Total Fat Volume Research Articles

Men develop more intraabdominal obesity and signs of the metabolic syndrome after hyperalimentation than women

We prospectively studied the effects of fast food–based hyperalimentation on insulin sensitivity and components of the metabolic syndrome and analyzed this with respect to sex. Twelve nonobese men and 6 nonobese women (26 ± 6.6 years old), and an age-matched control group were recruited. Subjects in the intervention group aimed for 5% to 15% weight increase by doubling their regular caloric intake based on at least 2 fast food meals a day while also adopting a sedentary lifestyle for 4 weeks (<5000 steps a day). Weight of subjects in the intervention group increased from 67.6 ± 9.1 to 74.0 ± 11 kg ( P < .001), with no sex difference with regard to this or with respect to changes of total abdominal fat volumes or waist circumferences. Fasting insulin (men: before, 3.8 ± 1.7 μU/mL; after, 7.4 ± 3.1 μU/mL; P = .004; women: before, 4.9 ± 2.3 μU/mL; after, 5.9 ± 2.8 μU/mL; P = .17), systolic blood pressure (men: before, 117 ± 13 mm Hg; after, 127 ± 9.1 mm Hg; P = .002; women: before, 102 ± 5.1 mm Hg; after, 98 ± 5.4 mm Hg; P = .39), serum low-density lipoprotein cholesterol, and apolipoprotein B increased only in the men of the intervention group. The sex differences in the metabolic responses to the intervention were linked to a considerable difference in the fat accumulation pattern; 41.4% ± 9.2% of the increase of the fat volume in the abdominal region was accumulated intraabdominally in men and 22.7 ± 6.5% in women ( P < .0001). This study thus showed that women are protected, compared with men, against developing intraabdominal obesity when adopting a standardized obesity-provoking lifestyle. Our findings suggest that it is not different lifestyles and/or behaviors that underlie the fact that men have a higher cardiovascular risk at the same level of percentage of body fat than women.

External Ultrasound-Assisted Liposuction of the Abdomen: A Report of our Experience

Introduction: Ultrasound-assisted liposuction (UAL) is currently an accepted and commonly used method, although the incidence of complications is noteworthy. In 1997, Silberg introduced the concept of external ultrasound-assisted liposuction (XUAL) to facilitate the standard technique with an expected decreased incidence of complications when compared with UAL. This article reports our experience with XUAL of the abdomen at a single cosmetic surgery center over a 1-year period. Methods: Two groups of 15 patients each underwent abdominal liposuction. Group 1 received the tumescent technique, and Group 2 received external ultrasound treatment, again using the tumescent technique. Ultrasonic energy was applied to the entire abdominal area in a standard fashion using the Intellect Legend Combo 2-C ultrasound unit set to 1.5 watts/cm2 continuous pulse for 10 minutes immediately following infusion of the tumescent solution. Patients were evaluated postoperatively for adverse events. Adverse events were defined as excessive edema, ecchymosis, seroma greater than 50 cc, hematoma, infection, and wound breakdown. Results: No cases of adverse events occurred in any patient in the immediate postoperative period. However, at the first postoperative appointment, it was notable that 2 of 15 patients in group 1 (13%) had developed a significant (&gt;50 cc) lower abdominal seroma. Both patients were successfully treated with a single closed drainage procedure in the office via needle aspiration. In group 2 at the first postoperative visit, it was notable that 5 of the 15 patients (33%) presented with a significant (&gt;50 cc) lower abdominal seroma. All patients in group 2 were successfully treated with drainage of the fluid via needle aspiration or by opening the midline lower port and placing a passive drain (in several cases). An average of 2.5 drainage procedures was required for resolution of the seromas in group 2. Discussion: The incidence of seroma formation was clearly linked to higher body mass index (BMI) and total fat volume removed. Consistent variables included tumescent volume infused, amount of ultrasound energy delivered, and cannula size used during the tumescent infusion and aspiration procedure. In most patients, the flanks and low back were also sculpted with the liposuction technique; however, the abdomen was the only area treated preoperatively with ultrasound. It is notable that the only area to develop a seroma was the abdomen, which suggests that the ultrasound could be related to seroma formation. The cause of seroma formation remains unknown; however, the possibilities of septal breakdown, lymphatic and venous damage, and cavity formation are reasonable. Conclusion: The incidence of seroma formation may be increased with XUAL of the abdomen. Additional studies are needed to prove that the benefits of XUAL treatment provided preoperatively outweigh the risk for adverse events.

