870 resultados para BODY MASS
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Thermal response of skin temperature (Tsk) has been studied during exercise and immediately after (Merla, 2010). However, more studies about the influence of exercise on Tsk through the time are required to understand the impact of physical activity on thermoregulatory system and metabolism
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¿Influye el índice de masa corporal, el sexo, el tratamiento y la edad en la pérdida de peso?
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Being overweight is associated with both higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) during pregnancy and increased risk of gestational hypertensive disorders. The objective of this study was to determine and quantify the effect of body mass index (BMI) on mean arterial pressure (MAP) at several time points throughout pregnancy in normotensive (NT) and chronic hypertensive pregnant (HT) women.
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Relatively little is known about the influence of psychosocial factors, such as familial role modeling and social network on the development and maintenance of childhood obesity. We investigated peer se- lection using an immersive virtual reality environment. In a virtual schoolyard, children were confronted with normal weight and overweight avatars either eating or playing. Fifty-seven children aged 7–13 participated. Interpersonal distance to the avatars, child's BMI, self-perception, eating behavior and parental BMI were assessed. Parental BMI was the strongest predictor for the children's minimal distance to the avatars. Specifically, a higher mothers' BMI was associated with greater interpersonal distance and children approached closer to overweight eating avatars. A higher father's BMI was associated with a lower interpersonal distance to the avatars. These children approached normal weight playing and overweight eating avatar peers closest. The importance of parental BMI for the child's social approach/ avoidance behavior can be explained through social modeling mechanisms. Differential effects of pa- ternal and maternal BMI might be due to gender specific beauty ideals. Interventions to promote social interaction with peer groups could foster weight stabilization or weight loss in children.
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Marine invertebrates with open circulatory system establish low and constant oxygen partial pressure (Po2) around their tissues. We hypothesized that as a first step towards maintenance of low haemolymph and tissue oxygenation, the Po2 in molluscan mantle cavity water should be lowered against normoxic (21 kPa) seawater Po2, but balanced high enough to meet the energetic requirements in a given species. We recorded Po2 in mantle cavity water of five molluscan species with different lifestyles, two pectinids (Aequipecten opercularis, Pecten maximus), two mud clams (Arctica islandica, Mya arenaria), and a limpet (Patella vulgata). All species maintain mantle cavity water oxygenation below normoxic Po2. Average mantle cavity water Po2 correlates positively with standard metabolic rate (SMR): highest in scallops and lowest in mud clams. Scallops show typical Po2 frequency distribution, with peaks between 3 and 10 kPa, whereas mud clams and limpets maintain mantle water Po2 mostly <5 kPa. Only A. islandica and P. vulgata display distinguishable temporal patterns in Po2 time series. Adjustment of mantle cavity Po2 to lower than ambient levels through controlled pumping prevents high oxygen gradients between bivalve tissues and surrounding fluid, limiting oxygen flux across the body surface. The patterns of Po2 in mantle cavity water correspond to molluscan ecotypes.
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Accurate estimates of body mass in fossil taxa are fundamental to paleobiological reconstruction. Predictive equations derived from correlation with craniodental and body mass data in extant taxa are the most commonly used, but they can be unreliable for species whose morphology departs widely from that of living relatives. Estimates based on proximal limb-bone circumference data are more accurate but are inapplicable where postcranial remains are unknown. In this study we assess the efficacy of predicting body mass in Australian fossil marsupials by using an alternative correlate, endocranial volume. Body mass estimates for a species with highly unusual craniodental anatomy, the Pleistocene marsupial lion (Thylacoleo carnifex), fall within the range determined on the basis of proximal limb-bone circumference data, whereas estimates based on dental data are highly dubious. For all marsupial taxa considered, allometric relationships have small confidence intervals, and percent prediction errors are comparable to those of the best predictors using craniodental data. Although application is limited in some respects, this method may provide a useful means of estimating body mass for species with atypical craniodental or postcranial morphologies and taxa unrepresented by postcranial remains. A trend toward increased encephalization may constrain the method's predictive power with respect to many, but not all, placental clades.
