BMI Data Research Articles

Obese men, higher PSA nadir values after radical prostatectomy (RP), and higher biochemical recurrence (BCR) rates: Results from the SEARCH database.

186 Background: Obesity is associated with risk of BCR after RP. It has been suggested this may be due to poor surgical technique and greater risk of positive margins. We examined whether obesity predicted the risk of a detectable PSA nadir after RP (as a measure of residual PSA-producing tissue left behind) and if this accounted for the greater risk of BCR in obese men in the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Methods: We identified 1,011 men treated with RP from 2001 to 2010 in SEARCH who had known data for pre-operative BMI and ultrasensitive PSA nadir within 6 months after RP. The association between BMI (<25, 25-29.9, and >30 kg/m2) and PSA nadir (0, 0.01-0.09, 0.10-0.19, and >0.2) was tested using chi-squared and linear regression adjusting for clinical and pathological characteristics. A proportional hazards model was used to test the association between BMI and BCR adjusted for clinical and pathological characteristics and with and without PSA nadir. Results: Higher BMI was associated with higher PSA nadir (chi-squared, p=0.03). On multivariate analysis, obesity (p<0.001) was associated with higher PSA nadir. Among men with a PSA nadir <0.2 ng/ml (i.e. those who did not recur based upon PSA nadir alone), obesity was associated with BCR when not adjusted for PSA nadir (HR 1.85, 95% CI 1.19-2.89, p=0.007). Adjusting for PSA nadir attenuated, but did not eliminate this association (HR 1.65, 95% CI 1.05-2.59, p=0.03). Even among men with an undetectable PSA nadir, obesity remained significantly associated with BCR (HR 3.45, 95% CI 1.41-8.47, p=0.007). Interestingly, among men with a detectable PSA nadir, but <0.2 ng/ml, obesity did not predict BCR with (HR 1.21, 95% CI 0.71-2.07, p=0.49) or without adjustment for PSA nadir (HR 1.41, 95% CI =0.82-2.41, p=0.22). Conclusions: Obese men are more likely to have a higher PSA nadir suggesting technical issues confound an ideal operation in obese men. However, the increased PSA nadir does not completely explain the higher PSA recurrence rates. These data further support the idea that obesity is biologically associated with prostate cancer progression. No significant financial relationships to disclose.

Family History of Diabetes and Parental Consanguinity: Important risk for Impaired Fasting Glucose

Abstract Objective: Offspring of type 2 diabetics have incre-ased risk of metabolic disturbances. The aim of the study was to access the potential effect of family his-tory of type 2 diabetes (FHD) and parental consangui-nity on fasting plasma glucose (FPG) levels. Design: Non diabetic offspring of one or both parents with type 2 diabetes and healthy controls of compar-able age, without a FHD were the subjects of this stu-dy. FHD was defined by the presence of type 2 diabe-tes in one or both parents of the subject. Consanguinity was defined as history of marriage with first cousin. FPG levels were determined in cases and controls. Results: IFG was identified in 42% subjects with a FHD and in 14% without FHD. We found a strong in-dependent association of FHD with impaired fasting glucose in both males and females by logistic regres-sion analysis after adjusting the data for age sex and BMI. Parental consanguinity modifies the effect of FHD on IFG. Conclusion: We concluded that family history of dia-betes and parental history of consanguinity determine the risk for impaired fasting glucose in our population. Keywords: Impaired fasting glucose; Parental con-sanguinity; Family history of diabetes.

Demographic, Residential, and Socioeconomic Effects on the Distribution of 19th Century White Body Mass Index Values

Little research exists on the body mass index values of 19th century Americans of European descent. Using a new BMI data set and robust statistics, between 1860 and 1880, BMIs decreased across the distribution; however, after 1880, BMIs in the highest quantiles increased, while those in lower BMI quantiles continued to decrease. Late 19th and early 20th century white BMIs increased at older ages in higher quantiles and decreased in lower quantiles, indicating significant net biological disparity by age. During industrialization, white BMIs were lower in Kentucky, Missouri, and urban Philadelphia.

