The obesity epidemic: pathophysiology and consequences of obesity

Resistance training in the treatment of the metabolic syndrome: a systematic review and meta-analysis of the effect of resistance training on metabolic clustering in patients with abnormal glucose metabolism

Over the last decade, investigators have given increased attention to the effects of resistance training (RT) on several metabolic syndrome variables. The metabolic consequences of reduced muscle mass, as a result of normal aging or decreased physical activity, lead to a high prevalence of metabolic disorders. The purpose of this review is: (i) to perform a meta-analysis of randomized controlled trials (RCTs) regarding the effect of RT on obesity-related impaired glucose tolerance and type 2 diabetes mellitus; and (ii) to investigate the existence of a dose-response relationship between intensity, duration and frequency of RT and the metabolic clustering. Thirteen RCTs were identified through a systematic literature search in MEDLINE ranging from January 1990 to September 2007. We included all RCTs comparing RT with a control group in patients with abnormal glucose regulation. For data analysis, we performed random effects meta-analyses to determine weighted mean differences (WMD) with 95% confidence intervals (CIs) for each endpoint. All data were analysed with the software package Review Manager 4.2.10 of the Cochrane Collaboration. In the 13 RCTs included in our analysis, RT reduced glycosylated haemoglobin (HbA(1c)) by 0.48% (95% CI -0.76, -0.21; p = 0.0005), fat mass by 2.33 kg (95% CI -4.71, 0.04; p = 0.05) and systolic blood pressure by 6.19 mmHg (95% CI 1.00, 11.38; p = 0.02). There was no statistically significant effect of RT on total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride and diastolic blood pressure. Based on our meta-analysis, RT has a clinically and statistically significant effect on metabolic syndrome risk factors such as obesity, HbA(1c) levels and systolic blood pressure, and therefore should be recommended in the management of type 2 diabetes and metabolic disorders.

Soft drinks consumption and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common clinical condition which is associated with metabolic syndrome in 70% of cases. Inappropriate dietary fat intake, excessive intake of soft drinks, insulin resistance and increased oxidative stress combine to increase free fatty acid delivery to the liver, and increased hepatic triglyceride accumulation contributes to fatty liver. Regular soft drinks have high fructose corn syrup which contains basic sugar building blocks, fructose 55% and glucose 45%. Soft drinks are the leading source of added sugar worldwide, and have been linked to obesity, diabetes, and metabolic syndrome. The consumption of soft drinks can increase the prevalence of NAFLD independently of metabolic syndrome. During regular soft drinks consumption, fat accumulates in the liver by the primary effect of fructose which increases lipogenesis, and in the case of diet soft drinks, by the additional contribution of aspartame sweetener and caramel colorant which are rich in advanced glycation end products that potentially increase insulin resistance and inflammation. This review emphasizes some hard facts about soft drinks, reviews fructose metabolism, and explains how fructose contributes to the development of obesity, diabetes, metabolic syndrome, and NAFLD.

1-(3',5'-dihydroxyphenoxy)-7-(2'',4'',6-trihydroxyphenoxy)-2,4,9-trihydroxydibenzo-1,4-dioxin inhibits adipocyte differentiation of 3T3-L1 fibroblasts

In this study, we isolated the phloroglucinol derivative, 1-(3',5'-dihydroxyphenoxy)-7-(2'',4'',6-trihydroxyphenoxy)-2,4,9-trihydroxydibenzo-1,4-dioxin (1), from Ecklonia cava and evaluated its potential inhibition on adipocyte differentiation in 3T3-L1 cells. Lipid accumulation along with the expression of several genes associated with adipogenesis and lipolysis was examined at the end of differentiation. Lipid accumulation level was examined by measuring triglyceride content and Oil-Red O staining. The expression levels of several genes and proteins were examined using reverse-transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, and Western blot analysis. Compound 1 significantly reduced lipid accumulation and downregulated peroxisome proliferator-activated receptor-gamma, sterol regulatory element-binding protein 1c, and CCAAT/enhancer-binding proteins alpha in a dose-dependent manner. Moreover, the presence of compound 1 induced downregulation of adipogenic target genes such as fatty acid binding protein 4, fatty acid transport protein 1, fatty acid synthase, acyl-CoA synthetase 1, lipoprotein lipase, and leptin. According to the lipolytic response, compound 1 downregulated perilipin and hormone-sensitive lipase while upregulating tumor necrosis factor alpha. Therefore, these results suggest that compound 1 might decrease lipid accumulation during adipocyte differentiation by modulating adipogenesis and lipogenesis. Furthermore, compound 1 could be developed as a functional agent effective in improving obesity.

Appropriate waist circumference cut-offs to predict diabetes in the Korean population - the Korean Genome and Epidemiology Study -

BACKGROUND

Waist circumference (WC) has been recommended as a screening test to identify individuals at high risk for diabetes. The aim of the present study was to identify the optimal WC cut-off to predict the development of diabetes in non-diabetic Korean subjects.

METHODS AND RESULTS

The Korean Genome and Epidemiology Study is a community-based prospective cohort study of 10,038 individuals over the age of 40, and biennial follow ups were conducted. In the present study 6,206 non-diabetic individuals (2,947 men and 3,259 women) participated. The incidence of diabetes was 22.1 cases/1,000 person-years for men and 17.0 cases/1,000 person-years for women. The incidence rate of diabetes was significantly increased as WC increased in both genders. The sensitivity, specificity, and the distance in the receiver operating characteristic curve indicated that the optimal WC cut-offs to predict diabetes were 85 cm for men and 80 cm for women.

CONCLUSIONS

WC may serve as a simple, precise marker for individuals who are at risk of developing diabetes. The results suggest that a WC of 85 cm for men and 80 cm for women is an appropriate cut-off to predict diabetes in the Korean population.

Serum uric acid is associated with metabolic risk factors for cardiovascular disease in the Uygur population

The prevalence of hyperuricemia is low in Uygurs, who have a high prevalence of cardiovascular risk factors such as hypertension, overweight-obesity, dyslipidemia, hyperglycemia, and insulin resistance (IR). This study sought to investigate the relationships between serum uric acid (UA) and these risk factors in this population. A cross-sectional study was conducted in Uygurs (859 males, 1268 females) aged 20 to 70 years. Demographic data, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and fasting and postprandial blood were obtained, and biological measurements were determined. The mean of BMI, SBP, DBP, total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides, fasting blood glucose, fasting insulin, and homeostasis model assessment insulin resistance index (HOMA-IR), and the prevalence of hypertension, IR, hyperglycemia, overweight-obesity, hypercholesteremia, hyper-LDL-c, and hypertriglyceridemia increased with UA but the prevalence of hypo-HDL-c decreased (p < 0.05). Logistic regression analysis showed that the odds ratios for IR, overweight-obesity, hypercholesteremia, hyper-LDL-c, and hypertriglyceridemia against the lowest UA group increased but decreased for hypo-HDL-c (p < 0.05). The UA in the hypo-HDL-c group was lower than that of the controls; the prevalence of hypo-HDL-c in hyperuricemia subjects was lower than in those with normal UA (p < 0.05). But the opposite results were observed between overweight-obesity, hyperglycemia, IR, hypercholesteremia, hypertriglyceridemia, and hyper-LDL-c and correspondence controls, respectively (p < 0.05). In Uygur, elevated UA is associated with overweight-obesity, hypercholesteremia, hyper-LDL-c, hypertriglyceridemia, hyperglycemia, and IR. The HDL-c level significantly increases with UA, whereas the prevalence of hypo-HDL-c decreases. Further studies are needed to clarify why UA is positively correlated to HDL-c.

