Design characteristics of worksite environmental interventions for obesity prevention

Objective: This paper describes the design characteristics of the National Heart, Lung, and Blood Institute (NHLBI)‐funded studies that are testing innovative environmental interventions for weight control and obesity prevention at worksites. Research Methods and Procedures: Seven separate studies that have a total of 114 worksites (～48,000 employees) across studies are being conducted. The worksite settings include hotels, hospitals, manufacturing facilities, businesses, schools, and bus garages located across the U.S. Each study uses its own conceptual model drawn from the literature and includes the socio‐ecological model for health promotion, the epidemiological triad, and those integrating organizational and social contexts. The interventions, which are offered to all employees, include environmental‐ and individual‐level approaches to improve physical activity and promote healthful eating practices. Environmental strategies include reducing portion sizes, modifying cafeteria recipes to lower their fat contents, and increasing the accessibility of fitness equipment at the workplace. Across all seven studies about 48% (N = 23,000) of the population is randomly selected for measurements. The primary outcome measure is change in BMI or body weight after two years of intervention. Secondary measures include waist circumference, objective, and self‐report measures of physical activity, dietary intake, changes in vending machines and cafeteria food offerings, work productivity, healthcare use, and return on investment. Discussion: The results of these studies could have important implications for the design and implementation of worksite overweight and obesity control programs.     

Using the satellite-derived NDVI to assess ecological responses to environmental change

Assessing how environmental changes affect the distribution and dynamics of vegetation and animal populations is becoming increasingly important for terrestrial ecologists to enable better predictions of the effects of global warming, biodiversity reduction or habitat degradation. The ability to predict ecological responses has often been hampered by our rather limited understanding of trophic interactions. Indeed, it has proven difficult to discern direct and indirect effects of environmental change on animal populations owing to limited information about vegetation at large temporal and spatial scales. The rapidly increasing use of the Normalized Difference Vegetation Index (NDVI) in ecological studies has recently changed this situation. Here, we review the use of the NDVI in recent ecological studies and outline its possible key role in future research of environmental change in an ecosystem context.     

Using the Edmonton obesity staging system to predict mortality in a population-representative cohort of people with overweight and obesity

Background:

Anthropometric-based classification schemes for excess adiposity do not include direct assessment of obesity-related comorbidity and functional status and thus have limited clinical utility. We examined the ability of the Edmonton obesity staging system, a 5-point ordinal classification system that considers comorbidity and functional status, in predicting mortality in a nationally representative US sample.

Methods:

We analyzed data from the National Health and Human Nutrition Examination Surveys (NHANES) III (1988–1994) and the NHANES 1999–2004, with mortality follow-up through to the end of 2006. Adults (age ≥ 20 yr) with overweight or obesity who had been randomized to the morning session at the mobile examination centre were scored according to the Edmonton obesity staging system. We examined the relationship between staging system scores and mortality, and Cox proportional hazards models were adjusted for the presence of the metabolic syndrome or hypertriglyceridemic waist.

Results:

Over 75% of the cohort with overweight or obesity were given scores of 1 or 2. Scores of 4 could not be reliably assigned because specific data elements were lacking. Survival curves clearly diverged when stratified by scores of 0–3, but not when stratified by obesity class alone. Within the data from the NHANES 1988–1994, scores of 2 (hazard ratio [HR] 1.57; 95% confidence interval [CI] 1.16 to 2.13) and 3 (HR 2.69; 95% CI 1.98 to 3.67) were associated with increased mortality compared with scores of 0 or 1, even after adjustment for body mass index and the metabolic syndrome. We found similar results after adjusting for hypertriglyceridemic waist (i.e., waist circumference ≥ 90 cm and a triglyceride level ≥ 2 mmol/L for men; the corresponding values for women were ≥ 85 cm and ≥ 1.5 mmol/L), as well as in a cohort eligible for bariatric surgery.

