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Biomedical subjects

O Bosello

Publications and source records attributed to O Bosello.

At least 55 records · Page 3Linked to original sources

Interrelationships between intraabdominal fat and total serum testosterone levels in obese women.

Thirty-six women aged 18 to 52 years with body mass indexes (BMIs) between 27 and 52 were studied. Visceral and subcutaneous fat areas and body fat were evaluated by computerized tomography with a single scan at the IV-V lumbar vertebra level. Glucose, insulin, and C-peptide levels were measured before and after a glucose load. Total and free serum testosterone and 24-hour urinary cortisol excretion were measured. A stepwise multiple regression equation showed the visceral to subcutaneous fat area ratio to be the most powerful predictor for glucose alterations both during fasting and after a glucose load, and showed BMI to be the most powerful predictor for insulin and C-peptide levels. Total serum testosterone, after matching for age and BMI, demonstrates a significant negative correlation with visceral fat area. We conclude that in obese women, as in men, intraabdominal fat negatively correlates with serum testosterone levels.

Abdomen↗

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.

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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.

Adipose Tissue↗

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.

Adipose Tissue↗

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.

Adipose Tissue↗

High-density lipoprotein cholesterol concentrations and postheparin hepatic and lipoprotein lipases in obesity: relationships with plasma insulin levels.

The concentration of high-density lipoprotein (HDL) cholesterol in patients with severe obesity is generally subnormal. The exact mechanism linking obesity with reduced levels of HDL cholesterol remains unclear. In this study we evaluated the postheparin plasma lipolytic enzymes lipoprotein lipoprotein lipase (LPL) and hepatic lipase (HL) in a group of 24 obese women compared with controls and analyzed the interrelationships between insulin, postheparin lipolytic enzymes and HDL subfractions. Total HDL cholesterol was significantly lower in the obese subjects than in the controls, and the difference was mainly due to HDL2 cholesterol concentrations. Mean fasting glucose, insulin and the summated means of glucose (sigma glucose) after the oral glucose tolerance test (OGTT) were not significantly different in the two groups. The summated means of insulin (sigma IRI) after the OGTT were significantly higher in the obese women than in the controls. LPL, HL and the HL-to-LPL ratio were significantly higher in the obese women than in the controls. HL and LPL correlated positively with sigma glucose, sigma IRI and body mass index (BMI) and negatively with plasma triglycerides. Partial correlation analysis demonstrated that, when exposed to similar sigma IRI values, HL and LPL were no longer correlated with sigma glucose, plasma triglycerides and BMI. HDL2 cholesterol levels were negatively correlated with HL, posthepatic plasma lipolytic activity, sigma glucose, plasma triglycerides and BMI. HDL2 cholesterol concentrations were directly correlated with LPL. Partial correlation analysis showed that when exposed to similar HL and LPL values, HDL2 cholesterol values were no longer correlated with sigma glucose, sigma IRI, plasma triglycerides and BMI. Therefore, our results demonstrate that the low HDL2 cholesterol levels found in obese women may be related to the high levels of HL and to the high HL-to-LPL ratio which in turn could be determined by the peripheral insulin resistance.

Adult↗

Total and intra-abdominal fat measurements by ultrasound and computerized tomography.

Computerized tomography, a method of proven reliability for direct measurement of both total and visceral body fat, is not widely usable and alternative means of assessing body fat are required. Several anthropometric parameters, including ultrasound measurements of intra-abdominal and subcutaneous fat, were considered in 119 females (age 15-72 years, body mass index 24-51 kg/m2). Computerized tomography was also performed for total and visceral fat areas at the L4-L5 level. Reliability of each of these measurements in predicting total fat was assessed. Tertiles for visceral fat area were calculated (< 114, 114-170, > 170 cm2). Only ultrasound intra-abdominal fat measurements were able to distinguish between all three VAT groups (16 +/- 10, 32 +/- 13, 50 +/- 22 mm); neither sagittal diameter nor waist/hip girth ratio were able to distinguish between the two > 114 cm2 groups. Predictive equations for total adipose tissue area confirmed weight/height ratio as the best predictor of total fat. Ultrasound intra-abdominal thickness was the 1 degree variable to enter the stepwise regression in predictive equations for visceral adipose tissue area. The 2 degrees was age, the 3 degrees sagittal diameter, the 4 degrees waist/hip girth ratio and the 5 degrees ultrasound subcutaneous abdominal thickness (adjusted r2 = 0.784; P < 0.001).

Abdomen↗

Alcohol consumption, smoking habits and body fat distribution in Italian men and women aged 20-60 years.