Sociodemographic status and self-reported BMI-related morbidity in Koreans

PURPOSE

This study examined whether the relationship between body mass index (BMI) and the morbidity of chronic diseases differs by marital status, education, and income level.

MATERIALS AND METHODS

From a nationally representative sample of 5,526 adults from the third Korean National Health and Nutrition Examination Survey (2005), data regarding measured height and weight to classify BMI category (< 23, 23-24.9, > or = 25), self-reported sociodemographics (marital status, education, income, age, sex, and residence area), health behaviors (smoking, alcohol use, exercise, sleep, stress perception, and depression), and morbidity from at least one chronic disease were collected.

RESULTS

Education, income, and marital status were significantly associated with morbidity regardless of adjustment for BMI and health behaviors. After adjusting for BMI, other sociodemographic factors, and health behaviors, the odds ratio (95% confidence interval) of morbidity was 2.9 (2.4-3.7) for those in the married group and 2.9 (2.1-4.0) for those in the separated/divorced/widowed group, 2.0 (1.6-2.5) for those in the lowest education group, and 1.3 (1.2-1.6) for those in the lowest income group. When the BMI category and sociodemographic factors were combined, the odds ratios were elevated for those in the combination group with higher BMI and lower sociodemographic position.

CONCLUSION

Korean subjects who were married, in the lowest education group, or in the lowest income level had a higher risk of morbidity in relation to BMI.

Diet-induced obesity impairs the T cell memory response to influenza virus infection

The Centers for Disease Control and Prevention has suggested that obesity may be an independent risk factor for increased severity of illness from the H1N1 pandemic strain. Memory T cells generated during primary influenza infection target internal proteins common among influenza viruses, making them effective against encounters with heterologous strains. In male, diet-induced obese C57BL/6 mice, a secondary H1N1 influenza challenge following a primary H3N2 infection led to a 25% mortality rate (with no loss of lean controls), 25% increase in lung pathology, failure to regain weight, and 10- to 100-fold higher lung viral titers. Furthermore, mRNA expression for IFN-gamma was >60% less in lungs of obese mice, along with one third the number of influenza-specific CD8(+) T cells producing IFN-gamma postsecondary infection versus lean controls. Memory CD8(+) T cells from obese mice had a >50% reduction in IFN-gamma production when stimulated with influenza-pulsed dendritic cells from lean mice. Thus, the function of influenza-specific memory T cells is significantly reduced and ineffective in lungs of obese mice. The reality of a worldwide obesity epidemic combined with yearly influenza outbreaks and the current pandemic makes it imperative to understand how influenza virus infection behaves differently in an obese host. Moreover, impairment of memory responses has significant implications for vaccine efficacy in an obese population.

US acculturation, food intake, and obesity among Asian-Pacific hotel workers

BACKGROUND

Both obesity and immigration continue to increase in the United States. Studies suggest that a transition in lifestyle patterns, such as food intake, may mediate the relationship between immigration and obesity.

OBJECTIVE

We examine obesity among hotel workers in relation to age, sex, race/ethnicity, and indicators of food intake, immigration, and acculturation.

SUBJECTS/SETTING

Four thousand five hundred thirty hotel workers in 30 hotels were studied from the first year of the Work, Weight and Wellness program, before intervention (during 2005-2006).

MAIN OUTCOME MEASURES

Weight and height were measured, whereas race/ethnicity, language, education, immigration, acculturation, and food intake variables were assessed by questionnaire.

RESULTS

The study included 43% male and 57% female hotel workers (mean age 44.4+/-11.3 years; 42% Filipino, 32% other Asian, 13% Pacific Islander, 9% white, 1% black/African American, and 3% other race/ethnicity). On average (mean value), 55% of participants were born outside the United States; 57% were overweight or obese (body mass index [BMI] >25). The BMI of those born in the United States was 1.3 higher than that of those born in another country, adjusting for sex and race/ethnicity. Intake of sweet drinks and meat was positively associated with BMI while intake of fruit was negatively associated with BMI. Age at arrival in United States ("generation") was negatively associated with BMI, whereas greater acculturation was positively associated with BMI.

CONCLUSIONS

Food intake behaviors are probably related to place of birth, generation of migration to the United States, and acculturation. Direct measures of food intake added explanatory power to models, suggesting the importance of food intake to obesity. Further study of the influence of immigration, acculturation, and food intake on obesity using longitudinal study designs is warranted.

Reduction in plasma levels of inflammatory and oxidative stress indicators after Roux-en-Y gastric bypass

BACKGROUND

Obesity is considered to be associated with high levels of oxidative stress and inflammation. Anticipated weight loss secondary to bariatric surgery may offer an opportunity to evaluate this association. We studied a few markers of oxidative stress and inflammation in 20 obese patients submitted to Roux-en-Y gastric bypass (RYGBP).

METHODS

Variations in plasma levels of indicators of oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH), glutathione disulfide (GSSG), and total radical antioxidant parameter (TRAP)) and inflammation (alpha1-acid glycoprotein (AGP) and C-reactive protein (CRP)), as well as variations in plasma levels of leptin, glucose, glycated hemoglobin (HbA1c), and insulin were investigated in the preoperative period and 12 months postsurgery in 20 class III obese individuals submitted to bariatric surgery (obese group) and 20 non-obese individuals (control group).

RESULTS

Twelve months postsurgery, there was a significant reduction (p < 0.01) in median values of BMI (46.75/30.17 kg/m(2)) and in plasma levels of MDA (16.70/9.11 nmol/g prot), SOD (10.70/9.24 U/mgHb), GSSG (210.80/148.20 mM/g of Hb), AGP (125.70/75.80 mg/dL), CRP (1.31/0.38 mg/dL), and leptin (15.04/3.58 ng/mL). A significant drop (p < 0.05) in plasma levels of HbA1c (5.81/4.98%) was also observed. On the other hand, a significant increase in plasma levels of GSH (2.002/2.823 mM/g of Hb) and TRAP (585.40/815.48 microM Trolox), p < 0.01, and in catalase plasma levels (12.06/13.22 Deltat/mgHb/min), p < 0.05, was seen. No statistically significant variations in glucose (96.3/84.8 mg/dL) or insulin plasma levels (9.91/7.88 U/mL) occurred. Calculated homeostasis model assessment index did not statistically change 12 months postsurgery (2.36/1.66).

