The influence of water on the intercalation of epoxy monomers in Na-montmorillonite.

The intercalation of a typical UV-curable epoxy monomer (CE) in unmodified montmorillonite and the effect of hydration on the intercalation reaction are studied. Montmorillonite in the sodium form was submitted to a controlled hydration/dehydration cycle and the water content was checked by TGA/XRD analyses. The structure of the hydrated Na+-montmorillonite was determined from the values of the basal spacings and from the water content of the hydrated form: a coordination of four water molecules per Na ion was found, corresponding to a minimum of energy calculated by molecular dynamics simulation. When dispersing the clay in the CE monomer, the anhydrous Na+-montmorillonite did not show any intercalation; on the contrary the hydrated form showed an increase of the basal spacing. A possible mechanism to explain the intercalation of the CE monomers is proposed.

Relation between body composition, fat distribution, and lung function in elderly men.

BACKGROUND: Body composition changes with age, with increases in fat mass and visceral fat and declines in skeletal muscle mass; lung function also declines with age. Age-related changes in body composition and fat distribution may be associated with the pulmonary impairment observed in the elderly. OBJECTIVE: Our goal was to evaluate the relations between body composition, fat distribution, and lung function in elderly men. DESIGN: We studied 97 men aged 67-78 y with body mass indexes (BMIs; in kg/m2) ranging from 19.8 to 37.1. Body composition was evaluated by using dual-energy X-ray absorptiometry and fat distribution was evaluated by using waist and hip circumferences, waist-to-hip ratio, and sagittal abdominal diameter (SAD). Spirometry was done in all subjects and the distance walked by each subject during a 6-min walking test was evaluated as was leg strength. RESULTS: A significant negative correlation was found between adiposity, fat distribution indexes, forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1). A positive correlation was found between fat-free mass and FVC. After adjustment for age, height, and weight, SAD still correlated negatively with FVC and FEV1 (r = -0.367 and -0.348, respectively; P < 0.01), whereas percentage body fat and fat mass correlated negatively and fat-free mass correlated positively with FVC (r = -0.313, -0.323, and 0.299, respectively; all P < 0.01). After the sample was subdivided by tertile of fat-free mass adjusted for age and BMI, FVC and FEV1 were significantly lower in the lowest fat-free mass tertile (P < 0.01). Stepwise multiple regression analysis performed with use of lung function variables as the dependent variables and age, height, fat mass, fat-free mass, waist circumference, and SAD as the independent variables showed that 3 variables entered the regression for predicting FVC: height, which entered the regression first; SAD, which entered second; and fat-free mass, which entered third. Only 2 variables entered the regression for predicting FEV1: height, which entered the regression first, and SAD, which entered second. CONCLUSION: Our cross-sectional data show a significant association between body composition, fat distribution, and lung function in elderly men.

Waist circumference and abdominal sagittal diameter as surrogates of body fat distribution in the elderly: their relation with cardiovascular risk factors.

OBJECTIVE: To evaluate the relationship between supine sagittal abdominal diameter (SAD) and other indicators of body fat distribution with cardiovascular (CVD) risk factors in the elderly. SUBJECTS: One-hundred and forty-six women aged from 67 to 78 y with a body mass index (BMI) ranging from 18.7 to 50.6 kg/m2 and 83 men aged between 67 and 78 y with BMI ranging from 19.8 to 37.1 kg/m2. MEASUREMENT: Body fat distribution was assessed using anthropometric indicators: waist circumference, SAD, waist-to-hip ratio (WHR), waist-to-height ratio and SAD-to-thigh ratio. RESULTS: In women, there was a negative correlation between HDL-cholesterol and body weight, BMI, waist, SAD, WHR, waist-to-height ratio and SAD-to-thigh ratio. A significant association was found between triglycerides, basal glucose, 2 h glucose during oral glucose tolerance test (OGTT), systolic blood pressure (SBP), diastolic blood pressure (DBP) and anthropometric variables. In men a negative correlation was found between HDL-cholesterol and all the anthropometric variables. A significant association was found between triglycerides, DBP and body weight, BMI, waist, SAD and waist-to-height ratio. In women, after adjusting for age and BMI, a significant correlation was observed between waist and HDL-cholesterol, triglycerides and basal glucose. This was also seen with SAD and SAD-to-thigh ratio and triglycerides, basal and 2 h glucose. In men, after adjusting for age and BMI a significant correlation was found between SAD and HDL-cholesterol and triglycerides. When adjustments were made for age and waist, the correlations between BMI and metabolic variables as well between BMI and SBP and DBP were no longer significant. CONCLUSIONS: Our study shows that indicators of body fat distribution are associated with CVD risk factors in the elderly independently of BMI. Our data also show that waist and SAD are the anthropometric indicators of fat distribution which are most closely related to CVD risk factors in old age.