Demographic, Residential, and Socioeconomic Effects on the Distribution of 19th Century African-American Body Mass Index Values

Little research exists on the body mass index values of late 19th and early 20th century African-Americans. Using a new BMI data set and robust statistics, this paper demonstrates that late 19th and early 20th century black BMI variation by age increased in their mid-30s but declined at older ages when worker physical productivity declined. Throughout the late 19th and early 20th centuries, black BMIs decreased across the distribution, indicating that the 20th century increase in black BMIs did not have its origin in the 19th century. During industrialization, black BMIs were lower in Kentucky, Missouri, and urban Philadelphia.

Abstract S2-1: Obesity at Diagnosis Is Associated with Inferior Outcomes in Hormone Receptor Positive Breast Cancer

Abstract Background: Obesity has been associated with worse outcomes in operable breast cancer. We evaluated the effect of obesity on outcomes in several adjuvant trials coordinated by the ECOG which included doxorubicin/cyclophosphamide plus other agents, including E1199 (NEJM 2008; 358: 1663), E5188 (JCO 2005; 23: 5973) and E3189 (JCO 10998; 16: 2382). Methods: The relationship between body mass index (BMI in kg/m2) and disease free survival (DFS) and overall survival (OS) was evaluated in multivariate models adjusted for covariates including age, tumor size, nodal status, race (black vs. other), surgery type, prior RT, menopausal status, treatment arm, and treatment adherence. Results are expressed as hazard ratios (HR) from Cox's proportional hazards models (HR > 1 indicates a worse outcome). All p-values are two sided. Results: The study characteristics and results are shown in the table below. We first evaluated results for the E1199 trial (for the 75% of those with BMI data available) and found a non-significant trend toward inferior DFS (HR 1.10, 95% CI 0.96, 1.26, p=0.18) and OS (HR 1.13, 95% CI 0.96, 1.33, p=0.15) for obese subjects compared with others. When evaluated by breast cancer subtype, however, obese subjects with ER and/or PR-positive/HER2-negative disease had significantly inferior DFS (HR 1.24, p=0.026) and OS (HR 1.42, p=0.003), an effect that was not seen for HER2-positive and triple negative disease. In a model including obesity, ER and/or PR-pos/HER2-neg disease, and their interaction, the interaction term was significant for OS (p=0.017) but not DFS (p=0.21). There was no evidence for differing chemotherapy delivery or endocrine therapy adherence, or differences in toxicity for obese subjects in the E1199 trial. We then evaluated the relationship between obesity and outcomes in two prior ECOG studies which included only premenopausal women with ER positive, node positive breast cancer (E5188) and women of any age with ER/PR negative, node positive disease (E3189), and confirmed a relationship between obesity and poor outcomes only in women with hormone receptor positive disease. HR-hazard ratio; ER/PR-estrogen/progesterone receptor Conclusions: Obesity was associated with significantly inferior DFS and OS in hormone receptor positive operable breast cancer treated with adjuvant chemotherapy. These findings suggest that hyperinsulinemia or other factors associated with obesity may predispose to recurrence specifically in hormone receptor positive disease, and requires further evaluation in prospective studies in order to identify modifiable factors contributing to this effect. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S2-1.

The influence of socioeconomic position and parental rules on sedentary behaviour in preschool children

A sample of 1403 participants (674 females and 729 males) was available for analysis. Data for BMI, physical fitness and activity, sedentary behaviour, socioeconomic status, motor competence, diet, self concept, and the school environment were used to develop exploratory structural equation models (AMOS, SPSS) at 6, 8, 10 and 14 years. The interrelationships between physical activity and sedentary behaviours changed across models at 6 years ( 2 (df = 22) = 25.036, p = .295), 8 years ( 2 (df = 32) = 33.326, p = .403), 10 years ( 2 (df = 40) = 47.820, p = .185) and 14 years ( 2 (df = 57) = 59.487, p = .385), withmotor competence becoming important at adolescence. The relationship between screen time and physical activity as predictors of BMI was complex, and changed between 6, 8, and 10 years. By 14 years of age motor competency, aerobic fitness and physical activity were highly interrelated and together predicted BMI. These exploratory analyses also identified that diet, the school environment, self-concept, and the valuing of physical activity were not important for BMI. Significant differences in pathways were also found between males and females. For example, the pathway between income and screen time was significant for males, but not females at age 14 years. Interrelationships among obesogenic factors are complex, dynamic and individualised. Their influence on BMI operates in both direct and indirect ways and changes with age between 6 and 14 years. Interventions for obesity must consider age and gender specific differences in pathways and mechanisms.

