Polychlorinated biphenyl (PCB) exposure and diabetes: results from the Anniston Community Health Survey

Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world.Objectives: Reports of increased diabetes in PCB-exposed populations led us to examine possible associations in Anniston residents.Methods: Volunteers (n = 774) from a cross-sectional study of randomly selected households and adults who completed the Anniston Community Health Survey also underwent measurements of height, weight, fasting glucose, lipid, and PCB congener levels and verification of medications. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationships between PCBs and diabetes, adjusting for diabetes risk factors. Participants with prediabetes were excluded from the logistic regression analyses.Results: Participants were 47% African American, 70% female, with a mean age of 54.8 years. The prevalence of diabetes was 27% in the study population, corresponding to an estimated prevalence of 16% for Anniston overall; the PCB body burden of 35 major congeners ranged from 0.11 to 170.42 ppb, wet weight. The adjusted OR comparing the prevalence of diabetes in the fifth versus first quintile of serum PCB was 2.78 (95% CI: 1.00, 7.73), with similar associations estimated for second through fourth quintiles. In participants < 55 years of age, the adjusted OR for diabetes for the highest versus lowest quintile was 4.78 (95% CI: 1.11, 20.6), whereas in those ≥ 55 years of age, we observed no significant associations with PCBs. Elevated diabetes prevalence was observed with a 1 SD increase in log PCB levels in women (OR = 1.52; 95% CI: 1.01, 2.28); a decreased prevalence was observed in men (OR = 0.68; 95% CI: 0.33, 1.41).Conclusions: We observed significant associations between elevated PCB levels and diabetes mostly due to associations in women and in individuals < 55 years of age.     

Visceral adipose tissue and the ratio of visceral to subcutaneous adipose tissue are greater in adults with than in those without spinal cord injury, despite matching waist circumferences

BACKGROUND: Abdominal obesity, particularly visceral adipose tissue (VAT), is associated with an increased risk of coronary heart disease (CHD). Despite an elevated risk of CHD mortality in persons with spinal cord injury (SCI), neither abdominal adipose tissue accumulation nor the validity of waist circumference (WC) has been determined in persons with SCI. OBJECTIVES: The objectives of this study were to compare total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and the ratio of VAT to SAT (VAT:SAT) between adults with SCI and age-, sex-, and WC-matched able-bodied (AB) controls and to determine the relation between WC and VAT in both groups. DESIGN: Thirty-one men and women (n = 15 SCI and 16 AB) with a mean (+/-SD) age of 38.9 +/- 7.9 y participated in this cross-sectional study. Abdominal adipose tissue was quantified by computed tomography at L4-L5. WC was measured at 3 sites: lowest rib, iliac crest, and the midpoint between the lowest rib and iliac crest. RESULTS: Persons with SCI had a 58% greater mean VAT (P = 0.003), 48% greater mean VAT:SAT (P = 0.034), and 26% greater mean TAT (P = 0.055) than did matched AB controls after differences in weight were accounted for. Mean SAT was not significantly different between groups. WC at all sites was correlated with VAT in both groups (SCI: 0.905 < or = r < or = 0.925; AB: 0.838 < or = r < or = 0.877; both P < 0.001). CONCLUSIONS: High levels of VAT exist in young people with SCI who classify themselves as active and healthy. WC may be a valid surrogate measure of VAT in this population and serve as a tool for clinicians to identify those at risk of CHD.     

Disparities in the prevalence of obesity in Boston: results from the Boston Area Community Health (BACH) survey

Objective

This study examined disparities in the prevalence of obesity to determine how future prevention and/or intervention efforts should be developed to remedy obesity.

Methods

We obtained individual information of sociodemographic characteristics, comorbid conditions, and lifestyle behaviors from the Boston Area Community Health (BACH) survey for 2002–2005. To account for the complex BACH sampling design, observations were weighted inversely to their probability of selection, and sampling weights were poststratified to the Boston population from the U.S. Census 2000. We tested all possible two- and three-way interaction terms from a multivariate logistic regression model.