Loss of Total and Visceral Adipose Tissue Mass Predicts Decreases in Oxidative Stress After Weight‐loss Surgery

It is not known whether there are mechanisms linking adipose tissue mass and increased oxidative stress in obesity. This study investigated associations between decreasing general and abdominal fat depots and oxidative stress during weight loss. Subjects were severely obese women who were measured serially at baseline and at 1, 6 (n = 30), and 24 months (n = 18) after bariatric surgery. Total fat mass (FAT) and volumes of visceral (VAT) and subcutaneous abdominal adipose tissue (SAT) were related to plasma concentrations of derivatives of reactive oxidative metabolites (dROMS), a measure of lipid peroxides and oxidative stress. After intervention, BMI significantly decreased, from 47.7 +/- 0.8 kg/m(2) to 43.3 +/- 0.8 kg/m(2) (1 month), 35.2 +/- 0.8 kg/m(2) (6 months), and 30.2 +/- 1.2 kg/m(2) (24 months). Plasma dROMS also significantly deceased over time. At baseline, VAT (r = 0.46), FAT (r = 0.42), and BMI (r = 0.37) correlated with 6-month decreases in dROMS. Similarly, at 1 month, VAT (r = 0.43) and FAT (r = 0.41) correlated with 6-month decreases in dROMS. Multiple regression analysis showed that relationships between VAT and dROMS were significant after adjusting for FAT mass. Increased plasma dROMS at baseline were correlated with decreased concentrations of high-density lipoprotein (HDL) at 1 and 6 months after surgery (r = -0.38 and -0.42). This study found longitudinal associations between general, and more specifically intra-abdominal adiposity, and systemic lipid peroxides, suggesting that adipose tissue mass contributes to oxidative stress.

Evaluation of the Doppler Technique for Fat Emboli Detection in an Experimental Flow Model

Pericardial suction blood (PSB) is known to be contaminated with fat droplets, which may cause embolic brain damage during cardiopulmonary bypass (CPB) This study aimed to investigate the possibility to detect fat emboli by a Doppler technique. An in vitro flow model was designed, with a main pump, a filter, a reservoir, and an injector. A Hatteland Doppler probe was attached to the circulation loop to monitor particle counts and their size distribution. Suspended soya oil or heat-extracted human wound fat was analyzed in the model. The concentrations of these fat emboli were calibrated to simulate clinical conditions with either a continuous return of PSB to the systemic circulation or when PSB was collected for rapid infusion at CPB weaning. For validation purpose, air and solid emboli were also analyzed. Digital image analysis was performed to characterize the nature of the tested emboli. With soya suspension, there was an apparent dose response between Doppler counts and the nominal fat concentration. This pattern was seen for computed Doppler output (p = .037) but not for Doppler raw counts (p = .434). No correlation was seen when human fat suspensions were tested. Conversely, the image analysis showed an obvious relationship between microscopy particle count and the nominal fat concentration (p &lt; .001). However, the scatter plot between image analysis counting and Doppler recordings showed a random distribution (p = .873). It was evident that the Doppler heavily underestimated the true number of injected fat emboli. When the image analysis data were subdivided into diameter intervals, it was discovered that the few large-size droplets accounted for a majority of total fat volume compared with the numerous small-size particles (&lt;10 μm). Our findings strongly suggest that the echogenecity of fat droplets is insufficient for detection by means of the tested Doppler method.

Abdominal fat distribution and insulin resistance in Indian women with polycystic ovarian syndrome

The relationship between insulin resistance and abdominal fat distribution was studied in Indian patients with PCOS. Subcutaneous fat, together with a family history of type 2 diabetes mellitus, was the best marker of insulin resistance.