034 Growth, weight and neuroleptics in children with Tourette syndrome

AimsChildren with Tourette syndrome are frequently given neuroleptics to suppress tics. These agents are generally associated with weight gain and other metabolic consequences which would clearly be of particular concern...

Pregestational body mass index, weight gain during pregnancy and maternal hyperglycemia

Objective. To evaluate the associations between pregestational BMI and weight gain during pregnancy and the risk for maternal hyperglycemia.Methods. The charts of all patients who delivered at our hospital between June 2001 and June 2006 were reviewed. Maternal hyperglycemia categories were defined as GDM (by the Carpenter and Coustan criteria); Impaired glucose tolerance (IGT – only one abnormal value in the 100 g OGTT); Abnormal GCT (≥140 mg/dL) but no high values on the OGTT. Women with GCT < 140 were defined as normal glucose tolerance (NGT).Results. Pregravid BMI and glucose tolerance data were available for 9269 women. We also had data on weight gain during pregnancy for 7766 of these women. There was strong graded association between increasing BMI category and all levels of maternal hyperglycemia. There was significant negative correlation between BMI and weight gain during pregnancy (R = −0.251, P value < 0.0001). However, in the multivariate logistic regression model, only pregestational BMI was significantly associated with maternal hyperglycemia, whereas weight gain during pregnancy was no longer significant.Conclusions. Obesity is a strong predictor for gestational maternal hyperglycemia. Weight gain during pregnancy has less effect. Every effort should be made for pregestational weight reduction in overweight women.

Health factors and longevity in men and women: a 26-year follow-up study

Health factors have the power to prevent and postpone diseases and death; however, studies using the same methodology in both men and women are sparse. We aimed to study the ability of health factors to prevent mortality in a population-based, 26-year follow-up of Swedish men and women. During 1969-70, a health-screening programme was offered to a stratified sample of 3,064 individuals aged 18-64 years to estimate health-care needs. Missing data (largely according to protocol) for physical fitness, BMI, and smoking habits left 935 subjects, 463 men and 472 women. Alcohol consumption in grams per week and BMI was calculated. Tobacco smoking was recorded as yes/no. Multivariate analysis was performed by Cox regression with age adjusted hazard ratios (HR) and 95% confidence interval (CI). Moderate alcohol consumption did not lead to any decrease in mortality. Having two health factors halved the mortality risk in men and women (hazard ratio (HR) 0.52, confidence interval (CI) 0.39-0.70). A further risk reduction was seen in men with three health factors (HR 0.17, CI 0.074-0.41). Men had about 70 per cent higher risk of mortality compared with women after adjustments for all health factors (HR 1.67, CI 1.26-2.23). Men compared to women had greater benefit of all three health factors. This in combination with the overall higher mortality risk in men makes a healthy lifestyle more important for them. The benefit of moderate alcohol consumption could not be detected in this study, and may be explained by an unhealthy drinking pattern in Sweden.