CONCLUSIONS

In the preoperative period, the obese group individuals showed higher oxidation and inflammation levels and lower indices of antioxidant defense than those of the control group. One year after RYGBP, an improvement in antioxidant protection, associated with a reduction in inflammatory and oxidative markers, was observed, indicating that these individuals presented a lower degree of oxidative stress.

Prevalence of diagnosed and undiagnosed diabetes mellitus and impaired fasting glucose in Sardinia

We aimed at updating the prevalence of impaired fasting glucose (IFG) and of undiagnosed (UD) and diagnosed diabetes (DD) among the Sardinian population. The survey was carried out from 2002 to 2005 on 4.737 subjects aged 20-80+ years. IFG was diagnosed when blood glucose was 110-125 mg/dl; UD when it was >or=126 mg/dl in the absence of personal history of diabetes; DD when personal history was positive, irrespective of blood glucose value. Prevalence rates (%) were adjusted for age by direct method to the Italian 2001 population. IFG was diagnosed in 11% of the sample (9.88% in females and 12.24% in males); UD was found in 5.65% (5.20 and 6.15%, females and males, respectively), DD in 8.72% (6.74 and 10.05%); and total diabetes (TD), i.e. the sum of UD + DD, was 14.37% (12.93 and 15.07%, females and males, respectively). In Sardinia, in about 5 years there was an increase of IFG (+61.8%), UD (+56.9%), DD (+55.7%), and TD (+57.9%). Thus Sardinia participates in the worldwide increase in prevalence of diabetes and its microvascular, macrovascular, and socioeconomic consequences.

Trends in the evolution of BMI in Belgian army men

Objectives

The first aim was to evaluate BMI cross-sectionally over a period of 14 years (1992 to 2005) in 43 343 army men and the second was to compare BMI using the paired data of 1497 army men. The data were analysed as a function of the military ranking system, used as an indicator for socio-economic position.

Design

Multiple cross-sectional and longitudinal design.

Results

A significant increase of BMI between age categories was detected over the 14-year period; BMI remained stable in each age category. In the paired cohort, median BMI increased during the same period from 23·9 (interquartile range 3·3) kg/m2 to 24·7 (interquartile range 3·5) kg/m2 (P < 0·0001). This age-dependent evolution was present in all military rankings. From age 40 years or more, BMI indicated a significant increase in the prevalence of overweight and obesity.

Conclusion

For the total cohort, BMI remained stable in each age category. For the paired cohort, BMI increased over time. The military leadership should emphasize prevention in order to reduce the health-care costs and disease burden in this cohort. This emphasis on prevention should target those aged less than 40 years.

Determinantes nutricionais e sóciodemográficos da variação de peso no pós-parto: uma revisão da literatura

Trata-se de um estudo de revisão sobre os fatores nutricionais e sócio-demográficos da variação de peso no pós-parto. Foi realizada uma busca bibliográfica nas bases de dados eletrônicas Scientific Eletronic Library On-line (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Medical Literature Analysis and Retrieval System Online (MEDLINE) referente a literatura publicada na última década (1997-2008). Treze artigos, um informe técnico e dois livros considerados relevantes sobre o assunto e publicados anteriormente ao ano 1997 foram citados na revisão. A revisão priorizou estudos de ensaios clínicos randomizados e de seguimento realizados com gestantes e mulheres no pós-parto. Os resultados obtidos mostram como principais fatores associados com a variação de peso no pós-parto o ganho de peso gestacional acima das recomendações do Institute of Medicine, Índice de Massa Corporal Pré-Gestacional > 25 kg/m2, dieta, tempo e intensidade do aleitamento materno e os fatores sócio-demográficos: raça negra, primiparidade, idade materna, baixa renda e baixa escolaridade. A prática regular de atividade física é recomendada como uma estratégia para evitar o ganho de peso excessivo e melhorar a perda de peso durante o pós-parto. No Brasil não existe uma estratégia nacional para prevenir o ganho de peso excessivo e garantir a adequada perda de peso nesse período. Durante o pós-parto, a maioria das ações de saúde visa basicamente garantir o aleitamento materno.

Prevalence and secular trends in overweight and obese Taiwanese children and adolescents in 1991-2003

OBJECTIVE

To describe recent trends in overweight and obese schoolchildren in Taiwan using international cut-off points.

DESIGN

Three independent cross-sectional surveys were used.

PARTICIPANTS

The study enrolled 157 485 students in 1991, 130 770 students in 1997 and 72 789 students in 2003, all aged 6-18 years, from elementary schools, secondary high schools and senior vocational high schools.

RESULTS

The prevalence of overweight and obese students increased significantly between 1991 and 2003. During this period, the percentage of male overweight and obese students increased from 5.7% to 14.2% and from 7.9% to 17.4%, respectively. The prevalence of female overweight and obese students increased from 11.1% to 13.4% and from 3.1% to 4.1%, respectively. Covariance analysis indicates that both sexes in 2003 had significantly higher percentages of overweight and obese subjects than those in 1991 and 1997 (p<0.001). Additionally, the prevalence of overweight and obese boys was higher than that for girls in each survey (p<0.001).

DISCUSSION

Analytical results demonstrate that prevalence and secular trends in overweight and obese Taiwanese children and adolescents increased significantly from 1991 to 2003. Taiwanese boys are more likely to become overweight and obese than their female counterparts.

Phosphorylated glucosamine inhibits adipogenesis in 3T3-L1 adipocytes

Phosphorylated glucosamine (glucosamine-6-phosphate, PGlc) was synthesized using methanesulfonic acid, phosphorus pentoxide (P(2)O(5)), NH(2)NH(2) and DMF. Its inhibitory effect on lipid accumulation in cultured 3T3-L1 adipocytes was investigated by measuring triglyceride contents and Oil Red O staining. In order to understand the mechanism by which lipid accumulation in adipocytes is decreased by PGlc, we examined the expression levels of several genes and proteins associated with adipogenesis and lipolysis using reverse transcription polymerase chain reaction, real-time polymerase chain reaction and Western blot analysis. Treatment with PGlc significantly reduced lipid accumulation during adipocyte differentiation and induced down-regulation of peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha in a dose-dependent manner. Moreover, treatment with PGlc during adipocyte differentiation induced significant up-regulation of preadipocyte factor 1 mRNA and down-regulation of such adipocyte-specific gene promoters as adipocyte fatty acid binding protein, fatty acid synthase, lipoprotein lipase and leptin. According to the lipolytic response, PGlc up-regulated hormone-sensitive lipase mRNA expression and suppressed the expression levels of tumor necrosis factor-alpha mRNA compared with fully differentiated adipose tissue. These results suggest that the inhibitory effect of PGlc on adipocyte differentiation might be mediated through the down-regulation of adipogenic transcription factors, such as peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha, which are related to the downstream adipocyte-specific gene promoters.