Results

After controlling for individual determinants in detail and focusing on the population within a single city, the associations of sociodemographic characteristics, comorbid conditions, and lifestyle behaviors with obesity were consistent with previous findings. Notably, three two-way interaction terms were significantly associated with obesity: (1) race/ethnicity and gender, (2) gender and other people in the household, and (3) race/ethnicity and alcohol consumption.

Conclusions

Future obesity prevention and/or intervention programs in Boston need to be primarily gender- and racially/ethnically specific to minimize cost and maximize results. Additional considerations are needed to take into account the differences in age, the presence of other people in the household, and education level.In the United States, the prevalence of obesity (defined as a body mass index [BMI] of ≥30 kilograms per meter squared [kg/m²]) has continued to increase during recent decades. The prevalence of obesity grew from 22.9% to 30.5% between the 1988–1994 and 1999–2000 National Health and Nutrition Examination Surveys.¹ This increasing trend was observed across gender, age, racial/ethnic minority groups, and other sociodemographic characteristics.² Regional variations are evident in the U.S., where the prevalence of obesity was higher in the South and Midwest and lower in the Northeast and West.³ Although a recent study indicated a change in the relationship between obesity and disabilities over time,⁴ the obese population is consistently at a higher risk of cardiovascular disease, stroke, hypertension, diabetes, and other health threats.⁵ With these health complications, obese individuals are confronting an economic burden associated with higher health-care and/or medical costs.^6,7 Moreover, they face a lower life expectancy and are associated with increased mortality relative to those with a normal weight (BMI of 18.5 to <25.0 kg/m²).^8,9 A recent study showed that obesity yields a significant increase in both cardiovascular disease- and cancer-related mortality.¹⁰Because of the health implications of obesity, effective prevention and/or intervention programs are deemed necessary to remedy obesity.^11,12 Such efforts require a comprehensive understanding of health inequalities and disparities among the population. In the U.S., significant differences are already evident by gender, age, race/ethnicity, and socioeconomic status (SES) (i.e., level of education and income).^13,14 In general, women, middle-aged adults, black people, those with low educational attainment, and/or low-income individuals are more likely to be obese. Additionally, lifestyle behaviors (e.g., smoking habits, drinking patterns, and exercise routines) are known to greatly influence body weight. For instance, individuals who are cigarette smokers and moderate alcohol drinkers have a lower BMI relative to nonsmokers and non-alcohol drinkers, respectively.^15,16 Those who engage in a high level of physical activity (i.e., those in a physically active occupation and those who exercise regularly during leisure time) are also less likely to become obese.¹⁷Although these national studies are informative to a certain extent, the relationship of obesity to socio-demographic characteristics, comorbid conditions, and lifestyle behaviors is complex and dynamic. In the U.S., dramatic obesity disparities exist in the intersection among gender, race/ethnicity, and SES. For example, a higher prevalence of obesity is evident among women, racial/ethnic minority groups, and those of low SES. The underlying factors for such disparities have been associated with the differences in stress-coping strategies, occupation-related lifestyle disorders, cultural norms, as well as home and residential settings.¹⁸ Therefore, to successfully implement future obesity prevention and/or intervention efforts, identifying the target population becomes crucial to minimize cost and maximize results. Doing so requires a better understanding of the prevalence of obesity and associated disparities at greater individual detail and in a specific geographic location. Such studies can provide local authorities, decision makers, and public health professionals with insight on resource allocation.To date, only a limited number of studies have been conducted in this capacity. Hence, this study attempts to fill this gap by examining the disparities in the prevalence of obesity in Boston, Massachusetts, using a community-based epidemiologic survey.     

The adipose tissue to serum dichlorodiphenyldichloroethane (DDE) ratio: some methodological considerations.

