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Visceral adiposity, insulin resistance and cancer risk
Claire L Donohoe, Suzanne L Doyle, John V Reynolds
Diabetology & Metabolic Syndrome , 2011, DOI: 10.1186/1758-5996-3-12
Abstract: Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.Numerous epidemiological studies consistently identify increased risk of developing carcinoma in the obese. Adipose tissue, particularly viscerally located fat, is metabolically active and exerts systemic endocrine effects. Putative pathophysiological mechanisms linking obesity and carcinogenesis include the paracrine effects of adipose tissue and systemic alterations associated with obesity. Systemic changes in the obese state include chronic inflammation and alterations in adipokines and sex steroids. Insulin and the insulin-like growth factor axis influence tumorigenesis and also have a complex relationship with adiposity. There is evidence to suggest that insulin and the IGF axis play an important role in mediating obesity associated malignancy.There is much evidence to support a role for obesity in cancer progression, however further research is warranted to determine the specific effect of excess visceral adipose tissue on tumorigenesis. Investigation of the potential mechanisms underpinning the association, including the role of insulin and the IGF axis, will improve understanding of the obesity and cancer link and may uncover targets for intervention.Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Search terms used included: obesity, overweight, cancer, adipose tissue, inflammation, insulin, metabolic syndrome, adipokines and sex steroids. More detailed search terms were used following identification of relevant mechanisms and to identify epidemiological studies. All meta-analyses addressing cancer incidence with respect to body mass index were identified by PubMed searches. Meta-analyses of cohort or nested case control studies only were included. When available, meta-analyses were preferenti
Indices of Abdominal Adiposity and Cardiorespiratory Fitness Test Performance in Middle-School Students  [PDF]
Ryan Burns,James C. Hannon,Timothy A. Brusseau,Barry Shultz,Patricia Eisenman
Journal of Obesity , 2013, DOI: 10.1155/2013/912460
Abstract: Background. Previous research suggests that use of BMI as a screening tool to assess health in youth has limitations. Valid alternative measures to assess body composition are needed to accurately identify children who are aerobically fit, which is an indicator of health status. The purpose of this study was to examine the associations between select anthropometric measures and cardiorespiratory fitness test performance in middle-school students. Methods. Participants included 134 students (65 boys and 69 girls) recruited from the 6th, 7th, and 8th grades. Anthropometric measures consisted of BMI, waist circumference (WC), waist-to-height ratio (WHtR), and percent body fat estimated from two-site skinfolds (%BF-SKF), as well as the hand-held OMRON BIA device (%BF-BIA). Cardiorespiratory fitness tests included the one-mile run and PACER test. Data were collected on four separate testing days during the students’ physical education classes. Results. There were statistically significant moderate correlations between the %BF estimations, WHtR, and cardiorespiratory fitness test scores in both genders . BMI at best only displayed weak correlations with the cardiorespiratory fitness test scores. Conclusions. The results suggest that alternative measures such as %BF-SKF, %BF-BIA, and WHtR may be more valid indicators of youth aerobic fitness lending to their preferred use over BMI. 1. Introduction The current pediatric obesity epidemic manifests concerns for adverse cardiovascular risk factors among overweight youth. However, Eisenmann et al. [1], using body mass index (BMI) as the marker of adiposity, found that youth in both the low- and high-BMI categories were associated with a more favorable cardiovascular disease (CVD) risk-factor profile than individuals whose BMIs were in the “healthy” range. This paradox leads to a significant issue in assessing health and fitness in youth when using BMI. Research has also