Resting energy expenditure, growth hormone indices, body composition and adipose tissue distribution in premenopausal women.

OBJECTIVES: A significant growth hormone (GH) contribution to interindividual variance in energy expenditure (REE) in women can be hypothesized. The present study examines the independent association between physiological levels of GH function indices and REE. SETTING: All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona. SUBJECTS: Twenty-four premenopausal overweight (BMI = 28-55 kg m-2) women aged 18-49 years. INTERVENTIONS: REE was estimated by indirect calorimetry and body composition and fat distribution by single slice computed tomography method. GH activity and GH status were determined by measuring serum levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). RESULTS: GH indices did not show any significant correlation with REE. The relation between GH indices and REE was also examined by multiple regression analysis to account for possible confounders such as body composition, adipose tissue distribution and age. When body composition was considered, body fat and fat-free mass were the only significant predictors of REE (R2 = 0.699, P = 0.0001). The contributions of GH indices were not significant. CONCLUSIONS: Our findings do not support the hypothesis that GH in physiological conditions could be an independent determinant of REE in women with obesity.

The relationship between body composition and physical performance in older women.

BACKGROUND: The relationship between age-associated change in body composition and physical disability is still unknown. Skeletal muscle mass declines with age in both sexes; however, since women have less muscle mass per unit of weight than men, these changes may be more debilitating in women. OBJECTIVE: To evaluate the relationship between body composition and physical performance. DESIGN: A cross-sectional study. PARTICIPANTS: 144 women aged 68 to 75 were selected randomly from the general population of Verona. MEASUREMENTS: Body composition was evaluated using dual energy X-ray absorptiometry and bioimpedance. Physical performance was evaluated using a modified version of the Activities of Daily Living scale. Distance walked in 6 minutes was calculated, and isometric knee strength was tested. RESULTS: Normal women had a significantly lower body mass index (BMI) and percent body fat. These women also had a higher ratio of body cell mass (BCM) and total fat free mass (FFM) than women with physical impairments. After adjusting for BMI, women in the lowest tertile of muscle strength had significantly lower BCM than those in the highest tertile. CONCLUSIONS: These cross-sectional data show that although muscle strength is related to fat-free mass, disability in older women is associated with heavier BMI and with a higher percentage of body fat.

Body fat distribution predicts the degree of endothelial dysfunction in uncomplicated obesity.

OBJECTIVE: To ascertain in obesity the role of body fat distribution (the strongest predictor of morbility and mortality in obese subjects) in determining the degree of endothelial dysfunction, an early marker of atherosclerotic disease. SUBJECTS: 18 premenopausal women with uncomplicated obesity excluding other cardiovascular risk factors and 12 age-matched slim healthy women. MEASUREMENTS: Endothelium-dependent vasodilation, studied as diameter variation in response to an increase in shear-stress, was evaluated in the right common femoral artery of obese and slim subjects by a non invasive approach and compared to glyceril-trinitrate vasodilation. To characterize better the vascular functional and/or structural properties, we studied the arterial wall distensibility by an echo-tracking system. Adipose tissue regional distribution was determined by computerised axial tomography. RESULTS: The endothelium-dependent vasodilation was significantly impaired in obese subjects (P<0.005 versus non-obese subjects) while glyceril-trinitrate vasodilation and arterial distensibility were similar in the two groups. In our obese subjects endothelial-dependent vasodilation was inversely correlated to body fat distribution (visceral/subcutaneous adipose tissue ratio: r=- 0. 624, P=0.0058). In contrast, metabolic parameters (except C-peptide response during oral glucose tolerance test (OGTT): r=-0.587, P=0. 01), blood pressure values and body weight did not correlate with the endothelial function. CONCLUSION: Uncomplicated obesity per se is characterised by an alteration of the endothelial function; the degree of this vascular damage is predicted by body fat distribution independently of body weight and metabolic and other haemodynamic parameters, and correlates with an index of insulin secretion.