Dichlorodiphenyldichloroethane (DDE) adipose tissue level has been regarded as a preferred indicator of accumulated human exposure to DDT; however, blood sera are more feasible to obtain and analyze than adipose tissue samples. Inconsistent and scarce information exists in relation to the adipose tissue/serum DDE ratio. As a part of a hospital-based case-control study performed in Mexico City from 1994 to 1996, 198 paired serum and adipose tissue samples were obtained from 72 women with histologically confirmed breast cancer and 126 women with benign breast disease. Both adipose tissue and serum DDE levels were determined by gas-liquid chromatography and reported as ppb lipid weight (ng/g) as well as wet basis (ng/ml). Results showed that the adipose tissue/serum DDE ratio (ADSE) varies according to the type of information (lipid vs wet basis, arithmetic vs geometric means) used for its estimation. ADSE gets a value near 1 (1.1) only when the geometric DDE levels in lipid basis are used for its estimation. The correlation between DDE serum and adipose tissue levels was found (r=0.364, P<0.001). The ADSE did not vary by disease status, nor was it altered by parity, history of breast-feeding, and other reproductive characteristics. We endorse the use of venipuncture instead of biopsy as a way to estimate DDT body burden levels in further research.     

Visceral adipose tissue in women: longitudinal study of the effects of fat gain,time, and race

OBJECTIVE: To determine the effects of fat gain, time, and race on the accumulation of visceral adipose tissue (VAT) in a group of normal-weight premenopausal women. RESEARCH METHODS AND PROCEDURES: Sixty-five women participated in the study (32 African American and 33 white). The mean age of subjects was 34 +/- 6 years (range, 22 to 47 years). Eligible subjects were women who had body mass indices <25 kg/m(2) at baseline and who had completed evaluations at baseline and at follow-up year 1, without intervention. A subset of subjects was reevaluated annually for up to 4 years. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. A linear mixed model was used to examine changes in VAT over time, with total body fat as a covariate RESULTS: Total fat mass was not significantly different between races at baseline and increased significantly in both groups over time (p < 0.001). Time-related increases in total body fat were greater in African-American women (p < 0.01). VAT was significantly higher in white women at baseline (p < 0.01) and increased significantly over time in both races (p < 0.01), but remained higher in white women (p < 0.001). Increases in VAT, relative to total body fat, were greater than the increases in total body fat over time, independent of age and race (p < 0.001). DISCUSSION: Gaining total body-fat mass results in a higher increase in VAT, relative to total body fat, regardless of race and age, although African-American women maintain a lower VAT levels across time.     

Fats, inflammation and insulin resistance: insights to the role of macrophage and T-cell accumulation in adipose tissue

High-fat diet-induced obesity is associated with a chronic state of low-grade inflammation, which pre-disposes to insulin resistance (IR), which can subsequently lead to type 2 diabetes mellitus. Macrophages represent a heterogeneous population of cells that are instrumental in initiating the innate immune response. Recent studies have shown that macrophages are key mediators of obesity-induced IR, with a progressive infiltration of macrophages into obese adipose tissue. These adipose tissue macrophages are referred to as classically activated (M1) macrophages. They release cytokines such as IL-1β, IL-6 and TNFα creating a pro-inflammatory environment that blocks adipocyte insulin action, contributing to the development of IR and type 2 diabetes mellitus. In lean individuals macrophages are in an alternatively activated (M2) state. M2 macrophages are involved in wound healing and immunoregulation. Wound-healing macrophages play a major role in tissue repair and homoeostasis, while immunoregulatory macrophages produce IL-10, an anti-inflammatory cytokine, which may protect against inflammation. The functional role of T-cell accumulation has recently been characterised in adipose tissue. Cytotoxic T-cells are effector T-cells and have been implicated in macrophage differentiation, activation and migration. Infiltration of cytotoxic T-cells into obese adipose tissue is thought to precede macrophage accumulation. T-cell-derived cytokines such as interferon γ promote the recruitment and activation of M1 macrophages augmenting adipose tissue inflammation and IR. Manipulating adipose tissue macrophages/T-cell activity and accumulation in vivo through dietary fat modification may attenuate adipose tissue inflammation, representing a therapeutic target for ameliorating obesity-induced IR.     