Comparison of resting energy expenditure prediction methods with measured resting energy expenditure in obese, hospitalized adults

BACKGROUND

Several methods are available to estimate caloric needs in hospitalized, obese patients who require specialized nutrition support; however, it is unclear which of these strategies most accurately approximates the caloric needs of this patient population. The purpose of this study was to determine which strategy most accurately predicts resting energy expenditure in this subset of patients.

METHODS

Patients assessed at high nutrition risk who required specialized nutrition support and met inclusion and exclusion criteria were enrolled in this observational study. Adult patients were included if they were admitted to a medical or surgical service with a body mass index > or = 30 kg/m(2). Criteria excluding patient enrollment were pregnancy and intolerance or contraindication to indirect calorimetry procedures. Investigators calculated estimations of resting energy expenditure for each patient using variations on the following equations: Harris-Benedict, Mifflin-St. Jeor, Ireton-Jones, 21 kcal/kg body weight, and 25 kcal/kg body weight. For nonventilated patients, the MedGem handheld indirect calorimeter was used. For ventilated patients, the metabolic cart was used. The primary endpoint was to identify which estimation strategy calculated energy expenditures to within 10% of measured energy expenditures.

RESULTS

The Harris-Benedict equation, using adjusted body weight with a stress factor, most frequently estimated resting energy expenditure to within 10% measured resting energy expenditure at 50% of patients.

CONCLUSION

Measured energy expenditure with indirect calorimetry should be employed when developing nutrition support regimens in obese, hospitalized patients, as estimation strategies are inconsistent and lead to inaccurate predictions of energy expenditure in this patient population.

Considerations for an obesity policy research agenda

The rise in obesity levels in the U.S. in the past several decades has been dramatic, with serious implications for public health and the economy. Experiences in tobacco control and other public health initiatives have shown that public policy may be a powerful tool to effect structural change to alter population-level behavior. In 2007, the National Cancer Institute convened a meeting to discuss priorities for a research agenda to inform obesity policy. Issues considered were how to define obesity policy research, key challenges and key partners in formulating and implementing an obesity policy research agenda, criteria by which to set research priorities, and specific research needs and questions. Themes that emerged were: (1) the embryonic nature of obesity policy research, (2) the need to study "natural experiments" resulting from policy-based efforts to address the obesity epidemic, (3) the importance of research focused beyond individual-level behavior change, (4) the need for economic research across several relevant policy areas, and (5) the overall urgency of taking action in the policy arena. Moving forward, timely evaluation of natural experiments is of especially high priority. A variety of policies intended to promote healthy weight in children and adults are being implemented in communities and at the state and national levels. Although some of these policies are supported by the findings of intervention research, additional research is needed to evaluate the implementation and quantify the impact of new policies designed to address obesity.

Comparison of overall obesity and abdominal adiposity in predicting chronic kidney disease incidence among adults

OBJECTIVE

Epidemiological data on the association between different aspects of adiposity and the risk for chronic kidney disease (CKD) in a cohort are limited. We compared the independent power of waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) in predicting CKD in a large cohort of adults.

DESIGN

This was a population-based cohort study.

SETTING, PARTICIPANTS, AND MEASUREMENTS

A representative sample of 3107 subjects (1309 men and 1798 women), aged over 20 years, and free of CKD at baseline, was followed for 7 years.

METHODS

We estimated glomerular filtration rate (GFR) by using the abbreviated equation from the Modification of Diet in Renal Disease Study, and defined CKD as an estimated GFR of less than 60 mL/min/1.73 m(2). Adjusted relative hazards of CKD were modeled using Cox proportional hazards regression, including BMI, WC, and WHR as risk factors.

RESULTS

During the 7-year follow-up (median of 2183 days), 13.5% of participants (n = 419) developed CKD. The WC was positively related to risk of CKD, after multivariable adjustment for age, sex, smoking, menopause, physical activity, blood pressure, prevalent and incident diabetes, and change in WC during study period: Hazard ratios for CKD incidence were 1.00 (reference), 1.60 (95% CI: 1.06, 2.42), 1.86 (0.95 CI: 1.21, 2.85), and 1.88 (0.95 CI: 1.17, 3.01) for WC categories 1 to 4, respectively (P for trend < .02). The WHR was not independently associated with CKD. The rate of GFR decline (measured in mL/min/1.73 m(2)/year) was associated with baseline waist categories: regression coefficient for 1 SD increase in WC = -0.18 (0.95 CI:-0.28, -0.07). Based on Harrell's measure of concordance statistics, baseline WC was a better predictor of CKD than WHR (P < .05) and BMI (P < .05).

CONCLUSIONS

Abdominal adiposity measured with WC, irrespective of general adiposity, is a more important determinant of CKD risk in adults than are WHR and BMI.

Increasing total fiber intake reduces risk of weight and fat gains in women

Research investigating fiber intake and changes in weight over time has not controlled for important covariates, especially physical activity. Moreover, studies have rarely examined the influence of fiber on changes in body fat, only weight. Hence, this study was conducted to determine whether changes in fiber intake (total, soluble, and insoluble) influence risk of gaining weight and body fat over time. Another objective was to examine the influence of age, energy intake, activity, season, and other potential confounders. A prospective cohort design was used and 252 women completed baseline and follow-up assessments 20 mo apart. Diet was measured using 7-d weighed food records. Fiber was expressed per 1000 kcal (4187 kJ). Body fat was assessed via the Bod Pod and physical activity was measured using accelerometers over 7 consecutive days. Across the 20 mo, almost 50% of the women gained weight and fat. For each 1 g increase in total fiber consumed, weight decreased by 0.25 kg (P = 0.0061) and fat decreased by 0.25 percentage point (P = 0.0052). Controlling for potential confounders did not affect the relationships, except changes in energy intake, which weakened the associations by 24-32%. Soluble and insoluble fibers were borderline predictors of changes in weight and fat. In conclusion, increasing dietary fiber significantly reduces the risk of gaining weight and fat in women, independent of several potential confounders, including physical activity, dietary fat intake, and others. Fiber's influence seems to occur primarily through reducing energy intake over time.

The interface between the eating disorders and obesity fields: moving toward a model of shared knowledge and collaboration

As more attention is being directed toward obesity, important questions facing the eating disorders field include: How should the eating disorders field deal with this increased focus on obesity? What are some models for work between the eating disorders and obesity fields? This paper briefly describes four potential models of interaction between the fields and possible scenarios demonstrating each model. The first model is one in which the obesity field overpowers the eating disorders field. In the second model, the two fields have minimal opportunities for interaction and for cross-fertilization of ideas. In the third model, there is antagonism and a lack of respect for the other field. The fourth, and recommended model, is one in which the two fields share knowledge to enhance the difficult work of preventing and treating both eating disorders and obesity. Examples of opportunities for shared knowledge and collaboration, and benefits of this fourth model for both the eating disorders and obesity fields, are discussed.

