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Query: UMLS:C0311277 (abdominal obesity)
 2,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Numerous interrelated metabolic and morphological variables such as plasma insulin levels, glucose tolerance and abdominal obesity are associated with changes in plasma lipoprotein levels. The present study was undertaken to differentiate, using a multivariate approach, the respective contributions of plasma glucose and insulin levels, obesity and regional adipose tissue distribution to the variance in plasma lipoproteins. The study group was composed of 69 healthy premenopausal women (age 35.4 +/- 5.0 years (mean +/- s.d.); percent body fat 40.7 +/- 10.1). Indices of carbohydrate metabolism showed significant univariate correlations with triglyceride (TG) and/or cholesterol (CHOL) content of plasma VLDL, LDL and HDL (P less than 0.05). Multivariate analyses indicated that the explained variance in plasma VLDL-TG (R2 x 100 = 44 percent, P less than 0.05) and LDL-apoprotein (apo) B levels (R2 x 100 = 33.1 percent, P less than 0.08) was entirely accounted for by indices of carbohydrate metabolism and body fat distribution, whereas total body fatness added no significant contribution to these models. Multivariate analyses also revealed that the best possible regression model to predict the variation in plasma HDL2-CHOL levels only included computed tomography-derived deep abdominal adipose tissue area (P less than 0.0001). All other variables were unable to further improve the explained variance in plasma HDL2-CHOL levels. In partial correlation analyses, indices of carbohydrate metabolism and the waist-to-hip circumference ratio (WHR) remained significantly correlated with plasma VLDL-TG and LDL-apo B levels after adjustment of VLDL-TG and LDL-apo B for either insulin and glucose levels, or for the WHR (P less than 0.08). After correcting for deep abdominal fat accumulation, no significant correlation was observed between indices of carbohydrate metabolism and plasma HDL2-CHOL levels whereas deep abdominal fat showed significant correlations with HDL2-CHOL levels (P less than 0.05) after correction for indices of carbohydrate metabolism. These results suggest that both disturbances in glucose-insulin homeostasis and abdominal obesity are significantly associated with changes in plasma VLDL-TG and LDL-apo B levels and that these associations are partly independent from each other. These results also indicate that mechanisms other than disturbances in glucose homeostasis and hyperinsulinemia are responsible for the association between the level of deep abdominal fat and plasma HDL2-CHOL levels.
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PMID:Contribution of glucose tolerance and plasma insulin levels to the relationships between body fat distribution and plasma lipoprotein levels in women. 175 29

Insulin responses to intravenous glucose infusion and glucose utilization during hyperinsulinaemic euglycaemic clamp were determined in a large homogeneous group of 65-year-old male subjects. Twenty-eight had untreated Type 2 (non-insulin-dependent) diabetes mellitus and the remaining 44 control subjects had a normal glucose tolerance. Diabetic patients with abdominal obesity displayed peripheral insulin resistance in combination with defective insulin secretion, whereas non-obese diabetic patients showed only a secretory defect. Thus, Type 2 diabetes in obese and non-obese elderly male subjects may take two forms where the cause of hyperglycaemia differs.
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PMID:Different aetiologies of type 2 (non-insulin-dependent) diabetes mellitus in obese and non-obese subjects. 191 53

This review concentrates on recent prospective studies concerning evaluation of the health risk of obesity with special reference to the impact of the distribution of the adipose tissue. Analysis of the data indicates that adipose tissue localized to the abdominal region (especially intraabdominal fat) is associated with an enhanced risk profile including elevated levels of triglycerides and insulin, low levels of high density lipoprotein-cholesterol and elevated blood pressure. Abdominal obesity, determined by the waist/hip ratio, was associated with cardiovascular disease, premature death and non-insulin demanding diabetes mellitus. On the other hand, the total fat mass (measured as body mass index) was positively associated only with non-insulin demanding diabetes mellitus. The androgen/estrogen activity seems to be an important factor for determining the topographical localization of the adipose tissue. The great amount of free fatty acids which may be released from the abdominal fat tissue seemed to be of great pathogenetic importance for the metabolic consequences of abdominal obesity. In conclusion, obesity and the abdominal localization of adipose tissue seem to be two separate entities with different pathogenesis and clinical consequences. The abdominal obesity is the type which is predominantly associated with enhanced health risks. These associations may result in an altered strategy of treatment of the obese population.
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PMID:[Health risks of obesity. Significance of the regional distribution of adipose tissue]. 202 93

The health risks of obesity increase with its severity and reach significance at a weight greater than 20% above optimal, by using life insurance tables, or at a body mass index greater than 27. Risks include hypertension, insulin resistance and diabetes mellitus, cardiovascular disease, hypertriglyceridemia, low high-density-lipoprotein cholesterol, and, in some studies, high total-and low-density-lipoprotein cholesterol. There is an increased mortality from endometrial cancer in women and from colorectal cancer in men. Chronic hypoxia and hypercapnia, sleep apnea, gout, and degenerative joint disease can occur with more severe obesity. The distribution of body fat is directly related to these health risks. Abdominal obesity is more dangerous than gluteal-femoral obesity because the amount of intraabdominal fat seems to determine much of the increased peril; therefore, risks of cardiovascular disease, stroke, hypertension, and diabetes increase with abdominal obesity, even independently of total fat mass.
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PMID:Health implications of obesity. 203 92

Plasma glucose and insulin concentration and the ability of physiological hyperinsulinemia to dispose of a glucose load were determined in 26 healthy, nondiabetic, Chinese females. The study population was divided in half on the basis of two indices of obesity: 1) body mass index (greater than or less than 25.3 kg/m2) and 2) ratio of waist to hip girth (greater than or less than 0.83). When these groups were compared on the basis of the three measured variables, the results indicated that the untoward metabolic effects of obesity were, if anything, more prominent when subjects were divided on the basis of body mass index as compared to a division based on the ratio of waist to hip girth. Similarly, correlation coefficients between body mass index and plasma glucose response, plasma insulin response, and insulin-stimulated glucose disposal were equal to or greater than the correlation coefficients between ratio of waist to hip girth and the same three variables. These data suggest that the impact of differences in abdominal obesity, as reflected in measurement of the ratio of waist to hip girth, is no greater than the effect of overall obesity, as estimated by calculation of body mass index, on plasma glucose and insulin responses to oral glucose and insulin-stimulated glucose disposal in Chinese females who are not massively obese.
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PMID:Comparison of the effects of differences in ratio of waist to hip girth and body mass index on carbohydrate metabolism in Chinese females. 207 16

Increased lipolysis in abdominal adipocytes has been suggested to be of importance for the insulin resistance typical for abdominal obesity. In order to differentiate between fat distribution, measured as waist/hip ratio (WHR), and amount of body fat, glucose disposal during a euglycaemic clamp as well as lipolysis in isolated cells from abdominal and gluteo-femoral regions were studied in 20 obese and 20 lean postmenopausal women with a high (n = 10) and low (n = 10) WHR, respectively. The lipolytic response was increased in cells from obese women irrespective of region. Furthermore, lipolysis was enhanced in abdominal compared with the gluteo-femoral cells in obese women with a high WHR. Fasting blood glucose and insulin were increased in both groups of obese women while the degree of insulin resistance was most pronounced in the obese women with a high WHR. It is concluded that increased body fat is associated with both insulin resistance and increased lipolysis, and that this relationship is stronger in the presence of a high WHR. A high WHR may increase the expression of obesity as a risk for insulin resistance and this may be mediated through an increased lipolytic rate.
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PMID:Increased insulin resistance and fat cell lipolysis in obese but not lean women with a high waist/hip ratio. 212 85

It is well established that abdominal obesity is related to numerous metabolic abnormalities and that this correlation represents a significant risk factor for coronary heart disease and related mortality. In the present study the relationships among the regional distribution of body fat, selected metabolic variables, and abdominal adipose cell lipolysis were investigated in 30 premenopausal women, 34 +/- 8 yr (mean +/- SD) of age, with body mass indices ranging from 17-45 kg/m2. Basal as well as epinephrine- and isoproterenol-stimulated lipolyses were positively correlated with fasting plasma insulin and triglyceride levels (0.48 less than r less than 0.64; 0.05 greater than P less than 0.0005 and 0.46 less than r less than 0.60; 0.05 greater than P less than 0.005, respectively) and with the insulin area measured during an oral glucose tolerance test (0.49 less than r less than 0.67; 0.005 greater than P less than 0.0005). With the exception of epinephrine-stimulated lipolysis, these correlations remained significant when lipolysis was corrected for cell surface area. Basal and maximal epinephrine- and isoproterenol-induced lipolyses were also negatively related to plasma high density lipoprotein cholesterol (-0.52 less than r less than -0.36; 0.05 greater than P less than 0.005). However, these relationships were no longer significant after control for fat cell surface. The associations between abdominal lipolysis and fat distribution did not remain significant when data were adjusted for total adiposity. Taken together, these results support the notion that variations in abdominal adipocyte lipolysis 1) depend more on total body fatness than on fat distribution, and 2) may be involved in the metabolic complications associated with abdominal obesity, particularly those pertaining to plasma insulin and triglyceride metabolism.
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PMID:Abdominal fat cell lipolysis, body fat distribution, and metabolic variables in premenopausal women. 214 56

Recent epidemiologic studies have shown that abdominal obesity, characterized by a high waist to hip circumference ratio (WHR), is associated with increased cardiovascular morbidity and mortality. The present study examines components of the fibrinolytic system in obese and lean middle-aged women with a high and low WHR. Ten women in each group were carefully matched with respect to age, body weight, lean body mass, and body fat. Fibrinogen and endothelial type of plasminogen activator inhibitor -1 (PAI-1) were significantly elevated in the obese women with a high WHR compared with the obese women with a low WHR or with both groups of lean women. In addition, obese women with a high WHR exhibited a greater metabolic risk profile (elevated glucose, insulin, and triglyceride levels). When all subjects were pooled for the analyses, both fibrinogen and PAI-1 levels correlated positively with glucose and insulin levels. PAI-1 was also negatively related to degree of insulin sensitivity measured with the euglycemic clamp technique. In the obese groups, WHR but not body mass index (BMI), correlated with PAI-1 levels. No such correlations were seen in the lean groups. In conclusion, the data show that a high WHR in obese, but not lean middle-aged women, is associated with an impaired fibrinolytic activity. This perturbation becomes enhanced when it is associated with hyperinsulinemia and insulin resistance, which is a typical feature of abdominal obesity.
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PMID:Abdominal obesity is associated with an impaired fibrinolytic activity and elevated plasminogen activator inhibitor-1. 221 52