The study was performed on 601 patients (294 males and 307 females) of a general practitioner. Alcohol intake and smoking habits were compared with other anthropometric measurements including waist-to-hip girth ratio. Patients were divided into non-smokers and smokers (subdivided into three groups according to the number of cigarettes smoked per day) and into non-drinkers and drinkers (subdivided into three groups with different alcohol intakes). Ex-smokers were excluded from the study. Analysis of covariance using age, body mass index, physical activity and menopausal status as covariates, showed that: (1) cigarette smoking is not accompanied by a specific pattern for body fat distribution; (2) waist-to-hip ratio was significantly different for the four classes of alcohol intake for women (non-drinkers: 0.809, < 11 g: 0.805, 11-20 g: 0.809, > 20 g: 0.826; F = 2.8, P < 0.05) but not for men (non-drinkers: 0.944, < 20 g: 0.934, 21-40 g: 0.940, > 40 g: 0.943; F = 0.9); (3) increased alcohol intake corresponds to an increased lipid and energy supply.

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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.

Acetates↗

Relation of body fat distribution in men and degree of coronary narrowings in coronary artery disease.

This study evaluates the relation between body fat distribution and severity of coronary artery disease (CAD). The study sample comprised 33 patients with angiographically demonstrated CAD and 10 angiographically normal control subjects. Body fat distribution was estimated by computed tomography and degree of coronary narrowings by angiographic score. Body weight, body mass index and total and subcutaneous abdominal adipose tissue areas showed no statistical differences in the 2 groups; visceral abdominal adipose tissue area and the visceral to subcutaneous abdominal adipose tissue area ratio were significantly higher in patients with CAD (p < 0.05). There was a significant correlation between visceral fat and triglycerides, apoprotein B and sum of glucose and insulin during glucose oral tolerance test. Sum of insulin during glucose oral tolerance test, visceral abdominal adipose tissue area and visceral/subcutaneous abdominal adipose tissue area ratio correlated significantly with severity of CAD, as evaluated by coronary score in all subjects and in CAD patients alone. Stepwise multiple regression analysis using the coronary score as the dependent variable and anthropometric and metabolic parameters as independent variables shows that in all subjects and in CAD patients alone, visceral/subcutaneous abdominal adipose-tissue area ratio entered the regression first and the sum of insulin during glucose oral tolerance test second. The results suggest that visceral abdominal adipose tissue area and visceral to subcutaneous abdominal adipose tissue area ratio may be cardiovascular risk factors.

Abdomen↗

Exocrine and endocrine functional reserve in the course of chronic pancreatitis as studied by maximal stimulation tests.

Thirty patients suffering from chronic alcoholic pancreatitis (18 calcified) were entered into a study of exocrine and endocrine pancreatic function based on two maximal stimulation tests, namely the secretin-cerulein test and the glucagon test with serum assays of C peptide. The glucagon test was also performed in 19 control subjects. In addition, 10 chronic pancreatitis patients and nine controls were subjected to an oral glucose tolerance test (OGTT) with serum insulin determinations. C peptide basal values were decreased only in patients with severe pancreatic exocrine insufficiency (P less than 0.001), while delta C peptide values were also reduced in patients with moderate exocrine insufficiency (P less than 0.001). Lipase output correlated very well with delta C peptide values (P less than 0.001). While serum insulin levels during OGTT and C peptide basal values showed no significant differences between the chronic pancreatitis and control groups, delta C peptide values were significantly reduced in chronic pancreatitis patients (P less than 0.02). Both endocrine and exocrine function are impaired in chronic pancreatitis, as demonstrated by maximal tests, even in early stages of the disease.

Adult↗

Resting metabolic rate, body-fat distribution, and visceral fat in obese women.

Resting metabolic rate (RMR) was evaluated in 27 obese women aged 16-49 y [body mass index (in kg/m2) 27-51] by indirect calorimetry. Visceral and subcutaneous adipose tissue areas, body fat, and fat-free mass (FFM) were measured by a single scan with computed tomography (CT); the waist-hip circumference ratio (W/H) was also used. Comparison between the lowest and the highest RMR quartiles--adjusted for age and FFM--revealed a higher W/H in the highest quartile (0.78 +/- 0.08 vs 0.88 +/- 0.08; P < 0.05). No difference was observed in CT indexes. No differences in W/H were observed after RMR was adjusted for age, FFM, and body fat. Our results point out that RMR, adjusted for FFM and age, correlates with body-fat distribution as evaluated by W/H, but not with visceral fat, as evaluated by CT. Correlations disappeared after RMR was adjusted for body fat as well.

Adipose Tissue↗

Evaluation of regional body fat distribution: comparison between W/H ratio and computed tomography in obese women.

