The Road to Obesity or the Path to Prevention: Motorized Transportation and Obesity in China

Objective: Dependence on motorized forms of transportation may contribute to the worldwide obesity epidemic. Shifts in transportation patterns occurring in China provide an ideal opportunity to study the association between vehicle ownership and obesity. Our objective was to determine whether motorized forms of transportation promote obesity. Research Methods and Procedures: A multistage random‐cluster sampling process was used to select households from eight provinces in China. Data were included on household vehicle ownership and individual anthropometric and sociodemographic status. Cross‐sectional data (1997) from 4741 Chinese adults aged 20 to 55 years were used to explore the association between vehicle ownership and obesity. Cohort data (1989 to 1997) from 2485 adults aged 20 to 45 years in 1989 (59% follow‐up) were used to measure the impact of vehicle acquisition on the odds of becoming obese. Results: Our main outcome measure was current obesity status and the odds of becoming obese over an 8‐year period. In 1997, 84% of adults did not own motorized transportation. However, the odds of being obese were 80% higher (p < 0.05) for men and women in households who owned a motorized vehicle compared with those who did not own a vehicle. Fourteen percent of households acquired a motorized vehicle between 1989 and 1997. Compared with those whose vehicle ownership did not change, men who acquired a vehicle experienced a 1.8‐kg greater weight gain (p < 0.05) and had 2 to 1 odds of becoming obese. Discussion: Encouraging active forms of transportation may be one way to protect against obesity.     

Overweight Associated with Increased Risk of Erosive Esophagitis in a Non-Obese Taiwanese Population

Objective

To investigate the relationship between overweight and erosive esophagitis (EE) in a non-obese Taiwanese population.

Design and Methods

A total of 7,352 subjects (non-obese, 5,826; obese, 1,526) from a health examination center at National Cheng Kung University Hospital were enrolled. Central obesity was defined by a waist circumference (WC) ≥90 cm in male and 80 cm in female. Overweight was defined as body mass index (BMI) of 24–26.9 kg/m², and general obesity as BMI ≥27 kg/m². The Los Angeles classification was adopted to determine the presence of EE.

Results

There were significant differences in the prevalence of central obesity and different BMI status between subjects with and without EE in total and non-obese population. In total population, multivariate analyses revealed central obesity (OR, 1.17, 95% CI, 1.02–1.34, p = 0.021) and being obese (OR, 1.28, 95% CI, 1.07–1.52, p = 0.007)/overweight (OR, 1.25, 95% CI, 1.08–1.45, p = 0.003) had positive associations with EE in different model, respectively. When considering the joint effect of central obesity and BMI status, overweight (OR, 1.22; 95% CI, 1.04–1.44; p = 0.016) remained as an independent associated factor of EE but central obesity (OR, 1.06; 95% CI, 0.89–1.26; p = 0.549)/being obese (OR, 1.22; 95% CI, 0.98–1.53; p = 0.082) did not. As for non-obese group, separate model showed central obesity (OR, 1.19, 95% CI, 1.00–1.40, p = 0.046) and overweight (OR, 1.24; 95% CI, 1.07–1.44, p = 0.005) was positively associated with EE, respectively. However, being overweight (OR, 1.20; 95% CI, 1.02–1.42, p = 0.030) but not central obesity (OR, 1.08; 95% CI, 0.90–1.31; p = 0.398) was positively related to EE with considering the effect of overweight and central obesity simultaneously.

Conclusion

Overweight effect on EE was more detrimental than central obesity in non-obese subjects. In addition, male gender, hiatus hernia and alcohol use were also associated with increased risk of EE.     

