General and abdominal adiposity and risk of death in Europe

Monocyte chemoattractant protein-1 deficiency protects against visceral fat-induced atherosclerosis

OBJECTIVE

To determine the role of monocyte chemoattractant protein-1 (Mcp-1) on the progression of visceral fat-induced atherosclerosis.

METHODS AND RESULTS

Visceral fat inflammation was induced by transplantation of perigonadal fat. To determine whether recipient Mcp-1 status affected atherosclerosis induced by inflammatory fat, apolipoprotein E-deficient (ApoE(-/-)) and ApoE(-/-) and Mcp-1-deficient (Mcp-1(-/-)) mice underwent visceral fat transplantation. Intravital microscopy was used to study leukocyte-endothelial interactions. To study the primary tissue source of circulating Mcp-1, both fat and bone marrow transplantation experiments were used. Transplantation of visceral fat increased atherosclerosis in ApoE(-/-) mice but had no effect on atherosclerosis in ApoE(-/-),Mcp-1(-/-) mice. Intravital microscopy revealed increased leukocyte attachment to the endothelium in ApoE(-/-) mice compared with ApoE(-/-),Mcp-1(-/-) mice after receiving visceral fat transplants. Transplantation of visceral fat increased plasma Mcp-1, although donor adipocytes were not the source of circulating Mcp-1 because no Mcp-1 was detected in plasma from ApoE(-/-),Mcp-1(-/-) mice transplanted with Wt fat, indicating that recipient Mcp-1-producing cells were affecting the atherogenic response to the fat transplantation. Consistently, transplantation of Mcp-1(-/-) fat to ApoE(-/-) mice did not lead to atheroprotection in recipient mice. Bone marrow transplantation between Wt and Mcp-1(-/-) mice indicated that the primary tissue source of circulating Mcp-1 was the endothelium.

CONCLUSIONS

Recipient Mcp-1 deficiency protects against atherosclerosis induced by transplanted visceral adipose tissue.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

Aging per se increases the susceptibility to free fatty acid-induced insulin resistance

Elevations in systemic free fatty acids (FFA) contribute to insulin resistance. To determine the effects of an acute elevation in FFA on insulin action with aging, we infused saline or intralipid (IL) during a hyperinsulinemic-euglycemic clamp in three groups of rats: young ad libitum-fed (YAL), old ad libitum-fed (OAL), and old on lifelong calorie restriction (OCR). The OCR group was included to distinguish between aging per se and age-related changes in body fat distribution. IL induced marked insulin resistance in both YAL and OCR, but the onset of insulin resistance was approximately two to three times more rapid in OCR as compared with YAL. In response to IL infusion, plasminogen-activating inhibitor-1 (PAI-1) expression was increased in subcutaneous fat from OAL animals. In visceral fat, a marked increase in PAI-1 and interleukin-6 expression was observed in OAL and OCR rats, but not YAL, in response to IL treatment. Thus, aging per se increases the inflammatory response to excess nutrients and vulnerability to FFA-induced insulin resistance with aging.

Abdominal and gynoid adipose distribution and incident myocardial infarction in women and men

OBJECTIVE

The relationships between objectively measured abdominal and gynoid adipose mass with the prospective risk of myocardial infarction (MI) has been scarcely investigated. We aimed to investigate the associations between fat distribution and the risk of MI.

SUBJECTS

Total and regional fat mass was measured using dual-energy X-ray absorptiometry (DEXA) in 2336 women and 922 men, of whom 104 subsequently experienced an MI during a mean follow-up time of 7.8 years.

RESULTS

In women, the strongest independent predictor of MI was the ratio of abdominal to gynoid adipose mass (hazard ratio (HR)=2.44, 95% confidence interval (CI) 1.79-3.32 per s.d. increase in adipose mass), after adjustment for age and smoking. This ratio also showed a strong association with hypertension, impaired glucose tolerance and hypertriglyceridemia (P<0.01 for all). In contrast, the ratio of gynoid to total adipose mass was associated with a reduced risk of MI (HR= 0.57, 95% CI 0.43-0.77), and reduced risk of hypertension, impaired glucose tolerance and hypertriglyceridemia (P<0.001 for all). In men, gynoid fat mass was associated with a decreased risk of MI (HR=0.69, 95% CI 0.48-0.98), and abdominal fat mass was associated with hypertriglyceridemia (P for trend 0.02).

CONCLUSION

In summary, fat distribution was a strong predictor of the risk of MI in women, but not in men. These different results may be explained by the associations found between fat distribution and hypertension, impaired glucose tolerance and hypertriglyceridemia.

Who eats healthily? A population-based study among young Swiss residents

OBJECTIVE

To assess whether Swiss residents aged 15-24 years follow current nutritional guidelines and whether differences exist according to gender and weight status.

DESIGN

Cross-sectional national survey.

SETTING

Switzerland.

SUBJECTS

The 1786 participants (48·4 % women) were divided into overweight, normal weight and underweight. We used traditional BMI cut-offs for people ≥18 years of age (underweight = BMI < 18·5 kg/m2, normal weight = BMI ≥ 18·5 kg/m2 and <25 kg/m2, overweight = BMI ≥ 25 kg/m2) and age- and gender-appropriate tables for people aged <18 years, with BMI calculated from self-reported weight and height. We performed bivariate analyses by gender, and then bivariate and multivariate analyses comparing overweight to normal weight people (excluding underweight, n 129, 71·6 % women) regarding adherence to recommendations for fruit, vegetables, meat, fish and dairy products; physical activity; attitude towards body weight; depression, smoking and alcohol consumption.

RESULTS

Overall, adherence to nutritional guidelines was low, particularly for vegetables and dairy products. Women had a higher adherence than men except for fish and dairy products. In the multivariate analyses, overweight women had a lower vegetable intake, were less satisfied with body weight and had more often been on a diet, whereas overweight men were less satisfied with body weight and wanted to lose weight more often than their normal weight peers. There were no significant differences for physical activity.

