Modelos matemáticos para estimativa do consumo máximo de oxigênio pela ventilometria de esforço em indivíduos saudáveis

The relation between metabolic demand and maximal oxygen consumption during exercise have been investigated in different areas of knowledge. In the health field, the determination of maximal oxygen consumption (VO2max) is considered a method to classify the level of physical fitness or the risk of cardiocirculatory diseases. The accuracy to obtain data provides a better evaluation of functional responses and allows a reduction in the error margin at the moment of risk classification, as well as, at the moment of determination of aerobic exercise work load. In Brasil, the use of respirometry associated to ergometric test became an opition in the cardiorespiratory evaluation. This equipment allows predictions concerning the oxyredutase process, making it possible to identify physiological responses to physical effort as the respiratory threshold. This thesis focused in the development of mathematical models developed by multiple regression validated by the stepwise method, aiming to predict the VO2max based on respiratory responses to physical effort. The sample was composed of a ramdom sample of 181 healthy individuals, men and women, that were randomized to two groups: regression group and cross validation group (GV). The voluntiars were submitted to a incremental treadmill test; objetiving to determinate of the second respiratory threshold (LVII) and the Peak VO2max. Using the método forward addition method 11 models of VO2max prediction in trendmill were developded. No significative differences were found between the VO2max meansured and the predicted by models when they were compared using ANOVA One-Way and the Post Hoc test of Turkey. We concluded that the developed mathematical models allow a prediction of the VO2max of healthy young individuals based on the LVII

A influência da adição de caulim, quartzo e feldspato potássico na formulação de massas cerâmicas para telhas: Modelo estatístico

The production of roof tiles in the state of Rio Grande do Norte accounts for around 60% of the total of ceramic pieces produced. There is a need for investment to improve quality and productivity, thereby promoting technological innovations. Accordingly, the aim of this study is to determine the effect of kaolin, potassium feldspar and quartz in two standard formulations, as well as the effect of sintering temperature on the technological properties of linear firing shrinkage, water absorption and bending rupture stress, by fitting the statistical model and using multiple linear regression to assess the relationship between technological properties and independent variables. The raw materials were characterized using the following techniques: X-ray fluorescence (XRF), X-ray diffraction (XRF), rational analysis (RA), differential thermal analysis (DTA) and granulometric analysis (GA). The test specimens were compacted by uniaxial pressure (25 MPa), dried in a stove at 110 ºC for 24 hours and sinterized at 850 ºC, 950 ºC and 1050 ºC and held isothermal for 30 minutes. The results obtained indicate that the addition of kaolin to two standard formulations (M and R) promoted a reduction in water absorption values and an increase in bending rupture stress values. The sintering temperatures for group M that resulted in the lowest linear firing shrinkage and water absorption values were 850 ºC and 950 ºC, respectively, and the highest bending rupture stress values were reached at a temperature of 950 ºC. In the case of group R, the sintering temperature that obtained the lowest water absorption and linear firing shrinkage values was 850 ºC, and the highest bending rupture stress values were attained at a temperature of 1050 ºC. This work explains the statistical approach used to fit the model that describes the relationship between the technological properties and percentage of kaolin, quartz and feldspar, as well as the models that enable predictions, provided that the lower and upper limits of the percentage of clay minerals, flux and quartz used in this study are respected. Statistica 6 software was used and results were obtained by stepwise forward regression

Avaliação da capacidade de caminhar do portador de obesidade mórbida utilizando teste de caminhada de 6 minutos