Paternal Smoking and Childhood Overweight: Evidence From the Hong Kong “Children of 1997”

This study examined, in a non-Western sociohistorical context, whether prenatal or postnatal secondhand smoke (SHS) exposure for children of nonsmoking mothers was associated with higher childhood BMI, and it clarified whether the observed associations were biologically mediated or socioeconomically confounded. A total of 6710 and 6519 children of nonsmoking mothers (N = 7924) with BMI data at approximately 7 and approximately 11 years, respectively, from a population-representative (N = 8327), Hong Kong Chinese birth cohort ("Children of 1997"), born in April or May 1997, were included in the analysis. Compared with no SHS exposure, daily paternal smoking increased mean BMI z scores, but not height, at 7 years (difference: 0.10 [95% confidence interval: 0.02-0.19]) and at 11 years (difference: 0.16 [95% confidence interval: 0.07-0.26]), with adjustment for gender, birth order, socioeconomic position, mother's place of birth, breastfeeding, serious morbidity, and pubertal status. Our findings, although preliminary, suggest that the association of paternal smoking with child overweight might be biologically mediated. Given the known harms of smoking, reducing SHS exposure from conception as a precautionary action for childhood overweight might be warranted.

Prevalence of Overweight and Obesity in Adolescents With Severe Mental Illness

Pediatric obesity (body mass index [BMI] > or = 95th percentile for sex and age) and overweight (BMI > or = 85th percentile < 95% percentile) are priority public health targets for the prevention of diabetes and cardiovascular disease. We examined the prevalence and risk of overweight and obesity in adolescents with serious mental disorders. Height, weight, demographic, diagnostic, and treatment data were reviewed for 114 adolescents attending a partial hospitalization program over 18 consecutive months between January 2003 and July 2004. Sample data were compared to normative National Health and Nutrition Examination Survey data and regional county data for BMI. Unadjusted odds ratios and their 95% CIs were calculated for each categorical risk factor using the chi-squared test. A logistic regression model was conducted to detect the effects of these risk factors on the occurrence of overweight and obesity. The combined prevalence of overweight and obesity was 55.4% (n = 63); the prevalence for obesity alone was 30% (n = 34), approximately double the rate in national and county norms. Lack of private insurance, smoking, and antidepressant and antipsychotic treatment were associated with overweight and obese status. Adolescents with severe mental illness are at increased risk for overweight and obesity. Identification of elevated BMI, associated risk factors, and efforts to prevent weight gain should begin at initiation of mental health treatment.

Global Trends, Dynamics and Correlates of Obesity: A 48‐country analysis of repeated surveys

This study looks at the global trends (changes in prevalence per year) of growth in overweight and obesity for adult women, and some of the associated macroeconomic factors. It uses repeated (3–5 per country) nationally representative surveys with directly measured BMI data from 48 countries, representing developing countries in Asia (East, South and South‐east), Middle East, Africa (North, West and East), Latin America(Central, South), Russia, and also developed countries of the UK, USA and Australia. We summarize these trends and examine acceleration in annualized prevalence using development indicators such as per capita GDP, female education attainment, equality and fertility measures. The prevalence of overweight and obesity have grown significantly in the past 20 years. In particular, developing nations have higher rates of increase compared to developed nations. These upward trends are especially steep in countries like Nicaragua, Peru, China and Indonesia, while prevalence levels are consistently high in developed nations and the Middle East. Levels of education, urbanization and GNP per capita differentially affect these trends across the globe.

The Great Chinese Famine Leads to Shorter and Overweight Females in Chongqing Chinese Population After 50 Years

This study investigated a possible association between early nutritional status during the famine, and the risk of overweight and obesity in adulthood in Chongqing Chinese population. The body weight, height, and BMI data were obtained from records of population (17,023) that had annual physical evaluations in the Public Health Center (in our hospital). Subjects born during 1956-1964 were divided into three groups: toddler group, all subjects who were born 1-3 years before the famine (1956-1958); gestational group, who were born during the famine period (1959-1961), and control group, who were born after the famine (1962-1964). The body weight and BMI were significantly higher, but the body height was significantly lower in the toddler and gestational groups (P < 0.05) in the female population as compared to the control group. The odds ratio of being overweight in females is more pronounced in the toddler group (1.48 times, 95% confidence interval (CI): 1.288-1.689) than in the gestational group (1.26 times, 95% CI: 1.089-1.457). The odds ratio of being obese in females is significantly higher in the toddler group (1.46 times, 95% CI: 1.288-1.689) than the control group. For males, the famine had no impact at all on the adulthood body weight in males. The Great Chinese Famine that affected the Chongqing population during 1959-1961 leads to shorter and overweight females, and the former is a risk factor for increased BMI in Chongqing. Second, the famine seems to be producing shorter but slimmer males in Chongqing. Furthermore, toddler's and maternal's malnutrition during the famine had important late consequences on the health status.