CONCLUSIONS

Overweight prevention programmes should target youth specifically by gender and promote an appropriate self-perception. Overweight women should be encouraged to eat more vegetables and men to be more sensitised on healthy food. Further research is needed to assess how to make nutritional guidelines more adaptable to young people's daily life.

Insulin resistance, adipose depots and gut: interactions and pathological implications

This review article focuses on the many metabolic actions of insulin at the level of muscle, liver and adipose tissue. In terms of pathogenetic mechanisms, the condition of insulin resistance is complex, as multiple genetic and environmental factors, among which an increasingly sedentary lifestyle associated with high-fat diet, mutually interact according to variable patterns in time in any given individual. It is well recognized that obesity (in particular abdominal obesity) favours the development of insulin resistance. Here we evaluate the impact of obesity and ectopic fat accumulation (visceral and hepatic) on insulin resistance at the level of different target organs, i.e., muscle, liver and adipose tissue. The roles of the gut and the liver, in particular of bile acids and gut microflora, are also discussed as possible determinants of energy balance and glucose metabolism.

Measurement site for waist circumference affects its accuracy as an index of visceral and abdominal subcutaneous fat in a Caucasian population

Following experts' consensus, waist circumference (WC) is the best anthropometric obesity index. However, different anatomic sites are used, and currently there is no universally accepted protocol for measurement of WC. In this study, we compare the associations between WC measured at different sites with total visceral adipose tissue (VAT) volume and cardiometabolic risk. Cross-sectional data were obtained from 294 adults and 234 children and adolescents. In addition, longitudinal data were provided in 75 overweight adults before and after dietary-induced weight loss. WC was measured below the lowest rib (WC(rib)), above the iliac crest (WC(iliac crest)), and midway between both sites (WC(middle)). Volumes of VAT and abdominal subcutaneous adipose tissue (SAT) were obtained using MRI. Cardiometabolic risk included blood pressure, plasma lipids, glucose, and homeostasis model (HOMA index). WC differed according to measurement site as WC(rib) < WC(middle) < WC(iliac crest) (P < 0.001) in children and women, and WC(rib) < WC(middle), WC(iliac crest) (P < 0.001) in men. Elevated WC differed by 10-20% in females and 6-10% in males, dependent on measurement site. In men and children, all WC had similar relations with VAT, SAT, and cardiometabolic risk factors. In women, WC(rib) correlated with weight loss-induced decreases in VAT (r = 0.35; P < 0.05). By contrast, WC(iliac crest) had the lowest associations with VAT and cardiometabolic risk factors in women. Each WC had a stronger correlation with SAT than with VAT, suggesting that WC is predominantly an index of abdominal subcutaneous fat. There is need for a unified measurement protocol.

Association of obesity and biomarkers of inflammation and endothelial dysfunction in adults in Inner Mongolia, China

BACKGROUND

Recent studies suggest that central obesity is an important predictor of cardiovascular disease (CVD) in addition to overall obesity. Both inflammation and endothelial dysfunction are associated with increased risk of CVD. We examined the association between body mass index (BMI) and waist circumference (WC) with plasma concentrations of biomarkers of inflammation and endothelial dysfunction.

METHODS

We conducted a cross-sectional study of 2589 lean, moderately active participants aged 20 years and older in Inner Mongolia, China. Overnight fasting blood samples were obtained to measure the biomarkers including C-reactive protein (CRP), soluble inter-cellular adhesion molecule-1 (sICAM-1), soluble E-selectin (sE-selectin), and angiotensin II. Height, body weight, and WC were measured by trained staff and BMI was calculated (kg/m(2)).

RESULTS

In univariate analysis, CRP, sICAM-1, and sE-selectin were all significantly higher among individuals with a higher BMI and WC. In multivariate analysis, each standard deviation (SD) increase in WC (9.6 cm) was associated with about 46% higher risk (odds ratio [OR] 1.46, 95% confidence interval [CI] 1.21-1.76) of elevated CRP but a 1 SD increase in BMI (3.5 kg/m(2)) was not associated with the risk of elevated CRP (OR 0.96, 95% CI 0.80-1.16). However, each SD increase in BMI was associated with about 30% higher risk of having elevated E-selectin (OR 1.30, 95% CI 1.08-1.55).

CONCLUSIONS

WC is a stronger predictor of inflammation while BMI is a stronger predictor for endothelial dysfunction. These results suggest measuring both BMI and WC will help to assess the risk of CVD in the Chinese population.

Beyond the BMI: the search for better guidelines for bariatric surgery

The application of the BMI of > or =35 as the major prerequisite for access to bariatric surgery is no longer appropriate because the index, now incorporated in the requirements of Medicare, Medicaid and most private carriers, does not reflect the degree or distribution of adiposity, it discriminates unfairly on the basis of gender, race, age, fitness, and body fat composition. Further, with increasing evidence that bariatric surgery can also induce full and durable remission of such comorbidities as type 2 diabetes even in patients with BMIs <30, new guidelines must be pursued.

Growth in foetal life and infancy is associated with abdominal adiposity at the age of 2 years: the generation R study

OBJECTIVE

Early weight gain is associated with an increased risk of obesity. It is not known whether rapid weight gain in foetal life and infancy is also associated with increased abdominal adiposity. We examined the associations of foetal and postnatal growth characteristics with abdominal fat mass at the age of 2 years.

DESIGN

This study was performed in 481 children participating in a prospective cohort study from early foetal life onward.

MEASUREMENTS

Foetal and postnatal growth characteristics in second and third trimester, at birth and at the age of 2 years were related to abdominal fat mass (subcutaneous distance and area, preperitoneal distance and area) measured by ultrasound at the age of 2 years.

