The obesity epidemic: pathophysiology and consequences of obesity

Health consequences of obesity in the elderly: a review of four unresolved questions

Obesity prevalence is growing progressively even among older age groups. Controversy exists about the potential harms of obesity in the elderly. Debate persists about the relation between obesity in old age and total or disease-specific mortality, the definition of obesity in the elderly, its clinical relevance, and about the need for its treatment. Knowledge of age-related body composition and fat distribution changes will help us to better understand the relationships between obesity, morbidity and mortality in the elderly. Review of the literature supports that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages. Weight gain or fat redistribution in older age may still confer adverse health risks (for earlier mortality, comorbidities conferring independent adverse health risks, or for functional decline). Evaluation of comorbidity and weight history should be performed in the elderly in order to generate a comprehensive assessment of the potential adverse health effects of overweight or obesity. The risks of obesity in the elderly have been underestimated by a number of confounders such as survival effect, competing mortalities, relatively shortened life expectancy in older persons, smoking, weight change and unintentional weight loss. Identification of elderly subjects with sarcopenic obesity is probably clinically relevant, but the definition of sarcopenic obesity, the benefits of its clinical identification, as well as its relation to clinical consequences require further study. Studies on the effect of voluntary weight loss in the elderly are scarce, but they suggest that even small amounts of weight loss (between 5-10% of initial body weight) may be beneficial. In older as well as in younger adults, voluntary weight loss may help to prevent the adverse health consequences of obesity.

Physical disability and obesity

Nearly 20% of US citizens are disabled. Epidemiologic studies have shown that people with physical disabilities have a 1.2- to 3.9-fold increase in obesity prevalence. Obesity is becoming a serious problem in disabled individuals. The mechanisms by which obesity occurs in people with physical disabilities is not clear, but pathophysiological changes of body composition and energy metabolism, physical inactivity, and muscle atrophy all favor the development of obesity. Health professionals should identify disabled patients at risk and provide early prevention guidance. Research is needed to help generate detailed clinical guidelines to promote weight control among people with physical disabilities.

Target identification of the novel antiobesity agent tungstate in adipose tissue from obese rats

Adipose tissue plays an active role in the development of obesity, and thus characterization of the molecular changes related to obesity in this tissue is a priority. Recently, we identified tungstate as a potent body weight reducing agent in obese animals, adipose tissue being one of the targets of its action. In this study a proteomics approach combining 2-DE and MS was used to identify proteins associated with obesity and targets of tungstate in white adipose tissue. Twenty-nine proteins were found differentially expressed between lean and diet-induced obese rats. Expression changes in transferrin, vimentin, vinculin, peroxiredoxins, Rho-GTP dissociation inhibitor, grifin, guanine deaminase and 3-phosphoglycerate dehydrogenase were associated here for the first time with obesity. Furthermore, tungstate treatment of obese rats reverted expression changes of 70% of the proteins modulated by obesity and another ten proteins were regulated by tungstate independently of the body weight reduction. The results suggest that the tungstate antiobesity effect can be mediated by the modulation of cellular structure, metabolism, redox state and signalling processes in adipose tissue. These findings open new avenues for the study of the aetiology of obesity and its treatment.

Unraveling the temporal pattern of diet-induced insulin resistance in individual organs and cardiac dysfunction in C57BL/6 mice

Type 2 diabetes is a heterogeneous disease characterized by insulin resistance and altered glucose and lipid metabolism in multiple organs. To understand the complex series of events that occur during the development of obesity-associated diabetes, we examined the temporal pattern of changes in insulin action and glucose metabolism in individual organs during chronic high-fat feeding in C57BL/6 mice. Insulin-stimulated cardiac glucose metabolism was significantly reduced after 1.5 weeks of high-fat feeding, and cardiac insulin resistance was associated with blunted Akt-mediated insulin signaling and GLUT4 levels. Insulin resistance in skeletal muscle, adipose tissue, and liver developed in parallel after 3 weeks of high-fat feeding. Diet-induced whole-body insulin resistance was associated with increased circulating levels of resistin and leptin but unaltered adiponectin levels. High-fat feeding caused insulin resistance in skeletal muscle that was associated with significantly elevated intramuscular fat content. In contrast, diet-induced hepatic insulin resistance developed before a marked increase in intrahepatic triglyceride levels. Cardiac function gradually declined over the course of high-fat feeding, and after 20 weeks of high-fat diet, cardiac dysfunction was associated with mild hyperglycemia, hyperleptinemia, and reduced circulating adiponectin levels. Our findings demonstrate that cardiac insulin resistance is an early adaptive event in response to obesity and develops before changes in whole-body glucose homeostasis. This suggests that obesity-associated defects in cardiac function may not be due to insulin resistance per se but may be attributable to chronic alteration in cardiac glucose and lipid metabolism and circulating adipokines.

Effects of 17beta-oestradiol plus different doses of drospirenone on adipose tissue, adiponectin and atherogenic metabolites in postmenopausal women

OBJECTIVE

To investigate how variation in the dose of the progestogen influence the impact of 17beta-oestradiol plus drospirenone (DRSP) treatment on adipose tissue and its secretor function with direct implications for atherogenic metabolites.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Primary care, single study site.

SUBJECTS

A total of 240 healthy postmenopausal women 53-65 years old, 178 completer.