suggested that along with body composition, aerobic fitness must also be considered to accurately assess health status in a population. Lee et al. [2] found that unfit lean men had a higher risk of cardiovascular disease and all-cause mortality than fit but overweight men. These findings suggest that fitness offers some protection against CVD risk even if the individual is overweight. Similar results have been reported for the female population [3]. Using skinfold thickness as the measure of body fatness and stratifying youth into high-fat/high-fitness, high-fat/low-fitness, low-fat/high-fitness, and low-fat/low-fitness groups, it was found that
Effect of Physical Exercise on the Cardiorespiratory Response in Overweight Adolescents
Diego A S Silva,Edio L Petroski,Andreia Pelegrini,Luiz G A Guglielmo
Turkish Journal of Endocrinology and Metabolism , 2012,
Abstract: Purpose: To evaluate the effects of an aerobic physical exercise program on the metabolic and cardiorespiratory response in overweight adolescents.Material and Method: This is a randomized study evaluating overweight adolescents divided into intervention and control groups before and after an aerobic exercise program. Pre- and post-intervention aerobic fitness was evaluated by a submaximal incremental test on a cycle ergometer. The training program lasted 12 weeks, when the intervention group exercised three times per week on a cycle ergometer at individual training intensities corresponding to lactate threshold (LT) and onset of blood lactate accumulation (OBLA). The individual workload was increased by 10% at 2-week intervals.Results: After intervention, an increase in workload levels corresponding to LT (33.3%) and OBLA (14.2%) was observed in the intervention group. In addition, the intervention group reached LT training intensity at a heart rate higher than that observed before intervention and that of controls (p<0.05). Discussion: The program resulted in positive changes in aerobic fitness and heart rate, improving exercise tolerance. Turk Jem 2012; 16: 14-8
Relationship of Adiposity and Insulin Resistance Mediated by Inflammation in a Group of Overweight and Obese Chilean Adolescents
Marcela Reyes, Sheila Gahagan, Erik Díaz, Estela Blanco, Laura Leiva, Lydia Lera, Raquel Burrows
Nutrition Journal , 2011, DOI: 10.1186/1475-2891-10-4
Abstract: Adolescent obesity is a major public health problem associated with cardiovascular (CV) risk factors including abdominal obesity, insulin resistance (IR), dyslipidemia and hypertension [1,2]. While visceral fat mass is strongly associated with CV risk, causality has not been established [3]. Furthermore, the underlying mechanisms by which excess fat mass (FM) leads to CV risk remain unclear. The mild chronic inflammatory state characterizing obesity may be an important pathophysiologic link between increased adiposity and CV disease [4]. Some investigators have found differences in these associations by sex [5,6]. The purpose of this study was to: assess associations between high-sensitivity CRP (hs-CRP), adiposity and the homeostatic model assessment of insulin resistance (HOMA-IR); explore sex differences in these relationships; and evaluate whether inflammation mediated the relationship between adiposity and HOMA-IR in a sample of overweight and obese Chilean adolescents.The sample was drawn from a larger study of nutrition and physical activity among Chilean adolescents (Tanner stage ≥ 2) attending school in Santiago, Chile (n = 1,780). Overweight and obese adolescents were invited to participate. Exclusion criteria included: chronic diseases; acute infections; hs-CRP values above 9 mg/L; or any medications. Parents signed informed consent and adolescents signed informed assent. Ethics Board of the Institute of Nutrition and Food Technology, University of Chile (INTA) approved this study. A pediatric endocrinologist performed all anthropometric measurements in duplicate. Each adolescent was measured in the Frankfurt position wearing underwear, without shoes. Body mass index (BMI), sex-and age-specific BMI Z-scores, and waist circumference (WC) percentiles were calculated based on the U.S. Centers for Disease Control and Prevention Growth Charts/National Center for Health Statistics standards [7,8]. Arterial blood pressure percentiles were classified according th