Prevalence of obesity and physical inactivity among farmers from Crete (Greece), four decades after the Seven Countries Study

BACKGROUND AND AIM

As first shown 40 years ago farmers from Crete had one of the healthiest lifestyles compared to other participants of the Seven Countries Study. Taking the above into account we investigated the prevalence of obesity and its indexes among farmers in Crete in 2005.

METHODS AND RESULTS

502 farmers (18-79 years old) from the Valley of Messara in Crete were randomly selected and examined. Body Mass Index (BMI), waist circumference (WC), waist-to-hip ratio (W/Hip Ratio), waist-to-height ratio (W/Height Ratio), conicity index, percentage of body fat and hours of daily light physical activity (LPhA) and moderate-to-vigorous physical activity (MVPhA) were calculated for each subject. 86,1% of the study population was overweight and/or obese. Specifically 42.9% had a BMI of 25.1-30 kg/m(2) and were overweight and 43.2% were obese with a BMI>30 kg/m(2). The percentage of body fat was estimated at 27.3% of total body weight among males and 39.3% among females, while all obesity indexes were found to differ between genders.

CONCLUSIONS

In comparison to middle aged male farmers from Crete in the 1960s, mean weight has increased by 20 kg (83 kg vs. 63 kg), which has lead to a 7 kg/m(2) in mean BMI (22.9 kg/m(2) vs. 29.8 kg/m(2)), findings that support the fact that the prevalence of obesity in Greece has risen dramatically over the years, even among farmers from Crete, a population historically known for being the gold standard of health status globally.

Determinants of Latina obesity in the United States: the role of selective acculturation

Obesity has reached epidemic proportions in the United States. Hispanic American women in particular have higher rates of obesity than their non-Hispanic White counterparts. In this article, the authors review the existing literature on acculturation as it relates to obesity and health behaviors among U.S. Hispanic women. In addition, a conceptual framework is proposed to examine factors contributing to obesity through "selective acculturation." This concept challenges traditionally held unilateral assumptions that underscore Hispanic women's unhealthful behavioral patterns by explaining a process whereby Hispanic women both maintain some older health-related behaviors and acquire new ones once they settle in a new culture.

Waist circumference measurement in clinical practice

The obesity epidemic is a major public health problem worldwide. Adult obesity is associated with increased morbidity and mortality. Measurement of abdominal obesity is strongly associated with increased cardiometabolic risk, cardiovascular events, and mortality. Although waist circumference is a crude measurement, it correlates with obesity and visceral fat amount, and is a surrogate marker for insulin resistance. A normal waist circumference differs for specific ethnic groups due to different cardiometabolic risk. For example, Asians have increased cardiometabolic risk at lower body mass indexes and with lower waist circumferences than other populations. One criterion for the diagnosis of the metabolic syndrome, according to different study groups, includes measurement of abdominal obesity (waist circumference or waist-to-hip ratio) because visceral adipose tissue is a key component of the syndrome. The waist circumference measurement is a simple tool that should be widely implemented in clinical practice to improve cardiometabolic risk stratification.

Adiposity and Alzheimer's disease

PURPOSE OF REVIEW

Alzheimer's disease is the most common form of dementia. There are no known preventive or curative measures. There is increasing evidence for the role of total adiposity, usually measured clinically as BMI, and central adiposity, in Alzheimer's disease. This topic is of enormous public health importance given the global epidemic of high adiposity and its consequences.

RECENT FINDINGS

Salient publications in 2007 and 2008 showed that (a) central adiposity in middle age predicts dementia in old age; (b) the relation between high adiposity and dementia is attenuated with older age; (c) waist circumference in old age, a measure of central adiposity, may be a better predictor of dementia than BMI; (d) lower BMI predicts dementia in elderly people; and (e) weight loss may precede dementia diagnosis by decades, which may explain seemingly paradoxical findings.

SUMMARY

The possibility that high adiposity increases Alzheimer's disease risk is alarming given global trends of overweight and obesity in the general population. However, prevention and manipulation of adiposity may also provide a means to prevent Alzheimer's disease. Treatment of weight loss in Alzheimer's disease may also be important but is beyond the score of this review.

Treatment with sitagliptin or metformin does not increase body weight despite predicted reductions in urinary glucose excretion

BACKGROUND

We used a mathematical model to estimate the contribution of urinary glucose excretion (UGE) to reported changes in body weight (BW) following oral antihyperglycemic agent (AHA) therapy. This modeling approach was used to gain novel insight into the mechanisms by which oral AHA affects BW.

METHODS

Twenty-four hour glucose profiles were used to predict UGE before and after treatment with oral AHA. Model-predicted changes in BW due to reduced UGE were compared with reported changes in BW to quantify non-UGE-dependent effects (fluid retention, food intake, and energy expenditure).

RESULTS

In type 2 diabetes patients [hemoglobin A1c (HbA1c) >7.3%], the energy lost to UGE is predicted to decrease an average of 100 kcal/day for each 1% decrease in HbA1c. This effect, alone, is predicted to increase BW 1.4 kg after 6 months. Differences from this value reported for changes in BW with oral AHA therapy (+1.4 kg for pioglitazone and rosiglitazone; -0.4 kg for glyburide; -0.9 kg for sitagliptin and vildagliptin; -2.3 kg for metformin) are therefore predicted to be due to additional, non-UGE-dependent mechanisms.

CONCLUSIONS

Weight gain following thiazolidinedione therapy is predicted to result from both reduced UGE and non-UGE-dependent mechanisms. Reduced UGE alone is predicted to account for most of the weight gain reported following sulfonylurea therapy. Weight loss observed in response to metformin and weight maintenance observed in response to dipeptidyl peptidase-4 inhibitors may result from an increase in satiety, energy expenditure, or both.

Adiposity, type 2 diabetes, and Alzheimer's disease

This manuscript provides a comprehensive review of the epidemiologic evidence linking the continuum of adiposity and type 2 diabetes (T2D) with Alzheimer's disease (AD). The mechanisms relating adiposity and T2D to AD may include hyperinsulinemia, advanced products of glycosylation, cerebrovascular disease, and products of adipose tissue metabolism. Elevated adiposity in middle age is related to a higher risk of AD but the data on this association in old age is conflicting. Several studies have shown that hyperinsulinemia, a consequence of higher adiposity and insulin resistance, is also related to a higher risk of AD. Hyperinsulinemia is a risk factor for T2D, and numerous studies have shown a relation of T2D with higher AD risk. The implication of these associations is that a large proportion of the world population may be at increased risk of AD given the trends for increasing prevalence of overweight, obesity, hyperinsulinemia, and T2D. However these associations may present a unique opportunity for prevention and treatment of AD. Several studies in the prevention and treatment of T2D are currently conducting, or have planned, cognition ancillary studies. In addition, clinical trials using insulin sensitizers in the treatment or prevention of AD are under way.

Obesity increases the risks of diverticulitis and diverticular bleeding

BACKGROUND & AIMS

Studies of obesity and diverticular complications are limited. We assessed the relationship between body mass index (BMI), waist circumference, and waist-to-hip ratio and diverticulitis and diverticular bleeding.