INTERVENTION

Daily treatment with 1 mg 17beta-oestradiol plus 1, 2, or 3 mg DRSP, or placebo for 2 years.

MAIN OUTCOME MEASURES

Absolute changes in central (CFM) and peripheral fat mass (PFM; dual-energy X-ray absorptiometry, DEXA), adipokines [interleukin (IL)-6 and adiponectin], atherogenic metabolites [triglycerides, high-density lipoprotein cholesterol (HDL-C), glucose] and blood pressure.

RESULTS

Oestradiol plus 1 mg DRSP evoked significant decreases in CFM and the CFM/PFM ratio from baseline. These benefits virtually decreased with increasing dose of DRSP confounded by dose-dependent increases in CFM and PFM in smokers (P-value for trends <0.001), in whom the increases in bioavailable oestradiol were half of that in nonsmokers (P < 0.001). Treatment with 3 mg DRSP induced decreases in serum adiponectin by month 6 (P < 0.05), which persisted in nonsmokers only and led to significant increases in glucose and triglycerides and decreases in HDL-C (P < 0.05). Adiponectin in smokers normalized by the end of the study parallel with the increases in body fat mass.

CONCLUSIONS

Interactions of the sex steroids with adipose tissue and its secretor function are important determinants of the overall impact of hormone therapy on cardiovascular risk. A DRSP dose up to 2 mg does not seem to exert adverse effects when combined with 1 mg 17beta-oestradiol.

Obesity, peroxisome proliferator-activated receptor, and atherosclerosis in type 2 diabetes

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. The 3 PPAR isotypes, PPAR-alpha, PPAR-gamma, and PPAR-delta, play a key role in the regulation of lipid and glucose metabolism. Obesity and the interrelated disorders of the metabolic syndrome have become a major worldwide health problem. In this review, we summarize the critical role of PPARs in regulating inflammation, lipoprotein metabolism, and glucose homeostasis and their potential implications for the treatment of obesity, diabetes, and atherosclerosis.

Reduced glycemic index and glycemic load diets do not increase the effects of energy restriction on weight loss and insulin sensitivity in obese men and women

Reducing the dietary glycemic load and the glycemic index was proposed as a novel approach to weight reduction. A parallel-design, randomized 12-wk controlled feeding trial with a 24-wk follow-up phase was conducted to test the hypothesis that a hypocaloric diet designed to reduce the glycemic load and the glycemic index would result in greater sustained weight loss than other hypocaloric diets. Obese subjects (n = 29) were randomly assigned to 1 of 3 diets providing 3138 kJ less than estimated energy needs: high glycemic index (HGI), low glycemic index (LGI), or high fat (HF). For the first 12 wk, all food was provided to subjects (feeding phase). Subjects (n = 22) were instructed to follow the assigned diet for 24 additional weeks (free-living phase). Total body weight was obtained and body composition was assessed by skinfold measurements. Insulin sensitivity was assessed by the homeostasis model (HOMA). At 12 wk, weight changes from baseline were significant in all groups but not different among groups (-9.3 +/- 1.3 kg for the HGI diet, -9.9 +/- 1.4 kg for the LGI diet, and -8.4 +/- 1.5 kg for the HF diet). All groups improved in insulin sensitivity at the end of the feeding phase of the study. During the free-living phase, all groups maintained their initial weight loss and their improved insulin sensitivity. Weight loss and improved insulin sensitivity scores were independent of diet composition. In summary, lowering the glycemic load and glycemic index of weight reduction diets does not provide any added benefit to energy restriction in promoting weight loss in obese subjects.

Microarray profiling of isolated abdominal subcutaneous adipocytes from obese vs non-obese Pima Indians: increased expression of inflammation-related genes

AIMS/HYPOTHESIS

Obesity increases the risk of developing major diseases such as diabetes and cardiovascular disease. Adipose tissue, particularly adipocytes, may play a major role in the development of obesity and its comorbidities. The aim of this study was to characterise, in adipocytes from obese people, the most differentially expressed genes that might be relevant to the development of obesity.

METHODS

We carried out microarray gene profiling of isolated abdominal subcutaneous adipocytes from 20 non-obese (BMI 25+/-3 kg/m2) and 19 obese (BMI 55+/-8 kg/m2) non-diabetic Pima Indians using Affymetrix HG-U95 GeneChip arrays. After data analyses, we measured the transcript levels of selected genes based on their biological functions and chromosomal positions using quantitative real-time PCR.

RESULTS

The most differentially expressed genes in adipocytes of obese individuals consisted of 433 upregulated and 244 downregulated genes. Of these, 410 genes could be classified into 20 functional Gene Ontology categories. The analyses indicated that the inflammation/immune response category was over-represented, and that most inflammation-related genes were upregulated in adipocytes of obese subjects. Quantitative real-time PCR confirmed the transcriptional upregulation of representative inflammation-related genes (CCL2 and CCL3) encoding the chemokines monocyte chemoattractant protein-1 and macrophage inflammatory protein 1alpha. The differential expression levels of eight positional candidate genes, including inflammation-related THY1 and C1QTNF5, were also confirmed. These genes are located on chromosome 11q22-q24, a region with linkage to obesity in the Pima Indians.

CONCLUSIONS/INTERPRETATION

This study provides evidence supporting the active role of mature adipocytes in obesity-related inflammation. It also provides potential candidate genes for susceptibility to obesity.

