Regional obesity and risk of cardiovascular disease; the Framingham Study

Identification of adipocyte adhesion molecule (ACAM), a novel CTX gene family, implicated in adipocyte maturation and development of obesity

Few cell adhesion molecules have been reported to be expressed in mature adipocytes, and the significance of cell adhesion process in adipocyte biology is also unknown. In the present study, we identified ACAM (adipocyte adhesion molecule), a novel homologue of the CTX (cortical thymocyte marker in Xenopus) gene family. ACAM cDNA was isolated during PCR-based cDNA subtraction, and its mRNA was shown to be up-regulated in WATs (white adipose tissues) of OLETF (Otsuka Long-Evans Tokushima fatty) rats, an animal model for Type II diabetes and obesity. ACAM, 372 amino acids in total, has a signal peptide, V-type (variable) and C2-type (constant) Ig domains, a single transmembrane segment and a cytoplasmic tail. The amino acid sequence in rat is highly homologous to mouse (94%) and human (87%). ACAM mRNA was predominantly expressed in WATs in OLETF rats, and increased with the development of obesity until 30 weeks of age, which is when the peak of body mass is reached. Western blot analysis revealed that ACAM protein, approx. 45 kDa, was associated with plasma membrane fractions of mature adipocytes isolated from mesenteric and subdermal adipose deposits of OLETF rats. Up-regulation of ACAM mRNAs in obesity was also shown in WATs of genetically obese db/db mice, diet-induced obese ICR mice and human obese subjects. In primary cultured mouse and human adipocytes, ACAM mRNA expression was progressively up-regulated during differentiation. Several stably transfected Chinese-hamster ovary K1 cell lines were established, and the quantification of ACAM mRNA and cell aggregation assay revealed that the degree of homophilic aggregation correlated well with ACAM mRNA expression. In summary, ACAM may be the critical adhesion molecule in adipocyte differentiation and development of obesity.

Which anthropometric measurements is most closely related to elevated blood pressure?

BACKGROUND

Epidemiological studies find a progressive increase in the prevalence of elevated blood pressure with increasing adipose tissue. But there is no common opinion about which effectiveness of the anthropometric measurement tools indicating general or android obesity are most important to follow up in patients with elevated blood pressures.

OBJECTIVES

To identify which anthropometric measurements are most closely related to blood pressure elevation.

METHODS

A cross-sectional descriptive study of 1727 subjects [894 (50.6%) men and 833 (48.2%) women, aged 18-65 years old] was held in Edirne, Turkey. Each subject's weight, height, waist and hip circumference, triceps skin fold and blood pressures was measured; waist to hip ratio and body mass index were calculated. The relations between blood pressure and different anthropometric variables in both genders were investigated in linear regression models.

RESULTS

The mean systolic and diastolic blood pressures were 123.49 +/- 17.60 and 78.79 +/- 10.37 mmHg. According to body mass index 23.7% of the subjects were obese (.29.9 kg/m(2)). When waist circumference cut-off points were compared with waist to hip ratio the android obesity ratio was doubled (32.3% versus 16.6%). 119 subjects (6.8%) were not obese according to body mass index but nonetheless had waist circumference measurements above the cut-off points suggesting a high cardiovascular risk. In the linear regression models waist circumference was found to be an independent risk factor for blood pressure in men; however body mass was more important index and waist circumference somewhat less so for women.

CONCLUSION

In primary care waist circumference should be a useful tool screening for and following android obesity in patients with elevated blood pressure.

Change in body mass index and its impact on blood pressure: a prospective population study

BACKGROUND

Overweight and obesity increase the risk of elevated blood pressure, but the knowledge of the effect of weight change on blood pressure is sparse.

OBJECTIVE

To investigate the association between change in body mass index (BMI) and change in diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension status.

DESIGN

Two population-based cross-sectional studies, one in 1984-86 and the other in 1995-97.

SETTING

The Nord-Trondelag Health Study (HUNT).

PARTICIPANTS

We included 15,971 women and 13,846 men who were 20 y or older at the first survey, without blood pressure medication at both surveys and without diabetes, cardiovascular disease or dysfunction in daily life at baseline.

MEASUREMENTS

Weight, height and blood pressure were measured standardised. Change in BMI was categorised as stable (initial BMI+/-0.1 kg/m2 each follow-up year), increased or decreased, and BMI was categorised by using World Health Organisation's categorisation (underweight BMI: <18.5 kg/m2, normal weight BMI: 18.5-24.9 kg/m2, overweight BMI: 25.0-29.9 kg/m2, obesity BMI> or =30 kg/m2).

RESULTS

An increase in BMI and a decrease in BMI were significantly associated with increased and decreased SBP and DBP, respectively, compared to a stable BMI in both genders and all age groups, although the strongest effect was found among those who were 50 y and older. The adjusted odds ratio for having hypertension at HUNT 2 was 1.8 (95% confidence interval (CI): 1.5, 2.2) among women and 1.6 (95% CI: 1.4,1.8) among men aged 20-49 y who increased their BMI compared to those who had stable BMI. A similar, but weaker association was found among women and men aged 50 y or more. The mean change in both SBP and DBP was higher for those who changed BMI category from first to the second survey than for those who were in the same BMI class at both surveys.

CONCLUSIONS

Our result supports an independent effect of change in BMI on change in SBP and DBP in both women and men, and that people who increase their BMI are at increased risk for hypertension.

Influence of physiological androgen levels on wound healing and immune status in men

Aging in men is associated with a progressive decline in the production of several hormones, including androgens. The extent to which an age-dependent decline in androgen levels lead to health problems or can affect quality of life remains under debate. Clinical results on replacement therapy do not yet provide a definitive clue on the benefit/risk balance. A sexual dimorphism of the immune system is well established, and the differences between female and male immune responses under normal, as well as pathological, conditions are generally attributed to the influence of estrogens, progestins, and androgens. The suppressive effects of male sex hormones on immune functions have been observed in a wide variety of disease processes and appear to be testosterone-mediated. Endogenous testosterone inhibits skin wound healing response in males and is associated with an enhanced inflammatory response. Although there are no known gender-related differences in permeability barrier function in adults, estrogens accelerates--whereas testosterone retards--barrier development in fetal skin, and male fetuses demonstrate slower barrier development than female littermates.

Comparison of CT and dual-energy DEXA using a modified trunk compartment in the measurement of abdominal fat

The quantification of abdominal fat is a marker of health risk. While dual-energy x-ray absorptiometry (DEXA) is easily applied, it measures overall fat, although abdominal fat may be a better indicator of health risk from obesity. We have evaluated whether a subcomponent of DEXA measurements correlates better with computed tomography (CT) for body fat than those traditionally used. Forty-seven healthy adults (22 M/25 F), aged 54.5+/-15.8 yr (mean+/-SD), with BMI of 27.1+/-4.6 kg/m2 participated in a cross-sectional study. Body fat was measured using abdominal CT and DEXA for total fat, trunk fat, and a modified trunk measurement that excludes the chest, termed "lower trunk," and compared. The coefficient of variation for DEXA measurements for trunk, lower trunk, and total body were 1.98, 3.12, and 0.85%, respectively. Mean DEXA for percentage fat ranged from 31.7% to 34.1% for trunk, lower trunk, and total body, compared to 54.2% for abdominal CT (p<0.003 for each pairwise comparison). Lower trunk, whole trunk, and total body DEXA measurements were not different. Measurement of subcomponents of fat content by DEXA is not superior to whole body measurements and remains consistently lower than measurements by CT.

A comparison of body mass index and waist-to-hip ratio as indicators of hypertension risk in an urban Argentine population: a hospital-based study

BACKGROUND AND AIM

To examine the relationship between 24-h ambulatory blood pressure monitoring (ABPM) and three commonest anthropometric measurements for obesity [body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR)] in patients with essential hypertension never treated or after a 3 week placebo period, living in Buenos Aires.

METHODS AND RESULTS

Cross-sectional survey among outpatients at the Hypertension Program of Buenos Aires University Hospital de Clinicas. Three-hundred seventy-seven essential hypertensives, aged 18-86 years, of either sex, were consecutively recruited. All subjects underwent 24 h ABPM performed with a blood pressure (BP) device. The prevalence of overweight-obesity was 56.76% in women and 75.86% in men. High WHR prevalence in non-obese women was 4.5% and 4.1% in non-obese men while high values of WC were observed in 3.0% of non-obese women and in 0% of non-obese men. The two-way ANCOVA showed that in women with high values of WHR, 24 h DBP was higher in those with BMI<25 than in those with BMI> or =25. Those females with a BMI> or =25 had a higher prevalence of top tertile values of PP (> or =68 mmHg) (P<0.05) than non-obese females. Only in women was mean pulse pressure (PP) significantly correlated with age (r=0.38; P<0.0001), WC (r=0.22; P<0.005), WHR (r=0.21, P<0.008), and BMI (r=0.20; P<0.01) while in men there was no significant correlation between variables. Logistic regression showed that the odds of morning blood pressure surge (MBPS) increased with age, central obesity (represented by high WHR and dipper status), while the odds of higher mean PP increased with age and high WHR.