Divergent effects of short-term, very-low-calorie diet on insulin-like growth factor-I and insulin-like growth factor binding protein-3 serum concentrations in premenopausal women with obesity.

OBJECTIVE: Insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) serum concentrations provide a good measure of the biological effects of growth hormone. The aims of the present study were to: (1) investigate the associations of IGF-I and IGFBP-3 with body fat mass and distribution, and (2) evaluate the effects of 3 weeks of very-low-calorie diet (VLCD) (318 kcal/day, with 40 g protein, 35 g carbohydrate, and 2 g fat) on IGF-I and IGFBP-3 serum concentrations. RESEARCH METHODS AND PROCEDURES: The study was performed in 21 nondiabetic premenopausal women with obesity (body mass index >27.0 kg/m2; age: ranging from 18 to 48 years). Body fat mass and distribution were measured by computed tomography. RESULTS: Before dietary treatment, IGF-I and IGFBP-3 serum concentrations were inversely associated with visceral adipose tissue (VAT) area (p<0.005 and p<0.05, respectively), but not with either total body fat or subcutaneous adipose tissue area. VLCD produced a significant decrease of body mass index (p<0.001), total body fat (p<0.001), VAT (p<0.005), subcutaneous adipose tissue (p<0.001), IGF-I concentrations (p<0.05), and an increase of IGFBP-3 serum levels (p<0.001). The association of VAT with either IGF-I or IGFBP-3 serum concentrations was not maintained following VLCD. DISCUSSION: Our study suggests that visceral adipose tissue, rather than adiposity per se, accounts for IGF-I and IGFBP-3 serum concentrations, and that rapid weight loss, possibly due to nutritional changes, results in lower IGF-I concentrations, higher IGFBP-3 concentrations, and abrogation of the inverse associations of VAT with IGF-I and IGFBP-3.

Sagittal abdominal diameter as a practical predictor of visceral fat.

OBJECTIVE: To evaluate the relationships between the supine sagittal abdominal diameter (SAD) and visceral fat, as well as to evaluate intra- and inter-observer reliability of sagittal diameter measurement. PATIENTS: Twenty-eight women ranging in age from 27-78 y with a body mass index (BMI) ranging from 16.9-48.1 kg/m2 and 23 men ranging in age from 32-75 y with BMI ranging from 20-41.6 kg/m2. MEASUREMENT: Body fat distribution was measured by waist circumference, waist to hip ratio (WHR), SAD, anthropometrically assessed and a single slice of computed tomography (CT) at the L4-L5 level. RESULTS: In both genders, a significant association was found between visceral adipose tissue (AT) and SAD, as evaluated by CT (women r = 0.80; men r = 0.83, P < 0.001), and SAD by anthropometry (women r = 0.76; men r = 0.82, P < 0.001), as well as between visceral AT and waist circumference (women r = 0.76, men r = 0.86, P < 0.001) and WHR (women r = 0.57, P < 0.01, men r = 0.80, P < 0.001). A significant association was also found between subcutaneous AT and SAD by anthropometry (women r = 0.79, men r = 0.74, P < 0.001). After adjusting for BMI, the association between subcutaneous AT and SAD was no longer significant in men and only moderately significant in women (r = 0.42, P < 0.05), while the association between visceral AT and SAD by anthropometry remained significant in both genders (women r = 0.63, P < 0.001; men r = 0.66, P < 0.001). When the subjects were divided into two groups according to BMI (lean to moderately overweight women with BMI < 28 and men with BMI < 30 and obese women with BMI > 28 and men with BMI > 30) we found that the relationships between SAD by anthropometry, as well as SAD by CT and visceral AT, were higher in lean to moderately overweight subjects than in those who were obese. High inter-observer correlation was found concerning SAD measurement (r = 0.99, P < 0.001). Intra- and inter-observer precision as evaluated by coefficient of variation and intraclass correlation coefficient for SAD measurement was very high. CONCLUSION: Our study shows the usefulness of SAD by anthropometry to predict visceral fat and its very high inter- and intra-observer precision.