The Relationship between Physical Activity and Body Mass Index: Issues in Model Specification

Abstract Objective: To investigate the best statistical models that describe the effect of physical activity on BMI.*Design*: Cross-sectional analyses of physical activity and BMI data. *Subjects*: 107 obese, overweight, and healthy college students (mean duration of physical activity for the normal, overweight, and obese students: 89, 59, and 24 months, respectively; mean BMI for the normal, overweight, and obese students: 21.61, 27.07, and 35.54 kg/m2, respectively).*Measurements*: Inverse linear, inverse logarithmic, and inverse logistics models were used to analyze survey data for physical activity (measured by both frequency and duration of exercise) and BMI. Gender, age, and physical intensity variables were also statistically controlled. *Results*: Coefficients of determination, r-squared, showed the inverse logarithmic model is more accurate in describing the effect of physical activity on BMI than is the inverse linear model. The inverse logistic method also showed physical activity affects BMI. Conclusions: Although the inverse logarithmic method can be used in some cases, the inverse logistic model seems to be theoretically and empirically best suited in describing the relationship between physical activity and body weight.

Clinical profile of patients enroled in a cell therapy trial for severe coronary artery disease

To compare the clinical profile of patients included in a clinical trial of autologous bone marrow cells as an adjunctive therapy to coronary artery bypass grafting with that of patients undergoing routine coronary artery bypass grafting. The therapeutic potential of autologous bone marrow cells has been explored in the treatment of severe coronary artery disease. There are few data regarding the clinical and socio-economic profile of patients included in clinical trials using bone marrow cell. Case-control study. Sixty-seven patients (61 SD 9) years, 82% men) with multivessel coronary artery disease were divided into two groups: patients in the bone marrow cell group (n = 34) underwent incomplete coronary artery bypass grafting + intramyocardial injection of autologous bone marrow cells (lymphomonocytic fraction -2.0 (SD 0.2 x 10(8)) cells/patient) in the ischaemic, non-revascularised myocardium, whereas patients in the coronary artery bypass grafting group (n = 33) underwent routine bypass surgery. Demographics, socio-economic status, clinical and echocardiographic data were collected. Statistical analysis included the Fisher's exact test (categorical variables) and the Student's t-test (continuous variables). There were no significant differences between groups regarding age, gender, BMI, heart rate, blood pressure and echo data. There was a greater prevalence of obesity (65 vs. 33%; OR = 3.7 [1.3-10.1]), of previous myocardial infarction (68 vs. 39%; OR = 3.2 [1.2-8.8]) and prior revascularisation procedures (59 vs. 24%; OR = 4.5 [1.6-12.7]) in the autologous bone marrow cells group and of smokers in the coronary artery bypass grafting group (51 vs. 23%; OR = 3.5 [1.2-10.4]). Patients included in this clinical trial of autologous bone marrow cells for severe coronary artery disease presented a greater prevalence of myocardial revascularisation procedures, indicating a more severe clinical presentation of the disease. Fewer smokers in this group could be attributable to life style changes after previous cardiovascular events and/or interventions. The knowledge of the clinical profile of patients included in cell therapy trials may help researchers in the identification of patients that may be enroled in future clinical trials of this new therapeutic strategy.