Health-related quality of life and physical well-being among a 63-year-old cohort of women with androgenetic alopecia; a Finnish population-based study

Background

The aim of this study was to assess the possible associations between female androgenetic alopecia (AGA), insulin resistance and health-related quality of life (HRQOL)-linked factors in women. We hypothesized that not only the mental aspects but also certain physical aspect of women's health, such as insulin resistance, have an important role in the determination of HRQOL among women with hair loss.

Methods

A population-based cohort of 330 healthy women aged 63 years, who participated in this study in the City of Oulu in Northern Finland, underwent a medical check-up including assessment of hair status on Ludwig's scale. Background data were collected with a standard questionnaire including a validated RAND 36-Item Health Survey (RAND-36) questionnaire.

Results

105 (31%) women with AGA and 225 (69%) controls completed the RAND-36 questionnaire. The women with AGA were more insulin-resistant than the women with normal hair (QUICKI 0.337 vs. 0.346, p = 0.012). Impaired glucose regulation (IGR) was more prevalent among the former than the latter group (39% vs. 25%). The mean RAND-36 scores were significantly lower on the dimensions of physical functioning, role limitation due to physical health and general health, but not on the mental or social dimensions, among the women with AGA compared with the controls. In multivariate logistic regression analyses with the lowest quintiles of the HRQOL dimensions as the dependent variables and AGA, depression, marital status, education and IGR or QUICKI as independent variables, AGA was independently associated with role limitations due to physical health (2.2, 95% CI 1.20–4.05, 2.45 95% CI 1.32–4.55, respectively).

Conclusion

In women aged 63 years, AGA was associated with role limitations due to physical health. Furthermore, the prevalence rates of IGR and insulin resistance measured by QUICKI were higher among the women with hair loss than those with normal hair.

Body size and risk of renal cell carcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Previous studies suggest that obesity is related to increased risk of renal cell carcinoma (RCC); however, only a few studies report on measures of central vs. peripheral adiposity. We examined the association between anthropometric measures, including waist and hip circumference and RCC risk among 348,550 men and women free of cancer at baseline from 8 countries of the European Prospective Investigation into Cancer and Nutrition (EPIC). During 6.0 years of follow-up we identified 287 incident cases of RCC. Relative risks were calculated using Cox regression, stratified by age and study center and adjusted for smoking status, education, alcohol consumption, physical activity, menopausal status, and hormone replacement therapy use. Among women, an increased risk of RCC was conferred by body weight (relative risk [RR] in highest vs. lowest quintile = 2.13; 95% confidence interval [CI] = 1.16-3.90; p-trend = 0.003), body mass index (BMI) (RR = 2.25; 95% CI = 1.14-4.44; p-trend = 0.009), and waist (RR = 1.67; 95% CI = 0.94-2.98; p-trend = 0.003) and hip circumference (RR = 2.30; 95% CI = 1.22-4.34; p-trend = 0.01); however, waist and hip circumference were no longer significant after controlling for body weight. Among men, hip circumference (RR = 0.44; 95% CI = 0.20-0.98; p-trend = 0.03) was related significantly to decreased RCC risk only after accounting for body weight. Height was not related significantly to RCC risk. Our findings suggest that obesity is related to increased risk of RCC irrespective of fat distribution among women, whereas low hip circumference is related to increased RCC risk among men. Our data give further credence to public health efforts aiming to reduce the prevalence of obesity to prevent RCC, in addition to other chronic diseases.

Obesity and the use of health care services

OBJECTIVE

This study investigated differences in the use of health care services and associated costs between obese and nonobese patients.

RESEARCH METHODS AND PROCEDURES

New adult patients (N = 509) were randomly assigned to primary care physicians at a university medical center. Their use of medical services and related charges was monitored for 1 year. Data collected included sociodemographics, self-reported health status using the Medical Outcomes Study Short Form-36, evaluation for depression using the Beck Depression Index, and measured height and weight to calculate BMI.

RESULTS

Obese patients included a significantly higher percentage of women and had higher mean age, lower mean education, lower mean health status, and higher mean Beck Depression Index scores. Obese patients had a significantly higher mean number of visits to both primary care (p = 0.0005) and specialty care clinics (p = 0.0006), and a higher mean number of diagnostic services (p < 0.0001). Obese patients also had significantly higher primary care (p = 0.0058), specialty clinic (p = 0.0062), emergency department (p = 0.0484), hospitalization (p = 0.0485), diagnostic services (p = 0.0021), and total charges (p = 0.0033). Controlling for health status, depression, age, education, income, and sex, obesity was significantly related to the use of primary care (p = 0.0364) and diagnostic services (p = 0.0075). There was no statistically significant relationship between obesity and medical expenditures in any of the five categories or for total charges.

DISCUSSION

Obesity is a chronic condition requiring long-term management, with an emphasis on prevention. If this critical health issue is not appropriately addressed, the prevalence of obesity and obesity-related diseases will continue to grow, resulting in escalating use of health care services.

Long-term weight gain prevention: a theoretically based Internet approach

BACKGROUND

A major focus of Healthy People 2010 is promoting weight management and physical activity because overweight, obesity, and a sedentary lifestyle are strongly associated with risk for heart disease and stroke, diabetes, cancers, and premature death.