Effects of visceral fat and weight loss on lipoprotein(a) concentration in subjects with obesity.

We studied the relationships between regional body fat distribution and metabolic variables with lipoprotein(a) [Lp(a)] as well as the effects of weight loss on Lp(a) in 25 women and 9 men with obesity. Regional body fat distribution, as evaluated by the use of computed tomography; Lp(a); and fasting glucose, insulin, cholesterol, and triglycerides were analyzed before and after a very low-energy diet. No significant correlations were found between visceral, subcutaneous, and total fat and Lp(a) or between metabolic variables and Lp(a). All anthropometric variables significantly decreased after a very low-energy diet. Fasting glucose, insulin, triglycerides, and cholesterol significantly decreased after a very low-energy diet. No significant changes in Lp(a) concentration after a very low-energy diet were found. The correlation between the initial values of Lp(a) and changes of Lp(a) after a very low-energy diet was slightly significant (rho = 0.33, p < 0.06). In conclusion, our study shows that Lp(a) is not influenced by obesity, visceral fat, metabolic variables, or weight loss induced by a very low-energy diet.

Effects of age on body fat distribution and cardiovascular risk factors in women.

We conducted a cross-sectional study of body fat distribution and metabolic variables and the interrelations among these factors in 134 women aged 18-71.9 y. Body fat distribution was measured with use of computerized tomography. A significant positive correlation was observed between age and visceral adipose tissue (VAT) and between VAT and body weight. When subjects were divided into five age groups, VAT values were significantly higher in older groups. Values for triacylglycerols, cholesterol, fasting glucose, 2-h glucose, and the sum of glucose values during an oral-glucose-tolerance test were significantly higher in older subjects. After adjustment for visceral fat, no significant differences in any metabolic variable studied, except cholesterol, were found across the five age groups. In conclusion, we found that regional body fat distribution in older women was different from that in younger subjects: older women had larger amounts o visceral fat. Values for metabolic variables were also higher in older subjects. Our data suggest that redistribution of body fat in older subjects is associated with changes in metabolic variables.

Interrelationships between weight loss, body fat distribution and sex hormones in pre- and postmenopausal obese women.

OBJECTIVES: Relationships between regional body fat distribution and sex hormones as well as changes in sex hormones after weight loss were evaluated. SETTING: All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona. SUBJECTS: Twenty-six premenopausal (age 33.7 +/- 10.2 years) and 15 postmenopausal (age 57.9 +/- 5.9 years) obese women. INTERVENTIONS: Body weight, body-mass index, waist and hip circumferences, visceral fat by computed tomography and sex hormones were evaluated before and after 4 weeks on a very low energy diet. RESULTS: Body-mass index was higher in pre-than in postmenopausal women, although the difference was not significant. Total and free testosterone were significantly higher in the pre- than in the postmenopausal group (P < 0.001). Significant negative correlations were found between age and total testosterone (r = -0.65; P < 0.001), free testosterone (r = -0.54; P < 0.001), androstenedione (r = -0.46; P < 0.01) and urinary cortisol excretion (r = -0.50; P < 0.01). A negative correlation was found between visceral fat and total testosterone (r = -0.41; P < 0.01). After adjusting for age, the negative correlation between total testosterone and visceral fat encountered both in the subject group as a whole and in premenopausal women was no longer significant, whilst a significant negative association between visceral fat and sex hormone binding globulin (SHBG) (r = -0.56; P < 0.001) was always found. When step-down regression analysis was used to evaluate the joint effect of age, menopausal status, and anthropometric and metabolic variables on sex hormones, age was the most powerful independent variable for predicting total testosterone, free testosterone and androstenedione levels, whilst menopausal status was the most powerful predictor of FSH and LH levels. Changes in hormones after VLED were analysed separately in pre- and postmenopausal women. None of the hormones changed significantly after VLED in the postmenopausal group, except for FSH values. LH, free testosterone and urinary cortisol excretion values decreased significantly after VLED in the premenopausal group. CONCLUSIONS: Our data show that age, to a greater extent than visceral fat, seems to be negatively associated with steroid sex hormones. Weight loss seems to be associated with changes in sex hormones only in premenopausal women.