Interpretation:

The Edmonton obesity staging system independently predicted increased mortality even after adjustment for contemporary methods of classifying adiposity. The Edmonton obesity staging system may offer improved clinical utility in assessing obesity-related risk and prioritizing treatment.Body mass index (BMI) is the most common measure used to classify excess adiposity. A BMI of 18.5–24.9 kg/m² is considered normal, a BMI of 25.0–29.9 kg/m² is considered overweight and a BMI of more than 30 kg/m² is considered obese.¹ Observational studies have consistently reported deleterious associations between elevated BMI and morbidity/mortality.² Each five-unit increment in BMI above 25 kg/m² is associated with increases of 29% for overall mortality, 41% for vascular mortality and 210% for diabetes-related mortality.³ Measures of central adiposity, including increased waist circumference, predict cardiometabolic risk independent of elevated BMI.⁴ Thus, measuring both BMI and central adiposity to classify and quantify obesity-related risk and assess the appropriateness of treatments such as starting the use of antiobesity drugs or bariatric surgery is recommended.^1,5BMI is a useful population-based tool to classify adiposity and estimate its prevalence.⁶ However, BMI possesses well-known limitations at the individual level,⁷ including the inability to directly distinguish between lean and fat tissue. Thus, at a given BMI, substantial variation in adiposity can occur.⁸ Furthermore, neither BMI nor waist circumference directly reflects the presence of underlying obesity-related comorbidity, reduced quality of life or diminished functional status — elements that are widely considered to be critically important to the clinical assessment of patients with excess body weight. For example, BMI thresholds are currently used to determine eligibility for bariatric surgery. This approach has been criticized, and recommendations for scoring systems that incorporate assessments of comorbidity have been proposed as alternatives.⁹Recently, we proposed a new clinical staging system that ranks people with excess adiposity on a 5-point ordinal scale, while incorporating obesity-related comorbidities and functional status into the assessment (Box 1).⁶ The Edmonton obesity staging system is intended to complement anthropometric measures, but it requires further validation. In this study, we examine the population distribution of Edmonton obesity staging system scores and assess the system’s ability to predict mortality independent of anthropometric indices in a large, nationally representative US sample.

Box 1:

The Edmonton obesity staging system

Endocrine disruption in aquatic systems: up‐scaling research to address ecological consequences

Endocrine‐disrupting chemicals (EDCs) can alter biological function in organisms at environmentally relevant concentrations and are a significant threat to aquatic biodiversity, but there is little understanding of exposure consequences for populations, communities and ecosystems. The pervasive nature of EDCs within aquatic environments and their multiple sub‐lethal effects make assessments of their impact especially important but also highly challenging. Herein, we review the data on EDC effects in aquatic systems focusing on studies assessing populations and ecosystems, and including how biotic and abiotic processes may affect, and be affected by, responses to EDCs. Recent research indicates a significant influence of behavioural responses (e.g. enhancing feeding rates), transgenerational effects and trophic cascades in the ecological consequences of EDC exposure. In addition, interactions between EDCs and other chemical, physical and biological factors generate uncertainty in our understanding of the ecological effects of EDCs within aquatic ecosystems. We illustrate how effect thresholds for EDCs generated from individual‐based experimental bioassays of the types commonly applied using chemical test guidelines [e.g. Organisation for Economic Co‐operation and Development (OECD)] may not necessarily reflect the hazards associated with endocrine disruption. We argue that improved risk assessment for EDCs in aquatic ecosystems urgently requires more ecologically oriented research as well as field‐based assessments at population‐, community‐ and food‐web levels.     

