RESUMO
CONTEXT: Low birth weight (LBW) is associated with infant morbidity and mortality. This is the first study of LBW in Kansas using vital statistics to determine maternal and health care system factors associated with LBW. OUTCOMES: Low birth weight. OBJECTIVE: Determine if prenatal care, maternal socio-demographic or medical factors, or insurance status were associated with LBW. METHODS: Birth certificate data were merged with Medicaid eligibility data and subjected to logistic regression analysis. RESULTS: Of the 37,081 single vaginal births, LBW rates were 5.5% overall, 10.8% for African Americans, and 5% for White Americans. Lacking private insurance was associated with 34% more LBW infants (AOR 1.34; 95% CI 1.13-1.58), increased comorbidity, and late or less prenatal care. Low birth weight was associated with maternal medical comorbidity and with previous adverse birth outcomes. CONCLUSIONS: Insurance status, prenatal care, and maternal health during pregnancy are associated with LBW. Private insurance was consistently associated with more prenatal care and better outcomes. This study has important implications regarding health care reform.
Assuntos
Recém-Nascido de Baixo Peso , Adolescente , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Criança , Feminino , Humanos , Cobertura do Seguro/estatística & dados numéricos , Seguro Saúde/estatística & dados numéricos , Kansas/epidemiologia , Modelos Logísticos , Masculino , Idade Materna , Saúde Materna/estatística & dados numéricos , Gravidez , Cuidado Pré-Natal/estatística & dados numéricos , Fatores de Risco , Fatores Socioeconômicos , População Branca/estatística & dados numéricos , Adulto JovemRESUMO
OBJECTIVE: The objective of this study is to examine associations between aspects of the environment in school neighborhoods and childhood body mass index percentile (BMIp). METHODS: Trained medical students visited 46 elementary schools in the Kansas City metropolitan area to conduct medical screenings that included the height and weight measurements of 12 118 boys and girls 4-12 years of age in the academic year 2008-2009. For the same time period, aspects of the built environment in a 2-mile radius around each school was obtained from the Walkscore database. Other environmental characteristics (for example, population change) of these areas were also obtained from various sources. Hierarchical linear modeling was used to estimate the associations between neighborhood- and individual-level factors and BMIp. RESULTS: Population size along with the number of fast-food restaurants and grocery stores were positively associated with BMIp, whereas population change along with the number of parks and fitness centers were inversely associated with BMIp. CONCLUSIONS: After considering individual-level factors and the random effects of schools, environmental elements of school neighborhoods predict childhood BMIp. This study offers evidence of the health influence of school neighborhoods in a way that can inform neighborhood redevelopment efforts.
Assuntos
Dieta , Exercício Físico , Obesidade Infantil/prevenção & controle , Características de Residência , Serviços de Saúde Escolar/organização & administração , Meio Social , Índice de Massa Corporal , Criança , Pré-Escolar , Comportamento de Escolha , Planejamento Ambiental , Feminino , Preferências Alimentares , Educação em Saúde , Humanos , Kansas/epidemiologia , Modelos Lineares , Masculino , Obesidade Infantil/epidemiologia , Prevalência , Restaurantes , Instituições Acadêmicas , Fatores SocioeconômicosRESUMO
The purpose of this study was to describe the relationships between Social Cognitive Theory (SCT) variables and frequency of moderate-vigorous physical activity in a sample of high school students. Days of moderate and vigorous physical activity were assessed using a previously validated one-day recall instrument administered on seven consecutive days. The SCT variables tested were: self-regulation, social situation, social outcome expectations, physical appearance outcome expectations, general health outcome expectations, negative outcome expectations, self-efficacy for ability, and self-efficacy for barriers. The SCT variables studied are potentially modifiable via educational interventions. Results revealed that 15 % of the subjects reported 3 or more days of physical activity. Four of the SCT were retained in the regression model accounting for 31 % of the variance in days or moderate-vigorous physical activity. SCT is useful for understanding frequency of moderate-vigorous physical activity among adolescents.