CONCLUSION

These results indicated a high prevalence of overweight-obesity (more than 56% of women and 75% of men) in our hospital-based sample of essential hypertension and that the WHR offers additional information beyond BMI and WC to predict the hypertension risk according to the ABPM.

Visceral adipose tissue-derived serine protease inhibitor: a unique insulin-sensitizing adipocytokine in obesity

There is a rapid global rise in obesity, and the link between obesity and diabetes remains somewhat obscure. We identified an adipocytokine, designated as visceral adipose tissue-derived serpin (vaspin), which is a member of serine protease inhibitor family. Vaspin cDNA was isolated by from visceral white adipose tissues (WATs) of Otsuka Long-Evans Tokushima fatty (OLETF) rat, an animal model of abdominal obesity with type 2 diabetes. Rat, mouse, and human vaspins are made up of 392, 394, and 395 amino acids, respectively; exhibit approximately 40% homology with alpha1-antitrypsin; and are related to serine protease inhibitor family. Vaspin was barely detectable in rats at 6 wk and was highly expressed in adipocytes of visceral WATs at 30 wk, the age when obesity, body weight, and insulin levels peak in OLETF rats. The tissue expression of vaspin and its serum levels decrease with worsening of diabetes and body weight loss at 50 wk. The expression and serum levels were normalized with the treatment of insulin or insulin-sensitizing agent, pioglitazone, in OLETF rats. Administration of vaspin to obese CRL:CD-1 (ICR) (ICR) mice fed with high-fat high-sucrose chow improved glucose tolerance and insulin sensitivity reflected by normalized serum glucose levels. It also led to the reversal of altered expression of genes relevant to insulin resistance, e.g., leptin, resistin, TNFalpha, glucose transporter-4, and adiponectin. In DNA chip analyses, vaspin treatment resulted in the reversal of expression in approximately 50% of the high-fat high-sucrose-induced genes in WATs. These findings indicate that vaspin exerts an insulin-sensitizing effect targeted toward WATs in states of obesity.

Predictors of weight loss and reversal of comorbidities in malabsorptive bariatric surgery

BACKGROUND

Cardiovascular and metabolic comorbidities are dramatically increased in severe obesity, a condition highly resistant to nonsurgical therapy.

OBJECTIVE

The objective was to identify predictors of weight loss and reversal of comorbidity in obese patients undergoing malabsorptive bariatric surgery.

DESIGN

Morbidly obese men and women (n = 107) were studied before and 2 y after biliopancreatic diversion (BPD). Body composition, serum lipid profile, oral glucose tolerance, and blood pressure were measured. Insulin sensitivity was determined by use of a euglycemic clamp. The length of the small intestine was measured during surgery.

RESULTS

Intestinal length was 671 +/- 99 cm, and the residual absorbing intestine after BPD ranged from 54% to 24% of initial length. Patients lost an average of 36% of their initial weight, with approximately 50% of them reaching a body mass index (in kg/m(2)) < 30. Serum cholesterol decreased (from 4.58 +/- 1.11 to 3.34 +/- 0.73 mmol/L; P < 0.0001), as did serum triacylglycerols (from 1.52 +/- 0.59 to 0.88 +/- 0.35 mmol/L; P < 0.0001), whereas insulin sensitivity rose 150% (from 26 +/- 4 to 64 +/- 11 micromol . min(-1) . kg fat-free mass(-1); P < 0.0001). Diabetes (in 23% of patients before surgery) and hypertension (in 83%) were reduced (by 88% and 96%, respectively) after surgery. In a multivariate model (including sex, age, intestinal length, presence of diabetes, insulin sensitivity, and initial fat mass), age and diabetes were independent, negative predictors of weight loss, whereas initial fat mass was a strong positive predictor (r(2) = 0.51).

CONCLUSIONS

Two years after BPD in morbidly obese patients, comorbidities are largely corrected and insulin resistance is fully reversed despite persistent obesity. Initial fat mass, but not residual intestinal length, is the strongest predictor of weight loss after BPD.

Mixed modelling to characterize genotype-phenotype associations

We propose using mixed effects models to characterize the association between multiple gene polymorphisms, environmental factors and measures of disease progression. Characterizing high-order gene-gene and gene-environment interactions presents an analytic challenge due to the large number of candidate genes and the complex, undescribed interactions among them. Several approaches have been proposed recently to reduce the number of candidate genes and post hoc approaches to identify gene-gene interactions are described. However, these approaches may be inadequate for identifying high-order interactions in the absence of main effects and generally do not permit us to control for potential confounders. We describe how mixed effects models and related testing procedures overcome these limitations and apply this approach to data from a cohort of subjects at risk for cardiovascular disease. Four (4) genetic polymorphisms in three genes of the same gene family are considered. The proposed modelling approach allows us first to test whether there is a significant genetic contribution to the variability observed in our disease outcome. This contribution may be through main effects of multi-locus genotypes or through an interaction between genotype and environmental factors. This approach also enables us to identify specific multi-locus genotypes that interact with environmental factors in predicting the outcome. Mixed effects models provide a flexible statistical framework for controlling for potential confounders and identifying interactions among multiple genes and environmental factors that explain the variability in measures of disease progression.

Dementia-free centenarians

BACKGROUND

A small percentage of centenarians, about 15-25%, are functionally cognitively intact. Among those who are not cognitively intact at 100, approximately 90% delayed the onset of clinically evident impairment at least until the average age of 92 yr.

OBJECTIVE

To review current and past findings related to the prevalence and incidence of dementia amongst the exceptionally long-lived.

METHODS

Findings from the various centenarian studies, world-wide, are reviewed.

RESULTS

Neuropsychological and neuropathological correlations thus far suggest that there are centenarians who demonstrate no evidence of neurodegenerative disease. There also appear to be centenarians who despite the substantial presence of neuropathological markers of Alzheimer's disease did not meet clinical criteria for having dementia, thus suggesting the existence of cognitive reserve. Epigenic studies suggest a significant familial component to these survival advantages.

CONCLUSION

Centenarians are of scientific interest as a human model of relative resistance to dementia.

Cardiorespiratory fitness attenuates metabolic risk independent of abdominal subcutaneous and visceral fat in men

OBJECTIVE

Moderate to high levels of cardiorespiratory fitness (CRF) are associated with a lower risk of the metabolic syndrome and all-cause mortality. Unknown is whether CRF attenuates health risk for a given level of abdominal visceral fat, subcutaneous fat, and/or waist circumference.

RESEARCH DESIGN AND METHODS

The sample studied comprised 297 apparently healthy men with available computed tomography or magnetic resonance imaging scans of the abdomen, metabolic data, and maximal treadmill exercise test results. Men were categorized into low-CRF (20%, n = 56), moderate-CRF (40%, n = 94), and high-CRF (40%, n = 147) groups based on age and exercise test results. All analyses were adjusted for age.

RESULTS

For a given level of waist circumference, visceral fat, or subcutaneous fat, the high-CRF group had lower triglyceride levels (P < 0.05) and higher HDL cholesterol levels than the low- or moderate-CRF groups. There was a significant group interaction (P < 0.01) for blood pressure, indicating that the increase in blood pressure per unit increase in visceral fat or waist circumference was greater in men in the low-CRF group compared with the high-CRF group. The relative risks of having the metabolic syndrome were 1.8 (95% CI 1.0-3.1) and 1.6 (0.9-2.7) times higher in the low- and moderate-CRF groups, respectively, compared with the high-CRF group after adjusting for age, visceral fat, and subcutaneous fat (P for trend = 0.06).

CONCLUSIONS

High levels of CRF are associated with a substantial reduction in health risk for a given level of visceral and subcutaneous fat.

PPARγ: A Critical Determinant of Body Fat Distribution in Humans and Mice

Evidence emerging from studies of humans and mice has indicated peroxisome proliferator-activated receptor gamma (PPARgamma) to be not only a key factor for adipogenesis but also a critical determinant of body fat distribution. Whereas genetically reduced PPARgamma activity in adipose tissue leads to reduction of total fat mass in humans and in mice, mutations in the ligand-binding domain of PPARgamma cause abnormal body fat distributions. It is less clear from mutation analysis how PPARgamma is involved in metabolic disturbances such as insulin resistance and its cardiovascular complications. Nevertheless, similarities and differences in the phenotypes associated with PPARgamma mutations in humans and in mouse models provide opportunities to dissect relationships between body fat distribution and its metabolic complications.