Associations between parental and child overweight and obesity

Results of the analysis showed that parents and children overweight/obesity were significantly correlated. The sample includes 318 pairs of mothers and children, and 336 pairs of fathers and children at the age 11.3 +/- 0.4 years in Trogir, Croatia. Child overweight and obesity were defined according to body mass index (BMI) 25 and 30 equivalents (kg/m2). The prevalence of total overweight in girls was 25.6% and among boys was 20.5%. Mother's weight (p = 0.003) and BMI (p = 0.006) were greater in obese than in other groups of children. Overweight/obese children were more often found among overweight/obese mothers (p = 0.009) and fathers (p = 0.039). Correlation between overweight/obese children and their father (odds ratio 3.2, 95% CI 1.5-6.8) was stronger than between overweight/obese children and their mothers (odds ratio 2.2, 95% CI 1.2-3.9). Associations with mothers' and daughters' overweight/obesity were stronger (p = 0.017) than mothers' and sons'(p = 0.12). Correlations between children's BMI and fathers' BMI (r = 0.265, p < 0.0001) and between children's BMI and mothers' BMI (r = 0.173, p = 0.002) were significant. Children whose parents are overweight/obese look for greater attention in future preventive programme.     

Global prevalence of overweight and obesity in preschoolers

Twenty-three studies reporting cross-sectional and longitudinal data were conducted in 14 different countries between 1998 and 2008. The number of preschool age children totaled more than 43,837 with one study not reporting a sample size. Studies used both international (i.e., International Obesity Task Force (IOTF), World Health Organization (WHO)) and national reference standards (i.e., United States - Centers for Disease Control and Prevention (CDC), Spain - SRS, Italy - Luciano) to classify children as overweight or obese. Within the same sample the percentage of children classified in these categories often showed a 1.5- to 2-fold difference in the prevalence of overweight/obesity with greatest differences in the between country-specific standards (CDC vs. Luciano). WHO percentages frequently exceeded the IOTF percentages. The prevalence of overweight/obese children escalated with increasing age from 2-5 years in both boys and girls with girls showing higher frequencies in 2/3rds of the 72 sex-paired comparisons. The results indicate a recent high prevalence of overweight and obesity in middle and high income countries, among both well-off and lower income segments of populations, in both rural and urban areas, and among all ethnic and racial groups represented. Because a high proportion of preschool overweight/ obese children will continue to increase their adiposity and are at risk for the early onset of metabolic syndrome, cardiovascular disease, type 2 diabetes, musculoskeletal disorders and behavioral problems, concerted public health efforts are needed to coordinate culturally-appropriate parental and caregiver education, home lifestyle changes, dietary and exercise modifications that will reverse the current trajectory.     

Parent- and adolescent-reported barriers to participation in an adolescent overweight and obesity intervention

This study explored reported barriers to treatment completion in a sample of adolescents and their parents who either completed or did not complete family-based cognitive behavioral lifestyle intervention for overweight and obese adolescents. The sample comprises 56 overweight or obese adolescents (52% female) aged 11.5-18.9 years (mean = 14.5, s.d. = 1.8) and a parent. 57% of families did not complete treatment and maintenance phases of the intervention. A telephone-administered questionnaire assessing barriers to participation was completed by 96% of adolescents and 91% of parent completers and 100% of adolescents and 94% of parent noncompleters. Adolescents and parents most commonly reported barriers to participation related to research demands, treatment approach, program components/strategies, practical barriers, and other individual/family demands. Parents also noted adolescent effort, parent-adolescent conflict, and adolescent unhappiness as barriers to participation. While both completers and noncompleters experienced barriers to participation, families who discontinued treatment reported experiencing more treatment barriers. Findings of the current study suggest that adolescents and parents may find it easier to participate in adolescent overweight and obesity interventions if research and out-of-session program demands are minimized, efforts are made to enhance adolescent motivation, and treatment is offered in a convenient location and scheduled around school holidays and other family demands. Results also suggest that targeting adolescent unhappiness, family stressors, and parent-adolescent conflict in treatment may improve retention. Future research should explore the impact of these modifications on treatment completion and outcomes.     

