Relation between BglII polymorphism in 3beta-hydroxysteroid dehydrogenase gene and adipose tissue distribution in humans

The aim of this study was to investigate the association between a restriction fragment length polymorphism (RFLP) at the 3beta-hydroxysteroid dehydrogenase locus and adipose tissue distribution phenotypes. A total of 132 unrelated individuals from the Quebec Family Study were followed prospectively for an average period of 11.3 years. The BglII polymorphism in exon 4 of the 3beta-HSD gene was detected by PCR. Body mass, body fat, and regional fat distribution indicators were adjusted for age and age2 within each gender. Associations were assessed in unrelated adults with ANOVA across three genotypes. No association was found for the indicators of body mass, body fat, and regional distribution of adipose tissue measured in 1992. In women, the changes (difference between data collected in 1992 and at entry) in the sum of six skinfolds (p=0.04), abdominal skinfold (p=0.01), and abdominal skinfold adjusted (p=0.03) for the sum of six skinfolds at entry were related to the BglII polymorphism at the 3beta-HSD locus. These relations were not found in men, but they gained less body mass and body fat over the 11.3-year period. This suggests that sequence variation at the 3beta-HSD locus or in neighboring genes on chromosome 1 may contribute to individual differences in body fat content and adipose tissue distribution in adult women, particularly in abdominal adipose tissue deposition as they grow older and gain body fat.     

Body fat distribution in white and black women: different patterns of intraabdominal and subcutaneous abdominal adipose tissue utilization with weight loss.

BACKGROUND: Intraabdominal adipose tissue (IAAT) is the body fat depot most strongly related to disease risk. Weight reduction is advocated for overweight people to reduce total body fat and IAAT, although little is known about the effect of weight loss on abdominal fat distribution in different races. OBJECTIVE: We compared the effects of diet-induced weight loss on changes in abdominal fat distribution in white and black women. DESIGN: We studied 23 white and 23 black women, similar in age and body composition, in the overweight state [mean body mass index (BMI; in kg/m(2)): 28.8] and the normal-weight state (mean BMI: 24.0) and 38 never-overweight control women (mean BMI: 23.4). We measured total body fat by using a 4-compartment model, trunk fat by using dual-energy X-ray absorptiometry, and cross-sectional areas of IAAT (at the fourth and fifth lumbar vertebrae) and subcutaneous abdominal adipose tissue (SAAT) by using computed tomography. RESULTS: Weight loss was similar in white and black women (13.1 and 12.6 kg, respectively), as were losses of total fat, trunk fat, and waist circumference. However, white women lost more IAAT (P < 0.001) and less SAAT (P < 0.03) than did black women. Fat patterns regressed toward those of their respective control groups. Changes in waist circumference correlated with changes in IAAT in white women (r = 0.54, P < 0.05) but not in black women (r = 0.19, NS). CONCLUSIONS: Despite comparable decreases in total and trunk fat, white women lost more IAAT and less SAAT than did black women. Waist circumference was not a suitable surrogate marker for tracking changes in the visceral fat compartment in black women.     

Visceral adipose tissue accumulation differs according to ethnic background: results of the Multicultural Community Health Assessment Trial (M-CHAT)

BACKGROUND: It was suggested that body fat distribution differs across ethnic groups, and this may be important when considering risk of disease. Previous studies have not adequately investigated differences in discrete regions of abdominal adiposity across ethnic groups. OBJECTIVE: We compared the relation between abdominal adipose tissue and total body fat between persons living in Canada of Aboriginal, Chinese, and South Asian origin with persons of European origin. DESIGN: Healthy Aboriginal, Chinese, European, and South Asian participants (n = 822) aged between 30 and 65 y were matched by sex, ethnicity, and body mass index (BMI; in kg/m(2)) range. Total abdominal adipose tissue (TAT), subcutaneous abdominal adipose tissue (SAT), visceral adipose tissue (VAT), total body fat mass, lifestyle, and demographics were assessed. Relations between BMI and total body fat, TAT, SAT, and VAT and between total body fat and TAT, SAT, and VAT were investigated. RESULTS: BMI significantly underestimated VAT in all non-European groups. Throughout a range of total body fat mass, VAT was not significantly different between the Aboriginals and the Europeans. With total body fat >9.1 kg, Chinese participants had increasingly greater amounts of VAT than did the Europeans (P for interaction = 0.008). South Asians had less VAT with total body fat >37.4 kg but more VAT below that amount than did Europeans (P for interaction < 0.001). CONCLUSION: Compared with Europeans, the Chinese and South Asian cohorts had a relatively greater amount of abdominal adipose tissue, and this difference was more pronounced with VAT. No significant differences were observed between the Aboriginals and the Europeans.     

Visceral obesity and insulin resistance are associated with plasma aldosterone levels in women.

OBJECTIVE: Both obesity and insulin resistance increase the risk of hypertension and other cardiovascular diseases, but the mechanisms linking these abnormalities are unknown. The current study was undertaken to examine the effects of obesity, fat distribution, and insulin resistance on plasma levels of aldosterone and other adrenal steroids that might contribute to sequelae of obesity. RESEARCH METHODS AND PROCEDURES: Twenty-eight normotensive premenopausal women and 27 normotensive men with a wide range of body fat underwent measurements of visceral adipose tissue by CT scan, total fat mass by dual energy X-ray absorptiometry, blood pressure, insulin sensitivity, and plasma levels of three adrenal steroid hormones. RESULTS: Plasma aldosterone in women correlated directly with visceral adipose tissue (r=0.66, p<0.001) and inversely with insulin sensitivity (r=-0.67, p<0.001), and these associations were independent of plasma renin activity. There were no corresponding correlations in men. Plasma aldosterone was significantly correlated with plasma cortisol and dehydroepiandrosterone sulfate in women. Seventeen women and 15 men completed a weight-reduction regimen, losing an average of 15.1+1.2 kg. After weight loss, plasma aldosterone was significantly lower and insulin sensitivity higher; however, the correlations of aldosterone with visceral adipose tissue and insulin sensitivity in women persisted (p = 0.09 and 0.07, respectively). Although none of the women were hypertensive, blood pressure correlated with plasma aldosterone both before and after weight loss. DISCUSSION: We conclude that visceral adiposity and insulin resistance are associated with increased plasma aldosterone and other adrenal steroids that may contribute to cardiovascular diseases in obese women.     

Increased cortisol bioavailability, abdominal obesity, and the metabolic syndrome in obese women

OBJECTIVE: This study was conducted to obtain a detailed profile of hypothalamo-pituitary-adrenal (HPA) axis activity and reactivity and its differential relationships with body fat distribution and total fat mass in premenopausal obese women. RESEARCH METHODS AND PROCEDURES: Cortisol responses to stimulation (awakening, food intake, exercise) and suppression (0.25 mg dexamethasone), cortisol metabolism, and tissue sensitivity to glucocorticoids were studied in 53 premenopausal obese women grouped according to their waist-to hip ratio: women with abdominal body fat distribution (A-BFD; n = 31) and women with peripheral fat distribution (P-BFD; n = 22). RESULTS: Comparatively, A-BFD women had 1) lower awakening salivary cortisol levels; 2) increased salivary responsiveness to a standardized lunch; 3) similar pituitary sensitivity to dexamethasone but decreased sensitivity of monocytes to dexamethasone; 4) similar 24-hour urinary free cortisol but increased 24-hour urinary ratio of cortisone-to-cortisol; and 5) no difference in corticosteroid binding protein parameters. DISCUSSION: Although abdominal obesity is not very different from generalized obesity in terms of HPA function, subtle variations in HPA axis activity and reactivity are evidenced in A-BFD premenopausal obese women.     

The influence of sex and obesity phenotype on meal fatty acid metabolism before and after weight loss

BACKGROUND: Regional differences in meal fat storage may explain the preservation of fat accumulation in obese persons. OBJECTIVE: The objective was to determine whether meal fatty acid (FA) metabolism differs by sex and obesity phenotypes before and after weight loss. DESIGN: A [(3)H]triolein-containing meal was given to trace meal FA oxidation ((3)H(2)O generation) and adipose tissue uptake (abdominal subcutaneous and gluteal biopsy samples) in 13 upper-body obese (UOb) men, 9 UOb women, and 8 lower-body obese (LOb) women (study 1). Dual-energy X-ray absorptiometry and abdominal computed tomography were used to measure fat distribution. The subjects participated in a diet and exercise weight-loss program, after which 23 subjects returned for an identical study (study 2). RESULTS: In study 1, the storage of meal FA (mg meal fat/g adipose lipid) was greater in gluteal than in abdominal fat (P = 0.022) in LOb women, but not in UOb women or UOb men. UOb men stored a lesser percentage of meal FAs in both upper- and lower-body subcutaneous fat than did the LOb and UOb women (P = 0.001 and P = 0.044, respectively). The participants who returned for study 2 had lost 14.1 +/- 1.1 kg. Changes in the uptake of meal FAs followed a pattern indicative of obesity phenotype maintenance by group. The uptake of meal FAs increased in upper-body subcutaneous fat (P = 0.028) in weight-reduced UOb women and UOb men (P = 0.046) and decreased in lower-body fat (P = 0.025) in UOb men. CONCLUSION: The differences in meal FA trafficking by obesity phenotype suggest that meal FA storage may play a role in regulating body fat distribution in obese persons.     

Subcutaneous and visceral fat distribution according to sex, age, and overweight, evaluated by computed tomography

Subcutaneous and visceral fat distribution as related to sex, age, and overweight was studied in 130 subjects and 10 women with Cushing's disease. Fat depots were evaluated by computed tomography at one thoracic and one abdominal level. Adipose tissue (density range - 50 to 250 Hansfield units) was highlighted and the fat areas were measured by a laser planimeter. The ratio between subcutaneous and visceral fat areas (S:V ratio) was assumed as an index. Ratios of both nonobese and obese groups were significantly higher in females than in males. Ratios decreased markedly over age 60. There was a significant inverse correlation between age and S:V ratios in females (r = 0.65; p less than 0.001) and in males (r = 0.61; p less than 0.001). Statistically significant correlations were found between S:V ratios at thoracic and abdominal levels. In Cushing's patients, the S:V ratio at the abdominal level was significantly lower than in controls matched for age, sex, and body mass index.     

Racial differences in insulin resistance and mid-thigh fat deposition in postmenopausal women

OBJECTIVE: To determine whether racial differences in insulin resistance between African American (AA) and white women exist in postmenopausal women and whether they are related to physical fitness and/or obesity. RESEARCH METHODS AND PROCEDURES: We studied 35 obese AA (n = 9) and white (n = 26) women of comparable maximal oxygen consumption, obesity, and age. Total body fat was measured by DXA. Abdominal and mid-thigh low-density lean tissue (a marker of intramuscular fat) were determined with computed tomography. Glucose utilization (M) was measured during the last 30 minutes of a 3-hour hyperinsulinemic-euglycemic clamp. Insulin sensitivity was estimated from the relationship of M to the concentration of insulin during the last 30 minutes of the clamp. RESULTS: The percentage of fat and total body fat mass were similar between AA and white women, whereas fat-free mass was higher in African American women. Visceral adipose tissue was not different between groups, but subcutaneous abdominal fat was 17% higher in the AA than in the white women. AA women had an 18% greater mid-thigh muscle area (p < 0.01) and a 34% greater mid-thigh low-density lean tissue area than the white women. Fasting glucose concentrations were not different, but fasting insulin concentrations were 29% higher in AA women. Glucose utilization was 60% lower in the AA women because of a lower non-oxidative glucose disposal. Insulin sensitivity was 46% lower in the AA women. DISCUSSION: AA postmenopausal women have more mid-thigh intramuscular fat, lower glucose utilization, and are less insulin sensitive than white women despite comparable fitness and relative body fat levels.     

Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women

Weight loss can have substantial health benefits for overweight or obese persons; however, the ratio of fat:lean tissue loss may be more important. We aimed to determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women. Ninety participants were randomized to 3 groups (n = 30/group): high protein, high dairy (HPHD), adequate protein, medium dairy (APMD), and adequate protein, low dairy (APLD) differing in the quantity of total dietary protein and dairy food-source protein consumed: 30 and 15%, 15 and 7.5%, or 15 and <2% of energy, respectively. Body composition was measured by DXA at 0, 8, and 16 wk and MRI (n = 39) to assess visceral adipose tissue (VAT) volume at 0 and 16 wk. All groups lost body weight (P < 0.05) and fat (P < 0.01); however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups (P < 0.05). The HPHD group gained lean tissue with a greater increase during 8-16 wk than the APMD group, which maintained lean mass and the APLD group, which lost lean mass (P < 0.05). The HPHD group also lost more VAT as assessed by MRI (P < 0.05) and trunk fat as assessed by DXA (P < 0.005) than the APLD group. The reduction in VAT in all groups was correlated with intakes of calcium (r = 0.40; P < 0.05) and protein (r = 0.32; P < 0.05). Therefore, diet- and exercise-induced weight loss with higher protein and increased dairy product intakes promotes more favorable body composition changes in women characterized by greater total and visceral fat loss and lean mass gain.     

Short-term, high-fat diets lower circulating leptin concentrations in rats

BACKGROUND: Leptin is produced in proportion to body fat mass and can act on the brain to induce satiety and regulate adipose tissue mass; factors other than adipose tissue mass may influence circulating leptin concentrations. OBJECTIVE: We explored the possibility that short-term, moderately high-fat diets induce weight gain by producing inappropriately low circulating leptin concentrations. DESIGN: Female Hooded Wistar rats were fed either a moderately high-fat diet or control diet. Body weight, energy intake, body composition, and fasting plasma leptin were compared after 4 and 14 wk of dietary treatment. RESULTS: After 4 wk, abdominal fat mass was 38% greater in rats fed the high-fat diet than in those fed the control diet (P < 0.01). However, plasma leptin concentrations were 24% lower in animals fed the high-fat diet (P < 0.05), resulting in significantly lower plasma leptin concentrations per unit abdominal fat mass than in control animals (P < 0.005). From 4 to 14 wk, animals fed the high-fat diet gained twice as much weight and consumed 32 kJ/d more than controls (both P < 0.05). At 14 wk, plasma leptin concentrations per unit abdominal fat mass were 27% lower in rats fed the high-fat diet (P = 0.058) and there was a significant negative association between leptin concentrations per unit abdominal fat mass and body weight (r = 0.44, P < 0.05). CONCLUSIONS: In the short term, a moderately high-fat diet is associated with lower than expected circulating leptin concentrations, which correlate with a higher body weight. A high-fat diet may therefore contribute to weight gain by reducing leptin secretion in adipose tissue.     

Apolipoprotein A-II polymorphism and visceral adiposity in African-American and white women

To determine the association between the -265 T to C substitution in the apolipoprotein A-II (APOA-II) gene and levels of visceral adipose tissue (VAT) in a group of premenopausal African-American and white women, we genotyped 237 women (115 African-American and 122 white) for this polymorphism. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. In addition to VAT, we examined the association between the polymorphism and other phenotypes (total body fat, total abdominal adipose tissue, and subcutaneous abdominal adipose tissue). The mutant C allele in the APOA-II gene was less frequent in African-American compared with white women, 23% vs. 36%, respectively (p < 0.01). VAT was significantly higher in carriers of the C allele compared with noncarriers after adjustment for total body fat (p < 0.05). When separate analyses by ethnic group were conducted, the association between the polymorphism and VAT was observed in white (p < 0.05) but not African-American (p = 0.57) women. There was no association between the polymorphism and the other phenotypes. These results indicate a significant association between the T265C APOA-II polymorphism and levels of VAT in premenopausal women. This association is present in white but not African-American women.     

Hip girth as a predictor of abdominal adiposity in postmenopausal women

OBJECTIVES: Our primary objective was to determine whether hip girth could accurately predict abdominal fat and total body fat in postmenopausal women. A secondary objective was to investigate the relation between body mass index (BMI) and hip girth in postmenopausal women. METHODS: Body weight, height, girths, skinfolds, and whole-body dual-energy x-ray absorptiometric scans were obtained in 75 postmenopausal women ages 45 to 76 y. Total body fat, abdominal fat, and the ratio of abdominal fat to lean mass (F:L) were calculated from the dual-energy x-ray absorptiometric scans. Equations predicting total and abdominal fat were developed for 50 subjects by using stepwise multiple regression analysis. These equations were then cross-validated in the remaining 25 subjects. RESULTS: Hip girth was a strong predictor of total fat (r = 0.86, P < 0.0001, standard error of the estimate = 4.9 kg) and abdominal fat (r = 0.92, P < 0.0001, standard error of estimate = 0.84 kg); with age added, the standard errors of the estimate were 3.8 and 0.8 kg, respectively. Hip girth correlated with BMI (r = 0.89, P < 0.0001). The "healthy" BMI cutoff value lower than 25 kg/m2 equated to a hip girth smaller than 100 cm and an abdominal F:L lower than 1.0. Waist girth (r = 0.83, P < 0.0001) and hip girth (r = 0.76, P < 0.0001) were good predictors of abdominal F:L. CONCLUSIONS: Hip girth is a practical and useful predictor of abdominal and total adiposity in postmenopausal women. A hip girth of 100 cm or an abdominal F:L of 1.0 can be used as an equivalent cutoff value for the "healthy" BMI value of 25 kg/m2 in this group of women.     

Yeast hydrolysate can reduce body weight and abdominal fat accumulation in obese adults

ObjectiveThe aim of this study was to examine the effect of yeast hydrolysate on the abdominal fat in obese humans.MethodsWe observed the effects of yeast hydrolysate that had a molecular weight below 10 kDa on the anti-abdominal fat accumulation in obese men and women ages 20 to 50 y for 10 wk. The abdominal fat mass was assessed by computed tomographic scans.ResultsBy the sixth week, the reductions in energy intake in the yeast group (yeast hydrolysate 1 g/d) were significantly greater than those in the control group (placebo 1 g/d) (P < 0.05). The body weight and body mass index (BMI) were significantly reduced by week 10 compared with baseline in the yeast group, and these differences were significantly greater than those in the control group: body weight 0.83 kg versus −2.60 k g (P < 0.001), BMI 0.29 kg/m² versus −0.90 kg/m² (P < 0.001). Despite the increased loss of body weight in the yeast group, lean body mass did not significantly differ between the two groups. Body fat mass in the control group did not significantly change between baseline and week 10. However, the yeast group lost a significant amount of body fat mass after 10 wk of treatment (P < 0.01). The differences in abdominal fat thickness and abdominal circumference between the two groups were significant after 10 wk of treatment (P < 0.001). The total abdominal fat area in the yeast group was significantly lower than in the control group after 10 wk of treatment (−7.06 cm² versus −17.34 cm²; P < 0.01).ConclusionsYeast hydrolysate can reduce body weight and the accumulation of abdominal fat without an adverse effect on lean body mass in obese adults, regardless of sex, via the reduction of energy intake.     

Role of fat oxidation in the long-term stabilization of body weight in obese women.

Two studies were performed to investigate the association between body fat mass and fat oxidation. The first, a cross-sectional study of 106 obese women maintaining stable body weight, showed that these two variables were significantly correlated (r = 0.56, P less than 0.001) and the regression coefficient indicated that a 10-kg change in fat mass corresponded to a change in fat oxidation of approximately 20 g/d. The second, a prospective study, validated this estimate and quantifies the long-term adaptations in fat oxidation resulting from body fat loss. Twenty-four moderately obese women were studied under controlled dietary conditions at stable weight before and after mean weight and fat losses of 12.7 and 9.8 kg, respectively. The reduction in fat oxidation was identical to that predicted by the above regression. We conclude that changes in fat mass significantly affect fat oxidation and that this process may contribute to the long-term regulation of fat and energy balance in obese individuals.     