The Association of Visceral Adiposity with Cardiovascular Events in Patients with Peripheral Artery Disease  [PDF]
Oliver Cronin, Barbara Bradshaw, Vikram Iyer, Margaret Cunningham, Petra Buttner, Philip J. Walker, Jonathan Golledge
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082350
Abstract: Background Previous studies have suggested that patients with peripheral artery disease (PAD) suffer from a high incidence of cardiovascular events (CVE). Visceral adiposity has been implicated in promoting CVEs. This study aimed to assess the association of relative visceral adipose volume with incident cardiovascular events in patients with peripheral artery disease. Methods This was a prospective cohort study including 260 patients with PAD who presented between 2003 and 2012. Cases were patients with diagnosed PAD including symptomatic lower limb athero-thrombosis and asymptomatic abdominal aortic aneurysm. All patients underwent computed tomography angiography (CTA). Abdominal visceral to total adipose volume ratio (relative visceral adipose volume) was estimated from CTAs using a previously validated workstation protocol. Cardiovascular risk factors were recorded at entry. The association of visceral adiposity with major CVEs (death, non-fatal myocardial infarction or stroke) was examined using Kaplan Meier and Cox proportional hazard analyses. Results A total of 92 major CVEs were recorded in 76 patients during a median follow-up of 2.8 (IQR 1.2 to 4.8) years, including myocardial infarction (n = 26), stroke (n = 10) and death (n = 56). At 3 years the incidence of major CVEs stratified by relative visceral adipose volume quartiles were 15% [Quartile (Q) 1], 17% (Q2), 11% (Q3) and 15% (Q4) (P = 0.517). Relative visceral adipose volume was not associated with major CVEs after adjustment for other risk factors. Conclusion This study suggests that visceral adiposity does not play a central role in the predisposition for major CVEs in patients with PAD.
Short-term effects of liraglutide on visceral fat adiposity, appetite, and food preference: a pilot study of obese Japanese patients with type 2 diabetes
Kana Inoue, Norikazu Maeda, Susumu Kashine, Yuya Fujishima, Junji Kozawa, Aki Hiuge-Shimizu, Kohei Okita, Akihisa Imagawa, Tohru Funahashi, Iichiro Shimomura
Cardiovascular Diabetology , 2011, DOI: 10.1186/1475-2840-10-109
Abstract: The study subjects were 20 inpatients with type 2 diabetes treated with liraglutide [age; 61.2 ± 14.0 years, duration of diabetes; 16.9 ± 6.6 years, glycated hemoglobin (HbA1c); 9.1 ± 1.2%, body mass index (BMI); 28.3 ± 5.2 kg/m2, mean ± SD]. After improvement in glycemic control by insulin or oral glucose-lowering agents, patients were switched to liraglutide. We assessed the estimated visceral fat area (eVFA) by abdominal bioelectrical impedance analysis, glycemic control by the 75-g oral glucose tolerance test (OGTT) and eating behavior by the Japan Society for the Study of Obesity questionnaire.Treatment with liraglutide (dose range: 0.3 to 0.9 mg/day) for 20.0 ± 6.4 days significantly reduced waist circumference, waist/hip ratio, eVFA. It also significantly improved the scores of eating behavior, food preference and the urge for fat intake and tended to reduce scores for sense of hunger. Liraglutide increased serum C-peptide immunoreactivity and disposition index.Short-term treatment with liraglutide improved visceral fat adiposity, appetite, food preference and the urge for fat intake in obese Japanese patients with type 2 diabetes.The prevalence of type 2 diabetes has rapidly increased worldwide [1] including Western and Asian countries [2]. Type 2 diabetes is a major risk for cardiovascular events. Obesity, especially visceral fat adiposity, also increases the risk of type 2 diabetes, hypertension, dyslipidemia, and atherosclerosis, suggesting that obese patients with type 2 diabetes are at high risk for cardiovascular diseases [3]. The World Health Organization (WHO) projects that 2.3 billion adults are overweight and > 700 million are obese [4]. The association between type 2 diabetes and overweight/obesity is indisputable. In this sense, it is necessary to develop effective and efficient therapeutic strategy for obese type 2 diabetes. However, the treatment for obese type 2 diabetes often encounters difficulties with regard to the control of weight and ap