Application of breast ultrasound in classification and plastic surgical management of gynecomaslia

Objective To investigate the possibility of using the results of breast ultrasound and Cohen-classification to determine the gynecomastia patients' subtype, and to evaluate the effectiveness of different surgical methods based on the classification. Methods In the past 3 years, 40 with gy-necomastia were treated in this hospital. The patients age ranged from 18 to 50 years, with an average of 21.38. All the had the bilateral lesions, and their pathological diagnosis was gynecomastia. The mammary gland resected from each side weighted from 30 to 180 grams. The total fat volume liposucted ranged from 200 ml to 1 200 ml. As a routine, we performed breast ultrasound examination before the op-eration on each patient. According to the different echo, we marked the extent of breast gland on the chest walls and determine the Cohen classification of the patients. For breast tissue hyperplasia, we only resected the gland under the direction of the chest wall marks. For fat tissue hyperplasia, we just per-formed liposuction. For with mixed fat and gland hyperplasia, we combined these two methods rationally. If necessary, the procedures was repeated. Results With the help of breast ultrasound exami-nation, the operating procedure was more accurate and simple, as a result, our treatments had less injury and no severe complications. After a following-up of 6-36 months, satisfactory results were achieved, with normal male chest appearance and small obscure scar. Conclusions Male breast surgery is totally different from the females. The Cohen classification has been determined for each gynecomastia patient, based on the results of breast ultrasound examination, which helps choose the surgical methods and procedures and decrease surgical injuries and complications, with satisfactory results. Key words: Gynecomastia; Cohen-lassification; Breast ultrasound examination

In vivo quantification of subcutaneous and visceral adiposity by micro-computed tomography in a small animal model

Accurate and precise techniques that identify the quantity and distribution of adipose tissue in vivo are critical for investigations of adipose development, obesity, or diabetes. Here, we tested whether in vivo micro-computed tomography (microCT) can be used to provide information on the distribution of total, subcutaneous and visceral fat volume in the mouse. Ninety C57BL/6J mice (weight range: 15.7–46.5 g) were microCT scanned in vivo at 5 months of age and subsequently sacrificed. Whole body fat volume (base of skull to distal tibia) derived from in vivo microCT was significantly ( p < 0.001) correlated with the ex vivo tissue weight of discrete perigonadal ( R 2 = 0.94), and subcutaneous ( R 2 = 0.91) fat pads. Restricting the analysis of tissue composition to the abdominal mid-section between L1 and L5 lumbar vertebrae did not alter the correlations between total adiposity and explanted fat pad weight. Segmentation allowed for the precise discrimination between visceral and subcutaneous fat as well as the quantification of adipose tissue within specific anatomical regions. Both the correlations between visceral fat pad weight and microCT determined visceral fat volume ( R 2 = 0.95, p < 0.001) as well as subcutaneous fat pad weight and microCT determined subcutaneous fat volume ( R 2 = 0.91, p < 0.001) were excellent. Data from these studies establish in vivo microCT as a non-invasive, quantitative tool that can provide an in vivo surrogate measure of total, visceral, and subcutaneous adiposity during longitudinal studies. Compared to current imaging techniques with similar capabilities, such as microMRI or the combination of DEXA with NMR, it may also be more cost-effective and offer higher spatial resolutions.

The vitamin D receptor gene BsmI polymorphism is not associated with anthropometric and biochemical parameters describing metabolic syndrome in postmenopausal women

