80 resultados para Multiple Additive Regression Trees (MART)
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The aim of this study was to evaluate risk factors for low bone mineral density (BMD) and vertebral fractures, in juvenile systemic lupus (JSLE). Thirty-one consecutive patients with JSLE were compared with 31 gender- and age-matched healthy controls. BNID and body composition from all participants were measured using dual-energy X-ray absorptiometry. Vertebral fractures were defined as a reduction of >= 20% of the vertebral height for all patients. Lumbar spine and total femur BMD was significantly decreased in patients compared with controls (P = 0.021 and P = 0.023, respectively). A high frequency of vertebral fractures (22.58%) was found in patients with JSLE. Analysis of body composition revealed lower lean mass (P = 0.033) and higher fat mass percentage (P = 0.003) in patients than in controls. Interestingly, multiple linear regression using BMD as a dependent variable showed a significant association with lean mass in lumbar spine (R(2) = 0.262; P = 0.004) and total femur (R(2) = 0.419, P = 0.0001), whereas no association was observed with menarche age, SLE Disease Activity Index, Systemic Lupus International Collaborating Clinics/American College of Rheumatology, and glucocorticoid. This study indicates that low BMD and vertebral fractures are common in JSLE, and the former is associated with low lean mass, suggesting that muscle rehabilitation may be an additional target for bone therapeutic approach.
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A risk score model was developed based in a population of 1,224 individuals from the general population without known diabetes aging 35 years or more from an urban Brazilian population sample in order to select individuals who should be screened in subsequent testing and improve the efficacy of public health assurance. External validation was performed in a second, independent, population from a different city ascertained through a similar epidemiological protocol. The risk score was developed by multiple logistic regression and model performance and cutoff values were derived from a receiver operating characteristic curve. Model`s capacity of predicting fasting blood glucose levels was tested analyzing data from a 5-year follow-up protocol conducted in the general population. Items independently and significantly associated with diabetes were age, BMI and known hypertension. Sensitivity, specificity and proportion of further testing necessary for the best cutoff value were 75.9, 66.9 and 37.2%, respectively. External validation confirmed the model`s adequacy (AUC equal to 0.72). Finally, model score was also capable of predicting fasting blood glucose progression in non-diabetic individuals in a 5-year follow-up period. In conclusion, this simple diabetes risk score was able to identify individuals with an increased likelihood of having diabetes and it can be used to stratify subpopulations in which performing of subsequent tests is necessary and probably cost-effective.
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This study aimed to compare the resting energy expenditure (REE) of white and non-white severely obese Brazilian women. REE was examined in 83 severely obese Brazilian women (n = 58 white and 25 non-white) with mean (+/- SD) age 42.99 +/- 11.35 and body mass index 46.88 +/- 6.22 kg/m(2) who were candidates for gastric bypass surgery. Body composition was assessed by air displacement plethysmography (ADP) BOD PODO body composition system (Life Measurement Instruments, Concord, CA) and REE was measured, under established protocol, with an open-circuit calorimeter (Deltatrac II MBM-200, Datex-Ohmeda, Madison, WI, USA). There was no significant difference between the REE of white and non-white severely obese women (1,953 +/- 273 and 1,906 +/- 271 kcal/d, respectively; p = 0.48). However, when adjusted for fat free mass (MLG), REE was significantly higher in non-white severely obese women (difference between groups of 158.4 kcal, p < 0.01). REE in white women was positively and significantly correlated to C-reactive protein (PCR) (r = 0.41.8; P < 0.001) and MLG (r = 0.771; P < 0.001). In the non-white women, REE was only significantly correlated to MLG (r = 0.753; P < 0.001). The multiple linear regression analysis showed that skin color, MLG and PCR were the significant determinants of REE (R(2) = 0.55). This study showed that, after adjustment for MLG, non-white severely obese women have a higher REE than the white ones. The association of body composition inflammation factors and REE in severely obese Brazilian women remains to be further investigated.