RESULTS

Foetal and birth weight were not associated with abdominal subcutaneous fat mass. Estimated foetal weight in second trimester of pregnancy was inversely associated with preperitoneal fat area [-3.73% (95% confidence interval -7.23, -0.10)] per standard deviation score increase in weight. Weight gain from birth to the age of 2 years was positively associated with preperitoneal fat mass measures. These associations remained significant after adjustment for age, sex, breastfeeding and body mass index. Positive associations were found between catch-up growth in weight and abdominal fat mass measures.

CONCLUSIONS

Our results suggest that rapid growth rates during foetal life and infancy are associated with increased abdominal subcutaneous and preperitoneal fat mass in healthy children. Further studies need to explore whether these associations persist in later life and are related to metabolic syndrome outcomes.

Relation of immediate postnatal growth with obesity and related metabolic risk factors in adulthood: the northern Finland birth cohort 1966 study

The authors examined associations between postnatal growth velocity through age 2 years and metabolic outcomes at age 31 years in a population-based birth-cohort study of 3,778 Finns (1966-1998). Approximately 8 height measurements and 9 weight measurements were obtained from birth to age 2 years. Peak height velocity (PHV) and peak weight velocity (PWV) in infancy were derived from parametric growth curves fitted to longitudinal height and weight growth data. Body mass index (BMI), waist circumference (WC), high density lipoprotein (HDL) cholesterol, triglycerides, glucose, systolic and diastolic blood pressure (BP), and the metabolic syndrome were measured at age 31 years. PHV was significantly positively associated with systolic and diastolic BP and WC in adulthood. For each 8-cm/year (2-standard-deviation) increase in PHV, WC increased by 1.60 cm (95% confidence interval: 0.73, 2.46), after adjustment for potential confounders, including birth weight. PWV was significantly associated with adulthood systolic BP, WC, and BMI. A 4-kg/year higher PWV was associated with a 1.87-cm (95% confidence interval: 1.08, 2.65) larger WC in adulthood, after adjustment for potential confounders. HDL cholesterol (direct), triglycerides (inverse), and metabolic syndrome (inverse) displayed associations with PWV only after BMI was accounted for. These results showed that growth during the immediate postnatal period is associated with adulthood obesity and BP. Lifestyle changes from early life might be important in reducing adulthood obesity and high-BP risk.

Traditional anthropometric parameters still predict metabolic disorders in women with severe obesity

It is well established that fat distribution rather than the total quantity of fat is the major determinant of cardiovascular risk in overweight subjects. However, it is not known whether the concept of fat distribution still makes sense in severely obese subjects. Particularly, the role of visceral fat accumulation and/or of adipocyte hypertrophy in insulin resistance (IR) has not been studied in this population. Therefore, the aim of this study was to clarify the determinants of metabolic disorders in severely obese women. We performed a cross-sectional study in 237 severely obese women (BMI >35 kg/m(2)). We assessed total body fat mass and fat distribution by anthropometric measurements (BMI and waist-to-hip ratio (WHR)) and by dual-energy X-ray absorptiometry (DXA). In 22 women, we measured subcutaneous and visceral adipocyte size on surgical biopsies. Mean BMI was 44 +/- 7 kg/m(2) (range 35-77), mean age 37 +/- 11 years (range 18-61). Lipid parameters (triglycerides, high-density lipoprotein cholesterol) and IR markers (fasting insulin and homeostasis model assessment (HOMA) index) correlated with fat distribution, whereas inflammatory parameters (C-reactive protein, fibrinogen) correlated only with total fat mass. An association was observed between android fat distribution and adipocyte hypertrophy. Visceral adipocyte hypertrophy was associated with both IR and hypertension, whereas subcutaneous fat-cell size was linked only to hypertension. Our results obtained in a large cohort of women showed that fat distribution still predicts metabolic abnormalities in severe obesity. Furthermore, we found a cluster of associations among fat distribution, metabolic syndrome (MS), and adipocyte hypertrophy.

Associations between diet, lifestyle factors, and telomere length in women

BACKGROUND

Leukocyte telomere length is associated with diseases of aging, but there is limited knowledge of diet and lifestyle determinants.

OBJECTIVE

The objective was to examine cross-sectionally the association between diet, body composition, and lifestyle factors on leukocyte telomere length in women.

DESIGN

Leukocyte telomere length was measured by quantitative polymerase chain reaction in 2284 female participants from the Nurses' Health Study, who were selected as controls for an investigation of biological predictors of cancer. Diet, lifestyle, and anthropometric data were assessed by questionnaire.

RESULTS

After multivariate adjustment, dietary fiber intake was positively associated with telomere length (z score), specifically cereal fiber, with an increase of 0.19 units between the lowest and highest quintiles (P = 0.007, P for trend = 0.03). Although total fat intake was not associated with telomere length, polyunsaturated fatty acid intake (-0.26 units, quintile 5 compared with quintile 1: P = 0.002, P for trend = 0.02), specifically linoleic acid intake, was inversely associated with telomere length after multivariate adjustment (-0.32 units; P = 0.001, P for trend = 0.05). Waist circumference was inversely associated with telomere length [0.15-unit difference in z score in a comparison of the highest (> or = 32 in, 81.28 cm) with the lowest (< or = 28 in, 71.12 cm) category (P = 0.01, P for trend = 0.02) in the multivariate model]. We found no association between telomere length and smoking, physical activity, or postmenopausal hormone use.

CONCLUSION

Although the strength of the associations was modest in this population of middle- and older-age women, our results support the hypothesis that body composition and dietary factors are related to leukocyte telomere length, which is a potential biomarker of chronic disease risk.

The predictive value of different measures of obesity for incident cardiovascular events and mortality

CONTEXT

To date, it is unclear which measure of obesity is the most appropriate for risk stratification.

OBJECTIVE

The aim of the study was to compare the associations of various measures of obesity with incident cardiovascular events and mortality.