METHODS

A prospective cohort study of 47,228 male health professionals (40-75 years old) who were free of diverticular disease in 1986 (baseline) was performed. Men reporting newly diagnosed diverticular disease on biennial follow-up questionnaires were sent supplemental questionnaires. Weight was recorded every 2 years, and data on waist and hip circumferences were collected in 1987.

RESULTS

We documented 801 incident cases of diverticulitis and 383 incident cases of diverticular bleeding during 18 years of follow-up. After adjustment for other risk factors, men with a BMI >or= 30 kg/m(2) had a relative risk (RR) of 1.78 (95% confidence interval [CI], 1.08-2.94) for diverticulitis and 3.19 (95% CI, 1.45-7.00) for diverticular bleeding compared with men with a BMI of <21 kg/m(2). Men in the highest quintile of waist circumference, compared with those in the lowest, had a multivariable RR of 1.56 (95% CI, 1.18-2.07) for diverticulitis and 1.96 (95% CI, 1.30-2.97) for diverticular bleeding. Waist-to-hip ratio was also associated with the risk of diverticular complications when the highest and lowest quintiles were compared, with a multivariable RR of 1.62 (95% CI, 1.23-2.14) for diverticulitis and 1.91 (95% CI, 1.26-2.90) for diverticular bleeding. Adjustment for BMI did not change the associations seen for waist-to-hip ratio.

CONCLUSIONS

In this large prospective cohort, BMI, waist circumference, and waist-to-hip ratio significantly increased the risks of diverticulitis and diverticular bleeding.

Blood pressure in firefighters, police officers, and other emergency responders

Elevated blood pressure is a major risk factor for cardiovascular morbidity and mortality. Increased risk begins in the prehypertensive range and increases further with higher pressures. The strenuous duties of emergency responders (firefighters, police officers, and emergency medical services (EMS) personnel) can interact with their personal risk profiles, including elevated blood pressure, to precipitate acute cardiovascular events. Approximately three-quarters of emergency responders have prehypertension or hypertension, a proportion which is expected to increase, based on the obesity epidemic. Elevated blood pressure is also inadequately controlled in these professionals and strongly linked to cardiovascular disease morbidity and mortality. Notably, the majority of incident cardiovascular disease events occur in responders who are initially prehypertensive or only mildly hypertensive and whose average premorbid blood pressures are in the range in which many physicians would hesitate to prescribe medications (140-146/88-92). Laws mandating public benefits for emergency responders with cardiovascular disease provide an additional rationale for aggressively controlling their blood pressure. This review provides a background on emergency responders, summarizes occupational risk factors for hypertension and the metabolic syndrome, their prevalence of elevated blood pressure, and evidence linking hypertension with adverse outcomes in these professions. Next, discrepancies between relatively outdated medical standards for emergency responders and current, evidence-based guidelines for blood pressure management in the general public are highlighted. Finally, a workplace-oriented approach for blood pressure control among emergency responders is proposed, based on the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.

A look inside the diabetic brain: Contributors to diabetes-induced brain aging

Central nervous system (CNS) complications resulting from diabetes is a problem that is gaining more acceptance and attention. Recent evidence suggests morphological, electrophysiological and cognitive changes, often observed in the hippocampus, in diabetic individuals. Many of the CNS changes observed in diabetic patients and animal models of diabetes are reminiscent of the changes seen in normal aging. The central commonalities between diabetes-induced and age-related CNS changes have led to the theory of advanced brain aging in diabetic patients. This review summarizes the findings of the literature as they relate to the relationship between diabetes and dementia and discusses some of the potential contributors to diabetes-induced CNS impairments.

Macronutrients and insulin resistance in cholesterol gallstone disease

Cholelithiasis is a major source of digestive morbidity worldwide. Cholesterol stones account for the majority of gallstones in the United States and other Western countries. The pathogenesis of cholesterol gallstone disease is multifactorial with key factors including cholesterol supersaturation of bile, altered biliary motility, and nucleation and growth of cholesterol crystals. Increasing evidence suggests that many, but not all, causative factors of cholesterol gallstones are related to insulin resistance which, in association with obesity, has reached an epidemic level worldwide. Experimental studies show that hyperinsulinemia, a key feature of insulin resistance, may cause increased hepatic cholesterol secretion and cholesterol supersaturation of bile and gallbladder dysmotility, and thereby may enhance gallstone formation. Insulin resistance syndrome can be modified by environmental factors, including dietary factors. The impact of diet on insulin sensitivity is mediated by both dietary composition and its energy content. The contribution of specific dietary elements to the prevalence and incidence of cholesterol gallstone disease has been explored in animal and human studies. There is considerable evidence to suggest that different types of fatty acids, independent of the total amount of fat consumption, affect insulin sensitivity and cholesterol gallstone disease differently. The effects of salt intake, consumption of protein and carbohydrates, and alcohol drinking on insulin resistance are controversial. Additional intervention trials and controlled experimental feeding studies are needed to further clarify these relationships and to provide useful prophylactic and therapeutic strategies.

The obesity paradox: impact of obesity on the prevalence and prognosis of cardiovascular diseases

Obesity has reached global epidemic proportions and is associated with numerous comorbidities such as hypertension (HTN), type 2 diabetes mellitus, dyslipidemia, certain cancers, and chronic kidney disease (CKD). Obesity, via its direct maladaptive effects on cardiac structure and through its impact on conventional risk factors, is strongly associated with cardiovascular (CV) diseases such as heart failure (HF) and coronary heart disease (CHD). Despite these adverse associations, numerous studies indicate an "obesity paradox" in that being overweight or obese is associated with a favorable prognosis in many patients with established CV disease, particularly in patients with HTN, HF, and CHD. This review summarizes the adverse effects of obesity on CV disease risk factors and its role in the genesis of HTN, HF, CHD, and the obesity paradox. It concludes with a discussion on the potential benefits of weight loss in these patient populations.

ROC analysis of subcutaneous adipose tissue topography (SAT-Top) in female coronary heart disease patients and healthy controls

The aim of this study was to investigate whether subcutaneous adipose tissue topography (SAT-Top) is different in female CHD patients (n=26) and healthy controls (n=36) matched to age, body size, weight, and BMI. The thicknesses of SAT layers were measured by LIPOMETER at 15 specified body sites. To calculate the power of the different body sites to discriminate between CHD women and healthy controls, receiver operating characteristic (ROC) curve analysis was performed. For each parameter, sensitivity and specificity were calculated at different cutoff points. CHD women showed a significant decrease to 78.36% (p=0.012) at body site 11-front thigh, 73.10% (p=0.012) at 12-lateral thigh, 72.20% (p=0.009) at 13-rear thigh, 66.43% (p<0.001) at 14-inner thigh, and 49.19% (p<0.001) at 15-calf. The best discriminators analysed by ROC curves between female CHD patients and healthy controls turned out to be calf and inner thigh (optimal cut off values: calf: 3.85 mm and inner thigh: 11.15 mm). Stepwise discriminant analysis identified the body sites calf, lateral chest, and inner thigh as significant. In conclusion, information was obtained on the extent to which SAT thickness at each measured body site is able to discriminate between the two subject groups. The good discrimination results obtained for the present dataset are encouraging enough to recommend applying LIPOMETER SAT-Top measurements in further studies to investigate individual risks for CHD.