Measurements of regional body fat distribution as determined by waist-to-hip ratio and visceral-to-subcutaneous adipose tissue ratio were compared in 63 obese women. Subjects were divided into three CT-evaluated tertiles on the basis of visceral-to-subcutaneous adipose tissue ratio (group I, 0.05-0.231; group II, 0.232-0.344; group III, 0.345-0.781). The three groups showed no appreciable differences in body weight, body mass index or total abdominal adipose tissue. Waist-to-hip ratio values were significantly lower in group I than in groups II and III. There was no statistically significant difference between groups II and III. Visceral abdominal adipose tissue was significantly and progressively higher in the three groups. Subcutaneous abdominal adipose tissue was significantly lower in group III than in group I. All metabolic variables and systolic and diastolic blood pressure were higher when visceral-to-subcutaneous adipose tissue ratio cut-off values were increased. Waist-to-hip ratio was significantly correlated with total adipose tissue, body mass index, visceral abdominal adipose tissue and subcutaneous abdominal adipose tissue. Visceral-to-subcutaneous adipose tissue ratio was correlated with visceral abdominal adipose tissue (r = 0.84, P < 0.01) and subcutaneous abdominal adipose tissue (r = -0.28, P < 0.05). There was no correlation between visceral-to-subcutaneous adipose tissue ratio and body mass index or total abdominal adipose tissue. Visceral-to-subcutaneous adipose correlated more closely with metabolic variables than did waist-to-hip ratio. Partial correlations between waist-to-hip ratio and visceral-to-subcutaneous adipose tissue ratio and metabolic variables, adjusted for body mass index, showed statistically significant relationships for visceral-to-subcutaneous adipose tissue ratio, but not for waist-to-hip ratio. Visceral-to-subcutaneous adipose tissue ratio correlated with waist-to-hip ratio in the study population as a whole, but only in group I did the correlation between visceral-to-subcutaneous adipose tissue ratio and waist-to-hip ratio prove statistically significant. The present study demonstrates that visceral-to-subcutaneous adipose tissue ratio is a better index of body fat distribution than waist-to-hip ratio.

Adipose Tissue↗

Effect of a diet high in monounsaturated fat from almonds on plasma cholesterol and lipoproteins.

The effect of almonds as part of a low saturated fat, low cholesterol, high-fiber diet was studied in 26 adults (13 men, 13 women). The baseline diet was modified in a similar way for all subjects by limiting meat, fatty fish, high-fat milk products, eggs, and saturated fat. Grains, beans, vegetables, fruit, and low-fat milk products were the foundation of the diet. During the almond diet period, raw almonds (100 mg/day) supplied 34 g/day of monounsaturated fatty acid (MUFA), 12 g/day of polyunsaturated fatty acid, and 6 g/day of saturated fatty acid. Almond oil was the only oil allowed for food preparation. There was a rapid and sustained reduction in low-density lipoprotein cholesterol without changes in high-density lipoprotein cholesterol. This was reflected in a total plasma cholesterol decrease from (means +/- SEM) 235 +/- 5.0 at baseline to 215 +/- 5.0 at 3 weeks, and to 214 +/- 5.0 mg/dl at 9 weeks (p less than 0.001). When the consumption of nuts high in MUFA increases the fat content of the diet, reduction rather than elevation of plasma cholesterol has to be expected, possibly due to the MUFA content of these nuts.

Adult↗

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)

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The association of body fat location with haemodynamic and metabolic status in men and women aged 21-60 years.

The importance of body fat location as a predictor of metabolic aberrations was evaluated in 214 males and 244 females [aged 21-60] randomly selected from the patients of one general practice of Castel D'Azzano (Italy). The metabolic pattern, indexed by blood pressure, blood glucose, uric acid, serum triglycerides, HDL- and LDL-cholesterol was summarized in a haemodynamic-metabolic score (HMS). Association of HMS with age, anthropometric variables (skinfold thicknesses, girth lengths) and degree of overweight (body mass index, BMI) was evaluated in males and females using multiple regression analysis. Body fat location was associated with metabolic status independent of age in both sexes. This association was also independent of the degree of overweight. BMI, in general, was associated with HMS to a greater extent than anthropometric variables, except for waist girth; when its effect was taken into account BMI did not significantly improve the prediction power of HMS values in males. Among skinfolds, epimesogastric showed in both sexes the highest association with HMS. These results support the abdominal adiposity hypothesis and suggest that waist circumference could be a good index for assessing metabolic status. The abdominal location of adipose tissue, more than just the degree of overweight, could play a role in obesity related disorders.

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Propionate lowers blood glucose and alters lipid metabolism in healthy subjects.

Incorporation of 3.3 g sodium propionate per 50 g available carbohydrate portion of bread reduced acutely the blood glucose response area in six healthy volunteers by 47.6 +/- 12.1% Similarly, in vitro digestibility was reduced by 47.4 +/- 1.1% (P less than 0.01). One week of dietary supplementation with 9.9 g sodium propionate in bread/d reduced the blood glucose area in comparison with standard propionate-free bread by 38.0 +/- 8.7% (P less than 0.05), but increased fecal bulk by 28.3 +/- 8.7% (P less than 0.05) and anaerobic microflora by 0.564 +/- 0.165 X 10(6)/g feces (P less than 0.05), specifically as bifidobacteria. Day-long breath hydrogen concentrations did not increase after 1 wk on propionate bread but methane production increased in the three methane producers. Although lipid changes were not significant, five subjects showed reduced high-density-lipoprotein and increased triglyceride concentrations, both of which correlated with increased fecal weight (P less than 0.05). Because propionate reduces the rate of starch digestion, studies using oral propionate must take into account its action as an enzyme inhibitor.

Adult↗