白蚁生物多样性及其对生态环境变化的指示作用

白蚁是热带和亚热带生态系统最主要的无脊椎动物分解者,具有十分重要的生态作用,但因长期缺乏标准化取样方法,白蚁生物多样性研究及其在生态管理中的应用受到限制。本文回顾了白蚁生物多样性及其对环境变化响应的研究进展,概述了白蚁功能分类的现状,介绍了白蚁多样性取样方法的发展,分析了白蚁多样性对生态环境的差异、人为干扰的响应及其生态指示作用,以期为白蚁生物多样性的深入研究及其在生态管理中的应用提供思路与方向。     

Prevalence of overweight and obesity in 2- to 6-year-old Italian children

Objective: To assess the prevalence of overweight and obesity in 2‐ to 6‐year‐old Italian children and to compare the prevalence between the north and the south of the country. Research Methods and Procedures: This was a cross‐sectional study of 2150 subjects (M/F: 1137/1013), 5.36 ± 0.83 years of age. The sampling areas were Verona (north Italy) and Messina (south Italy). We used definitions of overweight and obesity using BMI values, with cut‐off values proposed by the International Obesity Task Force. Results: The prevalence of overweight was 16.6% (males: 13.9%, females: 19.6%), and it was higher in the south (males: 17.8%, females: 22.4%) than in the north (males: 11.3%, females: 17.9%). The prevalence of obesity was 8.0% (males: 8.3%, females: 7.7%), and it was higher in the south (males: 12.3%, females: 10.7%) than in the north (males: 5.7%, females: 5.8%). Using the Centers for Disease Control reference charts, the prevalence of overweight and obesity of Italian children was close to that reported in children living in the United States (32% vs. 32.7%, respectively). Discussion: The prevalence of overweight and obesity in young Italian children is very high, and it is rapidly growing. In the south of the country, the prevalence is higher than in the north.     

Enhanced endothelin-1 system activity with overweight and obesity

Endothelin (ET)-1-mediated vasoconstrictor tone contributes to the development and progression of several adiposity-related conditions, including hypertension and atherosclerotic vascular disease. The aims of the present study were to determine 1) whether endogenous ET-1 vasoconstrictor activity is elevated in overweight and obese adults, and, if so, 2) whether increased ET-1-mediated vasoconstriction contributes to the adiposity-related impairment in endothelium-dependent vasodilation. Seventy-nine adults were studied: 34 normal weight [body mass index (BMI) < 25 kg/m(2)], 22 overweight (BMI ≥ 25 and < 30 kg/m(2)), and 23 obese (BMI ≥ 30 kg/m(2)). Forearm blood flow (FBF) responses to intra-arterial infusion of ET-1 (5 pmol/min for 20 min) and selective ET-1 receptor blockade (BQ-123, 100 nmol/min for 60 min) were determined. In a subset of the study population, FBF responses to ACh (4.0, 8.0, and 16.0 μg·100 ml tissue(-1)·min(-1)) were measured in the absence and presence of selective ET-1 receptor blockade. The vasoconstrictor response to ET-1 was significantly blunted in overweight and obese adults (～ 70%) compared with normal weight adults. Selective ET-1 receptor blockade elicited a significant vasodilator response (～ 20%) in overweight and obese adults but did not alter FBF in normal weight adults. Coinfusion of BQ-123 did not affect FBF responses to ACh in normal weight adults but resulted in an ～ 20% increase (P < 0.05) in ACh-induced vasodilation in overweight and obese adults. These results demonstrate that overweight and obesity are associated with enhanced ET-1-mediated vasoconstriction that contributes to endothelial vasodilator dysfunction and may play a role in the increased prevalence of hypertension with increased adiposity.     

体质测量在超重和肥胖研究中的应用

本文通过查阅文献,对体质测量在评估超重、肥胖和预测健康风险中的应用进行了回顾性调查、总结和分析,并对体质量指数、体脂肪指数和内脏脂肪指数等测量指标的优势和局限性进行了分析和讨论.由于预测结果受多种因素的影响,因而预测评价时应根据不同地域的不同的研究对象和不同的预测风险,选用不同的测量指标和不同的测量工具.为同行们今后应...     