Adipose tissue in muscle: a novel depot similar in size to visceral adipose tissue

BACKGROUND

The manner in which fat depot volumes and distributions, particularly the adipose tissue (AT) between the muscles, vary by race is unknown.

OBJECTIVE

The objective was to quantify a previously unstudied and novel intermuscular AT (IMAT) depot and subcutaneous AT, visceral AT (VAT), and total-body skeletal muscle mass in healthy sedentary African American (AA), Asian, and white adults by whole-body magnetic resonance imaging. IMAT is the AT between muscles and within the boundary of the muscle fascia.

DESIGN

Analyses were conducted on 227 women [AA (n = 79): body mass index (BMI; in kg/m(2)), 29.0 +/- 5.5; age, 45.7 +/- 16.9 y; Asian (n = 38): BMI, 21.7 +/- 2.9; age, 47.2 +/- 19.9 y; whites (n = 110): BMI, 24.9 +/- 5.4; age, 43.7 +/- 16.2 y]) and 111 men [AA (n = 39): BMI, 25.6 +/- 3.2; age, 45.5 +/- 18.8 y; Asian (n = 13): BMI, 24.9 +/- 2.5; age, 45.6 +/- 25.0 y; white (n = 59): BMI, 25.8 +/- 3.8; age 44.5 +/- 16.3 y].

RESULTS

IMAT depots were not significantly different in size between race groups at low levels of adiposity; however, with increasing adiposity, AAs had a significantly greater increment in the proportion of total AT (TAT) than did the whites and Asians (58, 46, and 44 g IMAT/kg TAT, respectively; P = 0.001). VAT depots were not significantly different in size at low levels of adiposity but, with increasing adiposity, VAT accumulation was greater than IMAT accumulation in the Asians and whites; no significant differences were observed in AAs.

CONCLUSION

Race differences in AT distribution extend to IMAT, a depot that may influence race-ethnicity differences in dysglycemia.

Obesidade visceral, hipertensão arterial e risco cárdio-renal: uma revisão

A maior parte da adversidade atribuída à obesidade é dada pelo risco cardiovascular/coronariano imputado à mesma, particularmente presente nos obesos com distribuição visceral de gordura corporal. O acúmulo de gordura visceral está sabidamente associado à maior prevalência de desarranjos metabólicos, hormonais, inflamatórios e hemodinâmicos, que no conjunto implicarão em maior acometimento da microvasculatura e impacto negativo sobre os órgãos-alvo, particularmente sobre o eixo cárdio-renal. Neste sentido, além da associação clássica com a doença coronariana, têm-se verificado uma associação maior da obesidade visceral com a hipertrofia ventricular esquerda e microalbuminúria, ambos fatores de risco cardiovascular e nefrológico reconhecidos. Assim, a abordagem terapêutica dos pacientes obesos, particularmente dos hipertensos, deve levar em conta a estratificação de risco baseada na distribuição de gordura corporal, o que permitirá uma terapêutica mais adequada, visando-se não só o controle dos fatores de risco como a monitorização do acometimento de órgãos-alvo nestas populações.

Comparison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes among men

BACKGROUND

Obesity is a strong risk factor for type 2 diabetes. However, few studies have compared the predictive power of overall obesity with that of central obesity. The cutoffs for waist circumference (WC) and waist-to-hip ratio (WHR) as measures of abdominal adiposity remain controversial.

OBJECTIVE

The objective was to compare body mass index (BMI), WC, and WHR in predicting type 2 diabetes.

DESIGN

A prospective cohort study (Health Professionals Follow-Up Study) of 27 270 men was conducted. WC, WHR, and BMI were assessed at baseline. Covariates and potential confounders were assessed repeatedly during the follow-up.

RESULTS

During 13 y of follow-up, we documented 884 incident type 2 diabetes cases. Age-adjusted relative risks (RRs) across quintiles of WC were 1.0, 2.0, 2.7, 5.0, and 12.0; those of WHR were 1.0, 2.1, 2.7, 3.6, and 6.9; and those of BMI were 1.0, 1.1, 1.8, 2.9, and 7.9 (P for trend < 0.0001 for all). Multivariate adjustment for diabetes risk factors only slightly attenuated these RRs. Adjustment for BMI substantially attenuated RRs for both WC and WHR. The receiver operator characteristic curve analysis indicated that WC and BMI were similar and were better than WHR in predicting type 2 diabetes. The cumulative proportions of type 2 diabetes cases identified according to medians of BMI (>/=24.8), WC (>/=94 cm), and WHR (>/=0.94) were 82.5%, 83.6%, and 74.1%, respectively. The corresponding proportions were 78.9%, 50.5%, and 65.7% according to the recommended cutoffs.

CONCLUSIONS

Both overall and abdominal adiposity strongly and independently predict risk of type 2 diabetes. WC is a better predictor than is WHR. The currently recommended cutoff for WC of 102 cm for men may need to be reevaluated; a lower cutoff may be more appropriate.

Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men

BACKGROUND

Catechins, the major component of green tea extract, have various physiologic effects. There are few studies, however, on the effects of catechins on body fat reduction in humans. It has been reported that the body mass index (BMI) correlates with the amount of malondialdehyde and thiobarbituric acid-reactive substances in the blood.

OBJECTIVE

We investigated the effect of catechins on body fat reduction and the relation between oxidized LDL and body fat variables.

DESIGN

After a 2-wk diet run-in period, healthy Japanese men were divided into 2 groups with similar BMI and waist circumference distributions. A 12-wk double-blind study was performed in which the subjects ingested 1 bottle oolong tea/d containing 690 mg catechins (green tea extract group; n = 17) or 1 bottle oolong tea/d containing 22 mg catechins (control group; n = 18).

RESULTS

Body weight, BMI, waist circumference, body fat mass, and subcutaneous fat area were significantly lower in the green tea extract group than in the control group. Changes in the concentrations of malondialdehyde-modified LDL were positively associated with changes in body fat mass and total fat area in the green tea extract group.

CONCLUSION

Daily consumption of tea containing 690 mg catechins for 12 wk reduced body fat, which suggests that the ingestion of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity.

Diversity of SREBP-1 gene expression in rat adipose tissue depots in response to refeeding after food restriction

The SREBP-1c mRNA level and precursor (microsomal) form of SREBP-1 abundance were significantly higher in epididymal and perirenal than in subcutaneous white adipose tissue of control rats. Moreover, the SREBP-1c mRNA level and an amount of precursor form of SREBP-1 were significantly higher in the epididymal and perirenal white adipose tissue of rats maintained on restricted diet and refed ad libitum for 48 h as compared to the control animals. No significant effects of food restriction/refeeding on SREBP-1c mRNA level and an amount of precursor form of SREBP-1 were found in subcutaneous white adipose tissue. The mature (nuclear) form of SREBP-1 was significantly increased in the epididymal, perirenal and subcutaneous white adipose tissue of the food restricted/refed animals. The activity, protein level and the mRNA abundance of malic enzyme (one of the target genes for SREBP-1) increased significantly in the epididymal, perirenal and subcutaneous white adipose tissue of the food restricted/refed rats as compared to the control animals, however the increase in perirenal and epididymal was higher than in the subcutaneous white adipose tissue. The results presented suggest that SREBP-1c is differently expressed in various rat white adipose tissue depots both under basal (control) and dieting conditions.

Management of the Elderly Person After Myocardial Infarction

Elderly persons after myocardial infarction should have their modifiable coronary artery risk factors intensively treated. Hypertension should be treated with beta blockers and angiotensin-converting enzyme inhibitors. The blood pressure should be reduced to &lt;140/85 mmHg and to ≥130/80 mmHg in persons with diabetes or renal insufficiency. The serum low-density lipoprotein cholesterol should be reduced to &lt;100 mg/dl with statins if necessary. Aspirin or clopidogrel, beta blockers, and angiotensin-converting enzyme inhibitors should be given indefinitely unless contraindications exist to the use of these drugs. Long-acting nitrates are effective antianginal and antiischemic drugs. There are no Class I indications for the use of calcium channel blockers after myocardial infarction. Postinfarction patients should not receive Class I antiarrhythmic drugs, sotalol, or amiodarone. An automatic implantable cardioverter-defibrillator should be implanted in postinfarction patients at very high risk for sudden cardiac death. Hormonal therapy should not be used in postmenopausal women after myocardial infarction. The two indications for coronary revascularization are prolongation of life and relief of unacceptable symptoms despite optimal medical management.