Total and subcutaneous adipose tissue in women: the measurement of distribution and accurate prediction of quantity by using magnetic resonance imaging

Total and subcutaneous adipose tissue in seven lean and seven obese women were quantified using magnetic resonance imaging (MRI). The distributions of adipose tissues along the body were closely correlated: subcutaneous with total, both within and between lean and obese groups. Lean women had proportionally less adipose tissue in the lower thorax and upper abdomen than did obese women. Reducing the number of MRI scans from 17 to 4 did not increase the residual SD of predicted body adipose tissue (2.9 percent) when body density was used as the reference measure. MRI gave an estimate of total-body adipose tissue significantly closer to the value for fat percent produced when the results from five other techniques (skinfold thickness, underwater weighing, 40K whole-body counting, isotopic water dilution, and tetrapolar bioelectrical impedance) were averaged than when any other technique was used alone. MRI-determined percent body adipose tissue in women is close to, and proportional to, estimates derived by underwater weighing.     

Plasma leptin response to an epinephrine infusion in lean and obese women.

OBJECTIVE: Because leptin production by adipose tissue is under hormonal control, we examined the impact of epinephrine administration on plasma leptin concentrations. RESEARCH METHODS AND PROCEDURES: We measured plasma leptin, insulin, and free fatty acid (FFA) responses after a 60-minute epinephrine infusion (0.010 microg/kg fat free mass/min) followed by a 30-minute recovery period (no infusion) in a group of 11 lean (mean body mass index +/- SD: 22.6 +/- 1.1 kg/m(2)) and 15 obese (30.0 +/- 1.3 kg/m(2)) premenopausal women. Leptin, insulin, and FFA levels were measured in plasma before (-15 and 0 minutes) and at every 30 minutes over the 90-minute period. RESULTS: In both lean and obese individuals, plasma leptin was significantly reduced by epinephrine (p < 0.0001). Body fat mass was associated with fasting leptin levels (r = 0.64, p < 0.0005) as well as with the decrease in leptinemia (r = -0.51, p < 0.01) produced by epinephrine administration. Furthermore, we noted a large range of leptin response to epinephrine among our subjects, especially in obese women (from -12 to -570 ng/mL per 60 minutes). However, there was no association between postepinephrine leptin and FFA levels (r = -0.14, p = 0.55). DISCUSSION: Results of this study indicate that leptin levels decrease after epinephrine administration in both lean and obese premenopausal women. However, the heterogeneity in the response of leptin to catecholamines suggests potential alterations of the leptin axis that may contribute to generate a positive energy balance and, thus, may favor weight gain in some obese individuals.     

Effects of beta2-adrenergic receptor gene variants on adiposity: the HERITAGE Family Study

We investigated whether the Arg16Gly and Gln27Glu polymorphisms of the beta2-adrenergic receptor gene were associated with body-fat and fat-distribution phenotypes measured before and in response to a 20-week endurance-training program. BMI, fat mass (FAT), percentage of body fat (%FAT), sum of eight skinfolds (SF8), and abdominal fat areas assessed by computed tomography were measured in adult sedentary white and black participants of the HERITAGE Family Study. Evidence of gene-by-obesity interaction was found in whites for several adiposity phenotypes measured before training. Analyses performed separately in nonobese and obese subjects revealed that obese men carrying the Glu27 allele have lower fat accumulation (BMI, FAT, and %FAT) than noncarriers. Among white obese women, Gly16Gly homozygotes had a lower fat accumulation (BMI, FAT, and SF8) than Arg16Gly and Arg16Arg carriers. In response to endurance training, white women with the Arg16Arg genotype exhibited a greater reduction in BMI, FAT, and %FAT. Results observed in blacks were mostly negative. These results suggest that polymorphisms in the beta2-adrenergic receptor gene influence the amount of body fat in white obese men (Gln27Glu) and women (Arg16Gly), as well as the changes in adiposity in response to endurance training in white women (Arg16Gly).     