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Background: There has been an increase in worldwide infections caused by carbapenem-resistant Acinetobacter. This poses a therapeutic challenge as few treatment options are available. Objectives: The aim of this study was to evaluate the efficacy and safety of polymyxins and ampicillin/sulbactam for treating infections caused by carbapenem-resistant Acinetobacter spp. and to evaluate prognostic factors. Methods: This was a retrospective review of patients from two teaching hospitals who had nosocomial infections caused by carbapenem-resistant Acinetobacter spp. from 1996 to 2004. Diagnosis of infection was based on CDC criteria plus the isolation of Acinetobacter from a usually sterile site or from bronchoalveolar lavage. Urinary tract infections were not included. Data on demographic and clinical features and treatment were collected from medical records. Prognostic factors associated with two outcomes (mortality during treatment and in-hospital mortality) were evaluated. Results: Eighty-two patients received polymyxins and 85 were treated with ampicillin/sulbactam. Multiple logistic regression analysis revealed that independent predictors of mortality during treatment were treatment with polymyxins, higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score, septic shock, delay in starting treatment and renal failure. On multivariate analysis, prognostic factors for in-hospital mortality were older age, septic shock and higher APACHE II score. Conclusions: This is the first study comparing current therapeutic options for infections due to carbapenem-resistant Acinetobacter. The most important finding of the present study is that ampicillin/sulbactam appears to be more efficacious than polymyxins, which was an independent factor associated with mortality during treatment.
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Objective: Metabolic syndrome (MS) is associated with subclinical atherosclerosis, but the relative role of obstructive sleep apnoea (OSA) is largely unknown. The main objective of this study is to determine the impact of OSA on markers of atherosclerosis in patients with MS. Methods: Eighty-one consecutive patients with MS according to the Adult Treatment Panel III underwent a clinical evaluation, polysomnography, laboratory and vascular measurements of carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV) and carotid diameter (CD) in a blind fashion. OSA was defined as an apnoea-hypopnoea index (AHI) >= 15 events/hour. Multiple linear regression was performed to determine the variables that were independently associated with the vascular parameters. Results: Fifty-one patients (63%) had OSA. No significant differences existed in age, sex, MS criteria, and cholesterol levels between patients with (MS+OSA) and without OSA (MS-OSA). Compared with MS-OSA patients, MS+OSA patients had higher levels of IMT (661 +/- 117 vs. 767 +/- 140 mu m), PWV (9.6 +/- 1.0 vs. 10.6 +/- 1.6 m/s), and CD (6705 +/- 744 vs. 7811 +/- 862 mu m) (P < 0.001 for each comparison). Among patients with MS+OSA, all vascular parameters were similar in patients with and without daytime sleepiness. The independent parameters associated with IMT, PWV, and CD were AHI, abdominal circumference, and systolic blood pressure (R(2) = 0.42); AHI and systolic blood pressure (R(2) = 0.38); and AHI, age, abdominal circumference and systolic blood pressure (R(2) = 0.45), respectively. The R(2) of AHI for IMT, PWV and CD was 0.12, 0.10 and 0.20, respectively. Conclusions: OSA is very common and has an incremental role in atherosclerotic burden in consecutive patients with MS. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
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OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.
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BACKGROUND Hypertension, a risk factor for cardiovascular diseases, and obesity are becoming a health problem in many developed and developing countries, as Brazil. Although hypertension and obesity are both closely associated, there is no universal anthropometric marker of this association. This is probably due to distinct population characteristics, and in the case of Brazil, the highly heterogeneous population. We evaluated which anthropometric measurement closely relates to high blood pressure in a sample of Brazilian factory workers. METHODS A cross-sectional study was designed. In this study, multiple logistic regression and receiver operating characteristics analysis were performed in order to obtain the precise relevance of each anthropometric measurement as a blood pressure marker. Nine hundred and thirteen men, 36 +/- 8 years-old, were submitted to a standardized questionnaire of demographic and risk factors knowledge, anthropometric and conventional blood pressure measurements were taken, and blood sample evaluations of glucose, total cholesterol, LDL-Cholesterol, and triglycerides were performed. RESULTS Overweightness or obesity was identified in 64, 11.1% were smokers and hypertension was detected in 29.2% of the participants. A linear correlation was significant (P < 0.001) between both the systolic and diastolic blood pressure and all anthropometric measurements, except for the systolic blood pressure and waist-to-hip ratio. Waist circumference (WC) was the only independent anthropometric measurement related to hypertension. Hypertensive patients presented all anthropometric measurements larger than normotensives. CONCLUSIONS Age and WC were the only independent predictors of hypertension, indicating that this simple measurement may be useful as a marker of hypertension in the Brazilian male, younger adult population. Am J Hypertens 2009; 22:980-984 (C) 2009 American Journal of Hypertension, Ltd.