Assuntos
Cognição , Exercício Físico , Modelos Psicológicos , Aptidão Física , Comportamento Social , Adolescente , Comportamento do Adolescente , Feminino , Comportamentos Relacionados com a Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Psicometria , EstudantesRESUMO
Obesity is a major health problem in the U.S., especially for Hispanic youth. Because maximal/peak oxygen consumption (V.O (2)peak) is one predictor of future weight gain in children, valid field-based methods for determining V.O (2)peak in Hispanic children are needed. The purpose of this study was to validate a field-based aerobic fitness test, the 20-m shuttle test (20-MST), in Hispanic boys (n = 58) and girls (n = 67), 10 - 12 years old (mean age +/- SD, 10.7 +/- 0.6 y). Measured V.O (2)peak was determined during a maximal, graded treadmill test using the Bruce protocol. The 20-MST was administered per a standard protocol. Maximal speed attained on the 20-MST and age were used to estimate V.O (2)peak. An intraclass coefficient of 0.82 was obtained on 35 students (16 boys; r = 0.85 and 19 girls; r = 0.79) who completed the 20-MST twice, 1-wk apart. Estimated (44.3 ml x kg (-1) x min (-1) ) and measured (45.1 ml x kg (-1) x min (-1)) V.O (2)peak were not significantly different (p = 0.33). The correlation between the two V.O (2)peak parameters was r = 0.62; p < 0.001, the standard error of the estimate (SEE) was 3.91 ml x kg (-1) x min (-1), and 85.5 % of the measured V.O (2)peak values fell within 5.9 ml x kg (-1) x min (-1) of estimated V.O (2)peak. The weight status of the child did not significantly change these results. The 20-MST combined with the Leger et al. equation is a valid method for predicting V.O (2)peak in Hispanic youth. The test can be used to provide valuable information for intervention design and disease prevention.
Assuntos
Aerobiose , Hispânico ou Latino , Aptidão Física/fisiologia , Análise de Variância , Criança , Teste de Esforço , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologiaRESUMO
OBJECTIVE: To evaluate a culturally appropriate intervention to increase activity in overweight Mexican American women. METHODS: Participants were randomly assigned to a physical activity program or wait-list control. RESULTS: Treated participants were not more active than controls at 6 or 12 months. In addition, we found no significant differences in the proportion of individuals who met an objective criterion for physical activity from baseline to 6 months in the treatment or control groups. CONCLUSION: The intervention did not increase physical activity in this population. Differences in baseline activity and contamination of the control group may partially account for the outcome.
Assuntos
Exercício Físico/psicologia , Hispânico ou Latino/psicologia , Estilo de Vida , Obesidade/etnologia , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/psicologia , Obesidade/terapia , TexasRESUMO
Study findings suggest that college women practice diet and health behaviors that contradict the 1995 Dietary Guidelines for Americans. To confirm this hypothesis, the authors surveyed the diet, exercise, and health habits of 60 female students enrolled in three university aerobics courses. They measured height and weight to calculate body mass index (BMI) and assessed physical activity, using the Self-Reported Physical Activity scale. To estimate food and nutrient intake, they used 3-day food records. Participants reported diets that were nutritionally adequate but exceeded national recommendations for fat, sugar, and sodium, and their reports of exercise habits suggested that the lifestyles of 66% of the respondents were sedentary. Although the students' mean BMIs suggested healthy weights, 25% of the women were classified as overweight. A majority of the participants were following at least 1 of the 7 dietary guidelines; however, no participant was adhering to all proposed behaviors.