DESIGN AND SETTING

We analyzed two German cohort studies, the DETECT study and SHIP, including primary care and general population.

PARTICIPANTS

A total of 6355 (mean follow-up, 3.3 yr) and 4297 (mean follow-up, 8.5 yr) individuals participated in DETECT and SHIP, respectively.

INTERVENTIONS

We measured body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip ratio (WHR) and assessed cardiovascular and all-cause mortality and the composite endpoint of incident stroke, myocardial infarction, or cardiovascular death.

RESULTS

In both studies, we found a positive association of the composite endpoint with WHtR but not with BMI. There was no heterogeneity among studies. The relative risks in the highest versus the lowest sex- and age-specific quartile of WHtR, WC, WHR, and BMI after adjustment for multiple confounders were as follows in the pooled data: cardiovascular mortality, 2.75 (95% confidence interval, 1.31-5.77), 1.74 (0.84-3.6), 1.71 (0.91-3.22), and 0.74 (0.35-1.57), respectively; all-cause mortality, 1.86 (1.25-2.76), 1.62 (1.22-2.38), 1.36 (0.93-1.69), and 0.77 (0.53-1.13), respectively; and composite endpoint, 2.16 (1.39-3.35), 1.59 (1.04-2.44), 1.49 (1.07-2.07), and 0.57 (0.37-0.89), respectively. Separate analyses of sex and age groups yielded comparable results. Receiver operating characteristics analysis yielded the highest areas under the curve for WHtR for predicting these endpoints.

CONCLUSIONS

WHtR represents the best predictor of cardiovascular risk and mortality, followed by WC and WHR. Our results discourage the use of the BMI.

A fresh look at NASH pathogenesis. Part 1: the metabolic movers

The strong relationship between over-nutrition, central obesity, insulin resistance/metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) suggest pathogenic interactions, but key questions remain. NAFLD starts with over-nutrition, imbalance between energy input and output for which the roles of genetic predisposition and environmental factors (diet, physical activity) are being redefined. Regulation of energy balance operates at both central nervous system and peripheral sites, including adipose and liver. For example, the endocannabinoid system could potentially be modulated to provide effective pharmacotherapy of NAFLD. The more profound the metabolic abnormalities complicating over-nutrition (glucose intolerance, hypoadiponectinemia, metabolic syndrome), the more likely is NAFLD to take on its progressive guise of non-alcoholic steatohepatitis (NASH). Interactions between steatosis and insulin resistance, visceral adipose expansion and subcutaneous adipose failure (with insulin resistance, inflammation and hypoadiponectinemia) trigger amplifying mechanisms for liver disease. Thus, transition from simple steatosis to NASH could be explained by unmitigated hepatic lipid partitioning with failure of local adaptive mechanisms leading to lipotoxicity. In part one of this review, we discuss newer concepts of appetite and metabolic regulation, bodily lipid distribution, hepatic lipid turnover, insulin resistance and adipose failure affecting adiponectin secretion. We review evidence that NASH only occurs when over-nutrition is complicated by insulin resistance and a highly disordered metabolic milieu, the same 'metabolic movers' that promote type 2 diabetes and atheromatous cardiovascular disease. The net effect is accumulation of lipid molecules in the liver. Which lipids and how they cause injury, inflammation and fibrosis will be discussed in part two.

Type 2 diabetes: assessing the relative risks and benefits of glucose-lowering medications

The selection of appropriate pharmacologic therapy for any disease requires a careful assessment of benefit and risk. In the case of type 2 diabetes, this decision typically balances the benefits accrued from improved glycemic control with the risks inherent in glucose-lowering medications. This review is intended to assist therapeutic decision-making by carefully assessing the potential benefit from improved metabolic control relative to the potential risks of a wide array of currently prescribed glucose-lowering agents. Wherever possible, risks and benefits have been expressed in terms of absolute rates (events per 1000 patient-years) to facilitate cross-study comparisons. The review incorporates data from new studies (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation, Action to Control Cardiovascular Risk in Diabetes, and the Veterans Affairs Diabetes Trial), as well as safety issues associated with newer glucose-lowering medications.

Effect of nutritional counselling and nutritional plus exercise counselling in overweight adults: a randomized trial in multidisciplinary primary care practice

OBJECTIVE

To compare the effects of nutritional counselling with nutritional plus exercise counselling on body weight and waist circumference in overweight adults in a multidisciplinary primary care setting.

METHODS

One hundred and thirty-four overweight adults (body mass index 28-35) were randomly assigned to individual counselling sessions by a dietician (D) or counselling sessions by a dietician plus physiotherapist (D + E) during 6 months with one follow-up session at 12 months. Outcomes were assessed at baseline, 6 and 12 months. Difference in changes of outcome measures between groups were analysed using generalized estimating equations.

RESULTS

Weight reduced from baseline to 6 months in D [-2.2 (-3.1 to -1.4) kg] and D + E [-3.0 (-4.0 to -2.0) kg] and was sustained at 12 months [-2.0 (-3.1 to -1.4) kg and -3.1 (-4.5 to -1.6) kg, respectively]. The reduction in weight did not significantly differ between D and D + E (P = 0.48). In both groups, waist circumference decreased from baseline to 6 months [-2.1 (-3.3 to -0.8) cm for D; -3.7 (-5.1 to -2.3) cm for D + E] and was sustained at 12 months [-2.1 (-3.5 to -0.7) cm and -4.2 (-6.0 to -2.5) cm, respectively]. Participants in D + E tended to decrease their waist circumference more than those in D (P = 0.14).

DISCUSSION

Nutritional counselling by a dietician resulted in modest reductions in weight and waist circumference in overweight adults, which were sustained up to 12 months. Adding exercise counselling by a physiotherapist did not significantly enhance the effect on body weight. Exercise counselling may, however, further improve waist circumference.