Body fat distribution before and after weight gain in anorexia nervosa.

OBJECTIVE: To study abdominal fat distribution in anorexia nervosa subjects and to assess the effects of initial weight regain on abdominal fat distribution. DESIGN: Longitudinal, clinical study. The baseline measurement was acquired within four days of admission to the eating disorders clinic. All patients were treated by re-feeding, reinforced by psychotherapy. Following weight regain of at least 5 kg, a second body fat distribution evaluation was performed. Of the 21 subjects evaluated at baseline, 14 achieved the goal of body weight regain and were retested. PATIENTS: Fourteen subjects (age: 18-38 y; body mass index: 11.5-18.3; relative body weight: 54.9-88.3%). MEASUREMENTS: Total, subcutaneous and visceral abdominal adipose tissue areas at the L4-L5 level were evaluated by computed tomography. RESULTS: At baseline the subjects showed a higher proportion of visceral adipose tissue (% visceral adipose tissue = 55.3 +/- 26.1). A significant association was observed between body weight and both subcutaneous adipose tissue and total adipose tissue. A regain of body weight of 7.3 +/- 1.6 kg was accompanied by a significant increase in total adipose tissue, comprising both subcutaneous and visceral adipose tissue. The increase observed in subcutaneous adipose tissue, however, was significantly greater than for visceral adipose tissue (212.6% vs 116.8%, respectively, P < 0.01). CONCLUSION: The results of the current study show a higher proportion of visceral adipose tissue than subcutaneous adipose tissue in anorexia nervosa subjects. With regain of body weight there is a preferential regain of subcutaneous adipose tissue. These data demonstrate a redistribution of abdominal adipose tissue with weight regain in anorexia nervosa subjects.

Body fat accumulation is possibly responsible for lower dehydroepiandrosterone circulating levels in premenopausal obese women.

OBJECTIVE: To determine whether any androgen is independently related with parameters of body fat accumulation and distribution in obese women. DESIGN: Circulating insulin and androgen levels (total testosterone (T), free testosterone (FT), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, sex hormone binding globulin (SHBG)) and the parameters of body fat accumulation and distribution (body mass index, waist-to-hip ratio, total body fat volume (TBF), visceral adipose tissue area (VAT) and subcutaneous adipose tissue area (SAT) were determined in a population of non-diabetic obese women. SUBJECTS: 28 premenopausal obese women, recruited at the Verona University Hospital Outpatient Clinic. MEASUREMENTS: TBF, VAT and SAT area were quantified by computed tomography. Hormone levels were measured by RIA. RESULTS: SHBG showed an inverse correlation with BMI (r: -0.452, P < 0.05), WHR (r: -0.388, P < 0.05), TBF (r: -0.509, P < 0.01), VAT (r: -0.378, P < 0.05) and SAT (r: -0.449, P < 0.05). DHEA was negatively associated with BMI (r: -0.376, P < 0.05), TBF (r: -0 < 0.05), VAT (r: -0.662, P < 0.001) and SAT (r: -0.401, p < 0.05). T was found to be inversely related with VAT (r: -0.401, P < 0.05). Androstenedione was positively correlated with WHR (r: 0.383, P < 0.05). DHEAS and FT did not show significant associations with BMI, WHR, or any CT-parameters. Stepwise multiple regressions were performed for all androgens: one of the age-adjusted androgens was considered as the dependent variable for each analysis, and insulin, VAT, SAT and all other androgens were entered into the regression model. DHEA was the only hormone to show an independent association (negative) with both SAT (t-value: -3.683, P < 0.01) and VAT (t-value: -2.252, P < 0.05), whereas DHEAS showed an independent positive correlation with SAT (t-value: -2.241, P < 0.05). CONCLUSIONS: Among the androgens, DHEA seems to be the most sensitive to body fat accumulation in premenopausal obese women.

Effect of regain of body weight on regional body fat distribution: comparison between pre- and postmenopausal obese women.