Assuntos
Comportamento Alimentar , Política Nutricional , Adolescente , Adulto , Consumo de Bebidas Alcoólicas , Índice de Massa Corporal , Exercício Físico , Feminino , Humanos , Texas , Estados UnidosRESUMO
OBJECTIVE: To compare peak oxygen consumption (VO2peak) and skeletal muscle oxidative metabolism between nine African-American and nine Caucasian men. METHODS: Subjects performed arm ergometry to exhaustion. On a separate occasion 31phosphorous-nuclear magnetic resonance spectroscopy (31P-NMRS) was used to determine the concentrations of phosphorous (Pi), phosphocreatine (PCr), and the intracellular pH of the flexor carpi radialis before and during 4 min of steady-state, wrist flexion exercise performed at 28% (15 W) of each subject's peak voluntary contraction. RESULTS: The Pi/PCr ratio was used as an indirect measure of skeletal muscle oxidative metabolism. VO2peak was lower in the African-Americans compared with the Caucasians (means +/- SD, 19.4 +/- 3.4 vs 23.3 +/- 4.0 mL x kg(-1) x min(-1)) (P < 0.05). No significant between group difference was noted in the Pi/PCr ratio at rest (0.10 +/- 0.02 both groups). However, resting pH was lower in the African-Americans (6.99 +/- 0.04 vs 7.03 +/- 0.05) (P < 0.05). Exercise caused an increase in the Pi/PCr ratio in the African-Americans (1.06 +/- 0.11), which was higher than the increase observed in the Caucasians (0.50 +/- 0.14) (P < 0.05). pH levels decreased to a lower level during exercise in the African-Americans (6.89 +/- 0.04) than in the Caucasians (6.98 +/- 0.05) (P < 0.05). CONCLUSIONS: This select group of African-American men achieved a lower VO2peak than the Caucasian men. Variations in skeletal muscle oxidative metabolic components may explain this difference.
Assuntos
População Negra , Metabolismo Energético , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Consumo de Oxigênio , População Branca , Adulto , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Fosfocreatina/análise , Fósforo/análiseRESUMO
OBJECTIVE: To describe the problem of obesity in Mexican American children and provide a method for identifying Mexican American children at risk for obesity. DESIGN: Cross-sectional and retrospective cohort study. SUBJECTS: Mexican American children, ages 5-11 (kindergarten (K)-5th grade) were studied in cross-sectional (girls = 463, boys = 448) and retrospective (girls = 124, boys = 92) samples. MEASUREMENTS: Weights (kg) and heights (cm) were extracted from each child's school medical records. Measurements were made by the school nurses (one nurse per school). Body mass index (BMI [w/h2]) was calculated from obtained weights and heights. RESULTS: The prevalence of obesity in the cross-sectional sample was 27.4% for girls and 23.0% for boys. The highest prevalence was noted in 4th grade for both the girls (32.4%) and boys (43.4%). The 5 year incidence rates derived from the retrospective sample were 17.7% for girls and 21.1% for boys. The largest increase in the number of girls becoming obese was observed between K and 1st grade (15.6%). The largest increase for boys was found between the 1st and 2nd grades (13.2%). Logistic regression parameters were calculated to estimate the probability of becoming obese in 5th grade given a child's K BMI. Using the generated equation, BMIs in K equal to 16.5, 20.9, and 23.7 would have a 21.0%, 70.0%, and 91.0% probability of being obese by 5th grade. CONCLUSION: This study provides schools with a simple procedure for identifying Mexican American children at risk for obesity. This procedure may assist in the development and implementation of interventions aimed at averting the onset of obesity in this population.
Assuntos
Americanos Mexicanos , Obesidade/etnologia , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/prevenção & controle , Pobreza , Valor Preditivo dos Testes , Prevalência , Estudos Retrospectivos , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
PURPOSE: This investigation was undertaken to examine substrate utilization and glucose turnover during exercise of varying intensities in NIDDM patients. METHODS: Six male NIDDM patients (N) and six male controls (C) of similar age, body weight, % body fat, and VO2peak were studied in two experimental sessions administered in a randomized counterbalanced order. During each session the subjects cycled at a power output corresponding to 50% of VO2peak or 70% of VO2peak. Duration of exercise was adjusted so that energy expenditure (EE) was equal in both the 50% and 70% trials. Isotope infusion technique and indirect calorimetry were used to assess substrate utilization and glucose turnover during exercise. RESULTS: Rates of carbohydrate (CHO) and lipid oxidation increased (P < 0.05) during both the 50% and 70% trials. Rates of CHO oxidation were greater (P < 0.05) during the 70% than during the 50% trial. However, rates of lipid oxidation were similar in the two trials. No differences in rates of CHO and lipid