Transplantation of adipose tissue and stem cells: role in metabolism and disease

Humans and other mammals have three main adipose tissue depots: visceral white adipose tissue, subcutaneous white adipose tissue and brown adipose tissue, each of which possesses unique cell-autonomous properties. In contrast to visceral adipose tissue, which can induce detrimental metabolic effects, subcutaneous white adipose tissue and brown adipose tissue have the potential to benefit metabolism by improving glucose homeostasis and increasing energy consumption. In addition, adipose tissue contains adipose-derived stem cells, which possess the ability to differentiate into multiple lineages, a property that might be of value for the repair or replacement of various damaged cell types. Adipose tissue transplantation has primarily been used as a tool to study physiology and for human reconstructive surgery. Transplantation of adipose tissue is, however, now being explored as a possible tool to promote the beneficial metabolic effects of subcutaneous white adipose tissue and brown adipose tissue, as well as adipose-derived stem cells. Ultimately, the clinical applicability of adipose tissue transplantation for the treatment of obesity and metabolic disorders will reside in the achievable level of safety, reliability and efficacy compared with other treatments.

Body size, body composition, and cardiovascular disease risk factors in NFL players

AIMS

We characterized the size of active National Football League (NFL) players by multiple criteria and analyzed their relation to traditional cardiovascular disease (CVD) risk factors with the objective of further clarifying the occurrence of cardiovascular risk factors in different player positions.

METHODS

This cross-sectional study was conducted in professional athletic training facilities. The participants were 504 active veteran players from a convenience sample of 12 NFL teams, grouped as interior linemen (IL) or all others (AO). Comparisons were made between the NFL groups and an age-equivalent general population database.

RESULTS

The IL group was significantly larger than AO by all size measures. Both groups were significantly larger than the Coronary Artery Risk Development in Young Adults (CARDIA) group. Mean percent body fat measurements in AO (mean, 13.4%; 95% confidence interval [CI], 12.9%-14%) and IL (mean, 25.2%; 95% CI, 24.4%-26%) groups were lower than estimates for the general population. Systolic blood pressure (BP) was higher in IL (mean, 131 mm Hg; 95% CI, 129-133 mm Hg) than AO (mean, 126 mm Hg; 95% CI, 125-127 mm Hg) and greater in both groups compared with the CARDIA group (mean, 112 mm Hg; 95% CI, 111-112 mm Hg). Mean low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (HDL-C), total cholesterol, triglycerides, and glucose were within the normal range for both IL and AO. Interior linemen had significantly lower HDL-C than AO and the CARDIA group. Both NFL groups had significantly lower fasting glucose than CARDIA.

CONCLUSION

Body fat in active NFL players was lower than predicted by standard measures of obesity. Although the players were large, they were in the normal range for most CVD risk factors. Mean BP in the prehypertensive range was found in both NFL position groups, but was significantly higher in IL than in AO. Prehypertension in these athletes warrants vigilance.

Brain size, body size and longevity

In this analysis, we bring together two research fields that have never been associated before: the clinical issue 'Quételet's body-mass index and longevity' and the comparative biological issue 'body-brain allometry'. Comparison of medical and biological data supports the view that body mass index is just a one-to-one mapping of the body-brain-energy balance-a biological variable indicating that an individual maintains its systemic energy homeostasis and therefore is likely to perform well in the coming years.

Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with a safety extension

BACKGROUND

HIV-infected patients receiving antiretroviral therapy often demonstrate excess visceral fat. A growth hormone-releasing factor, tesamorelin, may selectively reduce visceral fat in this population. We investigated the effects of tesamorelin (GHRH(1-44)) in HIV-infected patients with central fat accumulation.

METHODS

A 12-month study of 404 HIV-infected patients with excess abdominal fat in the context of antiretroviral therapy was conducted between January 2007 and October 2008. The study consisted of 2 sequential phases. In the primary efficacy phase (months 0-6), patients were randomly assigned to receive tesamorelin [2 mg subcutaneous (SC) every day] or placebo in a 2:1 ratio. In the extension phase (months 6-12), patients receiving tesamorelin were rerandomized to continue on tesamorelin (2 mg SC every day) or switch to placebo. Patients initially randomized to placebo switched to tesamorelin. Patients and investigators were blinded to treatment assignment throughout the study. The primary endpoint was visceral adipose tissue (VAT). Secondary endpoints included body image, IGF-I, safety measures, including glucose, and other body composition measures.

RESULTS

VAT decreased by -10.9% (-21 cm(2)) in the tesamorelin group vs. -0.6% (-1 cm(2)) in the placebo group in the 6-month efficacy phase, P < 0.0001. Trunk fat (P < 0.001), waist circumference (P = 0.02), and waist-hip-ratio (P = 0.001) improved, with no change in limb or abdominal SC fat. Insulin-like growth factor-1 increased (P < 0.001), but no change in glucose parameters was observed. Patient rating of belly appearance distress (P = 0.02) and physician rating of belly profile (P = 0.02) were significantly improved in the tesamorelin vs. placebo-treated groups. The drug was well tolerated. VAT was reduced by approximately 18% (P < 0.001) in patients continuing tesamorelin for 12 months. The initial improvements over 6 months in VAT were rapidly lost in those switching from tesamorelin to placebo.

CONCLUSIONS

Tesamorelin reduces visceral fat by approximately 18% and improves body image distress in HIV-infected patients with central fat accumulation. These changes are achieved without significant side effects or perturbation of glucose.