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Objectives: Study objectives were: 1) to describe the differences in the prevalence of CHID risk factors between Aboriginal people in a remote community and the general Australian population; and 2) to compare the predicted risks of CHD events between Aboriginal and non-Aboriginal Australians. Design: A cross-sectional study. Participants: 681 Aboriginal adults aged 25 to 74 years. Results: Aboriginal young adults had substantially higher prevalence of diabetes compared to non-Aboriginal Australians. The prevalence ratios for diabetes were 12.5, 5.6, 3.2, 1.3, and 0.73 for 25-, 35-, 45-, 55-, and 65- to 74-year-old females, respectively, The corresponding values for males were 12.1, 2.7, 2.9, 0.69, and 0.42. Young females had a higher prevalence of obesity, overweight, and abnormal waist circumference, while males and females 45 years and older tended to have a lower prevalence of overweight and ab. normal waist circumference. Compared to the general population, Aboriginal adults had a lower prevalence of abnormal total cholesterol but a higher prevalence of abnormal HDL, triglycerides, hypertension, and smoking. The risk ratios of abnormal total cholesterol for females ages 2534, 35-44, 45-54, 55-64, and 65-75 years were 0.38, 0.53, 0.48, 0.48, and 0.41, respectively. Conclusions: Aboriginal people in the remote community experienced different levels of CHD risk predictors from the general Australian population. They had a lower prevalence of abnormal total cholesterol and a higher prevalence of abnormal HDL, smoking, diabetes, and hypertension.
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Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.
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In large epidemiological studies missing data can be a problem, especially if information is sought on a sensitive topic or when a composite measure is calculated from several variables each affected by missing values. Multiple imputation is the method of choice for 'filling in' missing data based on associations among variables. Using an example about body mass index from the Australian Longitudinal Study on Women's Health, we identify a subset of variables that are particularly useful for imputing values for the target variables. Then we illustrate two uses of multiple imputation. The first is to examine and correct for bias when data are not missing completely at random. The second is to impute missing values for an important covariate; in this case omission from the imputation process of variables to be used in the analysis may introduce bias. We conclude with several recommendations for handling issues of missing data. Copyright (C) 2004 John Wiley Sons, Ltd.
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Weight reduction in clinical populations of severely obese children has been shown to have beneficial effects on blood pressure, but little is known about the effect of weight gain among children in the general population. This study compares the mean blood pressure at 14 years of age with the change in overweight status between ages 5 and 14. Information from 2794 children born in Brisbane, Australia, and who were followed up since birth and had body mass index (BMI) and blood pressure measurements at ages 5 and 14 were used. Systolic and diastolic blood pressure at age 14 was the main outcomes and different patterns of change in BMI from age 5 to 14 were the main exposure. Those who changed from being overweight at age 5 to having normal BMI at age 14 had similar mean blood pressures to those who had a normal BMI at both time points: age- and sex-adjusted mean difference in systolic blood pressure 1.54 ( - 0.38, 3.45) mm Hg and in diastolic blood pressure 0.43 ( - 0.95, 1.81) mm Hg. In contrast, those who were overweight at both ages or who had a normal BMI at age 5 and were overweight at age 14 had higher blood pressure at age 14 than those who had a normal BMI at both times. These effects were independent of a range of potential confounding factors. Our findings suggest that programs that successfully result in children changing from overweight to normal-BMI status for their age may have important beneficial effects on subsequent blood pressure.
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Purpose: Although the body-mass management strategies of athletes in high-participation weight-category sports such as wrestling have been thoroughly investigated, little is known about such practices among lightweight rowers. This study examined the body-mass management practices of lightweight rowers before competition and compared these with current guidelines of the International Federation of Rowing Association (FISA). Quantification of nutrient intake in the 1-2 h between weigh-in and racing was also sought. Methods: Lightweight rowers (N = 100) competing in a national regatta completed a questionnaire that assessed body-mass management practices during the 4 wk before and throughout a regatta plus recovery strategies after weigh-in. Biochemical data were collected immediately after weigh-in to validate questionnaire responses. Responses were categorized according to gender and age category (Senior B or younger than 23 yr old, i.e., U23, Senior A or OPEN, i.e., open age limit) for competition. Results: Most athletes (male U23 76.5%, OPEN 92.3%; female U23 84.0%, OPEN 94.1%) decreased their body mass in the weeks before the regatta at rates compliant with FISA guidelines. Gradual dieting, fluid restriction, and increased training load were the most popular methods of body-mass management. Although the importance of recovery after weigh-in was recognized by athletes, nutrient intake and especially sodium (male U23 5.3 &PLUSMN; 4.9, OPEN 7.7 &PLUSMN; 5.9; female U23 5.7 &PLUSMN; 6.8, OPEN 10.2 &PLUSMN; 5.4 mg-kg(-1)) and fluid intake (male U23 12.1 &PLUSMN; 7.1, OPEN 13.5 &PLUSMN; 8.1; female U23 9.4 &PLUSMN; 7.4, OPEN 14.8 &PLUSMN; 6.9 mL.kg(-1)) were below current sports nutrition recommendations. Conclusion: Few rowers were natural lightweights; the majority reduced their body mass in the weeks before a regatta. Nutritional recovery strategies implemented by lightweight rowers after weigh-in were not consistent with current guidelines.