The lifetime medical cost burden of overweight and obesity: implications for obesity prevention

This study quantifies age-specific and lifetime costs for overweight (BMI: 25-29.9), obese I (BMI: 30-34.9), and obese II/III (BMI: >35) adults separately by race/gender strata. We use these results to demonstrate why private sector firms are likely to underinvest in obesity prevention efforts. Not only does the existence of Medicare reduce the economic burden that obesity imposes on private payers, but, from the perspective of a 20-year-old obese adult, the short-term costs of obesity are small. This suggests that legislation that subsidizes wellness programs and/or mandates coverage for obesity treatments might make all firms better off. Ironically, Medicare has a greater incentive to prevent obesity because when an obese 65 year old enters the program, his/her costs are immediate and higher than costs for normal weight individuals.     

Current challenges to research on animal-assisted interventions

Studies of the effects of Animal-Assisted Interventions (AAIs) face a number of theoretical and practical challenges. Proposed theoretical processes for the effects of AAIs include those that address primarily the animal’s ability to facilitate human–human social engagement, those that emphasize animals’ apparent capacity to trigger social attachments and provide nonhuman social support, those that categorize certain animals as supernormal stimuli, those that advance a biophilia hypothesis that living organisms have an innate ability to attract and hold human attention, and those that promote an integrative biopsychosocial model. Each of these generates potentially testable hypotheses, and the field would benefit from systematic efforts to address their validity. Practical challenges to AAI research include issues of study design and methodology, the heterogeneity of both AAI recipients and the animals participating in these interventions, the welfare of these animals, and the unusual pressure from the public and media to report and publish positive findings. Such challenges need to be carefully considered in designing and implementing future studies in the field.     

Transition from overweight to obesity worsens pregnancy outcome in a BMI-dependent manner

Objective: To assess pregnancy outcomes in different BMI groups. Research Methods and Procedures: We analyzed 25, 601 singleton pregnancies from January 1989 to December 2001. Overweight women (prepregnancy BMI = 26 to 29 kg/m²) represented 13.2% (3388) of the cases, and 7.3% (1880) were obese (BMI ≥ 30 kg/m²). The data were obtained from self‐administered questionnaires at 20 weeks of pregnancy, complemented by nurse interviews and clinical records. Multiple logistic regression analysis was used to control for confounding factors. Results: Overweight and obese women had more previous deliveries, pregnancy terminations, miscarriages, and stillbirths, to have more diabetes and hypertension, and to smoke more often than normal weight women. The pregnancies were more often complicated by preeclampsia or chorioamnionitis (p < 0.001). Pregnancy outcomes were impaired in overweight and obese pregnant women, with respective odds ratios (95% confidence index) as follows: low Apgar score at 5 minutes, 1.54 (1.20 to 1.98) and 1.64 (1.22 to 2.28); newborn admission to a neonatal unit, 1.20 (1.06 to 1.37) and 1.38 (1.17 to 1.61); cesarean delivery, 1.22 (1.10 to 1.35) and 1.68 (1.48 to 1.91); fetal death, 1.54 (0.88 to 2.68) and 2.35 (1.28 to 4.32); perinatal death, 1.54 (0.98 to 2.42) and 2.19 (1.33 to 3.62). Discussion: Obesity, in particular during pregnancy, should be considered as an abnormal situation. An overweight condition increases obstetric risks in a BMI‐dependent manner. The risk of perinatal death more than doubles in the transition from an overweight to an obese condition. Modest weight loss could bring substantial advantages to obstetric outcome.     

Using research projects and qualitative conceptual modeling to increase novice scientists’ understanding of ecological complexity

A new program, Teaching Ecological Complexity, is working to develop a heightened capacity for systems thinking among high school biology and environmental sciences teachers. During a 2-week field-based course, the teachers use qualitative conceptual modeling, participate in all stages of field experimentation, and formulate plans to teach field research with their own classes. Qualitative conceptual modeling was found to be useful in revealing the underlying perceptions of ecosystem functioning for these novice scientists. Preliminary results showed improvement in their ability to recognize and apply some of the attributes of complex ecosystem: non-linear feedback loops, hierarchical organization, patterns illustrating the spatial arrangements of species diversity. In addition to using models, teachers used peer-learning techniques. Collegial discussions about what they understood at particular points in time were useful in improving their understanding of ecosystem phenomenon.