Dietary diacylglycerol prevents high-fat diet-induced lipid accumulation in rat liver and abdominal adipose tissue

The inhibitory effects of 1,3-diacylglycerol (DAG) on diet-induced lipid accumulation in liver and abdominal adipose tissue of rats were investigated in the present study. Male Sprague-Dawley rats were given free access to diets containing 7 wt% TAG (low TAG), 20 wt% TAG (high TAG), or 20 wt% DAG (high DAG), respectively, for 8 wk. The body weight of rats in the 20% high-TAG group increased significantly, and the weights of their abdominal adipose tissue and liver also showed a significant increase compared with rats in the low-TAG group. However, the high-DAG diet resulted in both a significant reduction in body weight gain (with a decrease of 70.5%) and an increase in the ratio of abdominal fat to body weight (by 127%) compared with the high-TAG diet. As well, the liver TAG and serum TAG levels of the high-DAG group were significantly lower than those of the high-TAG group. These effects were associated with up-regulation of acyl-CoA carnitine acyltransferase (ACAT) and down-regulation of acyl-CoA DAG acyltransferase (DGAT) in the liver. However, no significant difference was observed in the activities of alanine aminotransferase and aspartate aminotransferase among the groups (P > 0.05). The present results indicate that dietary DAG reduced fat accumulation in viscera and body, and these effects may be involved with up-regulation of ACAT and down-regulation of DGAT in the liver.

Body fat distribution of overweight females with a history of weight cycling

Weight cycling may cause a redistribution of body fat to the upper body fat compartments. We investigated the distribution of subcutaneous adipose tissue (SAT) in 30 overweight women with a history of weight-cycling and age-matched controls (167 normal weight and 97 overweight subjects). Measurements of SAT were performed using an optical device, the Lipometer. The SAT topography describes the thicknesses of SAT layers at 15 anatomically well-defined body sites from neck to calf. The overweight women with a history of weight cycling had significantly thicker SAT layers on the upper body compared to the overweight controls, but even thinner SAT layers on their legs than the normal weight women. An android fat pattern was attributed to overweight females and, even more pronounced, to the weight cyclers. The majority of normal weight women showed a gynoid fat pattern. Using stepwise discriminant analysis, 89.0% of all weight cyclers and overweight controls could be classified correctly into the two groups. These findings show the importance of normal weight maintenance as a health-promoting factor.

Abdominal obesity and respiratory function in men and women in the EPIC-Norfolk Study, United Kingdom

Poor respiratory function and obesity are associated with all-cause and cardiovascular disease mortality. Obese persons may also have impaired lung function, but the mechanism is unclear. The authors investigated the relation between abdominal pattern of obesity and respiratory function in the European Prospective Investigation into Cancer and Nutrition-Norfolk (EPIC-Norfolk) cohort in Norfolk, United Kingdom. This analysis included 9,674 men and 11,876 women aged 45-79 years with no known preexisting serious illness who had complete anthropometric and respiratory function measures obtained at a health visit between 1993 and 1997. Waist:hip ratio was used to assess abdominal obesity, and forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), obtained by spirometry, were used to assess respiratory function. Both FEV1 and FVC were linearly and inversely related across the entire range of waist:hip ratio in both men and women. This relation persisted after adjustment for age, body mass index, cigarette smoking, social class, physical activity index, prevalent bronchitis/emphysema, and prevalent asthma. The association remained significant among nonobese nonsmokers without preexisting respiratory disease. In the general adult population, abdominal fat deposition may play a role in the impairment of respiratory function among the abdominally obese.

Visceral obesity without insulin resistance in late-onset obesity rats

We describe a line of transgenic rats in which the males develop a unique autosomal dominant, late-onset obesity (LOB) phenotype. LOB males gradually accumulate fat specifically in visceral, but not peripheral, fat depots despite a normal intake of a low fat diet. LOB females normally develop only mild obesity with advanced age. However, the phenotype can be induced rapidly in young females by ovariectomy and prevented by estrogen replacement. LOB males are highly sensitive to dietary fat. Young, nonobese LOB males gain more weight on a 30% fat diet and lose more weight when treated with the lipase inhibitor, Orlistat, than their nontransgenic littermates. Remarkably, despite severe visceral obesity, LOB rats have normal fasting blood glucose, insulin, and corticosterone; show normal or increased insulin sensitivity in glucose and insulin tolerance tests; have increased plasma adiponectin levels; and display a heightened response to treatment with rosiglitazone. Their visceral adiposity reflects a specific increase in visceral adipocyte number, not size. Analysis of the transgene in LOB rats revealed a deletion in the gene encoding the S26 subunit of the mitochondrial ribosome that results in the production of a truncated protein, which we show to be imported into mitochondria. However, the transgene integrant is complex, so whether this is the sole molecular disruption underlying this phenotype remains to be established. Nevertheless, LOB rats provide a valuable new model of late-onset, male-preponderant, visceral-specific obesity, clearly dissociated from insulin resistance.

Indexes of abdominal adiposity in patients with type 2 diabetes

OBJECTIVE

To assess the relationship of waist circumference and weight/height ratio with height, and their association with components of the metabolic syndrome, in Type 2 diabetic patients.

DESIGN

multicenter cross-sectional survey on a cohort enrolled in a prospective observational study.

SUBJECTS

13,232 patients (6816 women and 6416 men) with Type 2 diabetes, not currently affected by macrovascular complications.

MEASUREMENTS

height, weight, waist and hip circumference, waist/hip and waist/height ratios.

RESULTS

waist circumference was significantly correlated with height after adjustment for potential confounders (adjusted r=0.19 and 0.23 in women and men, respectively), while waist/height ratio showed an inverse correlation with height (r=-0.14 and -0.15, respectively). Elevated waist/height ratio was more predictive of hypertension and hypertriglyceridemia, than waist circumference or waist/hip ratio.

CONCLUSIONS

Waist circumference is correlated with height; thresholds for waist circumference could need adjustment for height. Waist/height ratio, although inversely correlated with height, could be a better predictor of abnormalities associated with abdominal adiposity than waist circumference alone.

Waist circumference, body mass index, hip circumference and waist-to-hip ratio as predictors of cardiovascular disease in Aboriginal people

OBJECTIVE

To investigate waist circumference (WC), waist-hip ratio, hip circumference and body mass index (BMI) as risk factors for cardiovascular disease in Aboriginal Australians.

METHODS

This cohort study included 836 adults aged 20-74 y in a remote Aboriginal community. WC, waist-hip ratio, hip circumference and BMI were obtained from a screening program. The participants were followed for up to 10 y for cardiovascular events. A Cox regression model was used to calculate the rate ratio (RR) and 95% confidence interval (CI) for the first-ever cardiovascular event (fatal and nonfatal).

RESULTS

RRs for the first-ever cardiovascular event were 1.31 (95% CI: 1.11, 1.54), 1.29 (95% CI: 1.09,1.53), 1.28 (95% CI: 1.08, 1.52) and 1.10 (95% CI: 0.93, 1.30) per standard deviation increase in WC, BMI, hip circumference and waist-hip ratio, respectively, after adjustment for diabetes mellitus, total cholesterol, systolic blood pressure and smoking status. WC, BMI and hip circumference were significantly associated with cardiovascular risk, independent of other cardiovascular risk factors. Dividing each of the four parameters into quartiles, WC had the highest likelihood statistics (12.76) followed by BMI (11.45), hip circumference (10.57) and waist-hip ratio (3.15) for predicting first CV events.

CONCLUSION

WC, BMI and hip circumference are associated with cardiovascular outcome, independent of traditional risk factors. However, WC appears to be a better predictor for cardiovascular risk than other parameters. Waist-hip ratio is not as useful as other measurements.

Cardiorespiratory fitness is associated with lower abdominal fat independent of body mass index

PURPOSE

To determine whether, for a given body mass index (BMI), men with high cardiorespiratory fitness (CRF) have lower waist circumference (WC) and less total abdominal, abdominal subcutaneous, and visceral adipose tissue (AT) compared with men with low CRF.

METHODS

Subjects were categorized into HIGH CRF (N = 169) and LOW CRF (N = 124) groups based on age and CRF measured using a maximal treadmill test. Total abdominal, abdominal subcutaneous and visceral AT were measured by computerized tomography.

RESULTS

For a given BMI, men in the HIGH CRF group had significantly lower WC (P < 0.001), total abdominal (P < 0.001), visceral AT (P < 0.001), and abdominal subcutaneous AT (P < 0.001) compared with men in the LOW CRF group.

CONCLUSION

These findings suggest that the ability of CRF to attenuate the health risks associated with BMI may be partially mediated through a reduction in abdominal AT. Accordingly, our observations reinforce the importance of regular physical activity in the prevention and reduction of obesity-related health risk independent of a corresponding reduction in body weight.