Decreased Inpatient Mortality in Obese Patients With Abdominal Nets

ObjectiveNeuroendocrine tumors (NETs) of the abdomen are rare tumors with an incidence of 3.56 per 100,000 in the general population. Obesity is a growing public health problem with varying effects on the severities of other diseases. We investigated the association between obesity and inpatient morbidity/mortality in patients with abdominal NETs utilizing the Nationwide Inpatient Sample (NIS).MethodsWe analyzed data from the NIS database to investigate the association between obesity and abdominal NETs using patient information from 22,096 patient discharges from January 1, 2009 to December 31, 2010.ResultsWe demonstrate that obesity is strongly associated with decreased rates of inpatient mortality in patients with NET (odds ratio [OR] = 0.6, multivariate P = .02) and that malnutrition is associated with a nearly 5-fold higher risk of inpatient mortality (multivariate P < .0005). We did not find a statistical interaction between obesity and malnutrition; however, patients who were both malnourished and obese had a lower mortality risk than purely malnourished patients.ConclusionsOur data suggests that nutritional status may be an important factor in inpatient mortality in patients with NETs, with obesity being protective. (Endocr Pract. 2014;20:1309-1314)     

Genetic variation in SLC7A2 interacts with calcium and magnesium intakes in modulating the risk of colorectal polyps

Solute carrier family 7, member 2 (SLC7A2) gene encodes a protein called cationic amino acid transporter 2, which mediates the transport of arginine, lysine and ornithine. l-Arginine is necessary for cancer development and progression, including an important role in colorectal cancer pathogenesis. Furthermore, previous studies found that both calcium and magnesium inhibit the transport of arginine. Thus, calcium, magnesium or calcium:magnesium intake ratio may interact with polymorphisms in the SLC7A2 gene in association with colorectal cancer. We conducted a two-phase case–control study within the Tennessee Colorectal Polyps Study. In the first phase, 23 tagging single-nucleotide polymorphisms in the SLC7A2 gene were included for 725 colorectal adenoma cases and 755 controls. In the second phase conducted in an independent set of 607 cases and 2113 controls, we replicated the significant findings in the first phase. We observed that rs2720574 significantly interacted with calcium:magnesium intake ratio in association with odds of adenoma, particularly multiple/advanced adenoma. In the combined analysis, among those with a calcium:magnesium intake ratio below 2.78, individuals who carried GC/CC genotypes demonstrated higher odds of adenoma [OR (95% CI):1.36 (1.11–1.68)] and multiple/advanced adenoma [OR (95% CI): 1.68 (1.28, 2.20)] than those who carried the GG genotype. The P values for interactions between calcium:magnesium intake ratio and rs2720574 were .002 for all adenomas and <.001 for multiple/advanced adenoma. Among those with the GG genotype, a high calcium:magnesium ratio was associated with increased odds of colorectal adenoma [OR (95% CI): 1.73 (1.27–2.36)] and advanced/multiple adenomas [1.62 (1.05–2.50)], whereas among those with the GC/CC genotypes, high calcium:magnesium ratio was related to reduced odds of colorectal adenoma [0.64 (0.42–0.99)] and advanced/multiple adenomas [0.55 (0.31–1.00)].     

Prevalence and determinants of obesity in children in public schools of Sintra, Portugal

Objective: To assess the prevalence of and the factors related to overweight and obesity in a sample of children from the region of Sintra, Portugal. Methods and Procedures: Cross‐sectional study, stratified for freguesia with random selection of schools. Height, weight, triceps skinfold, upper arm and waist circumferences were measured, and overweight/obesity defined according to international criteria. Breast‐feeding, number of daily meals and parents' height and weight data were also collected. Results: One thousand two hundred and twenty‐five children aged 6–10 years were assessed. Overall prevalence of overweight and obesity was 35.6% (23% overweight and 12.6% obesity). Overweight or obese children had higher triceps skinfold, upper arm circumference, arm muscle area, and waist circumference than their normal weight counterparts (P < 0.001). On multivariate analysis, relatively to a child without obese progenitors, a child with one obese progenitor had an obesity risk multiplied by 2.78 (95% confidence interval (CI): 1.76–4.38), while a child with two obese progenitors had a risk multiplied by 6.47 (95% CI: 5.59–16.19). Conversely, being picky was significantly related with a smaller risk of obesity: for boys, odds ratio (OR) = 0.15 (95% CI: 0.04–0.63); for girls, OR = 0.19 (95% CI: 0.06–0.64). Finally, no relationships were found between obesity, birth weight, birth height or breast‐feeding. Discussion: Prevalence of overweight and obesity are elevated among children of the Sintra region in Portugal compared to most other regions of Europe. The relationship with the parents' nutritional state stresses the need to target families for preventing obesity.     