The aim of our study was to determine if regain of body weight increases visceral fat in obese women and if regain of weight has a different effect upon pre- and postmenopausal women. Twenty obese women (11 pre- and 9 postmenopausal) underwent a very low energy diet (VLED) for 2 weeks to lose weight. They then regained body weight in spite of the recommended hypocalorie diet. No significant modifications in body fat distribution indexes were found by computed tomography between VLED and after regain of weight. No significant changes were found in metabolic variables. No interactions between menopausal status and regain of body weight were observed. In conclusion, regain of weight does not seem to cause an increase in visceral fat; both pre- and postmenopausal women showed the same body fat distribution before weight loss and after regain of weight.

Effect of altitude on body composition during mountaineering expeditions: interrelationships with changes in dietary habits.

Loss of body weight occurs during high mountain expeditions but whether it is due to inadequate diet or other factors is unknown. Moreover the composition of the weight loss is unclear. The aim of our study was to compare the nutritional, anthropometric and metabolic changes during a mountaineering expedition in two groups of climbers, whose dietary energy intake was ad libitum, one given a lacto-fish-ovo-vegetarian diet and one an omnivorous diet. The intake of various nutrients, body weight, body composition and metabolic variables were evaluated before and during high altitude exposure and after the return to low altitude. The two groups were matched for age, body mass index and gender. No significant differences were found for nutritional variables between the two groups. Energy, animal and vegetable protein and fiber intake were significantly lower at climbing quote than before the beginning of the expedition. Significant differences between before the beginning and base camp in all variables were found. Energy and animal protein intake, but not vegetable protein and fiber intake, were significantly lower at climbing quote than at base camp. All subjects significantly reduced body weight, body mass index, waist and hip circumferences but not fat-free mass and fat mass. Metabolic variables significantly improved after the mountaineering expedition. Our study seems to confirm that a mountaineering expedition decreases energy and protein intake, reduces body weight and improves metabolic variables. Because our subjects spontaneously tended to have the same food intake despite the different dietary recommendations, our study failed to observe any differences between the two groups. However, our study shows that a low protein diet, in which the type of protein is mostly vegetable protein, could be adapted for climbers determining only a small decrease of fat-free mass.

Obesity and regional body-fat distribution in men: separate and joint relationships to glucose tolerance and plasma lipoproteins.

Relationships between obesity and fat distribution as evaluated by computed tomography and metabolic variables were studied in 35 men. Significant correlations emerged between body mass index and sum of glucose during oral glucose load and HDL3 triglycerides and also between visceral abdominal fat and triglycerides, apolipoprotein B, sum of insulin during oral glucose load, very-low-density-lipoprotein (VLDL) cholesterol, and VLDL and low-density-lipoprotein (LDL) triglycerides. Visceral abdominal fat correlated negatively with the ratio of HDL to LDL cholesterol. When the subjects were subdivided into four groups according to body mass index (< or = 26.7, > 26.7) and median visceral abdominal fat, no significant differences were found in body mass index, whereas significant differences were found for triglycerides, cholesterol, apolipoprotein B, VLDL cholesterol, HDL:LDL cholesterol, and VLDL triglycerides. Our study shows that the amount of visceral abdominal fat is the most relevant factor for metabolic abnormalities. Our data also suggest that the effect of visceral fat is independent of body mass index.

Relationship between visceral fat, steroid hormones and insulin sensitivity in premenopausal obese women.

OBJECTIVES: The relationships between visceral fat distribution, steroid hormones and peripheral insulin sensitivity were studied. SETTING: All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona, Italy. SUBJECTS: Nineteen fertile obese women were studied with ages ranging from 18 to 53 years and body mass indexes ranging from 27.3 to 48.4. INTERVENTION: Body fat distribution was evaluated by waist-to-hip circumference ratio and by computed tomography. The insulin tolerance test was used to evaluate peripheral insulin sensitivity. Glucose, insulin and C-peptide were measured in fasting conditions and during glucose load; total and free plasma testosterone and urinary cortisol excretion were also determined. RESULTS: Significant correlations emerged between visceral adipose tissue and fasting glucose, insulin, and C-peptide, but not between visceral adipose tissue and total testosterone, free testosterone or urinary cortisol excretion. A negative correlation emerged between visceral adipose tissue and insulin sensitivity (r = -0.70; P < 0.01). No significant correlations were found between insulin sensitivity and age, body weight, body mass index, total adipose tissue, subcutaneous adipose tissue or waist-to-hip ratio. Total testosterone correlated with body weight, subcutaneous adipose tissue and total adipose tissue. Free testosterone and urinary cortisol excretion correlated positively with body weight, and negatively with age. No correlation was found between insulin sensitivity and total testosterone, free testosterone or urinary cortisol excretion. The correlation between visceral adipose tissue and insulin sensitivity remained significant even after adjusting for both age and the body mass index. CONCLUSIONS: Our study shows that visceral fat is more closely associated with aberrations of insulin sensitivity than with obesity itself. Total testosterone, free testosterone and urinary cortisol excretion in our subjects do not seem to be associated with such aberrations.