Body morphology differentially predicts coronary calcium

OBJECTIVE

To test the hypothesis that three measures of body morphology would be differentially correlated with and predictive of coronary artery calcification.

DESIGN

Cross-sectional analytic study of body mass index (BMI), central adiposity ('visceral fat') and total body percent fat.

SUBJECTS

In a total of 3028 healthy, free living men and women (mean age and BMI: 56.7 and 27.0, respectively).

MEASUREMENTS

Coronary calcification and visceral fat (VF) content was measured using electron beam computed tomography while percent body fat (BF) was determined using bioimpedence.

RESULTS

In men, the median coronary calcium score increased from 6.7 for a BMI < or =24 to 30.9 for a BMI > or =30; from 3.6 to 46.4 between the first and fourth quartile of VF; and from 1 to 97.6 for the same in BF. There were no significant increases in calcium scores in women for any of these indices. There were also no significant age-adjusted correlations between BMI, BF and VF with the extent of coronary calcium in either gender. On multivariable logistic regression analysis, men with a BMI in the third and fourth quartiles had 1.64 and 2.01 times increase in risk, respectively, for the presence of any coronary calcium compared to those in the first quartile (P< or =0.01 for both) while men in the highest quartile for VF had a 63% increase in this same risk (P=0.04). For women, a BMI in the fourth quartile was associated with a 68% increase in risk for the presence of any coronary calcium (P=0.01).

CONCLUSION

BMI is a significant predictor of coronary calcium. In men, central adiposity is also an independent predictor. These findings lend further support to weight control for coronary disease prevention.

Are Kuwaitis getting fatter?

The purpose of the study is to compare temporal changes in BMI, overweight (BMI > 25 Kg/m2) and obesity (BMI > 30 Kg/m2) of two independent cross-sectional samples of Kuwaitis studied in 1980-81 and 1993-94. The earlier sample of 2067 (896 men and 1171 women) and the latter sample of 3435 (1730 men and 1705 women) adult Kuwaitis (aged > or = 18 years), were drawn from primary health care (PHC) clinics and studied for nutritional assessment and for prevalence of obesity in 1980-81 and 1993-94, respectively. Weight was measured in kilograms and height in meters to obtain the body mass index (BMI), which is the weight in kilograms divided by the height in meters squared (Kg/m2). BMI > 25 and > 30 Kg/m2 were classified as overweight and obesity, respectively. The results of the study show that mean BMI (Kg/m2) increased significantly (p < 0.001) by 10.0 and 6.2% (2.5 and 1.7 Kg/m2) among men and women, respectively. Prevalence of overweight and obesity (BMI > 25 and > 30 Kg/m2) increased by 20.6 and 15.4% and by 13.7 and 8.4% among men and women, respectively. After controlling for sociodemographic differences between the two study periods, mean BMI was 2.0 and 1.6 Kg/m2 higher in 1993-94 than in 1980-81 among men and women, respectively. Prevalence of overweight and obesity (BMI > 25 and > 30 Kg/m2) also increased among both genders between the two periods (OR = 2.1 , 95% CI 1.7-2.7 and OR = 1.9, 95% CI 1.5-2.4, for men and OR = 2.2, 95% CI 1.6-3.0 and OR = 1.4, 95% CI 2.2 CI 1.0-1.9, for women). It can be concluded that the BMI, prevalence of overweight and obesity increased among Kuwaitis between 1980-81 and 1993-94, probably due to the effects of modernization, affluence, increased food consumption and the concomitant changes to sedentary lifestyles. The rate of temporal changes in BMI and obesity were higher, by comparison, in Kuwait than in selected other countries.

Waist circumference and not body mass index explains obesity-related health risk

BACKGROUND

The addition of waist circumference (WC) to body mass index (BMI; in kg/m(2)) predicts a greater variance in health risk than does BMI alone; however, whether the reverse is true is not known.

OBJECTIVE

We evaluated whether BMI adds to the predictive power of WC in assessing obesity-related comorbidity.

DESIGN

Subjects were 14 924 adult participants in the third National Health and Nutrition Examination Survey, grouped into categories of BMI and WC in accordance with the National Institutes of Health cutoffs. Odds ratios for hypertension, dyslipidemia, and the metabolic syndrome were compared for overweight and class I obese BMI categories and the normal-weight category before and after adjustment for WC. BMI and WC were also included in the same regression model as continuous variables for prediction of the metabolic disorders.

RESULTS

With few exceptions, overweight and obese subjects were more likely to have hypertension, dyslipidemia, and the metabolic syndrome than were normal-weight subjects. After adjustment for WC category (normal or high), the odds of comorbidity, although attenuated, remained higher in overweight and obese subjects than in normal-weight subjects. However, after adjustment for WC as a continuous variable, the likelihood of hypertension, dyslipidemia, and the metabolic syndrome was similar in all groups. When WC and BMI were used as continuous variables in the same regression model, WC alone was a significant predictor of comorbidity.

CONCLUSIONS

WC, and not BMI, explains obesity-related health risk. Thus, for a given WC value, overweight and obese persons and normal-weight persons have comparable health risks. However, when WC is dichotomized as normal or high, BMI remains a significant predictor of health risk.

Safety and tolerability of atypical antipsychotics in patients with bipolar disorder: prevalence, monitoring and management

Atypical antipsychotics are associated with fewer movement disorders and a lower risk of tardive dyskinesia than conventional antipsychotics, but are not without side-effects. Metabolic side-effects associated with some of the atypical antipsychotics are a concern for both clinicians and patients. Adverse events related to central nervous system effects, weight gain, and alterations in glucose, lipid, and prolactin levels in patients with depression, bipolar, and anxiety disorders have been reported. Balancing the significant benefits of treatment with these agents against the potential risks of metabolic disturbances and other adverse effects is crucial. Emerging data are making it possible to determine the risk-benefit analysis for specific atypical antipsychotics in individual patients and allow for targeted selection of treatment. A new concept of effectiveness is emerging that attempts to balance adverse effects of treatment with patient quality of life. Patients treated with atypical antipsychotics should have their weight, waist circumference, glucose, and lipids monitored on a regular basis. Monitoring of prolactin levels is not suggested; however, a baseline measurement before initiating treatment can be useful, with subsequent assessment only if a patient demonstrates symptoms. Prevention of weight gain is important. Diet and exercise should be considered for prevention and management, with the use of pharmacologic strategies approached with caution in patients with mood disorders. If a patient is at high risk of developing diabetes, certain pharmacologic agents have been shown to delay the onset of overt diabetes. Once diabetes or dyslipidemia are diagnosed, management should proceed in accordance with approved guidelines for these conditions.

Abdominal obesity and carotid artery wall thickness. The Los Angeles Atherosclerosis Study

OBJECTIVE

To determine whether or not abdominal obesity is associated with the intima-media thickness (IMT) of the carotid artery wall independently of total body obesity and major risk factors for atherosclerosis.

DESIGN

: Longitudinal epidemiological study.

SUBJECTS

A total of 573 middle-aged employees of a utility company.

MEASUREMENTS

Sagittal and transverse abdominal diameters, their ratio and difference were used as measures of abdominal obesity.

RESULTS

Abdominal diameters and body mass index (BMI) were significantly associated with blood pressure, serum lipoproteins and fasting insulin. In cross-sectional multiple regression models, the sagittal/transverse ratio and BMI were significantly associated with IMT in the presence of atherosclerosis risk, but the sagittal diameter was not. In longitudinal models, baseline BMI was an independent predictor of IMT progression but the sagittal and transverse diameters were not.

CONCLUSION

These findings do not support the hypothesis that abdominal obesity is an independent predictor of carotid artery IMT. The consistent pattern of association of measures of general obesity with carotid artery IMT emphasizes the continuing need for prevention and control of this important risk factor.

Sonographic measurement of mesenteric fat thickness is a good correlate with cardiovascular risk factors: comparison with subcutaneous and preperitoneal fat thickness, magnetic resonance imaging and anthropometric indexes

OBJECTIVE

Visceral fat, notably mesenteric fat, which is drained by the portal circulation, plays a critical role in the pathogenesis of metabolic syndrome through increased production of free fatty acids, cytokines and vasoactive peptides. We hypothesize that mesenteric fat thickness as measured by ultrasound scan could explain most of the obesity-related health risk. We explored the relationships between cardiovascular risk factors and abdominal fat as determined by sonographic measurements of thickness of mesenteric, preperitoneal and subcutaneous fat deposits, total abdominal and visceral fat measurement by magnetic resonance imaging (MRI) and anthropometric indexes.