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Obesity is a risk factor for GERD and a potential modulator of esophageal motility. To assess whether obese patients differ from non-obese patients in terms of esophageal motility and reflux. Patients (n = 332) were categorized in GERD and controls after clinical assessment, esophageal manometry, and pH monitoring. Non-obese (BMI 16-29.9) and obese (BMI 30-68) were compared in regard of distal esophageal amplitude (DEA), LES pressure (LESP), manometric diagnosis, and esophageal acid exposure (EAE). Obese showed higher DEA in both controls (122 +/- A 53 vs. 97 +/- A 36 mmHg, p = 0.041) and GERD patients (109 +/- A 38 vs. 94 +/- A 46 mmHg, p < 0.001), higher LESP in GERD patients (20.5 +/- A 10.6 vs. 18.2 +/- A 10.6 mmHg, p = 0.049), higher frequency of nutcracker esophagus in controls (30 vs. 0%, p = 0.001), lower frequency of ineffective motility in GERD patients (6 vs. 20%, p = 0.001), and higher EAE in both controls [total EAE: 1.6% (0.7-5.1) vs. 0.9% (0.2-2.4), p = 0.027] and GERD patients [upright EAE: 6.5% (3.8-11.1) vs. 5.2% (1.5-10.6), p = 0.048]. Multiple linear regression showed that BMI was associated either with EAE (p < 0.001), DEA (p = 0.006), or LESP (in men, p = 0.007). Obese patients differed from non-obese in terms of esophageal motility and reflux, regardless of the presence of GERD. Obese patients showed stronger peristalsis and increased acid exposure in the esophagus.
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Objective: To investigate the association of different types of magnetic resonance imaging (MRI)-detected medial meniscal pathology with subregional cartilage loss in the medial tibiofemoral compartment. Methods: A total of 152 women aged >= 40 years, with and without knee osteoarthritis (OA) were included in a longitudinal 24-month observational study. Spoiled gradient recalled acquisitions at steady state (SPGR) and T2-weighted fat-suppressed MRI sequences were acquired. Medial meniscal status of the anterior horn (AH), body, and posterior horn (PH) was graded at baseline: 0 (normal), 1 (intrasubstance meniscal signal changes), 2 (single tears), and 3 (complex tears/maceration). Cartilage segmentation was performed at baseline and 24-month follow-up in various tibiofemoral subregions using computation software. Multiple linear regression models were applied for the analysis with cartilage loss as the outcome. In a first model, the results were adjusted for age and body mass index (BMI). In a second model, the results were adjusted for age, BMI and medial meniscal extrusion. Results: After adjusting for age, BMI, and medial meniscal extrusion, cartilage loss in the total medial tibia (MT) (0.04 mm, P=0.04) and the external medial tibia (eMT) (0.068 mm, P=0.04) increased significantly for compartments with grade 3 lesions. Cartilage loss in the total central medial femoral condyle (cMF) (0.071 mm, P=0.03) also increased significantly for compartments with grade 2 lesions. Cartilage loss at the eMT was significantly related to tears of the PH (0.074 mm; P=0.03). Cartilage loss was not significantly increased for compartments with grade 1 lesions. Conclusion: The protective function of the meniscus appears to be preserved in the presence of intrasubstance meniscal signal changes. Prevalent single tears and meniscal maceration were found to be associated with increased cartilage loss in the same compartment, especially at the PH. (C) 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
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Objectives. To compare pelvic floor muscle (PFM) strength between women undergoing vaginal delivery, cesarean section, and nulliparae, investigating the factors associated with PFM strength, and observing the correlation between vaginal digital palpation and use of a perineometer. Methods. A cross-sectional study was conducted, including 31 women following vaginal delivery, 30 women following cesarean section, and 30 nulliparous women. PFM strength was measured by vaginal digital palpation and use of a perineometer. Multiple linear regression analysis with adjustment for covariables was used to compare the mean PFM strength and identify its associated factors. Results. The mean PFM strength of women undergoing vaginal delivery and cesarean section was 25.6 +/- 14.5 cmH(2)O and 39.6 +/- 22.0 cmH(2)O (p < 0.01, adjusted for covariables), respectively. A correlation was observed between measurements of PFM strength obtained by vaginal digital palpation and use of a perineometer (tau = 0.82; p < 0.01). The non-white race/ethnicity was negatively associated with PFM strength (coefficient: -10.2424; p = 0.02). Conclusions. A lower PFM strength was observed in women with a history of vaginal delivery compared to those undergoing cesarean section. Non-white race/ethnicity negatively affected PFM strength. Our data suggest that vaginal digital palpation may be used in clinical practice because of its expressive correlation with use of a perineometer.