Aim. Vitamin D could have a direct effect on adipocyte differentiation and metabolism and might be involved in glucose regulation of insulin secretion. In recent years several polymorphisms in the gene encoding the vitamin D receptor (VDR), which are potent to alter the activity of VDR protein, have been described. The present study aimed to investigate the prevalence of the VDR BsmI polymorphism and its association with anthropometric and biochemical features of metabolic syndrome in postmenopausal women.Materials and methods. We studied 351 randomly selected healthy postmenopausal women, with mean age of 55.43 ± 2.75 years and mean body mass index (BMI) of 27.5 ± 4.78 kg/m2, to evaluate the frequency of BsmI polymorphism (by restriction fragment length polymorphism–polymerase chain reaction) in the VDR gene and to find out whether there is an association between this polymorphism and BMI, total fat volume and visceral fat (as determined by total body dual-energy X-ray absorptiometry), blood pressure, lipid profile (total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides) glucose and fasting insulin in the whole group, as well as subgroups of obese and non-obese women.Results. The prevalence of BsmI genotypes in the study group was 51.0% Bb, 37.3% bb and 11.7% BB. Genotype distribution did not differ from that expected under Hardy–Weinberg equilibrium conditions (χ2 = 2.95, p = 0.22). Apart from LDL-C levels (F = 3.46, p = 0.032), there were no significant differences in anthropometric or metabolic parameters between genotypes.Conclusions. The BsmI polymorphism in the VDR gene does not seem to predispose to obesity and insulin resistance, but the BB genotype is connected with an unfavorable lipid profile.

Pancreas volumes in humans from birth to age one hundred taking into account sex, obesity, and presence of type‐2 diabetes

Our aims were (1) by computed tomography (CT) to establish a population database for pancreas volume (parenchyma and fat) from birth to age 100 years, (2) in adults, to establish the impact of gender, obesity, and the presence or absence of type-2 diabetes on pancreatic volume (parenchyma and fat), and (3) to confirm the latter histologically from pancreatic tissue obtained at autopsy with a particular emphasis on whether pancreatic fat is increased in type-2 diabetes. We measured pancreas volume in 135 children and 1,886 adults (1,721 nondiabetic and 165 with type-2 diabetes) with no history of pancreas disease who had undergone abdominal CT scan between 2003 and 2006. Pancreas volume was computed from the contour of the pancreas on each CT image. In addition to total pancreas volume, parenchymal volume, fat volume, and fat/parenchyma ratio (F/P ratio) were determined by CT density. We also quantified pancreatic fat in autopsy tissue of 47 adults (24 nondiabetic and 23 with type-2 diabetes). During childhood and adolescence, the volumes of total pancreas, pancreatic parenchyma, and fat increase linearly with age. From age 20–60 years, pancreas volume reaches a plateau (72.4 ± 25.8 cm3 total; 44.5 ± 16.5 cm3 parenchyma) and then declines thereafter. In adults, total (∼32%), parenchymal (∼13%), and fat (∼68%) volumes increase with obesity. Pancreatic fat content also increases with aging but is not further increased in type-2 diabetes. We provide lifelong population data for total pancreatic, parenchymal, and fat volumes in humans. Although pancreatic fat increases with aging and obesity, it is not increased in type-2 diabetes. Clin. Anat. 20:933–942, 2007. © 2007 Wiley-Liss, Inc.

Clinical usefulness of quantitative evaluation of visceral fat by ultrasonography.

The aim of this work was to evaluate the usefulness of a proposed method for visceral fat volume assessment by ultrasonography (US) in identifying those at risk of metabolic syndrome, and also to establish the most suitable cutoff level of waist circumference for the diagnosis of visceral adiposity. One hundred and fifty-two outpatients with metabolic diseases such as hypertension, diabetes, or dyslipidemia were studied. The total visceral fat volume (total-VFA) was measured by computed tomography (CT), the visceral fat area at the level of the umbilicus was measured by CT (CT-VFA), and the visceral fat area was also measured by US (US-VFA), as we recently proposed. Significant correlation coefficients were found between total-VFA and CT-VFA, US-VFA, and waist circumference in men but not in women. The correlation co-efficient between US-VFA and waist circumference was significantly positive in men and weakly positive in women. According to receiver-operator characteristic curves, the cutoff value of waist circumference yielding the maximal sensitivity plus specificity for predicting more than 100 cm(2) of US-VFA was 85 cm in men and 84 cm in women. The change in US-VFA was significantly larger than that in waist circumference after a 6-month interval. The US-measured visceral fat area is more useful than waist circumference in a clinical setting.