DESIGN

A cross-sectional study.

SUBJECTS

Subjects included 18 healthy men and 19 women (age: 27-61 y, BMI: 19-33.4 kg/m(2)).

MEASUREMENTS

The maximum thickness of mesenteric, preperitoneal and subcutaneous fat was measured by abdominal ultrasound examination. MRI examinations of whole abdomen and pelvis were performed and the amount of total abdominal and visceral fat was quantified. The body mass index, waist circumference and waist-hip ratio were recorded. Cardiovascular risk factors were assessed by physical examination and blood taking.

RESULTS

Men had more adverse cardiovascular risk profile, higher visceral fat volume and thicker mesenteric fat deposits than women. Among all the investigated obesity indexes, the mesenteric fat thickness showed the highest correlations with total cholesterol, LDL-C, triglycerides, fasting plasma glucose, HbA(1c) and systolic blood pressure in men, and with triglycerides and HbA(1c) in women. On stepwise multiple regression analysis with different obesity indexes as independent variables, 30-65% of the variances of triglycerides, total cholesterol, LDL-C and HbA(1c) in men, and triglycerides in women were explained by the mesenteric fat thickness.

CONCLUSION

Compared with sonographic measurement of subcutaneous and preperitoneal fat thickness, MRI measurement of total abdominal and visceral fat and anthropometric indexes, sonographic measurement of mesenteric fat thickness showed better associations with some of the cardiovascular risk factors. It may potentially be a useful tool to evaluate regional distribution of obesity in the assessment of cardiovascular risk.

Body size and shape and glycemic control among Maya women in rural Yucatán

Studies on relationships between aspects of physique and glucose physiology generally focus on clinical glucose tolerance or on fasting glucose or insulin assays showing glycemic status at the time of testing. Little work has examined the associations between body variables and glycemic control, or average past glucose levels in regular living conditions. The aim of this research was to investigate connections between body size and shape and glycemic control. The sample consists of 60 nondiabetic Maya women, ages 40-85 years, residing in 16 rural villages around Mérida, Yucatán. Body morphology was assessed through anthropometric and derived measures of size and shape, including indicators of fat distribution and general adiposity. Glycemic control was measured through microvenous samples analyzed for glycated blood proteins HbA(1c) and fructosamine to demonstrate average circulating glucose under customary living conditions during the previous several months and weeks. Four-variable regression models explain 17% of the variance in HbA(1c) and 25% of the variance in fructosamine. Arm circumference has the largest positive effect on HbA(1c), while weight has the greatest positive impact on fructosamine. The predictor with the largest negative effect on both glycated blood proteins is calf circumference. In general, variables reflecting overall adiposity and central adiposity demonstrate positive associations with HbA(1c) and fructosamine, whereas lean body measures exhibit negative associations. Findings support the value of glycated blood proteins and of less common anthropometric measures, such as calf circumference, in population research on morphological relations with glycemia.

Serum bFGF levels are reduced in Japanese overweight men and restored by a 6-month exercise education

OBJECTIVE

To investigate whether the changes in vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) concentrations before and after weight reduction in Japanese overweight men are associated with changes in body mass index (BMI), visceral, subcutaneous fat, VO(2) and work rate (WR) at ventilatory threshold (VT).

DESIGN

Cross-sectional and longitudinal clinical intervention study with exercise education.

SUBJECTS

In total, 30 Japanese overweight men (BMI, 29.0+/-2.2 kg/m(2)) and 31 normal-weight men (BMI, 22.5+/-1.6 kg/m(2)) at baseline were enrolled: 30 overweight men (BMI, 29.0+/-2.2 kg/m(2)) were further enrolled into a 6-month exercise program.

MEASUREMENTS

Fat distribution evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, angiogenic peptides including VEGF and bFGF, exercise tests at baseline and after 6 months.

RESULTS

In normal-weight and overweight subjects at baseline, VEGF positively correlated with S area (r=0.350, P=0.007) but not with V area. In contrast, bFGF negatively correlated with BMI (r=-0.619, P<0.001), S (r=-0.457, P<0.001) and V areas (r=-0.466, P<0.001). By intervention with exercise education, 30 overweight subjects showed reduction in BMI (29.0+/-2.2 to 28.0+/-2.0, P<0.001), V and S areas, increase in VO(2) and WR at VT, increase in bFGF (9.21+/-5.82-21.2+/-7.04 ng/ml, P<0.001), and no change in VEGF (1.45+/-0.72-1.88+/-0.52 ng/ml, P=0.016). The stepwise multiple regression analysis revealed that DeltaBMI (beta=-6.052) and DeltaVO(2) (beta=2.806) were independently related to DeltabFGF (P<0.001) and all other variables including DeltaS area, and DeltaV area, and DeltaWR did not enter the equation at significant levels.

CONCLUSION

The present study indicated a negative correlation between serum bFGF levels and BMI at baseline as well as an association of DeltaBMI and DeltaVO(2) with DeltabFGF after exercise intervention. The exercise-induced elevation of bFGF may be beneficial in the prevention of the atherosclerosis in overweight subjects.

Androgen deficiency in the aging male: benefits and risks of androgen supplementation

There is now convincing evidence that in a subset of aging men, increasing with age, plasma testosterone levels fall below a critical level resulting in hypogonadism. This state of testosterone deficiency has an impact on bone, muscle and brain function and is maybe a factor in the accumulation of visceral fat which again has a significant impact on the cardiovascular risk profile. From the above it follows that androgen replacement to selected men with proven androgen deficiency will have beneficial effects. There is, however a concern that androgen administration to aging men may be harmful in view of effects on prostate disease. Benign prostate hyperplasia (BPH) and prostate cancer are typically diseases of the aging male, steeply increasing with age. But epidemiological studies provide no clues that the levels of circulating androgen are correlated with or predict prostate disease. Similarly, androgen replacement studies in men do not suggest that these men suffer in a higher degree from prostate disease than control subjects. It seems a defensible practice to treat aging men with androgens if and when they are testosterone-deficient, but long-term studies including sufficient numbers of men are needed.

The androgenic sex hormone profile is an essential feature of metabolic syndrome in premenopausal women: a controlled community-based study

OBJECTIVE

To evaluate sex hormones in premenopausal white women with metabolic syndrome (MBS).

DESIGN

Cross-sectional controlled community-based study.

SETTING

Pieksämäki District Health Center, Pieksämäki, Finland.

PATIENT(S)

Five hundred forty-three women, aged 34 to 54 years, were screened according to National Cholesterol Education Program criteria: waist >88 cm, hypertension >/=130/>/=85 mm Hg, hypertriglyceridemia >/=1.7 mmol/L, high-density lipoprotein (HDL)-cholesterol <1.3 mmol/L, and fasting glucose >/=6.1 mmol/L. Sixty-three women fulfilled at least three of the above-mentioned criteria and were enrolled. Eighty-eight age-matched women without MBS served as controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

Sex steroid levels in relation to insulin sensitivity and body composition.

RESULT(S)

A markedly lower insulin sensitivity index and higher free androgen index were detected in the women with MBS than in the controls. Abdominal obesity and increased diastolic blood pressure were significantly associated with high free androgen index in multiple regression analysis.

CONCLUSION(S)

A hyperandrogenic hormone profile appeared to be a typical feature of premenopausal female MBS even without polycystic ovary syndrome (PCOS).

Historical perspective: visceral obesity and related comorbidity in Joannes Baptista Morgagni's 'De sedibus et causis morborum per anatomen indagata'

In recent years, advances in epidemiological approaches and laboratory technology, along with the availability of sophisticated imaging methods to evaluate body fat distribution, made it possible to define the close correlation between visceral fat accumulation and the occurrence of metabolic abnormalities, cardiovascular diseases and respiratory disturbances in obese patients. Some 250 y ago, JB Morgagni with the help of only a knife for anatomical dissection, an acute mind, and an observational skillfulness was able to identify the intra-abdominal and mediastinal fat accumulation in android obesity. He clearly described the association between visceral obesity, hypertension, hyperuricemia, atherosclerosis and obstructive sleep apnea syndrome, long before the modern recognition of this syndrome.

Body composition estimates from NHANES III bioelectrical impedance data

BACKGROUND

Body composition estimates for the US population are important in order to analyze trends in obesity, sarcopenia and other weight-related health conditions. National body composition estimates have not previously been available.

OBJECTIVE

To use transformed bioelectrical impedance analysis (BIA) data in sex-specific, multicomponent model-derived prediction formulae, to estimate total body water (TBW), fat-free mass (FFM), total body fat (TBF), and percentage body fat (%BF) using a nationally representative sample of the US population.