Association of Adiposity, Cardiorespiratory Fitness and Exercise Practice with the Prevalence of Type 2 Diabetes in Brazilian Elderly Women
Maressa P. Krause, Tatiane Hallage, Mirnaluci Paulino Ribeiro Gama, Fredric L. Goss, Robert Robertson, Sergio G. da Silva
International Journal of Medical Sciences , 2007,
Abstract: Background: Diabetes incidence in people with advanced age is increasing at an alarming rate, and for this reason the screening of high-risk individuals such as elderly women is critically important. Objective: To analyze the association of adiposity, cardiorespiratory fitness and exercise practice with type 2 diabetes (T2D) in elderly Brazilian women. Methods: Participated of this cross sectional study 1,059 elderly women (mean 69.5 yr; SD 6.1), who self-reported family history of cardiovascular disease, smoking status, hypertension, and T2D diagnosed previously by a physician. The following independent variables were assessed: exercise practice, body mass index, waist circumference, and cardiorespiratory fitness. Logistic regression analysis was used to investigate the association between each independent variable with T2D using adjusted-models. Results: T2D prevalence was 16%. General and central adiposity were directly associated with T2D, whereas cardiorespiratory fitness was inversely related with T2D. The joint effect of exercise practice and central adiposity showed that inactive women had higher odds ratio for T2D when compared with active ones, within the same WC group. Inactive women with WC ≥ 94.0 cm had an odds ratio of 5.8 (95%IC 1.3-25.3). Conclusions: A direct positive association was found between general and central adiposity, as well as an inverse relation between CRF and exercise practice with T2D. Elderly women who practice exercise regularly had lower odds for T2D. Health professionals should encourage individuals of all ages to engage on regular exercise practice, which could reduce body fatness and may be beneficial in reducing the prevalence of T2D in older ages.
Predictive performance of the visceral adiposity index for a visceral adiposity-related risk: Type 2 Diabetes
Mohammadreza Bozorgmanesh, Farzad Hadaegh, Fereidoun Azizi
Lipids in Health and Disease , 2011, DOI: 10.1186/1476-511x-10-88
Abstract: Participants free of diabetes at baseline with at least one follow-up examination (5,964) were included for the current study. Weibull regression models were developed for interval-censored survival data. Absolute and relative integrated discriminatory improvement index (IDI) and cut-point-based and cut-point-free net reclassification improvement index (NRI) were used as measures of predictive ability for incident diabetes added by VAI, as compared to the MetS and WHtR.The annual incidence rate of diabetes was 0.85 per 1000 person. Mean VAI was 3.06 (95%CIs 2.99-3.13). Diabetes risk factors levels increased in stepwise fashion across VAI quintiles. Risk gradient between the highest and lowest quintile of VAI was 4.5 (95%CIs 3.0-6.9). VAI significantly improved predictive ability of the MetS. The relative IDI and cut-point free NRI for predictive ability added to MetS by VAI were 30.3% (95%CIs 18.8-41.8%) and 30.7% (95%CIs 20.8-40.7%), respectively. WHtR, outperformed VAI with cut-point-free NRI of 24.6% (95%CIs 14.1-35.2%).In conclusion, although VAI could be a prognostic tool for incident diabetes events, gathering information on its components (WC, BMI, TGs, and HDL-C) is unlikely to improve the prediction ability beyond what could be achieved by the simply assessable and commonly available information on WHtR.The prevalence of Type 2 diabetes (hereafter diabetes) is undergoing a rapid progression [1], largely as a consequence of the epidemic proportions reached by obesity in various populations of the world [2]. "However, physicians have been puzzled by the heterogeneity of obesity as not every obese patient develops chronic complications [3]." In this regard, visceral adiposity, has been found to be associated with an increased risk of a cluster of diabetogenic, atherogenic, prothrombotic and inflammatory metabolic abnormalities increasing the risk of diabetes [3]. Visceral obesity [4] is associated with deterioration of insulin sensitivity [5], increased risk o
