ferritina. Para a análise estatística foram usados os testes t de Student, Mann-Whitney, qui-quadrado e o exato de Fisher. RESULTADOS: Peso, estatura e escore Z das relações antropométricas foram significantemente menores no grupo de crianças de Laranjal comparados aos de Presidente Prudente. A prevalência de anemia em ambos os grupos foi 8,8%, não havendo diferença significante para a prevalência de ferropenia e para os valores de ferritina sérica. CONCLUSÕES: Pré-escolares do município com IDI baixo apresentam mais desnutrição, enquanto sobrepeso e obesidade são predominantes nos pré-escolares do município com IDI médio. Quanto às alterações dos níveis hematológicos e séricos de ferro, não há diferença entre os pré-escolares dos municípios estudados.Universidade Federal de São Paulo (UNIFESP)UNIFESPUNIFESPSciEL

Impact of Obesity on Metabolic Syndrome in Brazilian Adolescents: A Population-Based Study

Universidade Federal de São Paulo, Escola Paulista Med, Dept Postgrad, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Endocrinol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Postgrad, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Endocrinol, São Paulo, BrazilWeb of Scienc

Low-dietary fiber intake as a risk factor for recurrent abdominal pain in children

Objective: To evaluate dietary fiber intake in children with recurrent abdominal pain.Design: Cross-sectional study with control group.Setting: Outpatients of the Pediatric Gastroenterology public health clinic of the Darcy Vargas Children's Hospital, Brazil.Subjects: Forty-one patients with recurrent abdominal pain were evaluated and 41 children, as a control group.Interventions: Macronutrients and fiber intake evaluation by the Daily Food Intake method. Two tables of fiber composition in foods were used.Results: According to the Brazilian table the mean intake of fiber ( g/day) by the children of the recurrent abdominal pain groups with chronic constipation or not, and the control group was, respectively, 18.2, 16.6 and 23.7 for total fiber ( P 0.001), 7.5, 6.9 and 9.5 for soluble fiber ( P 0.001) and 10.7, 9.7 and 14.1 for insoluble fiber ( P 0.002). According to the AOAC table, the recurrent abdominal pain group with chronic constipation or not ( 10.6 and 9.9 g/day) also had lower intake of total fiber than the control group ( 13.4 g/day) ( P 0.008). the intake of fiber was lower than the minimum recommended value ( age+5g) and statistically associated ( P 0.021) with the recurrent abdominal pain group ( 78%) in comparison with the control one ( 51.2%). the odds ratio was 3.39 ( 95% CI, 1.18 - 9.95).Conclusion: fiber intake below the minimum recommended value is a risk factor for recurrent abdominal pain in children.Universidade Federal de São Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 São Paulo, BrazilDarcy Vargas Childrens Hosp, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 São Paulo, BrazilWeb of Scienc

Molecular analysis and association with clinical and laboratory manifestations in children with sickle cell anemia

Objectives: To analyze the frequency of βS-globin haplotypes and alpha-thalassemia, and their influence on clinical manifestations and the hematological profile of children with sickle cell anemia.Method: The frequency of βS-globin haplotypes and alpha-thalassemia and any association with clinical and laboratorial manifestations were determined in 117 sickle cell anemia children aged 3–71 months. The confirmation of hemoglobin SS and determination of the haplotypes were achieved by polymerase chain reaction-restriction fragment length polymorphism, and alpha-thalassemia genotyping was by multiplex polymerase chain reaction (single-tube multiplex-polymerase chain reaction).Results: The genotype distribution of haplotypes was 43 (36.7%) Central African Republic/Benin, 41 (35.0%) Central African Republic/Central African Republic, 20 (17.0%) Rare/atypical, and 13 (11.1%) Benin/Benin. The frequency of the α3.7 deletion was 1.71% as homozygous (−α3.7/−α3.7) and 11.9% as heterozygous (−α3.7/αα). The only significant association in respect to haplotypes was related to the mean corpuscular volume. The presence of alpha-thalassemia was significantly associated to decreases in mean corpuscular volume, mean corpuscular hemoglobin and reticulocyte count and to an increase in the red blood cell count. There were no significant associations of βS-globin haplotypes and alpha-thalassemia with clinical manifestations.Conclusions: In the study population, the frequency of alpha-thalassemia was similar to published data in Brazil with the Central African Republic haplotype being the most common, followed by the Benin haplotype. βS-globin haplotypes and interaction between alpha-thalassemia and sickle cell anemia did not influence fetal hemoglobin concentrations or the number of clinical manifestations.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL