Subcutaneous central fat is associated with cardiovascular risk factors in men independently of total fatness and fitness

The purpose of this study was to analyze the single and independent associations of whole body composition and fat distribution with cardiovascular disease (CVD) risk factors and fitness in middle-aged men. Sixty-two healthy Caucasian men (37.6 +/- 2.9 yr, 81.8 +/- 11.3 kg, 171.5 +/- 4.9 cm) participated in the study. Dual-energy x-ray absorptiometry (DXA) was used to assess total and regional body composition. The triceps, biceps, midthigh, calf, subscapular, chest, abdominal and suprailiac skinfolds, and the waist, hip and midthigh circumferences, and sagittal diameter were estimated. Cardiovascular fitness was estimated with a submaximal test. Bivariate and partial correlation analysis were used to study the association of total body percent fat (%fat), DXA trunk fat and trunk skinfolds (sum of subscapular, chest, abdominal, and suprailiac) and fitness with insulin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), TC/HDL-C, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein AI (apo AI), apolipoprotein B (apo B), lipoprotein(a) [Lp(a)], and diastolic and systolic blood pressure. All anthropometric and DXA body composition variables were significantly correlated with TC/HDL-C (from .26 to .50, P < .05). Similar relationships were found for insulin, HDL-C, and systolic blood pressure (r from .26 to .47, P < .05). Cardiovascular fitness was significantly (P < .05) associated with insulin (r = -.36), HDL-C (r = .27), TC/HDL (r = -.27), and with systolic blood pressure (r = -.37). After controlling for trunk skinfolds, none of the anthropometric and DXA body composition variables were correlated with any of the CVD risk factors. Similarly, when controlling for trunk skinfolds, cardiovascular fitness was not related to any of the metabolic variables. After adjusting for %fat, DXA trunk fat, and cardiovascular fitness, trunk skinfolds remained significantly (P < .05) related to insulin (r = .35), HDL-C (r = -.40), TC/HDL-C (r = .43), and apo AI (r = -.39). In conclusion, this study suggests that subcutaneous truncal fat, as estimated by skinfolds, is an independent predictor of CVD risk factors, and that the association between cardiovascular fitness and these risk factors may be mediated by the levels of abdominal subcutaneous fat in Caucasian middle-aged men.     

Improvement of glucose and lipid metabolism associated with selective reduction of intra-abdominal visceral fat in premenopausal women with visceral fat obesity.

Visceral fat obesity (VFO) with predominant intra-abdominal fat accumulation has been shown to be more often associated with metabolic disorders than subcutaneous fat obesity (SFO). In the present study, changes in fat distribution and their effects on metabolic complications were investigated in forty premenopausal female obese patients in whom substantial weight reduction was obtained by means of a low calorie diet. Analysis of fat distribution by CT scanning demonstrated that visceral fat decreased to a greater extent than abdominal subcutaneous fat, which was particularly evident in VFO patients. On the other hand, change of fat distribution was small in SFO patients. That is, visceral to subcutaneous abdominal fat ratio (V/S ratio) decreased from 0.62 +/- 0.36 to 0.46 +/- 0.33 in VFO, whereas from 0.23 +/- 0.07 to 0.20 +/- 0.09 in SFO after weight reduction. Although obese patients, especially those with VFO, were frequently associated with glucose intolerance and hyperlipidemia, marked diminution was observed in the elevated levels of plasma glucose area on 75g OGTT, serum total cholesterol and triglyceride after weight reduction. By the examination of interrelationship between the changes in body weight, BMI, total and regional fat volume and changes in glucose and lipid metabolism, we found that the decrease in the V/S ratio and visceral fat volume were more strongly correlated with the improvement in plasma glucose and lipid metabolism compared to the decrease in body weight, BMI, total fat volume and abdominal subcutaneous fat volume. Furthermore, partial correlation analyses demonstrated that the metabolic improvements were associated with changes in visceral abdominal fat after control for changes in total adipose tissue volume.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regional body fat distribution and metabolic profile in postmenopausal women

The aim of the study was to examine how body fat distribution variables were associated with metabolic parameters in a sample of 113 postmenopausal women not receiving hormone therapy (56.9 ± 4.4 years, 28.4 ± 5.1 kg/m²). Body fat distribution variables (visceral adipose tissue [AT], subcutaneous AT, and total midthigh AT) were measured using computed tomography; body fat mass was assessed by hydrostatic weighing; insulin sensitivity was determined with the euglycemic-hyperinsulinemic clamp; fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPG) concentrations were measured by a 75-g oral glucose load; and (high-sensitivity) C-reactive protein (hs-CRP) was measured using a highly sensitive assay. After controlling for fat mass, visceral AT was positively associated with plasma triglyceride, hs-CRP, FPG, and 2hPG, and negatively associated with high-density lipoprotein cholesterol (HDL-C) and insulin sensitivity. Total midthigh AT was negatively associated with apolipoprotein B, FPG, and 2hPG, and positively associated with insulin sensitivity. Stepwise multiple regression analyses including abdominal visceral AT, subcutaneous AT and total midthigh AT as independent variables showed that abdominal visceral AT best predicted the variance in plasma triglyceride, HDL-C, low-density lipoprotein peak particle size, hs-CRP, FPG, 2hPG, and insulin sensitivity. Abdominal subcutaneous AT was a significant predictor of only insulin sensitivity, whereas total midthigh AT predicted HDL-C, low-density lipoprotein peak particle size, and apolipoprotein B. These multivariate analyses also indicated that total midthigh AT was favorably related to these outcomes, whereas abdominal visceral AT and subcutaneous AT were unfavorably related. These results confirmed that abdominal visceral fat is a critical correlate of metabolic parameters in postmenopausal women. In addition, a higher proportion of AT located in the total midthigh depot is associated with a favorable metabolic profile.     

Relationship of visceral adipose tissue to metabolic risk factors for coronary heart disease: is there a contribution of subcutaneous fat cell hypertrophy?

Visceral adipose tissue (VAT) accumulation is an important correlate of the metabolic complications found in obese patients. The aim of this study was to evaluate the respective contribution of VAT deposition versus subcutaneous abdominal or femoral fat cell hypertrophy as correlates of the metabolic risk profile in 69 men and 65 premenopausal women (aged 35+/-5 years) with a wide range of fatness (body mass index, 18 to 57 kg/m2). In both genders, VAT accumulation was positively correlated with fasting plasma insulin, triglyceride (TG), and low-density lipoprotein (LDL)-apolipoprotein B (apo B) levels and the cholesterol (CHOL)/high-density lipoprotein (HDL)-CHOL ratio (.24 < or = r < or = .71, P < .05). A similar pattern of positive relationships was found between subcutaneous abdominal fat cell weight and metabolic risk variables in men and women (.33 < or = r < or = .60, P < .01). Positive associations were also observed in women between femoral fat cell weight and fasting plasma insulin, TG, and CHOL levels and the CHOL/HDL-CHOL ratio (.29 < or = r < or = .42, P < .05). However, only plasma TG concentrations and the CHOL/HDL-CHOL ratio were positively correlated with femoral fat cell weight in men (r = .30, P < .05). To better investigate the relationships between the metabolic risk profile and hypertrophic subcutaneous obesity, individuals with small versus large subcutaneous abdominal adipocytes were matched according to VAT accumulation. Men with large abdominal fat cells displayed higher plasma TG and LDL-apo B levels compared with men characterized by small abdominal adipocytes (P < .05). Stepwise multiple regression analyses showed that subcutaneous abdominal fat cell weight was the best independent variable predicting plasma TG and LDL-apo B levels in men. No significant difference was found in the metabolic profile of subjects displaying small versus large femoral adipocytes. Taken together, these results suggest that for a given VAT deposition, the presence of hypertrophied subcutaneous abdominal adipocytes in men appears to be associated with further deterioration in the metabolic risk profile. On the other hand, the hypertrophy of femoral adipocytes does not further alter the metabolic complications generally related to obesity in both men and women.     

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 fat distribution in pre- and post-menopausal women: metabolic and anthropometric variables and their inter-relationships.

The aim of the study was to compare body fat distribution and metabolic variables in pre- and post-menopausal women. Body fat distribution was measured using abdominal circumference and computerized tomography. No significant differences were found between the two groups as regards body weight, body mass index, waist-hip ratio and total abdominal adipose tissue areas. Subcutaneous abdominal adipose tissue areas were significantly higher in premenopausal women whereas visceral abdominal adipose tissue areas and the subcutaneous to visceral abdominal adipose tissue area ratios were significantly higher in post-menopausal subjects. After adjusting for body mass index, no significant differences emerged between the two groups as regards total abdominal adipose tissue areas, waist circumference, hip circumference and waist-hip circumference ratio; subcutaneous abdominal adipose tissue areas were significantly lower and both visceral abdominal adipose tissue areas and visceral to subcutaneous abdominal adipose tissue area ratios significantly higher in post-menopausal women (P less than 0.01). Basal glucose, sum of blood glucose values during oral glucose tolerance test and blood cholesterol values were significantly higher in the post-menopausal group (P less than 0.05), while no significant difference was observed in sum of blood insulin values during oral glucose tolerance test. Basal plasma insulin values, systolic blood pressure and diastolic blood pressure were higher in post-menopausal women, though the differences were not significant. Only blood cholesterol was significantly higher in post-menopausal women after adjusting for visceral abdominal adipose tissue areas. Positive correlations emerged between age and waist-hip ratio (P less than 0.05), visceral abdominal adipose tissue areas and the visceral to subcutaneous abdominal adipose tissue area ratio (P less than 0.001). A negative correlation was established between age and subcutaneous abdominal adipose tissue areas (P less than 0.01). There was a significant correlation between visceral abdominal adipose tissue areas and metabolic and haemodynamic variables in both pre- and post-menopausal women. In pre-menopausal women, body mass index correlated with basal glucose, basal insulin, sum of glucose during oral glucose tolerance test and systolic and diastolic blood pressure (P less than 0.05). When stepwise multiple regression analysis was used to evaluate the joint effect of anthropometric variables on metabolic variables, visceral abdominal adipose tissue area proved to be the most powerful variable for predicting metabolic disorders. Our data suggest that visceral abdominal adipose tissue areas and visceral to subcutaneous abdominal adipose tissue area ratios increase with age. Obesity correlates directly with the amount of subcutaneous fat, but not with the distribution pattern.(ABSTRACT TRUNCATED AT 400 WORDS)     

Insulin effect on adipose tissue (AT) adiponectin expression is regulated by the insulin resistance status of the patients

Objective  The objective of the present study was to determine a possible depot-specific effect of insulin-stimulation on adiponectin gene expression in adipose tissue (AT) explants from subcutaneous and visceral AT. A secondary aim was to analyse the associations of adiponectin plasma levels, as well as control and insulin-stimulated gene expression levels with different features of the metabolic syndrome.
Design  Visceral and subcutaneous AT biopsies were obtained from 20 subjects (10 men and 10 women) with morbid obesity. Metabolic syndrome and other clinical features were studied. Adiponectin expression from isolated adipocytes was measured both in control and after insulin-stimulation conditions by quantitative PCR.
Results  Subcutaneous adipocytes expressed significantly higher amounts of adiponectin mRNA than visceral tissue ( P =  0·027). Insulin increased adiponectin expression specifically in the omental tissue ( P =  0·011). In these patients, waist : hip ratio was directly correlated with adiponectin expression in the visceral depot ( r  = 0·660; P  = 0·014), while fasting glucose levels were inversely associated with adiponectin mRNA in the subcutaneous tissue ( r  = – 0·604; P  = 0·022). Adiponectin expression after addition of insulin was positively correlated with some metabolic risk factors (cholesterol, LDL-cholesterol, insulin, C-peptide). Interestingly, local insulin induced an up-regulation of adiponectin expression in the AT of those patients with higher metabolic syndrome disturbances.
Conclusions  Our results clearly demonstrate that insulin exerts a stimulating effect on adiponectin gene expression in a depot-specific manner. The AT response to insulin stimulus depends on the physiopathological situation, being higher in those individuals with impaired insulin-sensitivity and lipid metabolism.     

Abdominal fat distribution in pre- and postmenopausal women: The impact of physical activity, age, and menopausal status

Age-related increases in total body fat have been reported, but the impact of menopause on abdominal fat distribution is still unclear. The purpose of this study was to determine the impact of menopausal status on abdominal fat distribution using magnetic resonance imaging (MRI). In addition, we investigated the influence of abdominal fat distribution on blood lipid profiles and leptin concentrations. Twenty-three premenopausal (PRE), 27 postmenopausal (POST), and 28 postmenopausal women on estrogen replacement therapy (ERT) had measurements of regional abdominal fat, blood lipids, and serum leptin concentrations. The women were matched for body mass index (BMI) and total body fat mass. Age and menopausal status were not found to be significant predictors of total abdominal fat, visceral fat, or subcutaneous fat, while physical activity was a significant predictor (P <.01) for total abdominal fat (R(2) =.16), visceral fat (R(2) =.32) and percent visceral fat (R(2) =.25). There was a trend for a greater visceral fat content in the POST women compared with the PRE women (2,495.0 +/- 228.4 v 1,770.4 +/- 240.8 cm(2), respectively, P =.06). The percent visceral abdominal fat was significantly lower (P <.05) in the premenopausal women than in either postmenopausal group (PRE, 23.2% +/- 1.7%; POST, 28.9% +/- 1.8%; ERT, 28.9% +/- 1.6%). Menopausal status and age did not influence any of the blood lipid values. Abdominal fat distribution was a significant predictor of cholesterol concentrations and the cholesterol/high-density lipoprotein-cholesterol (HDL-C) ratio, but only accounted for approximately 15% of the variability in these levels. Total body fat and physical activity accounted for 47% of the variability in leptin concentrations, while abdominal fat distribution, age, and menopausal status were not significant predictors. In conclusion, in early postmenopausal women, the level of physical activity accounts for the variability in abdominal fat distribution observed, while menopausal status and age do not play a significant role. ERT was not associated with additional benefits in abdominal fat distribution compared with postmenopausal women not on ERT or in the blood lipid profile in these women.     

Exercise, visceral adipose tissue, and metabolic risk

Regular exercise is associated with a substantial reduction in risk across a broad range of health outcomes. The principal mechanisms by which exercise is associated with diminished health risks are unclear, but corresponding reduction in abdominal obesity, particularly visceral adipose tissue (AT), is a likely candidate. Visceral AT is a strong independent predictor of metabolic risk, morbidity, and mortality, and this depot is markedly reduced with regular exercise. This review focuses on the relationship between exercise and corresponding reductions in visceral adiposity and metabolic risk factors.     

Comparison of intermittent with continuous simvastatin treatment in hypercholesterolemic patients with end stage renal failure

Coronary artery disease is the most important cause of morbidity and mortality in patients with end-stage renal failure (RF). Hypercholesterolemia is an important risk factor for coronary heart disease. Patients with chronic renal failure (CRF) have difficulties in compliance with their care and treatment. Intermittent simvastatin treatment may help to increase compliance and can be a treatment alternative in patients with CRF at risk of coronary artery disease. We investigated the effects of simvastatin and compared intermittent with continuous simvastatin treatment in hypercholesterolamic patients with CRF. The study group included 40 of 422 CRF patients on dialysis in our clinic. The inclusion criterion was low density lipoprotein cholesterol (LDL-C) of 130 mg/dL or more. Twenty patients received simvastatin 10 mg/day (continuous group) and 20 patients received simvastatin 20 mg three times a week (only dialysis days- intermittent group) for four months. Nineteen patients served as controls and they were given a prescribed diet only. Total cholesterol (TC) and LDL-C decreased markedly in patients receiving intermittent and continuous simvastatin compared to controls. Continuous simvastatin decreased TC by 23% (P < 0.001) and LDL-C by 39% (P < 0.001). Intermittent simvastatin decreased TC by 26% (P < 0.001) and LDL-C by 40% (P < 0.001). The atherogenic index ratios in both the continuous and intermittent groups (TC/High density lipoprotein-cholesterol (HDL-C) and LDL-C/HDL-C) decreased significantly. There was no significant difference in patient compliance between the two groups. Intermittent simvastatin is as effective and reliable as continuous simvastatin treatment and can be an alternative treatment in hypercholesterolemic patients on dialysis.     

Abdominal obesity,muscle composition,and insulin resistance in premenopausal women

The independent relationships between visceral and abdominal sc adipose tissue (AT) depots, muscle composition, and insulin sensitivity were examined in 40 abdominally obese, premenopausal women. Measurements included glucose disposal by euglycemic clamp, muscle composition by computed tomography, abdominal and nonabdominal (e.g. leg) AT by magnetic resonance imaging and cardiovascular fitness. Glucose disposal rates were negatively related to visceral AT mass (r = -0.42, P < 0.01). These observations remained significant (P < 0.01) after control for nonabdominal and abdominal sc AT, muscle attenuation, and peak oxygen uptake. Total, abdominal, or leg sc AT or muscle attenuation was not significantly (P > 0.10) related to glucose disposal. Subdivision of abdominal sc AT into anterior and posterior depots did not alter the observed relationships. Further analysis matched two groups of women for abdominal sc AT but with low and high visceral AT. Women with high visceral AT had lower glucose disposal rates compared with those with low visceral AT (P < 0.05). A similar analysis performed on two groups of women matched for visceral AT but high and low abdominal sc AT revealed no statistically different values for insulin sensitivity (P > 0.10). In conclusion, visceral AT alone is a strong correlate of insulin resistance independent of nonabdominal, abdominal sc AT, muscle composition, and cardiovascular fitness. Subdivision of abdominal sc AT did not provide additional insight into the relationship between abdominal obesity and metabolic risk.     

Total cholesterol/HDL cholesterol ratio vs LDL cholesterol/HDL cholesterol ratio as indices of ischemic heart disease risk in men: the Quebec Cardiovascular Study.

BACKGROUND: Total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)/HDL-C ratios are used to predict ischemic heart disease risk. There is, however, no consensus on which of these 2 indices is superior. The objective of the present study was to present evidence that the LDL-C/HDL-C ratio may underestimate ischemic heart disease risk in overweight hyperinsulinemic patients with high triglyceride (TG)-low HDL-C dyslipidemia. METHODS: A total of 2103 middle-aged men in whom measurements of the metabolic profile were performed in the fasting state were recruited from 7 suburbs of the Quebec metropolitan area. RESULTS: The relationship of LDL-C/HDL-C to TC/HDL-C ratios was examined among men in the Quebec Cardiovascular Study classified into tertiles of fasting TG levels. For any given LDL-C/HDL-C ratio, the TC/HDL-C ratio was higher among men in the top TG tertile (>168 mg/dL [>1.9 mmol/L]) than in men in the first and second TG tertiles. Adjustment of the TC/HDL-C ratio for LDL-C/HDL-C by covariance analysis generated significant differences in average TC/HDL-C ratios among TG tertiles (P<.001). Greater differences in features of the insulin resistance syndrome (insulinemia, apolipoprotein B, and LDL size) were noted across tertiles of the TC/HDL-C ratio than tertiles of the LDL-C/HDL-C ratio. CONCLUSION: Variation in the TC/HDL-C ratio may be associated with more substantial alterations in metabolic indices predictive of ischemic heart disease risk and related to the insulin resistance syndrome than variation in the LDL-C/HDL-C ratio.     

Visceral fat loss evaluated by total body magnetic resonance imaging in obese women operated with laparascopic adjustable silicone gastric banding

OBJECTIVE: To investigate the changes of visceral fat, as compared with total and subcutaneous adipose tissue (AT) in obese patients operated with laparascopic adjustable silicone gastric banding (LAP-BAND). SUBJECTS: Six premenopausal morbid obese (body mass index range: 41.4-44.2 kg/m2) women, aged 38-42 y, operated with LAP-BAND, evaluated before, 8 weeks after, and 24 weeks after surgery. MEASUREMENTS: Fat distribution was analysed by total body multi-slices MRI. Total AT, gluteo-femoral subcutaneous AT, abdominal subcutaneous AT, and abdominal visceral AT volumes were measured. FM was calculated from MRI-determined total AT volume and AT density. RESULTS: A weight loss of 9.9+/-3.8 kg was observed in the first 8 weeks after LAP-BAND (0-8 weeks), and a further weight loss of 7.1+/-4.9 kg in the subsequent 16 weeks (8-24 weeks). Total AT showed a statistically significant reduction of 6.2+/-4.0 l in 0-8 weeks and a further significant reduction of 7.7+/-3.9 l in 8-24 weeks (P<0.01 from baseline). A similar trend was observed for both abdominal and gluteo-femoral subcutaneous AT. Visceral AT showed a statistically significant reduction of 1.0+/-0.9 l in the 0-8 weeks (P<0.05) and a further non-significant reduction of 0.6+/-0.7 l in 8-24 weeks (P<0.05 from baseline). In 0-8 weeks, the relative reduction of visceral AT was higher than the relative reduction of both total AT and gluteo-femoral subcutaneous AT. A highly significant correlation was observed between the reduction of total AT and the reduction of both abdominal and gluteo-femoral subcutaneous AT. By contrast, in 0-8 weeks, the reduction of total AT and the reduction of visceral AT were not correlated. In a subsequent analysis, both observations collected in the first 8 weeks after LAP-BAND and observations collected in the last 16 weeks are simultaneously considered, leading to a total of 12 time periods (two time periods for each individual patient). In order to identify factors associated with preferential visceral fat reduction, we calculated for each of the 12 time periods the difference between the percentage changes of visceral AT and the percentage changes of total AT. The relationship between this difference and several other variables were investigated by simple correlation analysis. The only variables found to be associated were the initial visceral AT volume, the absolute level of weight loss (kg) per week of observation, and the relative level of weight loss (%) per week of observation. CONCLUSION: In the phase of rapid weight loss following LAP-BAND, a preferential mobilization of visceral fat, as compared with total and subcutaneous AT, can occur. However, this preferential visceral fat reduction occurs only in those patients presenting higher levels of visceral fat deposition at baseline and higher levels of weight loss. International Journal of Obesity (2000)24, 60-69     

Reciprocal association between visceral obesity and adiponectin: in healthy premenopausal women

BACKGROUND: Obesity is one of the well-known risk factors of vascular disorders; however, the molecular mechanisms underlying the association between the two remain undetermined. Previous studies have demonstrated that the plasma levels of adiponectin, an adipose-derived hormone, are reduced in obese subjects, and that this hypoadiponectinemia is associated with ischemic heart disease. In this study, we sought to identify the primary determinants of plasma adiponectin levels in healthy premenopausal women. METHODS AND RESULTS: We analyzed the plasma adiponectin concentrations in age-matched healthy obese premenopausal women [n=37, body mass index (BMI)> or= 25 kg/m(2)] and in healthy nonobese premenopausal women (n = 23, BMI < 25 kg/m(2)). Visceral and subcutaneous fat (VCF and SCF) areas were determined by abdominal computed tomography (CT) scan. Plasma levels of adiponectin in obese subjects were lower than in nonobese subjects (3.24 +/- 1.08 vs. 4.90 +/- 2.06 ug/ml, P < 0.01). Significant, univariate inverse correlations were observed between adiponectin levels and visceral fat areas (r = -0.643, p < 0.001), subcutaneous fat areas (r = -0.407, p < 0.01), and hsCRP (r = -0.36, p = 0.007). Plasma levels of adiponectin correlated positively with insulin sensitivity [quantitative insulin sensitivity check index (QUICKI): r = 0.38, p = 0.005] and high-density lipoprotein (HDL) cholesterol (r = 0.44, p = 0.001), and negatively with low-density lipoprotein (LDL) cholesterol (r = -0.29, p = 0.028), triglyceride (r = -0.33, p = 0.013), and BMI (r = -0.48, p < 0.001). By multivariate analysis, only visceral fat areas affected adiponectin plasma levels (beta = -0.016, p < 0.05, R(2) = 0.504). Plasma levels of HDL cholesterol remained significantly correlated to plasma adiponectin concentrations in multivariate analysis (beta = 0.067, p < 0.05). CONCLUSIONS: These results collectively indicate that plasma HDL cholesterol levels and visceral fat masses are independently associated with plasma adiponectin concentrations.     

Contributions of total body fat, abdominal subcutaneous adipose tissue compartments, and visceral adipose tissue to the metabolic complications of obesity

Obesity is related to the risk for developing non-insulin-dependent diabetes mellitus (NIDDM), hypertension, and cardiovascular disease. Visceral adipose tissue (VAT) has been proposed to mediate these relationships. Abdominal subcutaneous adipose tissue (SAT) is divided into 2 layers by a fascia, the fascia superficialis. Little is known about the radiologic anatomy or metabolic correlates of these depots. The objective of this study was to relate the amounts of VAT, SAT, deep subcutaneous abdominal adipose tissue (DSAT), and superficial subcutaneous abdominal adipose tissue (SSAT) to gender and the metabolic complications of obesity after adjusting for total body fat and to discuss the implications of these findings on the measurement of adipose tissue mass and adipose tissue function. The design was a cross-sectional database study set in a nutrition research center. Subjects included 199 volunteers participating in nutrition research protocols who also had computed tomography (CT) and dual energy x-ray absorptiometry (DEXA) measurement of body fat. The amount of DSAT was sexually dimorphic, with women having 51% of the subcutaneous abdominal fat in the deep layer versus 66% for men (P <.05). Abdominal fat compartments were compared with metabolic variables before and after adjusting for body fat measured by DEXA using 2 separate methods. The unadjusted correlation coefficients between the body fat measures, R(2), were largest for fasting insulin and triglyceride and smaller for high-density lipoprotein (HDL) cholesterol and blood pressure. A large portion of the variance of fasting insulin levels in both men and women was explained by total body fat. In both men and women, the addition of VAT and subcutaneous abdominal adipose tissue depots only slightly increased the R(2). In men, when body fat compartments were considered independently, DSAT explained a greater portion of the variance (R(2) =.528) in fasting insulin than VAT (R(2) =.374) or non-VAT, non-DSAT subcutaneous adipose tissue (R(2) =.375). These data suggest that total body fat is a major contributor to the metabolic sequelae of obesity, with specific fat depots, VAT, and DSAT also making significant contributions.     