Role of Weight History on Functional Limitations and Disability in Late Adulthood: The ARIC Study

Objective: To examine associations of weight history with functional limitations and disability in white and African‐American men and women. Research Methods and Procedures: Data were from the Atherosclerosis Risk in Communities study (n = 11, 177). Associations of recalled weight status at age 25 and weight change from age 25 to ages 45 to 64 with functional limitations, activities of daily living (ADLs), and instrumental activities of daily living (IADLs) at follow‐up (ages 52 to 75) were examined using logistic regression. Results: Obesity (BMI ≥ 30 kg/m²) at age 25 was associated with functional limitations and ADL and IADL impairment at follow‐up in white and African‐American men and women. For example, obese compared with normal weight (BMI, 18.5 to 24.9 kg/m²) white women had higher odds of mild [odds ratio (95% confidence interval), 1.97 (1.18 to 3.29)] and severe [9.81 (5.92 to 16.27)] functional limitations and ADL [3.48 (2.36 to 5.13)] and IADL [2.95 (2.00 to 4.33)] impairment. In African‐American women, obesity was associated with higher odds of mild [2.71 (1.14 to 6.41)] and severe [6.01 (2.53 to 14.26)] functional limitations and ADL [1.82 (1.10 to 3.00)] and IADL [2.39 (1.47 to 3.90)] impairment. Similar associations were found in men. Compared with weight maintenance (±10 lbs), large weight gain (>30 lbs) from age 25 to ages 45 to 64 was also associated with functional limitations and ADL and IADL impairment in white and African‐American men and women. Discussion: Maintenance of a healthy body weight throughout adulthood may play a role in preventing or delaying the onset of functional limitations and disability, resulting in increased quality of life and decreased health care costs.     

Trends in obesity and associations with education and urban or rural residence in Thailand

Objective: To measure trends in the prevalence of overweight and obesity and the relationship with urban or rural residence and education in Thailand. Research Methods and Procedures: Data were from two nationally representative surveys of 38,323 individuals ≥18 years old (19,156 were 18 to 59 years old) in 2004 and 3375 individuals 18 to 59 years old in 1997. Overweight and obesity were defined using the World Health Organization's Asian criteria. Results: Among those ≥18 years old in 2004, 17.8% of men (95% confidence interval, 16.6% to 19.0%) were overweight, 18.4% (17.3% to 19.5%) had Class I obesity, 4.8% (4.1% to 5.5%) had Class II obesity, and 15.9% (14.6% to 17.1%) had abdominal obesity. In women, 18.2% (17.1% to 19.2%) were overweight, 26.1% (24.9% to 27.3%) had Class I obesity, 9.3% (8.6% to 10.0%) had Class II obesity, and 37.3% (35.3% to 39.2%) had abdominal obesity. In those 18 to 59 years old, the prevalence of Class I obesity in men and all four categories in women significantly increased between 1997 and 2004. There was an inverse relationship in women but a positive relationship in men between education and the odds of being overweight or obese. In 2004, there were significantly lower odds of being overweight or obese in rural compared with urban men but similar odds between urban and rural women. Discussion: The prevalence of overweight and obesity in Thailand is high and increasing. Although the transition of overweight and obesity to those of lower socioeconomic status is not complete, it is well on the way.     

Electronic Games and Environmental Factors Associated with Childhood Obesity in Switzerland