Total and Intraabdominal Fat Distribution in Preadolescents and Adolescents: Measurement with MR Imaging

To prospectively correlate single- and multisection magnetic resonance (MR) imaging measurements with clinical measurements for assessment of abdominal adipose tissue volumes in healthy (control subjects), overweight, and diabetic overweight preadolescents and adolescents. The study was approved by the institutional internal review board and was HIPAA compliant. Informed consent was obtained from parents, and assent was obtained from control subjects and patients. Thirty total study subjects (20 male, 10 female; age range, 10-18 years; mean, 14.5 years) underwent MR imaging, anthropometric measurement, and dual x-ray absorptiometry (DXA). A computer-assisted software program was used to quantify subcutaneous, visceral, and total abdominal adipose tissue volumes. Single-section measurements at disk space L4-L5 and whole-abdominal multisection measurements were compared, and each method was tested for correlations with anthropometric and DXA measurements with Spearman rho and Pearson correlation (r) coefficients. Single- and multisection image analyses required 5 and 25 minutes per subject, respectively. There was a high degree of correlation between single- and multisection MR imaging methods for measurement of subcutaneous (r = 0.97), visceral (r = 0.96), and total abdominal fat (r = 0.97). MR imaging fat measurements strongly correlated with anthropometric measurements (rho correlation range, 0.81-0.96; P <or= .02), with overlapping 95% confidence intervals (CIs) for single- and multisection MR imaging correlations. MR imaging percentage of intraabdominal fat measurements (mean, 23%; 95% CI: 17%, 29%) highly correlated with DXA abdominal fat measurements (mean, 26%; 95% CI: 21%, 31%). Significant differences were found among healthy subjects, overweight patients, and diabetic overweight patients for total fat volumes (P < .001) but not for fat distribution patterns. Single- and multisection MR imaging measurements for the quantitative assessment of abdominal adipose tissue strongly correlate with clinical and DXA fat measurements.

Correlation Between Anthropometric Parameters and Abdominal Fat Volumes Assessed by a Magnetic Resonance Imaging Method in Patients with Diabetes

Anthropometric measurements such as body mass index (BMI), waist-to-hip ratio, or waist circumference are used in clinical settings as a rough estimation of abdominal fat volumes. In contrast, abdominal magnetic resonance imaging (MRI) allows a precise and noninvasive imaging modality to measure the whole abdominal fat volumes. The main difference between the two methods is that only MRI provides detailed anatomical information about fat distribution in terms of a three-dimensional volumetric model. The aim of this study was to evaluate the relationship between selected anthropometric parameters and MRI-estimated abdominal fat volumes in patients with diabetes. Total fat volume coverage of the abdomen was obtained in a total of 37 patients with diabetes (mean +/- SD age, 48 +/- 13 years) with a BMI of 27.9 +/- 3.6 kg/m2 and a waist-to-hip ratio of 0.94 +/- 0.01 using T1-weighted magnetic resonance images. Quantification of intraabdominal, subcutaneous, and total abdominal fat volumes was performed using a semiautomated computer-assisted analysis of the images. Anthropometric parameters (height, weight, BMI, circumference hip, waist circumference, and waist-to-hip ratio) of all patients and abdominal fat volumes estimated by the MRI method proposed were correlated. The volumes estimated were as follows: intraabdominal fat, 10.5 +/- 5.0 L; subcutaneous fat, 15.2 +/- 7.3 L; and total abdominal fat, 25.7 +/- 11.5 L. The correlation coefficients between BMI and the three different fat volumes were, respectively, r = 0.38, r = 0.31, and r = 0.36. For the waist-to-hip ratio the respective correlation coefficients were r = 0.46, r = 0.14, and r = 0.29. Correlation in patients with diabetes of abdominal fat volumes estimated with a reliable MRI method with conventionally applied anthropometric parameters revealed poor correlation coefficients. In contrast, the fat volume determination by means of the novel MRI analysis method is rapid and reliable. Therefore, this method has the potential to be of high value in studies in patients with diabetes.

A rapid and reliable semiautomated method for measurement of total abdominal fat volumes using magnetic resonance imaging

The aim of this study was the development of a reliable and fast method to estimate total abdominal fat volumes (TAF) in diabetic subjects on the basis of T1-weighted MR images. Thirty-seven patients with diabetes were examined (age 48 ± 13 y mean ± SD). A semiautomated computer assisted software program was developed to quantify intraabdominal (IAF), subcutaneous (SCF), and total abdominal fat volumes (TAF). The variability of image analysis for fat measurements between two observers and within observers was assessed. Mean volumes (± SD) for IAF, SCF and TAF were 10.5 1 (± 5.0 1), 15.1 1 (±7.3 1) and 25.7 1 (±11.5 1), respectively. Inter- and intraobserver reliability was excellent (r = 0.999 to r = 1.0). Per patient, the analysis required nine minutes in addition to a scan duration of seven minutes. As this analytic method using T1-weighted MR images allows a fast and reliable quantification of TAF, IAF and SCF, it may serve as a valuable tool for respective studies in diabetic subjects.

The influence of diet properties and feeding rates on PCB toxicokinetics in the ring dove.

The influence of diet properties and feeding rate on the uptake and elimination of polychlorinated biphenyls (PCBs) was investigated in ring doves (Streptopelia rissoria). Elimination rates of PCBs were determined in birds dosed with an Aroclor mixture (1242:1248:1260, 1:1:1) and allowed to depurate on uncontaminated high-lipid or low-lipid/high-fiber diets for 105 days. Uptake rates for seven additional PCBs not found within the above Aroclor mixtures were studied in the same birds by feeding high- or low-lipid PCB-spiked diets for 15 days. The two diet treatments contributed to differences in feeding rates, fecal egestion rates, and total fat volume of the birds. Uptake rate constants of PCBs were higher for the low-lipid diet group, whereas PCB assimilation efficiencies were similar between the two groups. Whole-body elimination rates of Aroclor PCBs were most strongly influenced by the chlorine substitution pattern of the congeners, such that PCBs containing an open meta-para site on one of the phenyl rings were rapidly cleared from the animal. Whole-body elimination rates for persistent PCBs could only be determined for PCB 28; other congeners exhibited negligible elimination over the depuration period. For the latter compounds, fecal elimination rates were estimated using the excreta/carcass distribution coefficient and excreta production rates. For PCB 28, the fecal elimination rate was similar to the whole-body elimination rate, suggesting that fecal elimination of persistent PCBs dominates whole body elimination of these compounds. Diet treatment effects were less evident for PCB elimination rates compared to uptake rates. Steady-state biomagnification factors were estimated to range from 1.0 to 5.1 for rapidly cleared PCBs and from 27 to 97 for persistent congeners.

A novel method of measuring intra-abdominal fat volume using helical computed tomography.

:We present a novel method of scanning for intra-abdominal fat volume by helical computed tomography (CT), and describe the clinical significance of measuring the volumes of intra-abdominal visceral fat (V(vol)) and subcutaneous fat (S(vol)) vs these respective areas determined by conventional slice-by-slice CT at the umbilical level. Subjects with obesity or hyperlipidemia (79 men, 74 women) were recruited for this study. We obtained helical CT scans with a tube current of 150 mA, voltage of 120 kV and 2:1 pitch (table speed in relation to slice thickness), starting at the upper edge of the liver and continuing until the pelvis. The intra-abdominal visceral fat volume was measured by drawing a line within the muscle wall surrounding the abdominal cavity. The abdominal subcutaneous fat volume was calculated by subtracting the visceral fat volume from the total abdominal fat volume. By comparison, the intra-abdominal visceral and subcutaneous fat areas were determined at the umbilical level by the established slice-by-slice CT scanning technique. V(vol) was correlated positively with visceral fat area (V(area)) measured by conventional CT in both genders (in men (n=79) V(vol) vs V(area), r=0.81 P<0.0001; in women (n=74) V(vol) vs V(area), r=0.85, P<0.0001). S(vol) also showed a positive correlation with subcutaneous fat area (S(area)) in both genders (in men (n=78) S(vol) vs S(area), r=0.95, P<0.0001; in women (n=74) S(vol) vs S(area), r=0.92, P<0.0001). We have reported a novel method for measuring intra-abdominal fat volume by the use of helical CT.

VALIDITY EVALUATION OF THE TAIWAN CHINESE PERCENT FAT PREDICTION EQUATION

1571 Hsieh, Lin and Chan ( Med. Sci. Sports Exerc. 28(5): S150, 1996) studied adipose tissue samples from the Chinese population in Taiwan, and found that the fat density was 0.9449 g/ml, and the fat-free density was 1.0975 g/ml. A new Taiwan Chinese percent fat equation (TC Equation) was developed as (680/body density) - 618. The purpose of this study was to validate this new TC Equation using magnetic resonance imaging (MRI) measured% fat as criteria. Sixteen (16) Taiwan Chinese (8 male and 8 female, 34.0± 8.8yrs, 166.9 ± 8.6cm, 65.5 ± 12.3kg) who were all different from the previous study served as subjects. Total fat volume was determined using MRI, and total fat mass was calculated using 0.9449g/ml as the density. The MRI measured% body fat was 26.13 ± 7.66%. Furthermore, total body volume was determined by underwater weighing, and total body density (Db) was obtained. This Db value resulted in a 26.65 ± 7.40% fat from the TC Equation, which was highly correlated (r=0.99) with the MRI measured% fat. This Db value also produced a 20.00 ± 5.38% fat from the Siri (1956) equation, which was significantly less than the value from the TC Equation. Conclusions: The population specific Taiwan Chinese% fat equation is a valid equation for the Chinese people in Taiwan. Further use of the Siri equation for this population is not recommended.

Body fat estimation in children by magnetic resonance imaging, bioelectrical impedance, skinfold and body mass index: a pilot study.

The aim of this study was to identify the clinical method to estimate body fat which gave best correlation of total body fat and percentage body fat as measured on MRI. Magnetic resonance imaging (MRI) was used to estimate the total body fat volume and percentage body fat and this was compared with assessment by bioelectrical impedance (BEI), skinfold thickness and body mass index (BMI) in 8- to 12-year-old children. Total body fat measured on magnetic resonance imaging (TBF-MRI) significantly correlated with body mass index, triceps and subscapular skinfolds, and percentage body fat estimations by BEI. Multiple regression analysis showed that BMI and BEI together gave the best prediction of total body fat as measured on MRI from the equation: TBF-MRI=-25277.77+1457.61(BMI)+423.95(%fat-BEI), with R2=0.89. Percentage body fat measurement from MRI, BEI and skinfold were not significantly different but their results were not interchangeable. Linear regression of %body fat from MRI on those obtained from BEI and skinfold measurements showed a modest fit with R2=0.6973 and 0.5501, respectively. In children 8-12 years old, BMI gives a good estimation of the total body fat as measured on MRI. The estimation will be improved when both BEI and BMI are used in the prediction. Bioelectrical impedance has a low correlation with total body fat and its use alone in estimating total body fat is not recommended. Skinfold measurement also gives a reasonably good prediction of total body fat and addition of BMI and BEI does not improve the prediction. Both BEI and skinfold measurements give a modest prediction of %body fat measured by MRI method.

Relationship between volumes and areas from single transverse scans of intra-abdominal fat measured by magnetic resonance imaging.