Effects of lifestyle measures, antiobesity agents, and bariatric surgery on serological markers of inflammation in obese patients

Overweight and obesity are highly prevalent in developed countries and are also becoming more frequent in the developing world. Overweight and obese patients have elevated levels of several inflammatory markers and this inflammatory state might contribute to their increased vascular risk. We summarize the effects of lifestyle changes, antiobesity agents, and bariatric surgery on serological inflammatory markers in overweight and obese patients. Most studies showed a decrease in inflammation with all 3 interventions. However, it remains to be established whether the decrease in inflammatory markers induced by lifestyle changes or (where indicated) with antiobesity agents or bariatric surgery will translate into reduced vascular morbidity and mortality in overweight and obese patients.

Normal weight obesity: a risk factor for cardiometabolic dysregulation and cardiovascular mortality

AIMS

We hypothesized that subjects with a normal body mass index (BMI), but high body fat (BF) content [normal weight obesity (NWO)], have a higher prevalence of cardiometabolic dysregulation and are at higher risk for cardiovascular (CV) mortality.

METHODS AND RESULTS

We analysed 6171 subjects >20 years of age from the Third National Health and Nutrition Examination Survey (NHANES III) and the NHANES III mortality study, whose BMI was within the normal range (18.5-24.9 kg/m(2)), and who underwent a complete evaluation that included body composition assessment, blood measurements, and assessment of CV risk factors. Survival information was available for >99% of the subjects after a median follow-up of 8.8 years. We divided our sample using sex-specific tertiles of BF%. The highest tertile of BF (>23.1% in men and >33.3% in women) was labelled as NWO. When compared with the low BF group, the prevalence of metabolic syndrome in subjects with NWO was four-fold higher (16.6 vs. 4.8%, P < 0.0001). Subjects with NWO also had higher prevalence of dyslipidaemia, hypertension (men), and CV disease (women). After adjustment, women with NWO showed a significant 2.2-fold increased risk for CV mortality (HR = 2.2; 95% CI, 1.03-4.67) in comparison to the low BF group.

CONCLUSION

Normal weight obesity, defined as the combination of normal BMI and high BF content, is associated with a high prevalence of cardiometabolic dysregulation, metabolic syndrome, and CV risk factors. In women, NWO is independently associated with increased risk for CV mortality.

Telemedicine intervention effects on waist circumference and body mass index in the IDEATel project

BACKGROUND

We examine the changes in waist circumference (WC) and body mass index (BMI) in older adults enrolled in a diabetes telemedicine program. The subjects were elderly Medicare beneficiaries participating in the rural (upstate New York) cohort of Informatics and Diabetes Education and Telemedicine, a randomized, controlled trial using telemedicine to improve diabetes care in which the primary outcome was glycemic control.

METHODS

Ninety-two percent of the subjects had BMI >25 kg/m(2), and 65.8% had a BMI > or =30 kg/m(2). Intervention subjects received home televisits with a dietitian or nurse educator every 4-6 weeks. Blood glucose and blood pressure values were reviewed, and lifestyle and medication changes were recommended. Non-intervention subjects received usual care through their primary care physicians. Change in WC, BMI, diet, and exercise behaviors and knowledge were examined at baseline and 12 and 24 months. A mixed-effects path analysis was performed to examine direct and indirect effects.

RESULTS

The telemedicine participants increased diet and exercise knowledge over time (P < 0.001). It was estimated that women in the telemedicine group reduced their WC over the 2 years by 1.2 cm, whereas women in the usual care group increased their WC by almost 1 cm (P = 0.02). Path analysis demonstrated that the intervention, through improved diet and exercise knowledge, was related to the decrease in WC (P = 0.006) and BMI (P = 0.004).

CONCLUSIONS

Diabetes case management using telemedicine improved self-reported diet and exercise knowledge, practices, and behaviors, which in turn was associated with reductions in WC and BMI at 2 years.

Colonic complications of obesity

Obesity is a risk factor for colorectal cancer and adenomatous polyps. The increased prevalence of neoplasia coupled with the observation that obesity may be associated with a suboptimal bowel preparation may diminish the adequate detection of adenomas for obese who undergo colonoscopy. The colonic complications of obesity are reviewed in this article.

Body mass index and waist circumference predict both 10-year nonfatal and fatal cardiovascular disease risk: study conducted in 20,000 Dutch men and women aged 20-65 years

AIMS

Body mass index (BMI) and waist circumference (WC) are both predictors of cardiovascular diseases (CVD). We compared absolute risk, hazard ratio (HR), and population attributable risk of nonfatal and fatal CVD for BMI and WC in a large prospective cohort study with an average follow-up of 10 years.

METHODS AND RESULTS

Anthropometric data were measured between 1993 and 1997 in a general population sample of over 20,000 men and women aged 20-65 years in the Netherlands. All risks were adjusted for age and sex. Absolute risk of nonfatal CVD was on average 10 times higher than that of fatal CVD. In obese respondents (BMI >or=30 kg/m2), relative risk of fatal CVD was four-fold higher [HR=4.0 95% confidence interval (CI)=2.4-6.6], whereas risk of nonfatal CVD was two-fold higher (HR=1.8 95% CI=1.6-2.2) than in normal-weight respondents. Similar associations were observed for WC (>or=88 vs. <80 cm in women and >or=102 vs. 94 cm in men). In persons with overweight or obesity (BMI >or=25 kg/m2), half of all fatal CVD (attributable risk=54%, 95% CI=30-70) and a quarter of nonfatal CVD was ascribed to their overweight. On the population level, one-third of all fatal CVD cases could be attributed to overweight and obesity (population attributable risk=35%, 95% CI=14-52), and about one in seven of nonfatal CVD cases.

CONCLUSION

The associations of BMI and WC with CVD risk were equally strong. Overweight and obesity had a stronger impact on fatal CVD than on nonfatal CVD.

Comparison of the associations of body mass index and measures of central adiposity and fat mass with coronary heart disease, diabetes, and all-cause mortality: a study using data from 4 UK cohorts

BACKGROUND

Measures of regional adiposity have been proposed as alternatives to the measurement of body mass index (BMI) for identifying persons at risk of future disease.