Objective: Environmental factors and behaviors associated with obesity have not been well described in children living in Europe. Although television watching has been repeatedly associated with obesity, it is unclear whether other sedentary activities, such as use of electronic games, are independently associated with obesity in children. The hypothesis was that various types of sedentary activities are associated with obesity in children living in Switzerland. Research Methods and Procedures: This was a cross‐sectional study of children (grades one to three) from four communities in the Greater Zurich Area (Switzerland). Obesity was defined as a combination of overweight (BMI) and overfat (skinfold thicknesses). Environmental factors were assessed by questionnaire. The children's physical activity was estimated by their teacher (scale 0 to 10). Results: Of 922 eligible subjects, 872 (94.6%) took part in the study. Use of electronic games [odds ratio (OR) = 2.03 per hour per day, 95% confidence interval (CI): 1.57 to 2.61, p < 0.001], television (OR = 2.83 per hour per day, 95% CI: 2.08 to 3.86, p < 0.001), physical activity (OR = 0.80 per unit, 95% CI: 0.72 to 0.88, p < 0.001), maternal work (OR = 1.93, 95% CI: 1.13 to 3.29, p = 0.02), and paternal smoking (OR = 1.78, 95% CI: 1.07 to 2.96, p = 0.03) were independently associated with obesity. Further adjustment for socioeconomic status, when available, did not change these results. Discussion: In this sample of children living in Switzerland, the use of electronic games was significantly associated with obesity, independently of confounding factors. The association of obesity with television use and lack of physical activity confirms results from other populations and points to potential strategies for obesity prevention.     

Association of race and health insurance in treatment disparities of colon cancer: A retrospective analysis utilizing a national population database in the United States

BackgroundBoth health insurance status and race independently impact colon cancer (CC) care delivery and outcomes. The relative importance of these factors in explaining racial and insurance disparities is less clear, however. This study aimed to determine the association and interaction of race and insurance with CC treatment disparities.Study settingRetrospective cohort review of a prospective hospital-based database.Methods and findingsIn this cross-sectional study, patients diagnosed with stage I to III CC in the United States were identified from the National Cancer Database (NCDB; 2006 to 2016). Multivariable regression with generalized estimating equations (GEEs) were performed to evaluate the association of insurance and race/ethnicity with odds of receipt of surgery (stage I to III) and adjuvant chemotherapy (stage III), with an additional 2-way interaction term to evaluate for effect modification. Confounders included sex, age, median income, rurality, comorbidity, and nodes and margin status for the model for chemotherapy. Of 353,998 patients included, 73.8% (n = 261,349) were non-Hispanic White (NHW) and 11.7% (n = 41,511) were non-Hispanic Black (NHB). NHB patients were less likely to undergo resection [odds ratio (OR) 0.66, 95% confidence interval [CI] 0.61 to 0.72, p < 0.001] or to receive adjuvant chemotherapy [OR 0.83, 95% CI 0.78 to 0.87, p < 0.001] compared to NHW patients. NHB patients with private or Medicare insurance were less likely to undergo resection [OR 0.76, 95% CI 0.63 to 0.91, p = 0.004 (private insurance); OR 0.59, 95% CI 0.53 to 0.66, p < 0.001 (Medicare)] and to receive adjuvant chemotherapy [0.77, 95% CI 0.68 to 0.87, p < 0.001 (private insurance); OR 0.86, 95% CI 0.80 to 0.91, p < 0.001 (Medicare)] compared to similarly insured NHW patients. Although Hispanic patients with private and Medicare insurance were also less likely to undergo surgical resection, this was not the case with adjuvant chemotherapy. This study is mainly limited by the retrospective nature and by the variables provided in the dataset; granular details such as continuity or disruption of insurance coverage or specific chemotherapy agents or dosing cannot be assessed within NCDB.ConclusionsThis study suggests that racial disparities in receipt of treatment for CC persist even among patients with similar health insurance coverage and that different disparities exist for different racial/ethnic groups. Changes in health policy must therefore recognize that provision of insurance alone may not eliminate cancer treatment racial disparities.

Scarlett Hao and colleagues utilize a national population database to investigate the association of race and health insurance in treatment disparities of colon cancer in US.     