To determine the level of a single transverse scan of intra-abdominal fat between L1 and L5 vertebrae that best predicts intra-abdominal fat volumes. Sixteen male and seven female patients with non-insulin-dependent diabetes mellitus, aged 44-74 y. Volumes and areas from single scans of intra-abdominal fat measured by magnetic resonance imaging with a 1.5 Tesla magnetic field strength. Intra-abdominal fat volumes and were calculated from fat areas from eight cross-sectional transverse single scans (nine scans in eight men) of 20 mm thickness. Men and women, respectively, had mean body mass index (BMI) of 27.9 (s.d. 3.0) and 31.6 (s.d. 4.7) kg/m2, and intra-abdominal fat of 2.3 (s.d. 0.5) and 2.5 (s.d. 0.6) kg. Intra-abdominal fat area of the fourth scan (in the direction of L1 to L5) gave the highest prediction of total intra-abdominal fat both in men (r = 0.959, P < 0.001) and in women (r = 0.973, P < 0.001). The intra-abdominal fat area of the third scan gave almost as good a prediction. These third and fourth scans corresponded to L2 and L3 vertebrae. The intra-abdominal fat areas from the sixth and seventh scans, corresponded to the frequently used L4-L5 and had lower correlations with intra-abdominal fat. There were no gender differences in the prediction of volumes from areas of intra-abdominal fat. Intra-abdominal fat areas of the fourth scan explained 93% of variance (SEE = 0.14 kg) of total of intra-abdominal fat for both genders: intra-abdominal fat (kg) = 0.0108 x intra-abdominal fat area of the fourth scan (cm2) + 0.244. In large studies of intra-abdominal fat, using magnetic resonance imaging (MRI) or computerised tomography scanning, a single intra-abdominal fat area at the intervertebral disc between L-2 and L-3 vertebrae offers a cheaper, faster and safer method, with high prediction of total intra-abdominal fat volumes and masses.

Relationship of visceral adipose tissue and glucose disposal is independent of sex in black NIDDM subjects.

To determine the interrelationship among insulin action, total or regional adiposity, and sex, we measured insulin-mediated glucose disposal by the euglycemic insulin clamp and adipose distribution using computed axial tomography (22 scans) in 32 black men and 20 black women with non-insulin-dependent diabetes mellitus (age 48 +/- 9 and 54 +/- 9 yr, body mass index 26.3 +/- 2.3 and 27.2 +/- 2.6 kg/m2, respectively). Women had approximately 80% more total and subcutaneous fat volume than men (31.8 +/- 8.3 vs. 18.6 +/- 6.1 and 28.5 +/- 7.3 vs. 14.7 +/- 4.6 liters) and less muscle volume (22.9 +/- 3.7 vs. 35.1 +/- 3.8 liters). Visceral fat volume did not differ between men and women (3.49 +/- 1.65 vs. 2.96 +/- 1.22 liters). Despite these body composition differences, an inverse nonlinear relationship existed between glucose disposal and visceral fat independent of sex (r = -0.58, P < 0.0001; men r = -0.60 and women r = -0.59; the slope and intercept were not different in men and women). Visceral fat explained a significant portion (34%) of variance in insulin-mediated glucose disposal, whereas total or subcutaneous fat and sex did not. Visceral fat appears to affect glucose disposal over a restricted range (up to approximately 2.5 l/m2 body surface area.

FITNESS, FATNESS, AND EXERCISE TRAINING IN ADOLESCENT FEMALES 1377

The effects of exercise training on body composition is of particular relevance to adolescent females in whom fitness is known to decrease, and fatness to increase. We hypothesized that 1) fitness will be negatively correlated with fatness, and 2) that even a brief training intervention would lead to site-specific, changes in body fat and musculature. 44 healthy adolescent females (15-17 y.o.) were randomized to control (n=22) and training groups (5 weeks of endurance-type exercise). Subcutaneous fat was assessed by magnetic resonance imaging (MRI) of the abdomen (a single image at the umbilicus) and thigh (12 serial images from the knee to the hip). MR images were also used to determine thigh musculature. VO2max from cycle ergometry was normalized to the study sample and used to assess fitness. Abdominal fat percent was not correlated to fitness, but thigh fat was inversely correlated (r= -0.46, p<0.005). There were no significant changes in body weight, abdominal fat percent and total thigh fat volume in either group following the program. In contrast, an analysis of individual MRI sections revealed an increase in thigh fat percent in the distal thigh of the control subjects (7.5±2%, p<0.003), but not in the trained subjects. Training lead to a significant increase in thigh muscle CSA in the mid-muscle region (4.9±1.5%, p<0.03) while no changes were found in the control subjects. In conclusion, fitness was inversely correlated with thigh, but not abdominal, fat in healthy adolescent females. A brief training intervention increased mid-muscle CSA, and may have prevented the increase in distal thigh fat that was observed in the relatively less active control subjects.