OBJECTIVE

The objective was to compare the magnitudes of association of BMI and alternative measurements of adiposity with coronary heart disease, diabetes, and cardiovascular disease risk factors and all-cause mortality.

DESIGN

Data from 4 cohorts of adults [3937 women from the British Women's Heart and Health Study (BWHHS); 2367 and 1950 men from phases 1 and 3, respectively, of the Caerphilly Prospective Study (CaPS); 403 men and women from the Boyd Orr Study; and 789 men and women from the Maidstone-Dewsbury Study] were analyzed.

RESULTS

The magnitudes of associations of BMI with incident coronary heart disease and cardiovascular disease risk factors were similar to those with measurements of central adiposity [waist circumference (WC), waist-hip ratio (WHR), or waist-height ratio (WHtR)] and more direct measurements of fat mass (bioimpedance/skinfold thickness). In CaPS (men only), there was no strong evidence of differences in the strengths of association with incident diabetes between BMI, WC, WHR, and WHtR (P for heterogeneity > 0.49 for all). In the BWHHS (women only), there was statistical evidence that WC [hazard ratio (HR): 2.35; 95% CI: 2.03, 2.73] and WHtR (HR: 2.29; 95% CI: 1.98, 2.66) were more strongly associated with diabetes than with BMI (HR: 1.80; 95% CI: 1.59, 2.04) (P for heterogeneity < 0.02 for both). Central adiposity measurements were positively associated with all-cause mortality, as was BMI, but only when those with a BMI (in kg/m(2)) <22.5 were removed from the analyses.

CONCLUSION

No strong evidence supports replacing BMI in clinical or public health practice with other adiposity measures.

A comparison of obese and nonobese people with asthma: exploring an asthma-obesity interaction

OBJECTIVE

The objectives of our study were to compare patient characteristics and severity of disease in obese and normal-weight-confirmed people with asthma and to explore reasons for misdiagnosis of asthma, including potential interactions with obesity.

METHODS

We randomly selected patients with physician-diagnosed asthma from eight Canadian cities. Asthma diagnosis was confirmed via a sequential lung function testing algorithm. Logistic analysis was conducted to compare obese and normal-weight-confirmed people with asthma and to assess characteristics associated with misdiagnosis of asthma. Interaction with obesity was investigated.

RESULTS

Complete assessments were obtained on 496 subjects who reported physician-diagnosed asthma (242 obese and 254 normal-weight subjects); 346 had asthma confirmed with sequential lung testing, and in 150 subjects a diagnosis of asthma was ruled out. Obese subjects with asthma were significantly more likely to be men, have a history of hypertension and gastroesophageal reflux disease, and have a lower FEV(1) compared with normal-weight subjects with asthma. Older subjects, men, and subjects with higher FEV(1) were more likely to have received misdiagnoses of asthma. Obesity was not an independent predictor of misdiagnosis, however there was an interaction between obesity and urgent visits for respiratory symptoms. The odds ratio for receiving a misdiagnosis of asthma for obese individuals as compared with normal-weight individuals was 4.08 (95% CI, 1.23-13.5) for those with urgent visits in the past 12 months.

CONCLUSIONS

Obese people with asthma have lower lung function and more comorbidities compared with normal-weight people with asthma. Obese individuals who make urgent visits for respiratory symptoms are more likely to receive a misdiagnosis of asthma.

The discrimination of dyslipidaemia using anthropometric measures in ethnically diverse populations of the Asia-Pacific Region: the Obesity in Asia Collaboration

Dyslipidaemia is a major risk factor for cardiovascular disease and is only detectable through blood testing, which may not be feasible in resource-poor settings. As dyslipidaemia is commonly associated with excess weight, it may be possible to identify individuals with adverse lipid profiles using simple anthropometric measures. A total of 222 975 individuals from 18 studies were included as part of the Obesity in Asia Collaboration. Linear and logistic regression models were used to assess the association between measures of body size and dyslipidaemia. Body mass index, waist circumference, waist : hip ratio (WHR) and waist : height ratio were continuously associated with the lipid variables studied, but the relationships were consistently stronger for triglycerides and high-density lipoprotein cholesterol. The associations were similar between Asians and non-Asians, and no single anthropometric measure was superior at discriminating those individuals at increased risk of dyslipidaemia. WHR cut-points of 0.8 in women and 0.9 in men were applicable across both Asians and non-Asians for the discrimination of individuals with any form of dyslipidaemia. Measurement of central obesity may help to identify those individuals at increased risk of dyslipidaemia. WHR cut-points of 0.8 for women and 0.9 for men are optimal for discriminating those individuals likely to have adverse lipid profiles and in need of further clinical assessment.

Visceral adiposity is not associated with inflammatory markers in trauma patients

BACKGROUND

Excess visceral adiposity induces chronic subclinical inflammation resulting in the metabolic syndrome. Whether excess visceral adiposity impacts posttraumatic inflammatory profiles more is unknown. We hypothesized that obese patients (body mass index >30 kg/m) with higher visceral to subcutaneous adipose tissue distribution would have increased inflammatory outcomes.

METHODS

A secondary analysis of a prospective cohort of adult trauma patients requiring >48 hours of intensive care unit care over a 55-month period was analyzed. Body fat distribution was determined by radiologist review of computed tomography scans at L1. Concentric freeform regions were defined manually, and area was calculated. Visceral adiposity was defined as subcutaneous fat area: visceral area >1.35 (the median), whereas subcutaneous adiposity was defined as a ratio <1.35. Primary outcomes were proinflammatory biomarkers known to be associated with chronic visceral obesity (white blood cell count, interleukin 1, 2, 4, 6, 8, 10, and tumor necrosis factor alpha). Secondary outcomes were all-cause in-hospital mortality, adult respiratory distress syndrome, and nosocomial infections.