Factors affecting prevalence of overweight among 12- to 17-year-old urban adolescents in Hyderabad, India

Objective: The problem of overweight and obesity is not confined only to developed countries but is also widely prevalent in developing countries. The objective of this study was to assess the prevalence of overweight and obesity as defined by the International Obesity Task Force (IOTF) among school‐age children in Hyderabad, India, and identify its associated factors. Research Methods and Procedures: A cross‐sectional and institutional study, adopting a multistage stratified cluster sampling procedure, was carried out during 2003 on adolescents 12 to 17 years of age of both sexes from Hyderabad, India. Results: The overall prevalence of overweight was 6.1% [95% confidence interval (CI): 4.2, 8.0] among boys and 8.2% among girls (CI: 6.0, 10.4); 1.6% and 1.0% were obese, respectively. The prevalence was significantly higher (p < 0.05) among adolescents who watched television ≥3 h/d (10.4%) or belonged to a high socioeconomic background (14.9%, p < 0.001), whereas it was significantly lower among those participating regularly in outdoor games ≥6 h/wk (3.1%, p < 0.004) and household activities ≥3 h/d (4.7%, p < 0.001). The logistic regression analysis revealed that the prevalence of overweight was 4 times higher among the adolescents of high socioeconomic status [odds ratio (OR): 4.1; CI: 2.25, 7.52], 3 times higher in those not participating in outdoor games (OR: 2.75; CI: 1.56, 4.72), and 1.92 times higher in those watching television ≥3 h/d (OR: 1.92; CI: 1.16, 3.18). Discussion: This study confirmed the findings of earlier studies carried out in Western countries and emphasizes that regular physical exercise, doing household activities, regulated television viewing, and healthy eating behaviors could contribute to controlling overweight and obesity.     

Dietary behaviors as associated factors for overweight and obesity in a sample of adolescents from Aquitaine, France

This study aimed to identify dietary behaviors that might be considered as associated factors for overweight or obesity among French adolescents. Forty-nine of the 536 middle and high schools in Aquitaine (southwest of France) were invited to take part in the study. For each school, participating adolescents were selected using stratification by grade. A self-report questionnaire, including information about sex, age, dietary behaviors, physical and sedentary activities, and parental socioeconomic status (SES), was filled in by adolescents during class. Overweight and obesity were defined according to the age- and sex-specific body mass index cutoff points of the International Obesity Task Force. Multivariate analysis (logistic regression) was used to identify independent dietary factors associated with overweight including obesity and obesity alone (adjustment on sex, age, parental SES, and weight status and adolescents' sedentary activity). In addition to parental SES and weight status and adolescents' sedentary activity, some dietary behaviors are also independently and significantly associated with a higher prevalence of overweight including obesity: absence (OR 1.43, 0.91–2.23) or rare (OR 1.57, 1.23–2.01) breakfast intake (p?<?0.01) and absence (OR 5.03, 3.19–7.92) or rare (OR 1.90, 1.46–2.47) light afternoon meal intake (p?<?0.001). All variables were also significantly and independently associated with obesity alone. This study shows that socioeconomic factors and individual behaviors are associated with overweight or obesity. These results confirm the importance to carry out multifaceted educational actions among adolescents, by promoting physical activity and healthy food choices in order to prevent overweight and promote healthy lifestyle behaviors.     

Secular trends in prevalence of overweight and obesity from 2006 to 2009 in urban asian Indian adolescents aged 14-17 years

The present study examines the secular trends in prevalence of overweight and obesity among urban Asian Indian adolescents in New Delhi (North India). The data were derived from cross-sectional sampling of children, 3493 in year 2006 and 4908 in year 2009, aged 14-17 years studying in privately-funded and government-funded schools. Age, gender and Asian Indian-specific cut offs of body mass index (BMI) were used to define overweight and obesity. The prevalence of obesity increased significantly from 9.8% in 2006 to 11.7% in 2009 (p<0.01), whereas underweight decreased from 11.3% to 3.9% (p<0.001). There was a significantly higher risk of being overweight (OR 1.28; 95% CI, 1.15-1.42) and obese (OR 1.44; 95% CI, 1.24-1.66) in year 2009 than 2006, after adjusting for age, gender and type of school. Males and privately-funded school children had significantly higher increase in prevalence and risk of being overweight and obese over the three years. In conclusion, this study showed an increasing trend in prevalence of overweight and obesity in urban Asian Indian adolescents. More specifically, the study showed the association of this increasing trend of overweight and obesity prevalence with male gender and high socio-economic status, calling for an urgent need for immediate and targeted preventive measures.     