The contribution of biogeographical ancestry and socioeconomic status to racial/ethnic disparities in type 2 diabetes mellitus: results from the Boston Area Community Health Survey

PurposeRacial/ethnic disparities in the incidence of type 2 diabetes mellitus (T2DM) are well documented, and many researchers have proposed that biogeographical ancestry (BGA) may play a role in these disparities. However, studies examining the role of BGA on T2DM have produced mixed results to date. Therefore, the objective of this research was to quantify the contribution of BGA to racial/ethnic disparities in T2DM incidence controlling for the mediating influences of socioeconomic factors.MethodsWe analyzed data from the Boston Area Community Health Survey, a prospective cohort with approximately equal numbers of black, Hispanic, and white participants. We used 63 ancestry-informative markers to calculate the percentages of participants with West African and Native American ancestry. We used logistic regression with G-computation to analyze the contribution of BGA and socioeconomic factors to racial/ethnic disparities in T2DM incidence.ResultsWe found that socioeconomic factors accounted for 44.7% of the total effect of T2DM attributed to black race and 54.9% of the effect attributed to Hispanic ethnicity. We found that BGA had almost no direct association with T2DM and was almost entirely mediated by self-identified race/ethnicity and socioeconomic factors.ConclusionsIt is likely that nongenetic factors, specifically socioeconomic factors, account for much of the reported racial/ethnic disparities in T2DM incidence.     

Community Intervention Trial for Smoking Cessation (COMMIT): I. cohort results from a four-year community intervention.

OBJECTIVES. The primary hypothesis of COMMIT (Community Intervention Trial for Smoking Cessation) was that a community-level, multi-channel, 4-year intervention would increase quit rates among cigarette smokers, with heavy smokers (> or = 25 cigarettes per day) of priority. METHODS. One community within each of 11 matched community pairs (10 in the United States, 1 in Canada) was randomly assigned to intervention. Endpoint cohorts totaling 10,019 heavy smokers and 10,328 light-to-moderate smokers were followed by telephone. RESULTS. The mean heavy smoker quit rate (i.e., the fraction of cohort members who had achieved and maintained cessation at the end of the trial) was 0.180 for intervention communities versus 0.187 for comparison communities, a nonsignificant difference (one-sided P = .68 by permutation test; 90% test-based confidence interval (CI) for the difference = -0.031, 0.019). For light-to-moderate smokers, corresponding quit rates were 0.306 and 0.275; this difference was significant (P = .004; 90% CI = 0.014, 0.047). Smokers in intervention communities had greater perceived exposure to smoking control activities, which correlated with outcome only for light-to-moderate smokers. CONCLUSIONS. The impact of this community-based intervention on light-to-moderate smokers, although modest, has public health importance. This intervention did not increase quit rates of heavy smokers; reaching them may require new clinical programs and policy changes.     

上海市长宁社区卫生服务机构评价:技术性视角

根据工作完成状况、人均工作量、服务成本水平等指标,对发展效率进行评价;根据慢病管理率、卫生服务管理水平等指标对发展质量进行评价;根据硬件设施建设、人力资源水平等指标对发展潜力及其可持续性进行评价。     

Community Mobilization Approaches for Large-Scale Public Health Surveys: Experiences from the Population-based HIV Impact Assessment (PHIA) Project

Journal of Community Health - Community mobilization is an integral process of raising awareness and increasing participation in a specific program. Communities with long-standing mistrust of...     