Alzheimer's disease and vascular dementia in developing countries: prevalence, management, and risk factors

Despite mortality due to communicable diseases, poverty, and human conflicts, dementia incidence is destined to increase in the developing world in tandem with the ageing population. Current data from developing countries suggest that age-adjusted dementia prevalence estimates in 65 year olds are high (>or=5%) in certain Asian and Latin American countries, but consistently low (1-3%) in India and sub-Saharan Africa; Alzheimer's disease accounts for 60% whereas vascular dementia accounts for approximately 30% of the prevalence. Early-onset familial forms of dementia with single-gene defects occur in Latin America, Asia, and Africa. Illiteracy remains a risk factor for dementia. The APOE epsilon4 allele does not influence dementia progression in sub-Saharan Africans. Vascular factors, such as hypertension and type 2 diabetes, are likely to increase the burden of dementia. Use of traditional diets and medicinal plant extracts might aid prevention and treatment. Dementia costs in developing countries are estimated to be US$73 billion yearly, but care demands social protection, which seems scarce in these regions.

Blood loss is a stronger predictor of iron status in men than C282Y heterozygosity or diet

OBJECTIVE

To determine the relative importance of HFE gene, diet, lifestyle, and blood loss characteristics for predicting iron status in a sample of men aged 40 years or over.

DESIGN

Iron status (serum ferritin, transferrin saturation, soluble transferrin receptor) was measured in 44 C282Y heterozygote and 85 age- and BMI-matched wildtype men aged 40 years or over. Dietary intake of iron (total, heme and non-heme), and components known to influence iron bioavailability, was determined using a validated Meal-Based Intake Assessment Tool. Information on lifestyle and blood loss was obtained by questionnaire. Height and weight were measured to determine Quetelet's body mass index. Linear mixed models were used to determine the extent to which these variables predicted iron status.

RESULTS

C282Y heterozygosity was associated with 17% higher transferrin saturation (95% CI: 6%, 29%) but no difference in serum ferritin or soluble transferrin receptor concentrations. Blood donation was negatively associated with transferrin saturation (-13% (- 3%, -22%)) and serum ferritin (-58% (-44%, -68%)), and had a marginally significant positive association with soluble transferrin receptor concentration. Self-reported fecal blood loss was negatively associated with serum ferritin concentration (-35% (-54%, -7%)). Alcohol was the only dietary variable associated with iron status and was associated with all three of the iron status indices. Serum ferritin concentration was positively associated with body mass index (10% per unit increase (6%, 15%)).

CONCLUSIONS

Blood loss was a stronger predictor of iron status than either C282Y heterozygosity or diet in this population of men aged 40 years and over.

Effects of glucocorticoids on weight change during the treatment of Wegener's granulomatosis

OBJECTIVE

Weight gain is a side effect of glucocorticoid (GC) use, but the natural history and health implications of changes in weight that occur during the treatment of inflammatory disease are not understood.

METHODS

We evaluated data from the Wegener's Granulomatosis Etanercept Trial. Patients were categorized according to clinical outcome at 1 year: remission (no disease flares), single flare, or multiple flares. Risk factors for gaining > or =10 kg were examined in multivariate models.

RESULTS

Weights at baseline and 1 year were available for 157 (93%) of the 168 patients analyzed. During year 1, the mean cumulative prednisone dosage in the multiple flares subgroup was 7.9 gm, compared with 6.0 gm and 3.9 gm in the single flare and remission subgroups, respectively (P < 0.001). Patients in these subgroups gained an average of 2.6 kg, 4.1 kg, and 5.8 kg, respectively (P = 0.005). Weight gain did not correlate with cumulative GC dose (R = 0.10, P = 0.25). Thirty-five patients (22.3%) gained and maintained > or =10 kg in the first year. New diagnosis of Wegener's granulomatosis at baseline was an independent predictor of gaining > or =10 kg at 1 year (odds ratio 19.7, 95% confidence interval 2.4-162.6, P = 0.006). Among the 78 patients in the remission subgroup, 40 sustained remissions through the 2-year time point. For these 40 patients, the mean weight gained at year 1 did not regress by the end of year 2, despite the absence of continued GC use.

CONCLUSION

Disease control was associated with lower cumulative GC doses but greater weight gain. More than one-fifth of patients gained >10 kg in the first year of treatment. The quantity of weight gained by patients during treatment has potential future health implications.

Accuracy of body mass index in diagnosing obesity in the adult general population

BACKGROUND

Body mass index (BMI) is the most widely used measure to diagnose obesity. However, the accuracy of BMI in detecting excess body adiposity in the adult general population is largely unknown.

METHODS

A cross-sectional design of 13 601 subjects (age 20-79.9 years; 49% men) from the Third National Health and Nutrition Examination Survey. Bioelectrical impedance analysis was used to estimate body fat percent (BF%). We assessed the diagnostic performance of BMI using the World Health Organization reference standard for obesity of BF%>25% in men and>35% in women. We tested the correlation between BMI and both BF% and lean mass by sex and age groups adjusted for race.

RESULTS

BMI-defined obesity (> or =30 kg m(-2)) was present in 19.1% of men and 24.7% of women, while BF%-defined obesity was present in 43.9% of men and 52.3% of women. A BMI> or =30 had a high specificity (men=95%, 95% confidence interval (CI), 94-96 and women=99%, 95% CI, 98-100), but a poor sensitivity (men=36%, 95% CI, 35-37 and women=49%, 95% CI, 48-50) to detect BF%-defined obesity. The diagnostic performance of BMI diminished as age increased. In men, BMI had a better correlation with lean mass than with BF%, while in women BMI correlated better with BF% than with lean mass. However, in the intermediate range of BMI (25-29.9 kg m(-2)), BMI failed to discriminate between BF% and lean mass in both sexes.

CONCLUSIONS

The accuracy of BMI in diagnosing obesity is limited, particularly for individuals in the intermediate BMI ranges, in men and in the elderly. A BMI cutoff of> or =30 kg m(-2) has good specificity but misses more than half of people with excess fat. These results may help to explain the unexpected better survival in overweight/mild obese patients.