Introduction: The ability to walk is impaired in obese by anthropometric factors (BMI and height), musculoskeletal pain and level of inactivity. Little is known about the influence of body adiposity and the acute response of the cardiovascular system during whole the 6-minute walk test (6mWT). Objective: To evaluate the effect of anthropometric measures (BMI and WHR waist-to-hip ratio), the effort heart and inactivity in ability to walk the morbidly obese. Materials and Methods: a total 36 morbidly obese (36.23 + 11.82 years old, BMI 49.16 kg/m2) were recruited from outpatient department of treatment of obesity and bariatric surgery in University Hospital Onofre Lopes and anthropometric measurements of obesity (BMI and WHR), pulmonary function, pattern habitual physical activity (Baecke Questionnaire) and walking capacity (6mWT). The patient was checking to measure: heart rate (HR), breathing frequency (BF), peripheral oxygen saturation, level of perceived exertion, systemic arterial pressure and duplo-produto (DP), moreover the average speed development and total distance walking. The data were analysed between gender and pattern of body adiposity, measuring the behavior minute by minute of walking. The Pearson and Spearmam correlation coefficients were calculated, and stepwise multiple Regression examined the predictors of walking capacity. All analyses were performed en software Statistic 6.0. Results: 20 obese patients had abdominal adiposity (WHR = 1.01), waist circumference was 135.8 cm in women (25) and 139.8 cm in men (10). Walked to the end of 6mWT 412.43 m, with no differences between gender and adiposity. The total distance walked by obesity alone was explained by BMI (45%), HR in the sixth minute (43%), the Baecke (24%) and fatigue (-23%). 88.6% of obese (31) performed the test above 60% of maximal HR, while the peak HR achieved at 5-minute of 6mWT. Systemic arterial pressure and DP rised after walking, but with no differences between gender and adiposity. Conclusion: The walk of obese didn´t suffers influence of gender or the pattern of body adiposity. The final distance walked is attributed to excess body weight, stress heart, the feeling of effort required by physical activity and level of sedentary to obese. With a minute of walking, the obeses achieved a range of intensity cardiovascular trainning

Equações preditivas para as pressões respiratórias máximas de crianças brasileiras

I ntroduction: The assessment of respiratory muscle strength is important in the diagnosis and monitoring of the respiratory muscles weakness of respiratory and neuromuscular diseases. However, there are still no studies that provide predictive equations and reference values for maximal respiratory pressures for children in our population. Aim: The purpose of this study was to propose predictive equations for maximal respiratory pressures in healthy school children. Method: This is an observational cross-sectional study. 144 healthy children were assessed. They were students from public and private schools in the city of Natal /RN (63 boys and 81 girls), subdivided in age groups of 7-8 and 9-11 years. The students presented the BMI, for age and sex, between 5 and 85 percentile. Maximal respiratory pressures were measured with the digital manometer MVD300 (Globalmed ®). The maximal inspiratory pressure (MIP) and maximal expiratory pressures (MEP) were measured from residual volume and total lung capacity, respectively. The data were analyzed using the SPSS Statistics 15.0 software (Statistical Package for Social Science) by assigning the significance level of 5%. Descriptive analysis was expressed as mean and standard deviation. T'Student test was used for unpaired comparison of averages of the variables. The comparison of measurements obtained with the predicted values in previous studies was performed using the paired t'Student test. The Pearson correlation test was used to verify the correlation of MRP's with the independent variables (age, sex, weight and height). For the equations analysis the stepwise linear regression was used. Results: By analyzing the data, we observed that in the age range studied MIP was significantly higher in boys. The MEP did not differ between boys and girls aged 7 to 8 years, the reverse occurred in the age between 9 and 11 years. The boys had a significant increase in respiratory muscle strength with advancing age. Regardless sex and age, MEP was always higher than the MIP. The reference values found in this study are similar to a sample of Spanish and Canadian children. The two models proposed in previous studies with children from other countries were not able to consistently predict the values observed in this studied population. The variables sex, age and weight correlated with MIP, whereas the MEP was also correlated with height. However, in the regression models proposed in this study, only gender and age were kept exerting influence on the variability of maximal inspiratory and expiratory pressures. Conclusion: This study provides reference values, lower limits of normality and proposes two models that allow predicting, through the independent variables, sex and age, the value of maximal static respiratory pressures in healthy children aged between 7 and 11 years old

Equacões preditivas para as pressões respiratórias estáticas máximas de adolescentes brasileiros