RESULTS

Two hundred eighty-one (19%) obese patients with available computed tomography scans from 1,510 trauma patients were included. Visceral adiposity included 140 patients, subcutaneous adiposity included 141 patients. The two groups were similar in regards to age, Trauma Injury Severity Score, and Acute Physiology and Chronic Health Evaluation II score. There was no difference (p > 0.05) in proinflammatory biomarkers. Patients with visceral adiposity had similar clinical outcomes including mortality (p = 0.56), adult respiratory distress syndrome (p = 0.69), and infection (0.43).

CONCLUSIONS

Visceral body fat distribution in obese patients is not associated with increased inflammatory profiles or clinical outcomes after trauma. The impact of injury severity on acute inflammation likely overwhelms the metabolic disturbances and subclinical inflammation associated with visceral obesity in the chronic setting.

Incident cancer burden attributable to excess body mass index in 30 European countries

Excess adiposity is associated with increased risks of developing adult malignancies. To inform public health policy and guide further research, the incident cancer burden attributable to excess body mass index (BMI >or= 25 kg/m(2)) across 30 European countries were estimated. Population attributable risks (PARs) were calculated using European- and gender-specific risk estimates from a published meta-analysis and gender-specific mean BMI estimates from a World Health Organization Global Infobase. Country-specific numbers of new cancers were derived from Globocan2002. A ten-year lag-period between risk exposure and cancer incidence was assumed and 95% confidence intervals (CI) were estimated in Monte Carlo simulations. In 2002, there were 2,171,351 new all cancer diagnoses in the 30 countries of Europe. Estimated PARs were 2.5% (95% CI 1.5-3.6%) in men and 4.1% (2.3-5.9%) in women. These collectively corresponded to 70,288 (95% CI 40,069-100,668) new cases. Sensitivity analyses revealed estimates were most influenced by the assumed shape of the BMI distribution in the population and cancer-specific risk estimates. In a scenario analysis of a plausible contemporary (2008) population, the estimated PARs increased to 3.2% (2.1-4.3%) and 8.6% (5.6-11.5%), respectively, in men and women. Endometrial, post-menopausal breast and colorectal cancers accounted for 65% of these cancers. This analysis quantifies the burden of incident cancers attributable to excess BMI in Europe. The estimates reported here provide a baseline for future modelling, and underline the need for research into interventions to control weight in the context of endometrial, breast and colorectal cancer.

Lower cardiac vagal tone in non-obese healthy men with unfavorable anthropometric characteristics

OBJECTIVES

to determine if there are differences in cardiac vagal tone values in non-obese healthy, adult men with and without unfavorable anthropometric characteristics.

INTRODUCTION

It is well established that obesity reduces cardiac vagal tone. However, it remains unknown if decreases in cardiac vagal tone can be observed early in non-obese healthy, adult men presenting unfavorable anthropometric characteristics.

METHODS

Among 1688 individuals assessed between 2004 and 2008, we selected 118 non-obese (BMI <30 kg/m(2)), healthy men (no known disease conditions or regular use of relevant medications), aged between 20 and 77 years old (42 +/- 12-years-old). Their evaluation included clinical examination, anthropometric assessment (body height and weight, sum of six skinfolds, waist circumference and somatotype), a 4-second exercise test to estimate cardiac vagal tone and a maximal cardiopulmonary exercise test to exclude individuals with myocardial ischemia. The same physician performed all procedures.

RESULTS

A lower cardiac vagal tone was found for the individuals in the higher quintiles - unfavorable anthropometric characteristics - of BMI (p=0.005), sum of six skinfolds (p=0.037) and waist circumference (p<0.001). In addition, the more endomorphic individuals also presented a lower cardiac vagal tone (p=0.023), while an ectomorphic build was related to higher cardiac vagal tone values as estimated by the 4-second exercise test (r=0.23; p=0.017).

CONCLUSIONS

Non-obese and healthy adult men with unfavorable anthropometric characteristics tend to present lower cardiac vagal tone levels. Early identification of this trend by simple protocols that are non-invasive and risk-free, using select anthropometric characteristics, may be clinically useful in a global strategy to prevent cardiovascular disease.

Body fat distribution, adipocyte size, and metabolic characteristics of nondiabetic adults

CONTEXT

It is unclear whether adipocyte size or body fat distribution is most strongly linked to the metabolic complications of obesity.

OBJECTIVE

Our objective was to test whether adipocyte size better predicts metabolic characteristics of obesity than body composition.

DESIGN, PARTICIPANTS, AND SETTING

We analyzed the relationship between metabolic and anthropometric data collected from 432 largely Caucasian research volunteers (264 women) participating in studies conducted in the Mayo General Clinical Research Center between 1995 and 2008.

MAIN OUTCOME MEASURES

Metabolic variables included fasting plasma glucose, insulin, and triglyceride concentrations. Anthropometric variables included body composition, fat distribution, and sc abdominal and femoral adipocyte size.

RESULTS

Using both univariate and multivariate regression analysis, fasting triglyceride in both men and women was best predicted by computed tomography of visceral fat area. Fasting insulin concentrations were best predicted by sc abdominal fat area in women (r(2) = 0.40; P < 0.01) and body mass index in men (r(2) = 0.53; P < 0.0001); adipocyte size did not contribute independently. In men, fasting glucose concentrations were predicted by femoral adipocyte size (partial r(2) = 0.07; P = 0.002), body mass index (partial r(2) = 0.03; P = 0.07), and age (partial r(2) = 0.02; P = 0.06). In women, fasting glucose was predicted by abdominal sc fat area (partial r(2) = 0.12; P < 0.0001) and age (partial r(2) = 0.03; P = 0.01).

CONCLUSIONS

Our hypothesis that adipocyte size is the best predictor of metabolic characteristics was not supported in this population. The alternative explanation is that fat mass and body fat distribution have more influence on metabolic responses than adipocyte size.