Measured and predicted total and visceral adipose tissue in women. Correlations with metabolic parameters.

The aim of this study was the verification of the clinical utility of predictive equations for total and intra-abdominal adipose tissue areas. Formulas were calculated using computed tomography (CT) as the gold standard. Ninety-three females were randomly divided into two groups. The predictive equation group was used to calculate the predictive equations for computed tomography adipose tissue areas at the L4-L5 level. These equations were then used to predict total and intra-abdominal adipose tissue area in the validation group. Correlations were made between metabolic parameters and both measured and calculated areas and single predictors. The following measurements were carried out: age, weight/height ratio, body mass index, waist, hip, waist/hip ratio, ultrasound measurement of intra-abdominal distance between abdominal muscle and aorta, sagittal abdominal diameter by CT, adipose tissue intra-abdominal area by CT, total abdominal adipose tissue area by CT. Blood glucose and insulin both fasting and after glucose load. Fasting cholesterol and triglycerides. The best predictors of total and visceral adipose tissue areas were, respectively: weight/height ratio and ultrasound intra-abdominal measurement. Correlations between metabolic parameters and adipose tissue areas both as measured and as calculated by predictive equations were quite similar. Correlations between metabolic parameters and single best predictors of measured adipose tissue areas also gave the same results. Some simple and safe anthropometric measurements can be used, instead of total and visceral adipose tissue area as assessed by CT, when studying associations between adipose tissue and metabolic parameters on sufficiently large groups of patients.

Effect of weight loss on regional body fat distribution in premenopausal women.

This study evaluates effects of weight loss on regional fat distribution and compares waist-to-hip ratio (WHR) and computed tomography (CT) as methods of assessing body fat distribution in 16 premenopausal obese women (body weight 104.3 +/- 18.1 kg, WHR 0.84 +/- 0.08). Mean weight loss was 6.6 kg after 2 wk on a very-low-energy diet (VLED) and 16 kg after 14 additional weeks on a low-energy diet (LED). Visceral abdominal fat and sagittal diameter significantly decreased after both the VLED and LED. Subcutaneous abdominal fat decreased significantly only after the LED. WHR showed no significant reduction over the entire study period. The decrease in visceral fat after both the VLED and LED was greater than the decrease in subcutaneous fat. Changes in body weight over the entire study period correlated with initial body weight and with total and subcutaneous abdominal fat, but not with visceral abdominal fat. They also correlated with changes in subcutaneous abdominal fat, visceral abdominal fat, sagittal diameter, and WHR. In conclusion, weight loss is associated with changes in regional fat distribution. In premenopausal subjects weight loss correlates more closely with the amount of subcutaneous than visceral fat.

Plasma acetate levels in a group of obese diabetic, obese normoglycemic, and control subjects and their relationships with other blood parameters.

Acetate is a short-chain fatty acid derived from colonic fermentation of carbohydrate and dietary fiber, and from endogenous glucose and fatty acid metabolism in the liver. An impaired acetate metabolism has been reported in diabetic subjects. The aim of the study was to evaluate plasma acetate levels in a group of obese diabetic subjects, compared with obese normoglycemic subjects and normal control subjects. Eleven noninsulin-dependent diabetic patients taking oral antidiabetic drugs, eight obese normoglycemic subjects, and seven control subjects were studied. Liver, kidney, and gut functions were normal in all subjects. Blood acetate, glucose, insulin, and C-peptide were evaluated in all subjects. Acetate levels were significantly higher in the diabetic subjects than in obese normoglycemic and normal subjects. Significant correlations between HbA1c, glucose, and acetate levels, but not between acetate and C-peptide or insulin, were also observed.