METHODS

Prevalence data and a focused review of weight management and physical activity studies point to the long-term weight gain prevention in normal weight (21-25 BMI), overweight (25-29 BMI), and even moderate obese (30-34 BMI) people as one alternative to prioritizing weight loss in health behavior interventions. This is because on a population basis annual weight gain is small (approximately 0.8 kg/year) and preventing weight gain appears to require only an energy shift of about 100 cal/day either through a modest increase in physical activity and/or consuming slightly less calories to maintain an energy balance. A more dynamic use of social cognitive theory (SCT) for developing programs to maintain health behavior changes is emerging with some evidence of long-term maintenance. The high use of the Internet provides a vehicle to reach different population segments with readily accessible, SCT-tailored long-term programs. Research studies using the Internet with tailored SCT interventions have shown changes in nutrition practices, physical activity, and weight loss for up to a year.

CONCLUSIONS

One promising approach to weight gain prevention in population segments is the development and wide spread use of longer-term Internet programs using specific principles and procedures from SCT.

Genetics of leptin and obesity: a HuGE review

Leptin is an important regulator of the mass of adipose tissue and of body weight; it operates by inhibiting food intake and stimulating energy expenditure. Some polymorphic genes involved in the regulation of leptin-the leptin gene (LEP A19G), the leptin receptor gene (LEPR Q223R, K109R, and K656N), and the peroxisome proliferator-activated receptor-gamma gene (PPARG P12A and C161T)--have been investigated as possible factors associated with obesity. Allelic frequencies of these polymorphisms show ethnic variation. The authors performed a meta-analysis of the available data on the association between these polymorphisms and obesity based on case-control studies. Odds ratios and 95% confidence intervals for obesity associated with leptin polymorphisms were calculated by using both fixed- and random-effects models. Results suggest no evidence of association between the genes under study and obesity. The lack of association could be due to the complex pathogenesis of obesity, which involves a number of genetic and environmental factors. Large studies including testing of multiple genes in both obese and lean subjects, with epidemiologic data on dietary habits in different ethnic groups, are necessary to better understand the role of leptin in regulating weight in human populations.

Current concepts and future directions in the battle against obesity

Obesity is a significant unsolved public health problem. Future treatments of obesity will involve application of neuroendocrine concepts that are reviewed in this paper.

The evolving role of inflammation in obesity and the metabolic syndrome

Advances in adipose tissue biology over the past 10 years have led to an improved understanding of the mechanisms linking obesity with the metabolic syndrome and other complications. Obesity is characterized by a chronic, systemic low-grade state of inflammation. Biomarkers of inflammation, such as the leukocyte count, tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and C-reactive protein, are increased in obesity, associated with insulin resistance, and predict the development of type 2 diabetes and cardiovascular disease. It is now clear that the adipocyte is an active participant in the generation of the inflammatory state in obesity. Adipocytes secrete a variety of cytokines, including IL-6 and TNF-alpha, that promote inflammation. Moreover, recent studies suggest that obesity is associated with an increase in adipose tissue macrophages, which also participate in the inflammatory process through the elaboration of cytokines. An improved understanding of the role of adipose tissue in the activation of inflammatory pathways may suggest novel treatment and prevention strategies aimed at reducing obesity-associated morbidities and mortality.

Adolescent Obesity: Current Trends in Identification and Management

PURPOSE

To discuss the prevalence, identification, and clinical manifestations of adolescent obesity for the advanced practice nurse in primary care.

DATA SOURCES

Selected research and clinical articles.

CONCLUSIONS

Adolescent obesity has been historically attributed to inappropriate diet and exercise; however, recent research also attributes adolescent obesity to genetic factors and metabolic dysfunction. If left untreated, adolescent obesity may result in the metabolic complications of dyslipidemia, hypertension, cardiovascular disease, and early onset of type 2 diabetes.

IMPLICATIONS FOR PRACTICE

Practitioners should focus on using the new body mass index (BMI) national guidelines for early identification of obesity. Essential to the management of this condition are education, parental involvement, behavior modification, and psychological support.

The global epidemic of obesity: are we becoming more sympathetic?

The relationship between obesity and sympathetic nervous system (SNS) behavior has been controversial. Existing paradigms have been opposed in their views of the directional changes in SNS activity in obesity. In addition, limitations of previous approaches to assess SNS activity have produced inconsistent findings. However, the use of state-of-the-art neurochemical and neurophysiologic techniques has improved our current understanding of this issue. There is regional heterogeneity in the SNS activation associated with obesity, with the renal and skeletal muscle circulations, but not the heart, being targets for SNS activation. Abdominal visceral fat appears to be an important depot linking obesity and skeletal muscle SNS activation. The impact of this depot on SNS activity to the kidney or other regions is unknown. Future studies are needed to address this issue as well as the mechanisms and consequences of SNS activation in visceral obesity.