DESIGN

Anthropometric and BIA data were from the third National Health and Nutrition Examination Survey (NHANES III; 1988-1994). Sex-specific BIA prediction equations developed for this study were applied to the NHANES data, and mean values for TBW, FFM, TBF and %BF were estimated for selected age, sex and racial-ethnic groups.

RESULTS

Among the non-Hispanic white, non-Hispanic black, and Mexican-American participants aged 12-80 y examined in NHANES III, 15 912 had data available for weight, stature and BIA resistance measures. Males had higher mean TBW and FFM than did females, regardless of age or racial-ethnic status. Mean TBW and FFM increased from the adolescent years to mid-adulthood and declined in older adult age groups. Females had higher mean TBF and %BF estimates than males at each age group. Mean TBF also increased with older age groups to approximately 60 y of age after which it decreased.

CONCLUSIONS

These mean body composition estimates for TBW, FFM, TBF and %BF based upon NHANES III BIA data provide a descriptive reference for non-Hispanic whites, non-Hispanic blacks and Mexican Americans in the US population.

Impact of visceral fat on blood pressure and insulin sensitivity in hypertensive obese women

OBJECTIVE

The relationship among body fat distribution, blood pressure, serum leptin levels, and insulin resistance was investigated in hypertensive obese women with central distribution of fat.

RESEARCH METHODS AND PROCEDURES

We studied 74 hypertensive women (age, 49.8 +/- 7.5 years; body mass index, 39.1 +/- 5.5 kg/m(2); waist-to-hip ratio, 0.96 +/- 0.08). All patients were submitted to 24-hour blood pressure ambulatory monitoring (24h-ABPM). Abdominal ultrasonography was used to estimate the amount of visceral fat (VF). Fasting blood samples were obtained for serum leptin and insulin determinations. Insulin resistance was estimated by homeostasis model assessment insulin resistance index (HOMA-r index).

RESULTS

Sixty-four percent of the women were postmenopausal, and all patients showed central distribution of fat (waist-to-hip ratio > 0.85). The VF correlated with systolic 24h-ABPM values (r = 0.28, p = 0.01) and with HOMA-r index (r = 0.27; p = 0.01). VF measurement (7.5 +/- 2.3 vs. 5.9 +/- 2.2 cm, p < 0.001) and the systolic 24h-ABPM (133 +/- 14.5 vs. 126 +/- 9.8 mm Hg, p = 0.04), but not HOMA-r index, were significantly higher in the postmenopausal group (n = 48) than in the premenopausal group (n = 26). No correlations were observed between blood pressure levels and HOMA-r index, leptin, or insulin levels. In the multiple regression analysis, visceral fat, but not age, body fat mass, or HOMA-r index, correlated with the 24h-ABPM (p = 0.003).

DISCUSSION

In centrally obese hypertensive women, the accumulation of VF, more often after menopause, is associated with higher levels of blood pressure and insulin resistance. The mechanism through which VF contributes to higher blood pressure levels seems to be independent of leptin or insulin levels.

The extent of the problem of obesity

The prevalence of obesity is increasing worldwide. In the United States, in 1999, 27% of adults had a body mass index >30 kg/m(2), almost double the prevalence of 20 years earlier. The estimated mortality from obesity-related diseases in the United States is approximately 300,000 annually and growing. In the future, mortality related to obesity is expected to exceed that of smoking. Numerous diseases are caused or made worse by obesity. These include type 2 diabetes; hypertension; dyslipidemia; ischemic heart disease; stroke; obstructive sleep apnea; asthma; nonalcoholic steatohepatitis; gastroesophageal reflux disease; degenerative joint disease of the back, hips, knees, and feet; infertility and polycystic ovary syndrome; various malignancies; and depression. Type 2 diabetes is perhaps the most visible obesity-related problem. Present in at least 14 million Americans, it leads to serious complications and premature death. It is largely caused by obesity, and is generally cured by weight loss. The quality of life of the obese is markedly reduced, and the costs to health care systems are great. Preventive programs have yet to affect the rising prevalence. An effective solution is needed.

Neck circumference a good predictor of raised insulin and free androgen index in obese premenopausal women: changes with weight loss

OBJECTIVE

Severe obesity can be associated with evidence of androgen excess and insulin resistance, which are features of the metabolic and polycystic ovary syndromes (PCOS). In this study, we examined the association between clinical and biochemical features of these syndromes and assess changes with weight loss.

DESIGN

A consecutive series of 107 severely obese premenopausal women presenting for obesity surgery.

MEASUREMENTS

Pre-operative assessment included details of clinical comorbidity, anthropometric measures and biochemical measures, including fasting insulin, glucose, lipid profile and sex hormone analysis. Changes in these measures for 42 of 52 (81%) patients at 1 year post surgery are reported.

RESULTS

Neck circumference and younger age were independent predictors of higher free androgen index (FAI) (combined r2 = 0.36). If neck circumference is not included, then younger age, higher body mass index and raised fasting insulin levels were all independent predictors of FAI (r2 = 0.29). Waist to hip ratio showed no predictive value (r = 0.14). Neck circumference was also a good clinical predictor of menstrual irregularity, hirsutism, infertility, insulin resistance and the PCOS. Neck circumference of less than 39, 39-42 and greater than 42 cm reflect a low, intermediate and high risk of the metabolic and PCOS syndromes in obese premenopausal women. For 42 patients who were followed for 1 year after surgery, the weight loss was associated with reduction of FAI, less insulin resistance and improved menstrual regularity and resolution of the PCOS in 11 of 12 cases.

CONCLUSIONS

Neck circumference is a good predictive measure of hyperinsulinaemia and raised androgens in obese premenopausal women. Weight loss following surgery improves ovarian function and vasculopathic risk.

Dose-response effect of walking exercise on weight loss. How much is enough?

OBJECTIVE

Exercise is the cornerstone of behavioral weight loss programs. The total volume of exercise needed to both promote weight loss and elicit health benefits has not been sufficiently investigated. The aim of this study was to examine the effects of two different volumes of walking 'metabolic fitness' exercise prescriptions, in combination with a low-fat, ad libitum diet (LFAL) on weight loss and additional modifiable health-related variables (HRV) in an ethnically diverse sample of overweight premenopausal women.

DESIGN

Clinical 12 week weight loss intervention study with a 5.0-5.8 MJ diet daily with (a). participants walking 30 min, 5 days per week (DEX1), (b). participants walking 60 min, five times per week (DEX2) or (c). a diet only control group (DO).

SUBJECTS

A mixed racial sample (predominantly Hispanic) of 56 subjects (mean BMI=34.26+/-6.61, mean age= 39.45+/-7.34) completed the 12 week program.

MEASUREMENTS

Various body weight, body composition and fat distribution variables, dietary intake and additional HRV such as blood lipids, blood pressure and an estimate of cardiorespiratory fitness at baseline and after 3 months.

RESULTS

All groups showed similar and significant (P<0.001) declines in body weight, percentage body fat, BMI, WHR, fat mass, fat-free mass and diastolic blood pressure following the program. In addition, total cholesterol, triacylglycerol and the TC:HDL ratio displayed a significant time effect (P<0.05). Significant interactions (P<0.05) were found for waist circumference, sagittal diameter, estimated VO(2max) and LDL-C, with both exercise groups showing similar and significantly greater (P<0.05) improvements than DO. Significant interactions (P<0.05) were also observed for several dietary variables.

CONCLUSION

Our study showed no dose-response effect of walking exercise on weight loss over diet alone. Both lower and higher volume metabolic fitness prescriptions resulted in similar and significant beneficial changes in several HRV. This data suggests that 30 min of walking on most days of the week may be as beneficial as 60 min (in combination with diet) in promoting numerous additional healthful outcomes over diet alone following a 12 week weight loss program.

Daily walking reduces visceral adipose tissue areas and improves insulin resistance in Japanese obese subjects

OBJECTIVE

It is known that the accumulation of abdominal fat is one of the risk factors for atherosclerosis. Although exercise is commonly prescribed to reduce body weight, the efficacy of low intensity exercise for the reduction of abdominal visceral adipose tissue remains to be investigated.

RESEARCH DESIGN AND METHODS

Thirty one obese Japanese males (body mass index (BMI) > or = 25) ranging in age from 32 to 59, participated in a 1-year follow up study and they were instructed to have a modest increase in daily activity and record their daily walking. Before and after exercise prescription, body composition, blood pressure, physical fitness i.e. aerobic exercise level, muscle strength and flexibility were recorded. Insulin resistance was evaluated using a homeostasis model assessment, the HOMA index.