Immigration and obesity among lower income blacks

Objective: Our objective was to examine the associations of nativity, immigrant generation, and language acculturation with obesity among lower income black adult men and women. Research Methods and Procedures: Data from 551 black adult men and women were collected from participants in the Healthy Directions‐Health Centers Study. Race/ethnicity and nativity were self‐reported. Language acculturation was defined using participants’ first language, preferred reading language, and language spoken at home. Mixed model logistic regression models were estimated to account for within‐health center clustering. Results: Foreign‐born blacks had a lower obesity risk, compared with all U.S.‐born participants, in multivariable analyses [odds ratio (OR) = 0.57, 95% confidence interval (CI), 0.38, 0.84]. Among U.S.‐born participants, those with foreign‐born parents were significantly less likely to be obese than individuals with U.S.‐born parents (OR = 0.54; 95% CI, 0.37, 0.80). Low‐moderate language acculturation also decreased the odds of being obese (OR = 0.45; 95% CI, 0.23, 0.88). Discussion: Our findings suggest a protective effect of foreign‐born status and low‐moderate language acculturation on obesity risk among lower income black immigrants. These data highlight the importance of more frequently examining nativity in obesity‐related research conducted among blacks.     

Outdoor artificial light at night,obesity, and sleep health: Cross-sectional analysis in the KoGES study

Obesity is a common disorder with many complications. Although chronodisruption plays a role in obesity, few epidemiological studies have investigated the association between artificial light at night (ALAN) and obesity. Since sleep health is related to both obesity and ALAN, we investigated the association between outdoor ALAN and obesity after adjusting for sleep health. We also investigated the association between outdoor ALAN and sleep health. This cross-sectional survey included 8526 adults, 39–70 years of age, who participated in the Korean Genome and Epidemiology Study. Outdoor ALAN data were obtained from satellite images provided by the US Defense Meteorological Satellite Program. We obtained individual data regarding outdoor ALAN; body mass index; depression; and sleep health including sleep duration, mid-sleep time, and insomnia; and other demographic data including age, sex, educational level, type of residential building, monthly household income, alcohol consumption, smoking status and consumption of caffeine or alcohol before sleep. A logistic regression model was used to investigate the association between outdoor ALAN and obesity. The prevalence of obesity differed significantly according to sex (women 47% versus men 39%, p < 0.001) and outdoor ALAN (high 55% versus low 40%, p < 0.001). Univariate logistic regression analysis revealed a significant association between high outdoor ALAN and obesity (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.14–1.35, p < 0.001). Furthermore, multivariate logistic regression analyses showed that high outdoor ALAN was significantly associated with obesity after adjusting for age and sex (OR 1.25, 95% CI 1.14–1.37, p < 0.001) and even after controlling for various other confounding factors including age, sex, educational level, type of residential building, monthly household income, alcohol consumption, smoking, consumption of caffeine or alcohol before sleep, delayed sleep pattern, short sleep duration and habitual snoring (OR 1.20, 95% CI 1.06–1.36, p = 0.003). The findings of our study provide epidemiological evidence that outdoor ALAN is significantly related to obesity.     

High childhood obesity in an Australian population

Objective: The objective was to determine the prevalences of overweight and obesity in regional Australian children and to examine the association between BMI and indicators of socioeconomic status (SES). Research Methods and Procedures: Regionally representative cross‐sectional survey of 2184 children, 4 to 12 years of age, was conducted, and the socio‐demographic characteristics of their parents from regional Victoria, Australia, 2003 to 2004, were obtained. Results: The prevalences of overweight and obesity were 19.3 ± 0.8% (proportion ± standard error) and 7.6 ± 0.6%, respectively, using international criteria, and the proportion of overweight/obese girls was significantly higher than that of boys (29.6 ± 1.4% vs. 23.9 ± 1.3%, χ² = 9.01, p = 0.003). Children from households of lower SES had higher odds of being overweight/obese; lower SES was defined by lower paternal education (adjusted odds ratio, 1.18; 95% confidence interval, 1.08 to 1.30) and lower area‐level SES (adjusted odds ratio, 1.13; 95% confidence interval, 1.02 to 1.25), adjusted for age, gender, height, and clustering by school. Discussion: The prevalences of overweight and obesity are increasing in Australian children by about one percentage point per year. This equates to ～40,000 more overweight children each year, placing Australian children among those at highest risk around the world. In addition, girls are more likely to be overweight, and there is a general trend for children of lower SES to be at even greater risk of overweight and obesity.     