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Background: Birth weight is positively associated with adult bone mass. However, it is not clear if its effect is already evident in early adulthood. Objective: To investigate the association between birth weight, adult body size, the interaction between them and bone mass in young adults. Methods: Bone densitometry by DXA was performed on 496 individuals (240 men) aged 23-24 years from the 1978/79 Ribeirao Preto (southern Brazil) birth cohort, who were born and still residing in the city in 2002. Birth weight and length as well as adult weight and height were directly measured and converted to z-scores. The influence of birth weight and length, and adult weight and height on bone area (BA), bone mineral content (BMC) and bone mineral density (BMD) at the lumbar spine, proximal femur and femoral neck were investigated through simple and multiple linear regression models. Adjustments were made for sex, skin color, gestational age, physical activity level, smoking status and dietary consumption of protein, calcium and alcohol. Interaction terms between birth weight and adult weight, and birth length and adult height were tested. Results: Men in the highest fertile of birth weight distribution had greater BA and BMC at all three bone sites when compared with their counterparts in the lowest tertiles (p<0.008). For BMD, this trend was observed only in the lumbar spine. Adult weight and height were positively associated with BA and BMC at all three bone sites (p<0.05). For BMD, these associations were seen for adult weight, but for adult height an association was observed only in the lumbar spine. Birth weight retained positive associations with proximal femur BA and BMC after adjustments for current weight and height. No interaction was observed between variables measuring prenatal growth and adult body size. Conclusion: Birth weight and postnatal growth are independent determinants of adult bone mass in a sample of Brazilian adults. This effect is already evident in early adulthood. (C) 2010 Elsevier Inc. All rights reserved.
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Context: Genetic factors that influence the response to recombinant human GH (rhGH) therapy remain mostly unknown. To date, only the GH receptor gene has been investigated. Objective: The aim of the study was to assess the influence of a polymorphism in the IGF-binding protein-3 (IGFBP-3) promoter region (-202 A/C) on circulating IGFBP-3 levels and growth response to rhGH therapy in children with GH deficiency (GHD). Design and Patients: -202 A/C IGFBP3 genotyping (rs2854744) was correlated with data of 71 children with severe GHD who remained prepubertal during the first year of rhGH treatment. Main Outcome Measures: We measured IGFBP-3 levels and first year growth velocity (GV) during rhGH treatment. Results: Clinical and laboratory data at the start of treatment were indistinguishable among patients with different -202 A/C IGFBP3 genotypes. Despite similar rhGH doses, patients homozygous for the A allele presented higher IGFBP-3 SD score levels and higher mean GV in the first year of rhGH treatment than patients with AC or CC genotypes (first year GV, AA = 13.0 +/- 2.1 cm/yr, AC = 11.4 +/- 2.5 cm/yr, and CC = 10.8 +/- 1.9 cm/yr; P = 0.016). Multiple linear regression analyses demonstrated that the influence of -202 A/C IGFBP3 genotype on IGFBP-3 levels and GV during the first year of rhGH treatment was independent of other variables. Conclusion: The -202 A allele of IGFBP3 promoter region is associated with increased IGFBP-3 levels and GV during rhGH treatment in prepubertal GHD children. (J Clin Endocrinol Metab 94: 588-595, 2009)