RESULTS

HOMA index, parameters of body composition, blood pressure, triglyceride and HDL cholesterol were significantly improved. The aerobic exercise level, leg strength, weight-bearing index (leg strength/body weight) and the steps taken per day were significantly increased. By stepwise multiple regression analysis, Delta visceral adipose tissue area was the major determinant for Delta HOMA index. (Delta HOMA index=-0.386+0.016 Delta visceral adipose tissue area, r2=0.267, P<0.01). Exercise capacity and calorie intake were not significantly related to Delta visceral adipose tissue area, while Delta steps per day was significantly correlated with Delta visceral adipose tissue area (Delta visceral adipose tissue area=-21.363-0.004 Delta steps per day, r2=0.184, P=0.0326).

CONCLUSIONS

Taken together, intra-abdominal visceral adipose tissue is critically involved in insulin resistance and daily walking rather than improvement of exercise capacity correlated with the reduction of visceral adipose tissue in obese Japanese males.

Waist circumference, body mass index, and risk for stroke in older people: a 15 year longitudinal population study of 70- year-olds

OBJECTIVES

To investigate waist circumference (WC) and body mass index (BMI) at age 70 as risk factors for stroke.

DESIGN

Cohort study of 70-year-olds with 15-year follow-up.

SETTING

Geriatric Medicine Department, Göteborg University, Sweden.

PARTICIPANTS

Two thousand two hundred eighty-seven (1,045 men; 1,242 women) 70-year-olds examined between 1971 and 1981 in Göteborg, Sweden.

MEASUREMENTS

Cox regression model was used to calculate relative risk (RR) and 95% confidence interval (CI) for first-ever stroke (fatal and nonfatal) in reference to the lowest quartiles of WC and BMI. Tests for trend were performed fitting WC and BMI in their original continuous form.

RESULTS

In men and women, RRs for stroke, in the highest WC quartile were 1.65 (95% CI = 1.08-2.51) and 1.31 (95% CI = 0.88-1.92), respectively, after adjustment for cohorts, smoking habit, coronary heart disease (CHD), diabetes mellitus, total cholesterol (TC), systolic blood pressure (SBP), and height at age 70. In men, RR for stroke in the highest BMI quartile (> or=28 kg/m2) was 1.68 (95% CI = 1.12-2.53) after adjustment for cohorts, smoking habits, CHD, diabetes mellitus, TC, and SBP at age 70. In women, adjusted RRs for stroke across the BMI quartiles were not significantly different. In men, population attributable fractions of stroke were 24.8% and 25.2% for the highest quartiles of WC and BMI, respectively.

CONCLUSIONS

High WC (> or =99 cm) and BMI (> or =28 kg/m2) are risks for stroke in older men but not in older women.

Relationship between cholesteryl ester transfer protein and atherogenic lipoprotein profile in morbidly obese women

OBJECTIVE

Obesity is associated with increased morbidity and mortality from atherosclerotic disease. Lipid abnormalities contribute to the increased relative risk in obese subjects. Cholesteryl ester transfer protein (CETP) mass is increased in these patients and might mediate the atherogenic lipoprotein pattern observed in obesity.

METHODS AND RESULTS

Twenty-one morbidly obese, middle-aged, female subjects participated in this prospective study. Subjects were examined before and 1 year after surgical treatment. Fat mass was determined by body impedance analysis; CETP mass, by ELISA; CETP activity, by exogenous substrate assay; and LDL particle diameter, by gradient gel electrophoresis. Mean weight loss after 1 year was 28.7 kg; mean fat mass loss was 22.6 kg. Mean CETP mass decreased from 1.81 to 1.32 microg/mL (P=0.008); mean CETP activity decreased from 244 to 184 nmol x mL(-1) x h(-1) (P=0.004); and in parallel, the mean diameter of LDL particles increased (256.8 to 258.4 A, P=0.04).

CONCLUSIONS

We conclude that weight loss is associated with a pronounced decrease in CETP mass and activity and a consistent increase in LDL particle diameter. After 1 year of this prospective study in morbidly obese subjects undergoing weight loss by surgical treatment, it has been determined that some features of the atherogenic lipoprotein profile can be reversed.

Influence of obesity on cardiovascular risk. Twenty-three-year follow-up of 22,025 men from an urban Swedish population

OBJECTIVE

To assess to what extent the incidence of coronary events and death related to smoking, hypertension, hyperlipidemia and diabetes is modified by obesity.

DESIGN

Prospective cohort study.

SUBJECTS

A total of 22 025 men aged 27 to 61-y-old at entry.

MEASUREMENTS

Incidence of coronary events (CE, ie acute myocardial infarctions and deaths due to chronic ischaemic heart disease) and death during 23 y of follow-up was studied in relation to body mass index (BMI), heart rate, blood pressure, blood lipids, glucose and insulin, lifestyle factors, history of angina pectoris, history of cancer, self-reported health and socio-economic conditions.

RESULTS

At the end of follow-up 20% of the obese men were no longer alive, and 13% had had a coronary event. Incidence of CE was 16% lower (RR (relative risk) 0.84; 95% confidence interval (CI) 0.65-1.10) among underweight (n=1171), 24% higher (RR 1.24; CI 1.12-1.37) among overweight (n=7773), and 76% higher (RR 1.76; 95% CI 1.49-2.08) among obese men (n=1343) than it was among men with normal BMI (n=11 738). The risk associated with overweight and obesity remained statistically significant after adjustment for potential confounders (RR 1.18; CI 1.07-1.31; and 1.39; 1.17-1.65, respectively). The association between BMI and mortality was J-shaped. In all, 1.7% of the obese men were smokers with hypertension, hyperlipidaemia and diabetes, 16.3% were not exposed to any of these risk factors. The cardiovascular risk associated with obesity was small in the absence of other risk factors. Between smoking and obesity there was a statistically significant synergistic effect.

CONCLUSIONS

Obesity is associated with an increased incidence of coronary events and death. The risk associated with obesity is substantially increased by exposure to other atherosclerotic risk factors, of which smoking seems to be the most important. The preventive potential of these associations should be evaluated in controlled trials.

Genetic variability of adult body mass index: a longitudinal assessment in framingham families

OBJECTIVE

To explore the contribution of genetics to the mean, SD, maximum value, maximum less the mean, and change over time in body mass index (BMI) and the residual of body weight after adjustment for height. BMI is frequently used as a general indicator of obesity because of its ease and reliability in ascertainment. Cross-sectional twin and family studies have shown a moderate-to-substantial genetic component for BMI. However, the contribution of genetics to the long-term average, variability, or change over time in BMI is less clear.

RESEARCH METHODS AND PROCEDURES

Longitudinal data from the Framingham heart study were used to create pedigrees of age-matched individuals. Heritability estimates were derived using variance-decomposition methods on a total of 1051 individuals from 380 extended pedigrees followed for a period of 20 years. All subjects were followed from approximately age 35 to 55 years.

RESULTS

Moderate heritability estimates were found for the mean BMI (h(2) = 0.37), maximum BMI (h(2) = 0.40), and the mean residual of body weight (h(2) = 0.36). Low heritability estimates (h(2) congruent with 0.20) were found for the maximum less the mean in BMI and the SDs of BMI and residual of body weight. No additive genetic contribution was found for the average change over time in BMI or the residual of body weight.

DISCUSSION

These findings suggest that there is a significant genetic component for the magnitude of BMI throughout an individual's middle-adult years; however, little evidence was found for a genetic contribution to the variability or rate of change in an individual's BMI.

Fat depot origin affects adipogenesis in primary cultured and cloned human preadipocytes

Fat distribution varies among individuals with similar body fat content. Innate differences in adipose cell characteristics may contribute because lipid accumulation and lipogenic enzyme activities vary among preadipocytes cultured from different fat depots. We determined expression of the adipogenic transcription factors peroxisome proliferator activated receptor-gamma (PPAR-gamma) and CCAAT/enhancer binding protein-alpha (C/EBP-alpha) and their targets in abdominal subcutaneous, mesenteric, and omental preadipocytes cultured in parallel from obese subjects. Subcutaneous preadipocytes, which had the highest lipid accumulation, glycerol-3-phosphate dehydrogenase (G3PD) activity, and adipocyte fatty acid binding protein (aP2) abundance, had highest PPAR-gamma and C/EBP-alpha expression. Levels were intermediate in mesenteric and lowest in omental preadipocytes. Overexpression of C/EBP-alpha in transfected omental preadipocytes enhanced differentiation. The proportion of differentiated cells in colonies derived from single subcutaneous preadipocytes was higher than in mesenteric or omental clones. Only cells that acquired lipid inclusions exhibited C/EBP-alpha upregulation, irrespective of depot origin. Thus regional variation in adipogenesis depends on differences at the level of transcription factor expression and is a trait conferred on daughter cells.