Identification, cloning, expression, and purification of three novel human calcium-independent phospholipase A2 family members possessing triacylglycerol lipase and acylglycerol transacylase activities

Genetic knockout of hormone-sensitive lipase in mice has implicated the presence of other intracellular triacylglycerol (TAG) lipases mediating TAG hydrolysis in adipocytes. Despite intense interest in these TAG lipases, their molecular identities thus far are largely unknown. Sequence data base searches for proteins containing calcium-independent phospholipase A2 (iPLA2) dual signature nucleotide ((G/A)XGXXG) and lipase (GXSXG) consensus sequence motifs identified a novel subfamily of three putative iPLA2/lipase family members designated iPLA2epsilon, iPLA2zeta, and iPLA2eta (previously named adiponutrin, TTS-2.2, and GS2, respectively) of previously unknown catalytic function. Herein we describe the cloning, heterologous expression, and affinity purification of the three human isoforms of this iPLA2 subfamily in Sf9 cells, and we demonstrate that each possesses abundant TAG lipase activity. Moreover, iPLA2epsilon, iPLA2zeta, and iPLA2eta also possess acylglycerol transacylase activity utilizing mono-olein as an acyl donor which, in the presence of mono-olein or diolein acceptors, results in the synthesis of diolein and triolein, respectively. (E)-6-(Bromomethylene)-3-(1-naphthalenyl)-2H-tetrahydropyran-2-one, a mechanism-based suicide substrate inhibitor of all known iPLA2s, inhibits the triglyceride lipase activity of each of the three isoforms similarly (IC50=0.1-0.5 microm). Quantitative PCR revealed dramatically increased expression of iPLA2epsilon and iPLA2zeta transcripts during the hormone-induced differentiation of 3T3-L1 cells into adipocytes and identified the presence of all three iPLA2 isoforms in human SW872 liposarcoma cells. Collectively, these results identify three novel TAG lipases/acylglycerol transacylases that likely participate in TAG hydrolysis and the acyl-CoA independent transacylation of acylglycerols, thereby facilitating energy mobilization and storage in adipocytes.

The effects of antipsychotic therapy on serum lipids: a comprehensive review

OBJECTIVES

The purpose of this paper is to review the literature since 1970 documenting the effects of antipsychotic agents on serum lipids, including a discussion of possible mechanisms for the observed phenomena, the clinical significance and recommendations for monitoring hyperlipidemia during antipsychotic therapy.

RESULTS

High-potency conventional antipsychotics (e.g., haloperidol) and the atypical antipsychotics, ziprasidone, risperidone and aripiprazole, appear to be associated with lower risk of hyperlipidemia. Low-potency conventional antipsychotics (e.g., chlorpormazine, thioridazine) and the atypical antipsychotics, quetiapine, olanzapine and clozapine, are associated with higher risk of hyperlipidemia. Possible hypotheses for lipid dysregulation include weight gain, dietary changes and the development of glucose intolerance.

CONCLUSIONS

Given the multiple cardiovascular risk factors seen in patients with schizophrenia, great care must be exercised in the choice of antipsychotic therapy to minimize the medical burden of additional risk imposed by hyperlipidemia. It is recommended that a lipid panel be obtained at baseline in all patients with schizophrenia, annually thereafter for patients on agents associated with lower risk of hyperlipidemia and quarterly in patients on agents associated with higher risk for hyperlipidemia. All patients with persistent dyslipidemia should be referred for lipid-lowering therapy or switched to a less lipid-offending antipsychotic agent.

Cardiovascular risk factors in males with hypertriglycemic waist (Tehran Lipid and Glucose Study)

BACKGROUND

Many studies performed on nontraditional risk factors have proposed a metabolic triad including increased serum level of apolipoprotein B, hyperinsulinemia and high small, dense LDL-C as a risk factor of cardiovascular diseases. Hypertriglycemic waist (increased waist circumference as well as high fasting triglyceride level) can be used as a simple criterion to predict the metabolic triad. The aim of this study was to investigate the prevalence of hypertriglycemic waist and the frequency of cardiovascular risk factors in the affected population.

MATERIALS AND METHODS

The study was performed on 4169, 18-70 y-old male subjects of the population of Tehran Lipid and Glucose Study (TLGS). The subjects fell into four groups with respect to serum level of fasting triglycerides (Tg) and waist circumference (WC). Subjects of group 1 had serum Tg > or =1.8 mmol/l as well as WC > or =95 cm, while those of group 2 had Tg > or =1.8 mmol/l and WC <95 cm. The triglycerides level was less than 1.8 mmol/l in groups 3 and 4, whereas WC was > or =95 cm and lower than 95 cm, respectively. Cardiovascular risk factors, anthropometric and laboratory variables were compared between the groups.

RESULTS

In total, 784 subjects had high serum levels of Tg as well as increased WC. The mean age of subjects was significantly higher in groups 1 and 3 compared to others (37+/-15, 48+/-14, 41+13 and 46+/-13 y of age in groups 4, 3, 2 and 1, respectively, P<0.001). The prevalence of cardiovascular risk factors was significantly higher in group 1 as compared with others. Systolic and diastolic blood pressure, body mass index and WC were significantly higher in group 1 than in the others. Serum total cholesterol, Tg and LDL-C were significantly higher in group 1 compared to others, whereas HDL-C was significantly lower in this group. The prevalence of subjects who had at least four risk factors was 75 and 8% in groups 1 and 4, respectively.

CONCLUSION

Hypertriglycemic waist can be used as a simple criterion to predict cardiovascular risk factors.