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Background. Respiratory symptoms associated with smoking habit seem to be age dependent. However, there are few reports about the effect of tobacco in young populations. The objective of this study was to analyze the effect of smoking on respiratory symptoms and lung function in 23- to 25-year-old adults in Brazil. This study had a cross-sectional design and included 2063 young people in the city of Ribeirao Preto, Sao Paulo State. Methods: Subjects completed a questionnaire used by the European Community Respiratory Health Survey and underwent spirometry and bronchial challenge test with methacholine. Multiple logistic regression analysis and multiple linear regression analysis were carried out to assess the association between smoking and respiratory symptoms, bronchial hyperresponsiveness, forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC), adjusted for confounding variables. Results: Prevalence of smoking habit was 17.2% with consumption (median) of 10 cigarettes per day (interquartile range 3-20). There was a significant association between smoking and respiratory symptoms. Smoking was associated to wheezing with odds ratio (95%Cl) of 6.11 (4.03-9.28) among those smoking :10 cigarettes per day and 3.36 (2.11-5.37) among those smoking <10 cigarettes per day. Associations were found for other respiratory symptoms. Smoking was associated with lower FEV1/FVC ratio. No association was detected between smoking and FEV1 or bronchial hyperresponsiveness. Conclusions: These findings highlight the early health consequences of smoking among young adults. These results prompt the necessity to elaborate urgent programs to reduce tobacco habit in young populations.
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Although antibodies to Bartonella henselae have been described in all neotropical felid species, DNA has been detected in only one species, Leopard us wiedii. The aim of this study was to determine whether DNA of Bartonella spp. could be detected in blood of other captive neotropical felids and evaluate risk factors and hematological findings associated with infection. Blood samples were collected from 57 small felids, including 1 Leopard us geoffroyi, 17 L wiedii, 22 Leopardus tigrinus, 14 Leopardus pardalis, and 3 Puma yagouaroundi; 10 blood samples from Panthera onca were retrieved from blood banks. Complete blood counts were performed on blood samples from small felids, while all samples were evaluated by PCR. DNA extraction was confirmed by amplification of the cat GAPDH gene. Bartonella spp. were assessed by amplifying a fragment of their 16S-23S rRNA intergenic spacer region; PCR products were purified and sequenced. For the small neotropical felids, risk factors [origin (wild-caught or zoo-born), gender, felid species, and flea exposure) were evaluated using exact multiple logistic regression. Hematological findings (anemia, polycythemia/hyperproteinemia, leukocytosis and leukopenia) were tested for association with infection using Fisher`s exact test. The 635 bp product amplified from 10 samples (10/67 = 14.92%) was identified as B. henselae by sequencing. Small neotropical felid males were more likely to be positive than females (95% CI = 0.00-0.451, p = 0.0028), however other analyzed variables were not considered risk factors (p > 0.05). Hematological abnormalities were not associated with infection (p > 0.05). This is the first report documenting B. henselae detection by PCR in several species of neotropical felids. (C) 2009 Elsevier B.V. All rights reserved.
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Objective. The aim of this study was to assess the prevalence, extent, and risk indicators of tooth loss in an isolated population of Brazil. Material and methods. Two-hundred-and-forty-two subjects, ranging in age from 14 to 82 years (mean 36.2 years), were identified by census in an isolated population of Brazil. All consenting subjects received a full-mouth clinical (DFT index and information about missing teeth) and periodontal examination of 6 sites per tooth. Furthermore, they were interviewed using a structured written questionnaire in order to gather information about demographic, environmental, and biological variables. Results. Of the 200 subjects (80% response rate), 19 (9.5%) were edentulous, 90% had lost at least one tooth, and 39% had lost more than 8 teeth. The mean number of teeth lost was 9.5 (95% CI = 8.2-10.8). First mandibular molars were the most commonly missing teeth. In a multiple logistic regression analysis based on a theoretical hierarchical model of tooth loss, having more than 8 teeth lost was strongly associated with adult age (OR = 18.3-17.3, 95% CIs = 4.8-69.7 and 4.0-75.1) and female gender (OR = 5.9, 95% CI = 1.9-18.2) in the final model. Conclusions. Tooth loss was highly prevalent and extensive in this isolated population. Demographic and behavioral factors played an important role in tooth loss prevalence in this population.