Visceral Abdominal and Subfascial Femoral Adipose Tissue Have Opposite Associations with Liver Fat in Overweight and Obese Premenopausal Caucasian Women  [PDF]
Paulo M. Rocha,José T. Barata,Cláudia S. Minderico,Analiza M. Silva,Pedro J. Teixeira,Luís B. Sardinha
Journal of Lipids , 2011, DOI: 10.1155/2011/154672
Abstract: Abdominal obesity has been associated with liver fat storage. However, the relationships between other body composition depots and metabolic syndrome features with hepatic fat are still unclear. We examined abdominal and thigh adipose tissue (AT) compartments associations with liver fat in 140 overweight and obese premenopausal Caucasian women. Blood lipids and, proinflammatory and atherothrombotic markers associations with hepatic fat were also analyzed. A larger visceral AT (VAT) was related with liver fat ( ). Contrarily, thigh subfascial AT was inversely related to liver fat ( ). Increased fasting insulin, triglycerides, PAI-1 concentrations, and a higher total-cholesterol/HDL-cholesterol ratio were also associated with hepatic fat, even after adjustment for VAT ( ). Thigh subfascial adiposity was inversely associated with liver fat, suggesting a potential preventive role against ectopic fat storage in overweight and obese women. These results reinforce the contribution of an abdominal obesity phenotype associated with a diabetogenic and atherothrombotic profile to liver lipotoxicity. 1. Introduction Obesity-related comorbidities seem to be more closely related to body fat distribution (e.g., upper versus lower, visceral versus subcutaneous, and truncal versus peripheral) rather than the total amount per se [1]. Abdominal obesity is a relevant predictor of a higher metabolic risk, assuming that insulin resistance (IR) is the common link between visceral adiposity and dyslipidemia [2–4], type 2 diabetes mellitus (DM) [5, 6], liver fat storage [7], hypertension [8], and other cardiovascular diseases (CVD) [8–10]. Two major pathophysiological hypotheses have been proposed to explain the dysmetabolic milieu observed in abdominal obese individuals. It has been proposed that neuroendocrine perturbations, mediated by hypothalamic-pituitary-adrenal (HPA) axis stimulation, are responsible for IR and abdominal obesity [11, 12]. Alterations in cortisol secretion, inhibition of steroid and growth hormones production, and stimulation of sympathetic nervous centers are some of the dysfunctions which may precipitate metabolic disturbances [12]. Conversely, according to the “portal hypothesis,” the increased lipolytic activity in visceral adipocytes leads to an augmented release of free fatty acids (FFA) into portal circulation, promoting liver fat storage that is accompanied by hepatic metabolism disturbances and IR [6, 13, 14]. In this context, abdominal obesity has been associated with ectopic fat storage, defined as fat accumulation outside “classical” depots
Dietary Determinants of Changes in Waist Circumference Adjusted for Body Mass Index – a Proxy Measure of Visceral Adiposity  [PDF]
Dora Romaguera,Lars ?ngquist,Huaidong Du,Marianne Uhre Jakobsen,Nita G. Forouhi,Jytte Halkj?r,Edith J. M. Feskens,Daphne L. van der A,Giovanna Masala,Annika Steffen,Domenico Palli,Nicholas J. Wareham,Kim Overvad,Anne Tj?nneland,Heiner Boeing,Elio Riboli,Thorkild I. A. S?rensen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011588
Abstract: Given the recognized health effects of visceral fat, the understanding of how diet can modulate changes in the phenotype “waist circumference for a given body mass index (WCBMI)”, a proxy measure of visceral adiposity, is deemed necessary. Hence, the objective of the present study was to assess the association between dietary factors and prospective changes in visceral adiposity as measured by changes in the phenotype WCBMI.
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