Programmed obesity in intrauterine growth-restricted newborns: modulation by newborn nutrition

The degree of nutrient enhancement during the newborn period may modulate programming of appetite-regulating hormones, body composition, and propensity to adult obesity in intrauterine growth-restricted (IUGR) newborns. Pregnant rats received, from day 10 to term gestation and throughout lactation, ad libitum food (AdLib) or 50% food restriction (FR) to produce IUGR newborns. AdLib vs. FR offspring were studied at day 1, and, to create two distinct groups of newborn catch-up growth (immediate, delayed) among the IUGR newborns, cross-fostering techniques were employed. The four groups of pups at 3 wk were IUGR immediate catch-up growth (FR/AdLib), IUGR delayed catch-up growth (FR/FR), control (AdLib/AdLib), and lactation FR control (AdLib/FR). From 3 wk to 9 mo, all offspring had AdLib rat chow. Maternal FR during pregnancy resulted in IUGR pups (6.0 +/- 0.3 vs. 7.1 +/- 0.3 g, P < 0.01) with decreased leptin (0.66 +/- 0.03 vs. 1.63 +/- 0.12 ng/ml, P < 0.001) and increased ghrelin (0.43 +/- 0.03 vs. 0.26 +/- 0.02 ng/ml, P < 0.001). Maternal FR during lactation (FR/FR) further impaired IUGR offspring growth at 3 wk. However, by 9 mo, these pups attained normal body weight, percent body fat, and plasma leptin levels. Conversely, IUGR offspring nursed by AdLib dams (FR/AdLib) exhibited rapid catch-up growth at 3 wk and continued accelerated growth, resulting in increased weight, percent body fat, and plasma leptin levels. Thus the degree of newborn nutrient enhancement and timing of IUGR newborn catch-up growth may determine the programming of orexigenic hormones and offspring obesity.

Biochemical and morphological effects of K-111, a peroxisome proliferator-activated receptor (PPAR)alpha activator, in non-human primates

K-111 has been characterized as a potent peroxisome proliferator-activated receptor (PPAR)alpha activator. Antidiabetic potency and amelioration of disturbed lipid metabolism were demonstrated in rodents, which were accompanied by elevations of peroxisomal enzymes and liver weight. To examine the possible therapeutic application of K-111 we have now assessed its efficacy in non-human primates with high transferability to humans. For this purpose obese, hypertriglyceridaemic, hyperinsulinaemic prediabetic rhesus monkeys were dosed sequentially with 0, 1, 3 and 10mg/kg per day orally over a period of 4 weeks each. In addition, the effect of K-111 on the peroxisome compartment was analyzed in cynomolgus monkeys using liver samples obtained following a 13-week oral toxicity study. In prediabetic monkeys, the reduction of hyperinsulinaemia and improvement of insulin-stimulated glucose uptake rate indicated amelioration of insulin resistance. These effects were nearly maximal at a dose of 3mg/kg per day, while triglycerides and body weight were lowered significantly in a dose-dependent manner. This reduction of body weight contrasts sharply with the adipogenic response observed with thiazolidinediones, another family of insulin-sensitizing agents. In young cynomolgus monkeys at a dosage of 5mg/kg per day and more, K-111 induced an up to three-fold increase in lipid beta-oxidation enzymes with an 1.5- to 2-fold increase in peroxisome volume density. This moderate increase in peroxisomal activity by K-111 in monkeys is consistent with its role as an PPARalpha activator and corresponds to the observations with fibrates in other low responder mammalian species. The increase in beta-oxidation may explain, at least in part, the lipid modulating effect as well as the antidiabetic potency of K-111. This pharmacological profile makes K-111 a highly promising drug candidate for clinical applications in the treatment of type 2 diabetes, dyslipidaemia, obesity and the metabolic syndrome.

Tumor necrosis factor and its potential role in insulin resistance and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic pathology that resembles alcohol-induced fatty liver disease(AFLD), but which develops in individuals who are not heavy drinkers. In people, NAFLD is associated strongly with obesity,insulin resistance, and dysmetabolic syndrome, but the exact mechanisms that promote liver disease in this clinical context remain poorly understood. The proinflammatory cytokine, funor necrosis factor alpha is known to be a key mediator of AFLD. This article discusses clinical and experimental evidence that tumor necrosis factor plays a role in the pathogenesis of insulin resistance syndromes, including nonalcoholic fatty syndromes, including nonalcoholic fatty liver disease.

Insulin resistance and the pathogenesis of nonalcoholic fatty liver disease

The prevalence of obesity has reached epidemic proportions in most of the western world. Current estimates suggest that 22.5%of the population of the United States suffers from obesity and is at risk for development of obesity-related complications, including hypertension, coronary artery disease, diabetes, hyperlipidemia,increased predisposition for various cancers, and nonalcoholic fatty liver disease. Fatty liver disease is currently the most common abnormality observed in hepatology practice. Since it was first reported in the 1980s in obese diabetic females, our understanding of nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) has undergone significant metamorphosis. It is now universally accepted that insulin resistance and subsequent hyperinsulinemia are key factors that lead to both NAFL and NASH.This article reviews the role of insulin resistance in the genesis of these conditions.