Relationship between perceptions about neighborhood environment and prevalent obesity: data from the dallas heart study

Objectives:

Although psychosocial stress can result in adverse health outcomes, little is known about how perceptions of neighborhood conditions, a measure of environment‐derived stress, may impact obesity. The association between perceptions of neighborhood environment and obesity (defined as body mass index [BMI] ≥ 30 kg/m²) among 5,907 participants in the Dallas Heart Study, a multi‐ethnic, probability‐based sample of Dallas County residents was examined.

Design and Methods:

Participants were asked to respond to 18 questions about perceptions of their neighborhood. Factor analysis was used to identify three factors associated with neighborhood perceptions: neighborhood violence, physical environment, and social cohesion. Logistic regression analyses were performed to determine the relationship between each factor (higher quintile = more unfavorable perceptions) and the odds of obesity.

Results:

Decreasing age, income, and education associated with unfavorable overall neighborhood perceptions and unfavorable perceptions about specific neighborhood factors (P trend <0.05 for all). Increasing BMI was associated with unfavorable perceptions about physical environment (P trend <0.05) but not violence or social cohesion. After adjustment for race, age, sex, income, education, and length of residence, physical environment perception score in the highest quintile remained associated with a 25% greater odds of obesity (OR 1.25, [95% CI 1.03‐1.50]). Predictors of obesity related to environmental perceptions included heavy traffic (OR 1.39, [1.17‐1.64]), trash/litter in neighborhood (OR 1.27, [1.01‐1.46]), lack of recreational areas (OR 1.21, [1.01‐1.46]), and lack of sidewalks (OR 1.25, [95% CI 1.04‐1.51]).

Conclusions:

Thus, unfavorable perceptions of environmental physical conditions are related to increased obesity. Efforts to improve the physical characteristics of neighborhoods, or the perceptions of those characteristics, may assist in the prevention of obesity in this community.     

Ethnic Differences in Physical Activity and Inactivity Patterns and Overweight Status

Objective: To examine the relationship between physical activity and inactivity patterns and overweight in U.S. adolescents using baseline and 1-year change in activity and inactivity data. Research Methods and Procedures: Nationally representative data from 12,759 participants (6997 non-Hispanic whites, 2676 non-Hispanic blacks, 2185 Hispanics, and 901 Asians) in the National Longitudinal Study of Adolescent Health (1995 and 1996). Data on moderate to vigorous and low-intensity physical activity, TV/video viewing, and video game/computer use were obtained from questionnaires. Multivariate models assessed the association of overweight (body mass index ≥ 95th percentile Centers for Disease Control and Prevention/National Center for Health Statistics 2000 curves) with initial (and 1-year change) activity and inactivity levels, controlling for age, ethnicity, socioeconomic status, urban residence, cigarette smoking, and region of residence. Results: Overweight prevalence was positively associated with high level TV/video viewing among white boys (odds ratio [OR] = 1.52; 95% confidence interval [1.08 to 2.14]) and girls (OR = 2.45 [1.51 to 3.97]). The odds of overweight decreased with high levels of moderate to vigorous physical activity among white boys (OR = 0.81 [0.76 to 0.87]), non-Hispanic black boys (OR = 0.86 [0.76 to 0.98]) and girls (OR = 0.88 [0.78 to 0.99]), and Hispanic boys (OR = 0.90 [0.83 to 0.97]) and girls (OR = 0.91 [0.84 to 0.99]). Discussion: Predicted probabilities generated from the logistic regression models, which examined the experimental effects of altering hours of TV/video viewing and bouts of moderate to vigorous physical activity, show lower overweight among adolescents who watched less TV per week combined with frequent moderate to vigorous physical activity than those who watched more TV per week combined with fewer bouts of weekly moderate to vigorous physical activity. Predicted probabilities suggest important sex and ethnic differences in these associations.     