Comparison of the Body Mass Index to other Methods of Body Fat Assessment in Bulgarian Children and Adolescent

ABSTRACTThe purpose of this study is to assess the body composition and body nutritional status of children and adolescents with the values of BMI and the percentage of body fat. We transversally examined 2269 children and adolescents from South Bulgaria/1114 boys and 1155 girls/, aged 7 to 17 during 2008–2009. We applied the anthropometric and bioimpedance-metric methods. The results show that throughout the observed age period, boys have a bigger amount of fat-free body mass per unit height, and girls accumulate greater amount of fat mass per unit height. According to the BMI data, the average frequency of occurrence of underweight is 5% higher in girls, while the frequency of occurrence of overweight is on average 9% higher in boys. The comparison of the results for body nutritional status from both methodical approaches shows that according to the percentage of body fat, the average frequency of underweight occurrence is higher than the average frequency of overweight and obesity occurrences, but according to the discriminatory BMI values, the frequency of overweight occurrence is much higher. This is probably due to the fact that the discriminatory values of BMI were developed for each age and gender groups, while those for the percentage of body fat, although developed for both sexes, were the same for the entire age period. The results obtained confirm the need the body nutritional status of children and adolescents to be assessed through at least the two components of the body weight.

Recent dynamics suggest selected countries catching up to US obesity

The United States has been the country with the highest body mass indexes (BMIs; in kg/m(2)) at higher centiles, but research that compares the United States with other nations is lacking. To present a picture of global obesity and examine the shifts in BMI in children, I examined BMI data for men and women at the upper ends of the BMI distributions in Australia, China, the United Kingdom, and the United States. As representative data, I used directly measured weight and height for children aged 6-18 y and for men and women aged > or =19 y. Quantile regression analysis with BMI was used to determine the outcome, and the coefficients of age, age squared, and age cubed represented the explanatory variables plotted to determine mean BMI at the 95th centile for each age group. Overweight and obesity measures across all selected countries, with the use of nationally representative surveys and the 95th centile mean BMI, were determined. Among women, much larger increases were found in mean BMI at the 95th percentile in Australia (+5.7 BMI units) and the United Kingdom (+3.7 BMI units) than in the United States (+2.7 BMI units) in one-half the time. In contrast, among children, younger Chinese children experienced the largest increase. For example, the mean BMI at the 95th centile for 6-y-old Chinese children is 24.8 (a 5.0 increase), which is 2.6 BMI units more than the BMI at the 95th centile for children in the United States. Among children, BMIs for US children at the 95th centile are below those in China, whereas among women, Australian and UK women are rapidly approaching BMIs found in US women.

Correlation of Fat Distribution in Whole Body MRI With Generally Used Anthropometric Data

: Obesity is a commonly known risk for many diseases such as metabolic syndrome and cardiovascular disease. Especially important is the discrimination of the adipose tissue inside the abdomen and the subcutaneous adipose tissue. Aim of this study was to compare the whole body fat distribution, and the volume of different adipose tissue compartments respectively, with anthropometric data. : Sixty-eight volunteers (20 males, 48 females, 42.3 +/- 15.4 years) were investigated in the context of 2 whole body magnetic resonance imaging (MRI) studies which compared the body fat distribution of depressive and bulimic patients with healthy controls. Unpublished data acquired in these studies were analyzed retrospectively.The sample consisted of 38 healthy volunteers, 17 patients with a depressive syndrome and 13 women suffering from bulimia nervosa. Individual body volume, total adipose tissue (TAT) volume, subcutaneous adipose tissue (SCAT) volume at the trunk, and visceral adipose tissue (VAT) volume were determined, using whole body MRI. Additionally, body fat profiles were standardized and a mean body distribution was calculated. Other modalities to acquire body fat content were: skin fold caliper, body impedance (3 different devices) and simple anthropometric data (Waist to Hip Ratio [WHR], Body Mass Index [BMI], distance of the aponeurosis of the rectus abdominis muscle to the ventral rim of the abdominal aorta (measured in MRI images on umbilical level) (AD) and subcutaneous adipose tissue thickness at the same level). The different modalities were correlated with the MRI data. : There were highly significant correlations between the skin fold data and TAT (Spearman coefficient 0.668, P >/= 0.0004) and SCAT (0.662, P >/= 0.0004). But there was no correlation with VAT. Impedance data revealed significant correlations of TAT and SCAT (Spearman 0.7, P >/= 0.0004).Simple anthropometric data like waist and hip circumference, WHR, and BMI revealed significant correlations (Spearman coefficient around 0.7-0.4, P < 0.05) with the fat compartments TAT, VAT, and SCAT.The standardized body fat slices and the VAT slices were correlated with the anthropometric data and impedance data to explore specific areas along the body axis where the correlations were higher or weaker. Skinfold data, BMI, and body impedance data yielded significant correlations with TAT along the whole body axis, as well as with VAT in almost the whole analyzed area. However, there was no special body region with locally higher correlations. WHR depicted high correlations with whole VAT, and regional TAT at the abdomen (and not with the other body regions) especially in women. Therefore, it seems to be the best marker for abdominal fat and VAT in this study. : We compared different body measures and body fat devices with the whole body fat distribution acquired by MRI. Generally, there were significant correlations of all modalities with body fat content (TAT) and mainly with SCAT. Correlations with VAT compartment were much weaker and an adequate estimation of VAT is, therefore, not possible. Only WHR revealed significant correlations with the fat in the body center, but only in women. If it is important to investigate especially the VAT which is responsible for a higher cardiovascular risk, risk for a metabolic syndrome and that is correlated with the course of different psychiatric diseases, cross sectional techniques such as MRI can not be substituted by simpler methods.