Subdivision of the subcutaneous adipose tissue compartment and lipid-lipoprotein levels in women

OBJECTIVE: The aim of this study was to compare the relative importance of computed tomography-measured abdominal fat compartment areas, including adipose tissue located posterior to the subcutaneous Fascia, in predicting plasma lipid-lipoprotein alterations. RESEARCH METHODS AND PROCEDURES: Areas of visceral as well as subcutaneous deep and superficial abdominal adipose tissue were measured by computed tomography in a sample of 66 healthy women, ages 37 to 60 years, for whom a detailed lipid-lipoprotein profile was available. RESULTS: Strong significant associations were observed between visceral adipose tissue area and most variables of the lipid-lipoprotein profile (r = -0.25, p < 0.05 to 0.62, p < 0.0001). Measures of hepatic lipoprotein synthesis such as very-low-density lipoprotein-triglyceride and cholesterol content as well as total and very-low-density lipoprotein-apolipoprotein B levels were also strongly associated with visceral adipose tissue area (r = 0.57, 0.57, 0.61, and 0.62, respectively, p < 0.0001). Significant associations were found between these variables and the deep subcutaneous adipose tissue area or DXA-measured total body fat mass. However, the correlation coefficients were of lower magnitude compared to those with visceral adipose tissue area. Multivariate regression analyses demonstrated that visceral adipose tissue area was the strongest predictor of lipid-lipoprotein profile variables (7% to 48% explained variance, 0.02 > or = p < or = 0.0001). DISCUSSION: Although previous studies have generated controversial data as to which abdominal adipose tissue compartment was more closely associated with insulin resistance, our results suggest that visceral adipose tissue area is a stronger correlate of other obesity-related outcomes such as lipid-lipoprotein alterations.     

Visceral adipose tissue in women: longitudinal study of the effects of fat gain,time, and race

OBJECTIVE: To determine the effects of fat gain, time, and race on the accumulation of visceral adipose tissue (VAT) in a group of normal-weight premenopausal women. RESEARCH METHODS AND PROCEDURES: Sixty-five women participated in the study (32 African American and 33 white). The mean age of subjects was 34 +/- 6 years (range, 22 to 47 years). Eligible subjects were women who had body mass indices <25 kg/m(2) at baseline and who had completed evaluations at baseline and at follow-up year 1, without intervention. A subset of subjects was reevaluated annually for up to 4 years. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. A linear mixed model was used to examine changes in VAT over time, with total body fat as a covariate RESULTS: Total fat mass was not significantly different between races at baseline and increased significantly in both groups over time (p < 0.001). Time-related increases in total body fat were greater in African-American women (p < 0.01). VAT was significantly higher in white women at baseline (p < 0.01) and increased significantly over time in both races (p < 0.01), but remained higher in white women (p < 0.001). Increases in VAT, relative to total body fat, were greater than the increases in total body fat over time, independent of age and race (p < 0.001). DISCUSSION: Gaining total body-fat mass results in a higher increase in VAT, relative to total body fat, regardless of race and age, although African-American women maintain a lower VAT levels across time.     

Lack of correspondence among measures identifying the obese

Correspondence among eight measures commonly used to identify the obese was investigated in 225 men and 212 women 18-59 years of age. Measures included weight, body mass index (BMI), relative weight, skinfold thicknesses at triceps and subscapular sites, the sum of four skinfolds, percentage body fat (%BF) determined hydrostatically, and total weight of fat. Intercorrelations within various measures of body mass and total fat are high (0.86-0.99), while correlations between the two skinfolds, and among measures of body mass, subcutaneous fatness, and total body fat are much lower (0.57-0.70). The amount of variation in %BF accounted for by correlations with the other individual measures of obesity (other than fat weight) ranges from 32% to 48%. When analyzed categorically, the upper quintiles of the various measures poorly identify the same individuals as the fattest. The median chance-adjusted correspondences were 0.57 and 0.64 for men and women, respectively, with single values as low as 0.40. Analyses of variance (ANOVA) indicate the misclassification occurring among upper quintiles is nonrandom with respect to mean levels of these obesity measures. We find a considerable lack of correspondence among measures commonly used to identify the obese. This lack of correspondence may lead to unanticipated dissimilarity among people variously classified as obese and to bias regarding risks of associated disease or mortality.