Nutrigenomic analysis of diet-gene interactions on functional supplements for weight management

Recent advances in molecular biology combined with the wealth of information generated by the Human Genome Project have fostered the emergence of nutrigenomics, a new discipline in the field of nutritional research. Nutrigenomics may provide the strategies for the development of safe and effective dietary interventions against the obesity epidemic. According to the World Health Organization, more than 60% of the global disease burden will be attributed to chronic disorders associated with obesity by 2020. Meanwhile in the US, the prevalence of obesity has doubled in adults and tripled in children during the past three decades. In this regard, a number of natural dietary supplements and micronutrients have been studied for their potential in weight management. Among these supplements, (-)-hydroxycitric acid (HCA), a natural extract isolated from the dried fruit rind of Garcinia cambogia, and the micronutrient niacin-bound chromium(III) (NBC) have been shown to be safe and efficacious for weight loss. Utilizing cDNA microarrays, we demonstrated for the first time that HCA-supplementation altered the expression of genes involved in lipolytic and adipogenic pathways in adipocytes from obese women and up-regulated the expression of serotonin receptor gene in the abdominal fat of rats. Similarly, we showed that NBC-supplementation up-regulated the expression of myogenic genes while suppressed the expression of genes that are highly expressed in brown adipose tissue in diabetic obese mice. The potential biological mechanisms underlying the observed beneficial effects of these supplements as elucidated by the state-of-the-art nutrigenomic technologies will be systematically discussed in this review.

Adiposity, hyperinsulinemia, diabetes and Alzheimer's disease: an epidemiological perspective

The objective of this manuscript is to provide a comprehensive review of the epidemiologic evidence linking the continuum of adiposity, hyperinsulinemia, and diabetes with Alzheimer's disease. The mechanisms for these associations remain to be elucidated, but may include direct actions from insulin, advanced products of glycosilation, cerebrovascular disease, and products of adipose tissue metabolism. Elevated adiposity in middle age is related to a higher risk of Alzheimer's disease. The evidence relating adiposity in old age to Alzheimer's disease is conflicting. Several studies have shown that hyperinsulinemia, a consequence of higher adiposity and insulin resistance, is also related to a higher risk of Alzheimer's disease. Hyperinsulinemia is a risk factor for diabetes, and numerous studies have shown a relation of diabetes with higher Alzheimer's disease risk. Most studies fail the take into account the continuum linking these risk factors which may result in underestimation of their importance in Alzheimer's disease. The implication of these associations is that a large proportion of the world population may be at increased risk of Alzheimer's disease given the trends for increasing prevalence of overweight, obesity, hyperinsulinemia, and diabetes. However, if proven causal, these associations also present a unique opportunity for prevention and treatment of Alzheimer's disease.

Health perceptions and demographic characteristics associated with underassessment of body weight

OBJECTIVES

To describe the relationship between BMI and perceived weight status and to determine how underassessment of weight status is associated with demographic characteristics, self-reported general health, and perceived health risk in relation to one's body weight.

METHODS AND PROCEDURES

In the 2004 Styles surveys, 3,888 US adult participants described their current weight status (underweight, about right, slightly overweight, very overweight), which we compared with self-reported BMI in order to determine concordance. We used multivariable logistic regression to evaluate associations between underassessment of body weight and characteristics of interest.

RESULTS

Among persons with a BMI>or=25, women were more likely than men to recognize their overweight status (slightly or very overweight; 93.0% of women vs. 73.5% of men) and the extent to which they were overweight: 70.4% of obese women vs. 49.5% of obese men described themselves as very overweight. Among the overweight and obese of both sexes, disagreement with regard to current weight as a health risk was associated with underassessment of weight. Additional factors associated with underassessment were education and race/ethnicity among overweight women; race/ethnicity among overweight men; household income and self-rated health among obese women; and self-rated health among obese men (P<0.05).

DISCUSSION

While most of the obese participants recognized that they were overweight, many of them, particularly among the men, did not realize the extent to which they were overweight. Public health messages may be more effective if they are specifically tailored to target audiences, besides emphasizing the health risks associated with excess body weight.

Obesity and cardio-metabolic risk factors in urban adults of Benin: relationship with socio-economic status, urbanisation, and lifestyle patterns

BACKGROUND

There is a dearth of information on diet-related chronic diseases in West Africa. This cross-sectional study assessed the rate of obesity and other cardiovascular disease (CVD) risk factors in a random sample of 200 urban adults in Benin and explored the associations between these factors and socio-economic status (SES), urbanisation as well as lifestyle patterns.

METHODS

Anthropometric parameters (height, weight and waist circumference), blood pressure, fasting plasma glucose, and serum lipids (HDL-cholesterol and triglycerides) were measured. WHO cut-offs were used to define CVD risk factors. Food intake and physical activity were assessed with three non-consecutive 24-hour recalls. Information on tobacco use and alcohol consumption was collected using a questionnaire. An overall lifestyle score (OLS) was created based on diet quality, alcohol consumption, smoking, and physical activity. A SES score was computed based on education, main occupation and household amenities (as proxy for income).

RESULTS

The most prevalent CVD risk factors were overall obesity (18%), abdominal obesity (32%), hypertension (23%), and low HDL-cholesterol (13%). Diabetes and hypertriglyceridemia were uncommon. The prevalence of overall obesity was roughly four times higher in women than in men (28 vs. 8%). After controlling for age and sex, the odds of obesity increased significantly with SES, while a longer exposure to the urban environment was associated with higher odds of hypertension. Of the single lifestyle factors examined, physical activity was the most strongly associated with several CVD risk factors. Logistic regression analyses revealed that the likelihood of obesity and hypertension decreased significantly as the OLS improved, while controlling for potential confounding factors.

CONCLUSION

Our data show that obesity and cardio-metabolic risk factors are highly prevalent among urban adults in Benin, which calls for urgent measures to avert the rise of diet-related chronic diseases. People with higher SES and those with a longer exposure to the urban environment are priority target groups for interventions focusing on environmental risk factors that are amenable to change in this population. Lifestyle interventions would appear appropriate, with particular emphasis on physical activity.

Obesity and workplace traumatic injury: does the science support the link?

OBJECTIVE

To explore whether obesity is associated with non-fatal traumatic occupational injury.

DESIGN

Systematic literature review.

METHODS

The peer-reviewed literature was searched from 1 January 1980 to 31 December 2005 for studies on the risk of overweight and obesity on non-fatal traumatic occupational injuries among non-office employees. The search was conducted using Medline, eLCOSH, NIOSHTIC-2, CINAHL, PsycLit, and OSH-ROM. Studies were excluded that focused on military populations, chronic/repetitive workplace injuries, back pain, only height as a risk factor, or were not written in English.

RESULTS

The search identified only 12 studies. The risk of injury for obese versus non-obese employees overall was slightly increased, although many of the estimates were not statistically significant. In studies in which increased risk estimates were shown, there was limited exploration of the mechanism of obesity-related injury, but the influence of chronic disease, fatigue or sleepiness, ergonomics, and physical limitations were most often hypothesized.

DISCUSSION

With the current growing prevalence of obesity worldwide, more research is needed to better establish its impact on workplace injuries and lost work time. Studies are needed that use large diverse samples, advanced statistical methods, and control for potential confounders, and explore issues related to temporality. Gaining a better understanding of how obesity influences workplace injury may foster the development of interventions that address weight, while still emphasizing the important environmental and sociocultural risk factors for injury.