Health Hazards in the Home: An Assessment of a Southern Nevada Community

As a sub-grantee of a Department of Housing and Urban Development (HUD) Lead Hazard Control and Healthy Homes Program, the University of Nevada, Las Vegas’ Department of Environmental and Occupational Health performed lead and Healthy Homes investigations and collected data regarding conditions in the home environment in Henderson, Nevada. The purpose of this research is to characterize housing conditions in southern Nevada, compare data to census data, and to highlight the health outcomes associated with adverse housing conditions. Visual home assessments were conducted in 106 homes in southern Nevada, and specific hazards were characterized using the Healthy Homes Rating System. The results were then compared, when possible, to American Housing Survey (AHS) data for the Las Vegas metropolitan area. Lead, domestic hygiene, carbon monoxide, damp and mold, excess cold and heat, and structural collapse were the most frequently identified hazards, found in at least 101 (90%) of participant households. Median household income of program participants was half (50%) that of the surrounding zip code, which was expected, as classification as “low-income” by HUD standards was a requirement for participation. Our data indicated that the AHS data may not be representative of very low income housing in southern Nevada and may underreport actual conditions. In-home inspections performed by trained personnel provide a more accurate picture of conditions than the self-report method used by the AHS. In addition, we recommend the development of a standardized Healthy Homes visual assessment tool to allow for the comparison of housing conditions between communities.     

Health Technology Assessment With Diminishing Returns to Health: The Generalized Risk-Adjusted Cost-Effectiveness (GRACE) Approach

ObjectivesCost-effectiveness analysis (CEA) embeds an assumption at odds with most economic analysis–that of constant returns to health in the creation of happiness (utility). We aim to reconcile it with the bulk of economic theory.MethodsWe generalize the traditional CEA approach, allow diminishing returns to health, and align CEA with the rest of the health economics literature.ResultsThis simple change has far-reaching implications for the practice of CEA. First, optimal cost-effectiveness thresholds should systematically rise for more severe diseases and fall for milder ones. We provide formulae for estimating how these thresholds vary with health-related quality of life (QoL) in the sick state. Practitioners can also use our approach to account for treatment outcome uncertainty. Holding average benefits fixed, risk-averse consumers value interventions more when they reduce outcome uncertainty (‘insurance value’) and/or when they provide a chance at positively skewed outcomes (‘value of hope’). Finally, we provide a coherent way to combine improvements in QoL and life expectancy (LE) when people have diminishing returns to QoL.ConclusionThis new approach obviates the need for increasingly prevalent and ad hoc exceptions to CEA for end-of-life care, rare disease, and very severe disease (eg, cancer). Our methods also show that the value of improving QoL for disabled people is greater than for comparable non-disabled people, thus resolving an ongoing and mathematically legitimate objection to CEA raised by advocates for disabled people. Our Generalized Risk-Adjusted Cost-Effectiveness (GRACE) approach helps align HTA practice with realistic preferences for health and risk.     

Effect of Deploying Trained Community Based Reproductive Health Nurses (CORN) on Long‐Acting Reversible Contraception (LARC) Use in Rural Ethiopia: A Cluster Randomized Community Trial

To investigate the effect of innovative means to distribute LARC on contraceptive use, we implemented a three arm, parallel groups, cluster randomized community trial design. The intervention consisted of placing trained community‐based reproductive health nurses (CORN) within health centers or health posts. The nurses provided counseling to encourage women to use LARC and distributed all contraceptive methods. A total of 282 villages were randomly selected and assigned to a control arm (n = 94) or 1 of 2 treatment arms (n = 94 each). The treatment groups differed by where the new service providers were deployed, health post or health center. We calculated difference‐in‐difference (DID) estimates to assess program impacts on LARC use. After nine months of intervention, the use of LARC methods increased significantly by 72.3 percent, while the use of short acting methods declined by 19.6 percent. The proportion of women using LARC methods increased by 45.9 percent and 45.7 percent in the health post and health center based intervention arms, respectively. Compared to the control group, the DID estimates indicate that the use of LARC methods increased by 11.3 and 12.3 percentage points in the health post and health center based intervention arms. Given the low use of LARC methods in similar settings, deployment of contextually trained nurses at the grassroots level could substantially increase utilization of these methods.