Hypolipidemic effects of crude extract of adlay seed (Coix lachrymajobi var. mayuen) in obesity rat fed high fat diet: relations of TNF-alpha and leptin mRNA expressions and serum lipid levels

To find out whether the expressions of these adipocyte markers are influenced by oriental medicine, obesity rats induced by high fat diet (HFD) for 8 weeks were injected with 50 mg/100 g body weight adlay seed crude extract (ACE), daily for 4 weeks. The results are summarized as follows: HFD + ACE group significantly reduced food intakes and body weights. Weights of epididymal and peritoneal fat were dramatically increased in HFD groups compared with those of normal diet (ND) group but significantly decreased more in HFD + ACE group than those of HFD + saline group (sham). Those of brown adipocytes were increased in HFD + ACE group compared to ND and sham groups but there was no significant difference. The sizes in white adipose tissue (WAT) by microscope were markedly larger in HFD groups than ND group but considerably reduced in HFD + ACE group compared with sham group. The levels of triglyceride, total-cholesterol and leptin in blood serum were significantly decreased in HFD + ACE group compared to those of sham group. Leptin and TNF-alpha mRNA expressions in WAT of rats were remarkably increased more in sham group than in those of ND group. Those of HFD + ACE group were significantly decreased compared with those of sham group, especially. TNF-alpha mRNA expression in HFD + ACE group was declined more than that of ND group. In conclusion, treatments of ACE modulated expressions of leptin and TNF-alpha and reduced body weights, food intake, fat size, adipose tissue mass and serum hyperlipidemia in obesity rat fed HFD. Accordingly, the oriental medicine extract, adlay seed crude extract, can be considered for obesity therapies controlling.

Sensitivity to reward: implications for overeating and overweight

Sensitivity to reward (STR)-a personality trait firmly rooted in the neurobiology of the mesolimbic dopamine system-has been strongly implicated in the risk for addiction. This construct describes the ability to derive pleasure or reward from natural reinforcers like food, and from pharmacologic rewards like addictive drugs. Recently experts in the field of addiction research have acknowledged that psychomotor stimulant drugs are no longer at the heart of all addictions, and that brain circuits can also be deranged with natural rewards like food. The present study tested a model in which STR was expected to relate positively to overeating, which in turn would be associated with higher body weight in woman aged 25-45 years. As predicted, STR was correlated positively with measures of emotional overeating. Also, overweight woman were significantly more sensitive to reward than those of normal weight. Interestingly, however, the obese woman (Body Mass Index>30) were more anhedonic than the overweight woman (Body Mass Index>25<30). These findings are discussed in the context of neuroadaptations to overactivity of brain reward circuits. Results also indicate that STR may serve as a risk factor for overeating and overweight, especially in cultures such as ours where palatable, calorically-dense food is plentiful.

Association between size at birth, truncal fat and obesity in adult life and its contribution to blood pressure and coronary heart disease; study in a high birth weight population

OBJECTIVE

The aim of the study was to assess the relationship between size at birth and obesity as well as truncal fat, and its contribution to cardiovascular risk in a high birth weight population.

DESIGN

Cohort-study with retrospectively collected data on size at birth.

SETTING

Reykjavik, Iceland.

SUBJECTS

A total of 1874 men and 1833 women born in Reykjavik during 1914-1935.

MAIN OUTCOME MEASURES

Size at birth. Adult weight, height and skinfold thickness measurements, systolic and diastolic blood pressure, fatal and nonfatal coronary heart disease (CHD).

RESULTS

Birth weight was positively related to adult body mass index (BMI) in both genders (B=0.35+/-0.14 kg/m(2), adj. R(2)=0.015, P=0.012 and B=0.34+/-0.17 kg/m(2), adj. R(2)=0.055, P=0.043 in men and women, respectively). However, high birth weight was not a risk factor for adult obesity (BMI>/=30 kg/m(2)). In the highest birth weight quartile, the odds ratio (95% CI) for being above the 90th percentile of truncal fat was 0.7 (0.6-1.0, P=0.021) for men and 0.4 (0.3-0.8, P=0.002) for women, compared with the lowest birth weight quartile. Truncal fat and BMI were positively related to blood pressure in both genders (P<0.05), but not to CHD. The regression coefficient for the inverse association between birth weight and blood pressure hardly changed when adding truncal fat to the model.

CONCLUSION

In this high birth weight population, high birth weight was related to higher BMI in adulthood without being a risk factor for adult obesity. The inverse association between birth weight and truncal fat in adulthood suggests a role for foetal development in determining adult fat distribution. The inverse relationship of birth weight to blood pressure seems not to be mediated through the same pathway as to truncal fat.

Behavioral and clinical factors associated with depression among individuals with diabetes

OBJECTIVE

The goal of this study was to determine the behavioral and clinical characteristics of diabetes that are associated with depression after controlling for potentially confounding variables.

RESEARCH DESIGN AND METHODS

A population-based mail survey was sent to patients with diabetes from nine primary care clinics of a health maintenance organization. The Patient Health Questionnaire was used to diagnose depression, and automated diagnostic, pharmacy, and laboratory data were used to measure diabetes treatment intensity, HbA(1c) levels, and diabetes complications.

RESULTS

Independent factors that were associated with a significantly higher likelihood of meeting criteria for major depression included younger age, female sex, less education, being unmarried, BMI > or = >30 kg/m(2), smoking, higher nondiabetic medical comorbidity, higher numbers of diabetes complications in men, treatment with insulin, and higher HbA(1c) levels in patients <65 years of age. Independent factors associated with a significantly higher likelihood of meeting criteria for minor depression included younger age, less education, non-Caucasian status, BMI > or = 30 kg/m(2), smoking, longer duration of diabetes, and a higher number of complications in older (> or = 65 years) patients.

CONCLUSIONS

Smoking and obesity were associated with a higher likelihood of meeting criteria for major and minor depression. Diabetes complications and elevated HbA(1c) were associated with major depression among demographic subgroups: complications among men and HbA(1c) among individuals <65 years of age. Older patients with a higher number of complications had an increased likelihood of minor depression.