Health behaviours, socioeconomic status, and mortality: further analyses of the British Whitehall II and the French GAZEL prospective cohorts

Background

Differences in morbidity and mortality between socioeconomic groups constitute one of the most consistent findings of epidemiologic research. However, research on social inequalities in health has yet to provide a comprehensive understanding of the mechanisms underlying this association. In recent analysis, we showed health behaviours, assessed longitudinally over the follow-up, to explain a major proportion of the association of socioeconomic status (SES) with mortality in the British Whitehall II study. However, whether health behaviours are equally important mediators of the SES-mortality association in different cultural settings remains unknown. In the present paper, we examine this issue in Whitehall II and another prospective European cohort, the French GAZEL study.

Methods and Findings

We included 9,771 participants from the Whitehall II study and 17,760 from the GAZEL study. Over the follow-up (mean 19.5 y in Whitehall II and 16.5 y in GAZEL), health behaviours (smoking, alcohol consumption, diet, and physical activity), were assessed longitudinally. Occupation (in the main analysis), education, and income (supplementary analysis) were the markers of SES. The socioeconomic gradient in smoking was greater (p<0.001) in Whitehall II (odds ratio [OR]  = 3.68, 95% confidence interval [CI] 3.11–4.36) than in GAZEL (OR  = 1.33, 95% CI 1.18–1.49); this was also true for unhealthy diet (OR  = 7.42, 95% CI 5.19–10.60 in Whitehall II and OR  = 1.31, 95% CI 1.15–1.49 in GAZEL, p<0.001). Socioeconomic differences in mortality were similar in the two cohorts, a hazard ratio of 1.62 (95% CI 1.28–2.05) in Whitehall II and 1.94 in GAZEL (95% CI 1.58–2.39) for lowest versus highest occupational position. Health behaviours attenuated the association of SES with mortality by 75% (95% CI 44%–149%) in Whitehall II but only by 19% (95% CI 13%–29%) in GAZEL. Analysis using education and income yielded similar results.

Conclusions

Health behaviours were strong predictors of mortality in both cohorts but their association with SES was remarkably different. Thus, health behaviours are likely to be major contributors of socioeconomic differences in health only in contexts with a marked social characterisation of health behaviours. Please see later in the article for the Editors'' Summary     

Interaction between the NOS3 Gene and Obesity as a Determinant of Risk of Type 2 Diabetes: The Atherosclerosis Risk in Communities Study

Endothelial nitric oxide synthase 3 (NOS3) catalyzes the production of nitric oxide from L-arginine in endothelial cells. Obesity is a modifiable risk factor for diabetes, and obese individuals have been reported to have reduced nitric oxide availability compared to controls whose weight is in the normal range. Since homozygous carriers of the NOS3 G894T variant are predicted to have decreased enzyme activity, the association between NOS3 genotype and type 2 diabetes, and possible effect modification by body mass index (BMI) were evaluated. The prevalence of diabetes and BMI was determined at baseline in 14,374 participants 45–66 years of age from the prospective biracial population-based Atherosclerosis Risk in Communities (ARIC) Study of the development of atherosclerosis in four communities in the United States. Individuals with a BMI ≥30 kg/m² were considered obese. Those subjects not meeting the case definition were the comparison groups for the 728 African American and 980 white participants with diabetes. Multivariable logistic regression models adjusted for age, sex, and field center were used to test for main genetic effects and interaction with obesity. Although the NOS3 G894T variant was not independently associated with diabetes in either African Americans or whites, significant interaction between BMI and the NOS3 polymorphism indicated that obesity was an effect modifier of diabetes risk for white individuals with the TT genotype (odds ratio (OR) for interaction = 1.65, p = 0.04). In stratified analyses, homozygosity for the NOS3 T allele in obese white participants but not in those whose BMI <30 kg/m² was associated with an elevated risk of diabetes (OR = 1.47, p = 0.02) when compared to the common GG genotype. These results suggest that interaction between obesity and NOS3 genotype may be a determinant of diabetes case status in whites in the ARIC cohort. Replication in other populations will be required to confirm these observations.