oxidation were observed in N and C. Rates of hepatic glucose production (Ra) and plasma glucose utilization (Rd) increased (P < 0.05) during exercise, and the increases were similar in the 50% and 70% trials. Ra did not differ between N and C. However, Rd was greater (P < 0.05) in N than in C. Plasma glucose concentration decreased (P < 0.05) in N, with the decrease being similar in the 50% and 70% trials. In contrast, plasma glucose concentration remained unchanged during both the 50% and 70% trials in C. CONCLUSIONS: Exercise results in a greater increase in plasma glucose utilization in patients with NIDDM compared with that in normal individuals, and this increase mediates the decline in plasma glucose concentrations in patients with NIDDM. Under isocaloric conditions, the changes in plasma glucose utilization and plasma glucose concentrations are similar during exercise of varying intensities. Despite a greater glucose utilization, carbohydrate and fat oxidation are similar in the two groups and their relations to exercise intensity are not altered by NIDDM.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Exercício Físico/fisiologia , Adulto , Metabolismo dos Carboidratos , Gorduras/metabolismo , Glicogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , OxirreduçãoRESUMO
This study was conducted to compare gross efficiency (GE), net efficiency (NE), work efficiency (WE), and delta efficiency (DE) between arm crank and cycle exercise at the same relative intensities. Eight college-aged males underwent two experimental trials presented in a randomized counterbalanced order. During each trial subjects performed three intermittent 7-min exercise bouts separated by 10-min rest intervals on an arm or semirecumbent leg ergometer. The power outputs for the three bouts of arm crank or cycle exercise corresponded to 50, 60, and 70% of the mode-specific VO2peak. GE, NE, and WE were determined as the ratio of Kcal.min-1 equivalent of power output to Kcal.min-1 of total energy expended, energy expended above rest and energy expended above unloaded exercise, respectively. DE was determined as the ratio of the increment of Kcal.min-1 of power output above the previous lower intensity to the increment of kcal.min-1 of total energy expended above the previous lower intensity. GE and NE did not differ between arm crank and cycle exercises. However, WE was lower (P < 0.05) during arm crank than cycle exercise at 50, 60, and 70% VO2peak. DE was also lower (P < 0.05) during arm crank than cycle exercise at delta 50-60 and at delta 60-70% VO2peak. It is concluded metabolic efficiency as determined by work and delta efficiency indices was lower during arm crank compared with cycle exercise at the same relative intensities. These findings add to the understanding of the difference in metabolic efficiency between upper and lower body exercise.
Assuntos
Braço/fisiologia , Metabolismo Energético , Perna (Membro)/fisiologia , Esforço Físico/fisiologia , Adulto , Índice de Massa Corporal , Eficiência/fisiologia , Ergometria , Teste de Esforço , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio , Respiração , Descanso/fisiologia , Trabalho/fisiologiaRESUMO
Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30, 60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg lysine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
Assuntos
Arginina/farmacologia , Exercício Físico/fisiologia , Hormônio do Crescimento Humano/sangue , Lisina/farmacologia , Adulto , Humanos , MasculinoRESUMO
This investigation examined the effect of carbohydrate substrate availability on ratings of perceived exertion (RPE) during cycling at moderate intensity to exhaustion and the relation between submaximal endurance performance and RPE obtained following 2 hr. of cycling at moderate intensity. Seven male cyclists performed two exercise trials at power output corresponding to 70% of their peak oxygen uptake until exhaustion. Subjects ingested either a 6% glucose/sucrose solution at the rate of 0.6 g.kg-1 (Body Weight).hr.-1 or an equal volume of artificially flavored placebo every 20 min. throughout the exercise trials. RPE for the legs, chest, and over-all body, and oxygen consumption, expired ventilation, carbohydrate oxidation rate, and blood concentrations of glucose, glycerol, and lactate were measured every 20 min. throughout exercise and at exercise termination. Statistical analysis of these dependent variables indicates that (1) an exercise-induced decrease in blood-borne carbohydrate substrate intensifies leg and over-all perceptions of exertion during the later stages of prolonged cycling at 70% VO2peak. (2) Factors other than availability of blood-borne carbohydrate substrate may influence perceptual intensity at exhaustion. (3) Ratings of perceived exertion for the legs and over-all body obtained after 2 hr. of cycling at moderate intensity may be useful in predicting submaximal endurance performance.