肥胖者内脏脂肪蓄积与脂代谢的关系

目的:研究内脏脂肪蓄积与脂代谢的相关性。方法:选择首次就诊的163名单纯性肥胖病人。采用CT测定腹腔内脂肪面积,依据腹腔内脂肪面积分为内脏型肥胖组(腹腔内脂肪面积≥100cm2,115例)及皮下型肥胖组(腹腔内脂肪面积<100cm2,48例),并进行人体指标、脂代谢指标测定。结果:与皮下型肥胖组比较,内脏型肥胖组甘油三酯[TG,(1.69±1.51)mmol/L比(2.67±2.61)mmol/L]、总胆固醇[TC,(5.07±1.03)mmol/L比(5.65±1.19)mmol/L]水平显著升高(P<0.01),高密度脂蛋白胆固醇[HDL-C,(1.17±0.48)mmol/L比(1.02±0.22)mmol/L]水平显著降低(P<0.05)。直线相关分析显示,腹腔内脂肪面积与TG呈正相关(r=0.235,P=0.003),与HDL-C负相关(r=-0.162,P=0.039)。结论:内脏脂肪蓄积与脂代谢紊乱密切相关。     

Plasma lipid and lipoprotein levels during the follicular and luteal phases of the menstrual cycle

Estrogen levels are higher during the luteal compared with the follicular phase of the menstrual cycle. It was hypothesized that the luteal compared with the follicular phase has a lipid and lipoprotein profile associated with decreased coronary heart disease (CHD) risk. This was tested using well-defined data from healthy, well-characterized premenopausal Caucasian women under very controlled metabolic conditions. The percent differences in lipid, lipoprotein, and sex hormone levels between the follicular and luteal phases were estimated using generalized estimating equations after adjusting for age, body mass index, calendar time, and season. The low-density lipoprotein cholesterol (LDL-C) level was 6.2% lower (P = 0.015), and the total cholesterol/high-density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratios were 5.1% (P = 0.0006) and 8.4% (P = 0.002) lower, respectively, during the luteal phase. Levels of estradiol and other estrogens were significantly higher (by>100% each; P < 0.0001 in all cases) in the luteal phase. These findings support the study hypothesis. Fluctuations in levels of LDL-C and the total cholesterol/HDL-C and LDL-C/HDL-C ratios between menstrual cycle phases need to be considered in the screening and medical monitoring of premenopausal women, especially those with borderline levels. Although small, such fluctuations may prove to be clinically significant in the long run. Studies involving premenopausal women need to more clearly define and validate menstrual cycle phase in the design and interpretation of study results.     

Greater beneficial effects of visceral fat reduction compared with subcutaneous fat reduction on parameters of the metabolic syndrome: a study of weight reduction programmes in subjects with visceral and subcutaneous obesity.

AIMS: To evaluate the effect of weight reduction on parameters of the metabolic syndrome in obese patients according to their pattern of abdominal fat distribution. METHODS: A longitudinal intervention study, consisting of a 12-week weight reduction programme, including lifestyle modification and adjuvant appetite suppressant, in 38 subjects with visceral obesity and 47 subjects with subcutaneous obesity. Visceral, subcutaneous and total adipose tissue areas were determined by CT scan at the level of L4-L5. Parameters for components of the metabolic syndrome were measured before and after weight reduction. RESULTS: Reductions in body weight, BMI and subcutaneous adipose tissue area were greater in the subcutaneous than in the visceral obesity group. In contrast, changes in fasting plasma glucose, insulin, and HOMA score were higher in the visceral than in the subcutaneous obesity group. Changes in visceral adipose tissue area were significantly related to changes in fasting plasma glucose, triglycerides and HOMA score. CONCLUSIONS: Visceral fat reduction induced greater beneficial effects on parameters of the metabolic syndrome than subcutaneous fat reduction. Evaluation of changes in abdominal fat distribution is necessary when obese subjects enter a weight reduction programme.     

Visceral and Intrahepatic Fat Are Associated with Cardiometabolic Risk Factors Above Other Ectopic Fat Depots: The Framingham Heart Study

Background

We examined the associations among 8 different fat depots accumulated in various anatomic regions and the relationship between these fat depots and multiple cardiometabolic risk factors.