Endothelial dysfunction in obesity and insulin resistance: a road to diabetes and heart disease

Obesity, insulin resistance, and endothelial dysfunction closely coexist throughout the natural history of type 2 diabetes. They all can be identified not only in people with type 2 diabetes, but also in various groups at risk for the disease, such as individuals with impaired glucose tolerance, family history of type 2 diabetes, hypertension, dyslipidemia, prior gestational diabetes, or polycystic ovary syndrome. Whereas their evident association cannot fully establish a cause-effect relationship, fascinating mechanisms that bring them closer together than ever before are rapidly emerging. Central or abdominal obesity leads to insulin resistance and endothelial dysfunction through fat-derived metabolic products, hormones, and cytokines. Insulin resistance leads to endothelial dysfunction through the frequent association with traditional cardiovascular risk factors and through some more direct novel mechanisms. Some specific and shared insulin signaling abnormalities in muscle, fat, and endothelial cells, as well as some new genetic and nontraditional factors, may contribute to this interesting association. Some recent clinical studies demonstrate that nonpharmacological and pharmacological strategies targeting obesity and/or insulin resistance ameliorate endothelial function and low-grade inflammation. All these findings have added a new dimension to the association of obesity, insulin resistance, and endothelial dysfunction that may become a key target in the prevention of type 2 diabetes and cardiovascular disease.

Position of the American Dietetic Association: Integration of medical nutrition therapy and pharmacotherapy

It is the position of the American Dietetic Association that the application of medical nutrition therapy (MNT) and lifestyle counseling as a part of the Nutrition Care Process is an integral component of the medical treatment for management of specific disease states and conditions and should be the initial step in the management of these situations. If optimal control cannot be achieved with MNT alone and concurrent pharmacotherapy is required, then The Association promotes a team approach to care for clients receiving concurrent MNT and pharmacotherapy and encourages active collaboration among dietetics professionals and other members of the health care team. There are a number of medical conditions, many of them chronic, that will respond to MNT and, therefore, MNT should be the first intervention for these conditions. In addition to being a vital element of the optimal management and control of these conditions, MNT is also a cost-effective method of management. However, because of the long-term nature of these conditions, concurrent pharmacotherapy may become necessary to achieve or maintain optimal control. In cases where this is necessary, MNT should continue to be an integral component of the therapy because it may complement or enhance the therapeutic effectiveness of pharmacotherapy, thereby reducing or eliminating the need for multiple medications. The utilization of a coordinated multidisciplinary team approach is critical to the success of the concurrent use of MNT and pharmacotherapy because of the long-term duration of the treatments, the necessity of monitoring compliance and effectiveness, and the likelihood of multiple medication-nutrient interactions.

Interval Jejunoileal Bypass Reduces the Morbidity and Mortality of Roux-en-Y Gastric Bypass in the Super-Obese

Among Roux-en-Y gastric bypass (RYGB) patients, large male patients carry the greatest risk for severe, life-threatening complications. The higher complication rate is partly related to large amounts of intra-abdominal fat that increases the technical difficulty of the RYGB. In order to minimize the risk for complications, we established a staged approach for weight loss surgery for high-risk, super-obese patients. Patients with intra-abdominal fat at exploration which precluded the performance of RYGB underwent jejunoileal bypass (JIB). Following an initial period of weight loss (6–24 months), they were converted to a RYGB during a second operation. Twenty-four patients underwent initial JIB that was associated with a major complication rate of 8.3 per cent (2/24) and no mortality. Eight patients lost 53.4 ± 6.3 kg prior to their conversion to RYGB (mean, 14.1 months). There was one major complication (12%) and no deaths (0%). Following RYGB, an additional period of weight loss resulted in overall excess weight loss (EWL) totaling 62 per cent. A two-step procedure is a safe and effective approach for minimizing complications for high-risk patients undergoing RYGB. The initial JIB was associated with low morbidity and no mortality, and the follow-up RYGB procedure was a technically simple operation that could be performed with few complications.

The telmisartan Programme of Research tO show Telmisartan End-organ proteCTION (PROTECTION) Programme

Angiotensin-II receptor blockers (ARBs) have been shown to provide stroke, cardiac and renal protection in high-risk hypertensive patients. Telmisartan is a powerful and selective ARB that provides sustained blood pressure reduction for a full 24 h after a single dose and continues to protect against circadian blood pressure surges in the critical early morning hours. The objective of the Programme of Research tO show Telmisartan End-organ proteCTION (PROTECTION) is to measure the end-organ protective effects of telmisartan in patients at high risk of renal, cardiac and vascular damage. An extensive series of clinical trials is being conducted to compare telmisartan with valsartan, losartan, amlodipine and ramipril in patients at increased risk of end-organ damage. Nine clinical studies will examine the effects of telmisartan in about 5000 hypertensive patients with isolated systolic hypertension, type 2 diabetes, obesity, left ventricular hypertrophy or renal disease. All of the studies will be conducted using state-of-the-art technology, including such techniques as ambulatory blood pressure monitoring and magnetic resonance imaging. This programme will also investigate the effects of an ARB on key surrogate markers of organ tissue damage. This series of trials will characterize the end-organ protective effects of telmisartan in hypertensive patient populations at high risk of clinical events.