Assuntos
Atitude Frente a Saúde , Glicemia/metabolismo , Solução Hipertônica de Glucose/administração & dosagem , Resistência Física/fisiologia , Esforço Físico/fisiologia , Sacarose/administração & dosagem , Método Duplo-Cego , Fadiga/sangue , Fadiga/psicologia , Glicerol/sangue , Humanos , Lactatos/sangue , Ácido Láctico , MasculinoRESUMO
OBJECTIVE: The primary purpose of this study was to evaluate the acute effect of exercise of differing intensity on plasma glucose and insulin responses to an oral glucose challenge. RESEARCH DESIGN AND METHODS: Six obese men and six obese men with NIDDM of similar age, weight, percentage body fat, and VO2peak participated in the study. Each subject underwent two 7-day exercise programs in a counterbalanced order at 2-week intervals. During each 7-day exercise period, the subjects cycled every day at a power output corresponding to 50% VO2peak for 70 min or 70% VO2peak for 50 min. Muscle glycogen utilization was estimated during exercise on day 7 using a [3H]glucose infusion technique in conjunction with indirect calorimetry. During the day before and after each 7-day exercise period, a 3-h oral glucose tolerance test (OGTT) was administered after a 12-h overnight fast. RESULTS: The average caloric expenditure did not differ between exercise at 50 and 70% VO2peak in both obese and obese NIDDM subjects. However, the carbohydrate oxidation was higher (P < 0.05) during exercise at 70 than 50% VO2peak in obese subjects (77 +/- 5 vs. 68 +/- 6 g) and obese NIDDM subjects (70 +/- 4 vs. 58 +/- 6 g). Muscle glycogen utilization was also higher (P < 0.05) during exercise at 70 than 50% VO2peak in obese subjects (59 +/- 9 vs. 30 +/- 7 g) and in obese NIDDM subjects (48 +/- 5 vs. 24 +/- 5 g). In obese subjects, plasma glucose response area during the OGTT did not change after 7 days of exercise at either 50 or 70% VO2peak. Plasma insulin response area during the OGTT also did not change after 7 days of exercise at 50% VO2peak. However, plasma insulin response area was reduced (P < 0.05) after 7 days of exercise at 70% VO2peak (9,644 +/- 1,783 vs 7,538 +/- 1,522 microU.ml-1.180 min-1). In obese NIDDM subjects, both plasma glucose and insulin response areas during the OGTT did not decrease after 7 days of exercise at either 50 or 70% VO2peak. CONCLUSIONS: It is concluded that the exercise-induced improvement in insulin sensitivity is influenced by exercise intensity in obese individuals. The improved insulin sensitivity after 7 days of exercise at 70% VO2peak in obese individuals may be related to greater muscle glycogen utilization during exercise. The lack of improvement in glucose tolerance and insulin sensitivity after 7 days of exercise at either 50 or 70% VO2peak in obese NIDDM patients may be due to the fact that the NIDDM patients selected in the present study were relatively hypoinsulinemic.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus/fisiopatologia , Exercício Físico , Insulina/sangue , Obesidade/fisiopatologia , Esforço Físico , Tecido Adiposo/anatomia & histologia , Adulto , Calorimetria Indireta , Colesterol/sangue , Diabetes Mellitus/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Teste de Tolerância a Glucose , Glicogênio/metabolismo , Humanos , Masculino , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Consumo de Oxigênio , Triglicerídeos/sangueRESUMO
This investigation determined whether carbohydrate ingestion during prolonged moderate-intensity exercise enhanced endurance performance when the exercise was preceded by carbohydrate supercompensation. Seven male trained cyclists performed two trials at an initial power output corresponding to 71 +/- 1% of their peak oxygen consumption. During the trials, subjects ingested either a 6% glucose/sucrose (C) solution or an equal volume of artificially flavored and sweetened placebo (P) every 20 min throughout exercise. Both C and P were preceded by a 6-day carbohydrate supercompensation procedure in which subjects undertook a depletion-taper exercise sequence in conjunction with a moderate- and high-carbohydrate diet regimen. Statistical analysis of time to exhaustion, plasma glucose concentration, carbohydrate oxidation rate, fat oxidation rate, and plasma glycerol concentration indicated that in spite of a carbohydrate supercompensation procedure administered prior to exercise, carbohydrate ingestion during exercise can exert an additional ergogenic effect by preventing a decline in blood glucose levels and maintaining carbohydrate oxidation during the later stages of moderate-intensity exercise.