It has been proposed that central obesity, by virtue of the enhanced lipolytic activity of abdominal adipose tissue, leads to higher plasma FFA concentrations, which, in turn, decrease both hepatic removal of insulin and insulin-stimulated glucose uptake by peripheral tissues. In short, the predicted consequences of abdominal obesity are elevations in circulating FFA and insulin levels as well as insulin resistance. The goal of this study was to evaluate the relationships predicted by the overall hypothesis; this study was carried out in 31 obese females, defined as having normal glucose tolerance (n = 12), impaired glucose tolerance (n = 8), or noninsulin-dependent diabetes mellitus (n = 11). Abdominal obesity was estimated by determining the ratio of waist to hip girth, fasting and postprandial plasma FFA and insulin concentrations were measured at hourly intervals from 0800-1600 h, and insulin-stimulated glucose disposal was quantified by the euglycemic hyperinsulinemic clamp technique. The first step in the postulated sequence of events to be tested was that the greater the WHR, the higher the total integrated plasma FFA response. The correlation coefficient between these two variables was 0.29, indicating that the results did not support the prediction. Furthermore, we could not demonstrate any relationship between the magnitude of the plasma FFA and insulin responses (r = 0.20; P = NS). However, there was a modest inverse relationship between height of circulating plasma insulin concentration and a decrease in insulin-stimulated glucose uptake (r = -0.43; P less than 0.03) in the group as a whole. On the other hand, when the three groups were analyzed individually, a significant inverse relationship was only seen in the control group (r = -0.67), and a direct relationship was actually seen in patients with impaired glucose tolerance (r = 0.88). Furthermore, when the mean responses for the variables in each of the three groups were compared, it was apparent that the postulated relationships between abdominal obesity, plasma FFA concentration, and insulin secretion and action were not present. Thus, the data presented do not support the hypothesis that differences in the degree of central obesity play an important role in regulation of plasma concentrations of either FFA or insulin or in modulation of insulin-stimulated glucose uptake in the patients we studied.
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PMID:Effect of central obesity on regulation of carbohydrate metabolism in obese patients with varying degrees of glucose tolerance. 222 87

The effects of free fatty acids (FFA) on insulin receptor binding and processing (internalization, degradation, dissociation, and release) were examined in hepatocytes isolated from 12-week-old female rats. Animals were fasted for 24 h to deplete liver glycogen and lipid content. Cells were preincubated for 30 min or 3 h at 37 degrees C in media containing 10 mM lactate, 1 mM pyruvate, and 3.5 percent albumin with increasing concentrations of palmitate (0.00, 0.05, 0.2, 0.5, 1.0 and 2.0 mM). Under these conditions palmitate is the primary substrate for cellular metabolism, and its major fate is oxidation. Equilibrium binding was determined after 18-20 h of incubation at 4 degrees C with radiolabeled insulin and increasing concentrations of unlabeled hormone. With increasing palmitate concentration, a dose-dependent decline in cell-surface insulin receptor binding was observed. Binding decreased by 35 percent and 44 percent after 30 min and 3 h of preincubation with 2 mM palmitate, respectively. This decrease was due to a reduction in insulin receptor number. Receptor-mediated insulin processing was evaluated in cells prelabeled at 4 degrees C with 125I (A14)-monoiodoinsulin at an insulin concentration of 100 pM and reincubated at 37 degrees C for up to 30 min. The amount of internalized insulin was decreased by preincubation of hepatocytes with palmitate. This decrease was proportional to the reduction in cell-surface insulin receptor density at palmitate concentrations of 0.05-0.5 mM, but was disproportionally greater at higher fatty acid concentrations. Receptor-mediated insulin degradation decreased at palmitate concentrations between 0.05 and 1.0 mM. At 2 mM, however, insulin degradation was enhanced. This enhancement was observed after 30 min or 3 h of exposure to the fatty acid. Dissociation and/or release of cell-associated internalized insulin was not influenced by the FFA exposure. The effects of FFA on hepatocyte insulin binding and processing were contingent upon cellular metabolism, since no changes were noted when cells were preincubated with palmitate at 4 degrees C under otherwise similar conditions. Thus the in vitro exposure of hepatocytes to FFA influences both receptor and postreceptor events mediating insulin metabolism. These effects may account for the altered hepatic insulin extraction and sensitivity that accompany abdominal obesity and its progression to diabetes.
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PMID:Receptor and postreceptor effects of free fatty acids (FFA) on hepatocyte insulin dynamics. 226 78


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