Sequential Monte Carlo Point-Process Estimation of Kinematics from Neural Spiking Activity for Brain-Machine Interfaces

Many decoding algorithms for brain machine interfaces' (BMIs) estimate hand movement from binned spike rates, which do not fully exploit the resolution contained in spike timing and may exclude rich neural dynamics from the modeling. More recently, an adaptive filtering method based on a Bayesian approach to reconstruct the neural state from the observed spike times has been proposed. However, it assumes and propagates a gaussian distributed state posterior density, which in general is too restrictive. We have also proposed a sequential Monte Carlo estimation methodology to reconstruct the kinematic states directly from the multichannel spike trains. This letter presents a systematic testing of this algorithm in a simulated neural spike train decoding experiment and then in BMI data. Compared to a point-process adaptive filtering algorithm with a linear observation model and a gaussian approximation (the counterpart for point processes of the Kalman filter), our sequential Monte Carlo estimation methodology exploits a detailed encoding model (tuning function) derived for each neuron from training data. However, this added complexity is translated into higher performance with real data. To deal with the intrinsic spike randomness in online modeling, several synthetic spike trains are generated from the intensity function estimated from the neurons and utilized as extra model inputs in an attempt to decrease the variance in the kinematic predictions. The performance of the sequential Monte Carlo estimation methodology augmented with this synthetic spike input provides improved reconstruction, which raises interesting questions and helps explain the overall modeling requirements better.

Introduction to Issues and Implications of Screening, Surveillance, and Reporting of Children's BMI

On January 16 and 17, 2008, the Robert Wood Johnson Foundation convened a forum of researchers and practitioners working on the issue of childhood obesity to discuss the issues related to surveillance, screening, and reporting of children's BMI. Because obesity has become a major concern of the foundation, it seemed essential to understand the use and limitations of the BMI measurement on which the diagnosis of obesity depended. The goals of the meeting were to gather and review experience in the collection of BMI data and to understand how to communicate BMI results to parents. In addition, the group explored cultural differences in how the BMI was interpreted, and considered the legal and confidentiality implications of collecting and reporting BMI data. Because of the ease and reliability of measures of height and weight that are used to calculate BMI, BMI is the recommended measure for the identification of overweight and obesity. Obesity in children and adolescents, defined as a BMI at ≥95th percentile for age and gender, provides a useful measure of risk of metabolic complications and persistence. Furthermore, weight increases above the 95th percentile almost always reflect increases in body fatness. Overweight, defined as a BMI between the 85th and 95th percentiles for age and gender, is associated with a lower risk of metabolic … Address correspondence to William H. Dietz, MD, PhD, Centers for Disease Control and Prevention, Division of Nutrition, Physical Activity, and Obesity, 4770 Buford Hwy NE, Mailstop K-24, Atlanta, GA 30341-3717. E-mail: wcd4{at}cdc.gov