Introduction: The reference values and prediction equations for maximal respiratory pressures (MRP) differ significantly between the available studies. This large discrepancy can be attributed to the different methodologies proposed. Although the importance of MRP is widely recognized, there are no Brazilian studies that provide predictive equations and reference values for PRM adolescents. Objectives: The purpose of this study was to provide normal values and propose predictive equations for maximal static respiratory pressures of Brazilian adolescents. Methods: An observational cross-sectional study, which evaluated 182 adolescents of both sexes aged between 12 and 18 years, enrolled in schools of the state and private in the city of Natal / RN. The selection of schools and participants of the study was randomly through a lottery system. The spirometric evaluation was performed through the digital spirometer One Flow FVC prior to the assessment of respiratory muscle strength. The MICs were measured with MVD digital manometer 300. Statistical analysis was performed using the SPSS 17.0 software STATISTICS, assigning the significance level of 5%. The normality of data distribution was verified using the Kolmogorov-Smirnov (KS). The descriptive analysis was expressed as mean and standard deviation. We used one-way ANOVA test to verify the difference of the averages of MRPs between age and gender and comparing the averages of MRPs between levels of physical activity. The test t'Student unpaired compared the averages of MRPs being ages and sexes. The comparison of mean values obtained in this study PRM with the values predicted using the equations mentioned above was relizada by testing paired t'Student. To verify the correlation between the PRM and the independent variables (age, weight, height) was used Pearson correlation test. Levene's test evaluated the homogeneity of variance. To obtain predictive equations analysis was used stepwise multiple linear regression. Results: There was no significant difference in mean age between the PRM. The male adolescents, regardless of age, showed superiority in MRP values when compared to the opposite sex. Weight, height and sex correlated with the PRM. Regression analysis suggested in this study, pointed out that the weight and sex had an influence in MIP and MEP only in relation to sex influenced. The mean for each PRM adolescents classified as very active were superior to those observed in adolescents classified as irregularly active. Conclusion: This study provides reference values and two models of predictive equations for maximal inspiratory and expiratory pressures, and to establish the lower limits of normality that will serve as an indispensable condition for careful evaluation of respiratory muscle strength in Brazilian adolescents

Prevalência de incontinência urinária e fatores associados em idosos institucionalizados

Urinary incontinence (UI) is a geriatric syndrome that is especially prevalent in institutionalized individuals, and that causes economic and social impacts derived from treatment costs and overload of caregiver. UI also entails physical consequences to the health of the elderly, such as urinary tract infections or pressure ulcers, among other health problems. However, the existing national research on this condition is still scarce and comprises serious methodological biases. Therefore, the objective of this study is to determine the prevalence of urinary incontinence and associated factors in institutionalized elderly. A cross-sectional study is presented herein, conducted between October and December, 2013 and carried out in 10 nursing homes in the city of Natal (Northeast Brazil). UI was verified through the program Minimum Data Set version 3.0, which was also used to assess fecal incontinence, urinary devices and UI control programs. Data collection included sociodemographic information, UI characterization, as well as variables related to the institution itself and to health conditions (comorbidities, medication, pelvic floor surgery, Barthel Index for functional capacity and Pfeiffer test for cognitive status). Bivariate analysis was performed using the Chi-Square Test (or Fisher‟s Exact Test) and the Linear Chi-Square Test, calculating the prevalence ratio with 95% confidence interval. Variables with p value under 0.20 were included in the multivariate analysis, which was performed using the Stepwise Forward logistic regression. The inclusion of variables in the final model depended on the likelihood ratio test, absence of multicollinearity and on the Hosmer-Lemeshow test. A statistical significance level of 0.05 was considered. Six (1.8%) hospitalized elderly, one individual in palliative care (0.3%) and one (0.3%) individual under the age of 60 were excluded from the study. The final sample consisted of 321 elderly, mostly females, with a mean age of 81.5 years. The prevalence of UI was 59.43% and the final model revealed statistically a significant association between UI and white race, physical inactivity, stroke, mobility constraints and cognitive decline. The most frequent UI type was functional UI due to physical or cognitive disability, and incontinence control measures were applied only to a minority of residents (approximately 8%). It is concluded that UI is a health issue that affects more than half of the institutionalized elderly, and is associated with white race, physical inactivity, stroke and other geriatric syndromes such as immobility and cognitive disability. Most of these associated factors are modifiable and therefore the findings of this study highlight the importance of UI prevention and treatment in nursing homes, which include general measures, such as physical and psychosocial activities, and specific measures, such as prompted voiding