Waist circumference correlates with metabolic syndrome indicators better than percentage fat

Objective : Percent fat is often considered the reference for establishing the magnitude of adipose tissue accumulation and the risk of excess adiposity. However, the increasing recognition of a strong link between central adiposity and metabolic disturbances led us to test whether waist circumference (WC) is more highly correlated with metabolic syndrome components than percent fat and other related anthropometric measures such as BMI. Research Methods and Procedures : BMI, WC, and percent fat, measured by DXA, were evaluated in 1010 healthy white and African‐American men and women [age, 48.3 ± 17.2 (standard deviation) years; BMI, 27.0 ± 5.3 kg/m²]. The associations of BMI, WC, and percent fat with age and laboratory‐adjusted health risk indicators (i.e., serum glucose, insulin, triglycerides, high‐density lipoprotein cholesterol, blood pressure) in each sex and ethnicity group were examined. Results : For 18 of 24 comparisons, the age‐ and laboratory‐adjusted correlations were lowest for percent fat and in 16 of 24 comparisons were highest for WC. Fifteen of the between‐method differences reached statistical significance. With health risk indicator as the dependent variable and anthropometric measures as the independent variable, the contribution of percent fat to the WC regression model was not statistically significant; in contrast, adding WC to the percent fat regression model did make a significant independent contribution for most health risk indicators. Discussion : WC had the strongest associations with health risk indicators, followed by BMI. Although percent fat is a useful measure of overall adiposity, health risks are best represented by the simply measured WC.     

Sugar-sweetened and diet beverages in relation to visceral adipose tissue

Frequent sugar-sweetened beverage (SSB) intake has been consistently associated with increased adiposity and cardio-metabolic risk, whereas the association with diet beverages is more mixed. We examined how these beverages associate with regional abdominal adiposity measures, specifically visceral adipose tissue (VAT). In a cross-sectional analysis of 791 non-Hispanic white men and women aged 18-70 we examined how beverage consumption habits obtained from a food frequency questionnaire associate with overall and abdominal adiposity measures from MRI. With increasing frequency of SSB intake, we observed increases in waist circumference (WC) and the proportion of visceral to subcutaneous abdominal adipose tissue (VAT%), with no change in total body fat (TBF%) or BMI. Greater frequency of diet beverage intake was associated with greater WC, BMI, and TBF%, but was not associated with variation in visceral adiposity We conclude that increased frequency of SSB consumption is associated with a more adverse abdominal adipose tissue deposition pattern.     

Surrogate Markers of Visceral Adiposity in Young Adults: Waist Circumference and Body Mass Index Are More Accurate than Waist Hip Ratio,Model of Adipose Distribution and Visceral Adiposity Index

Surrogate indexes of visceral adiposity, a major risk factor for metabolic and cardiovascular disorders, are routinely used in clinical practice because objective measurements of visceral adiposity are expensive, may involve exposure to radiation, and their availability is limited. We compared several surrogate indexes of visceral adiposity with ultrasound assessment of subcutaneous and visceral adipose tissue depots in 99 young Caucasian adults, including 20 women without androgen excess, 53 women with polycystic ovary syndrome, and 26 men. Obesity was present in 7, 21, and 7 subjects, respectively. We obtained body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), model of adipose distribution (MOAD), visceral adiposity index (VAI), and ultrasound measurements of subcutaneous and visceral adipose tissue depots and hepatic steatosis. WC and BMI showed the strongest correlations with ultrasound measurements of visceral adiposity. Only WHR correlated with sex hormones. Linear stepwise regression models including VAI were only slightly stronger than models including BMI or WC in explaining the variability in the insulin sensitivity index (yet BMI and WC had higher individual standardized coefficients of regression), and these models were superior to those including WHR and MOAD. WC showed 0.94 (95% confidence interval 0.88–0.99) and BMI showed 0.91 (0.85–0.98) probability of identifying the presence of hepatic steatosis according to receiver operating characteristic curve analysis. In conclusion, WC and BMI not only the simplest to obtain, but are also the most accurate surrogate markers of visceral adiposity in young adults, and are good indicators of insulin resistance and powerful predictors of the presence of hepatic steatosis.     

Abdominal fat and metabolic risk in obese children and adolescents

The aim of this study was to investigate fat distribution, mainly abdominal fat, and its relationship with metabolic risk variables in a group of 126 children and adolescents (60 males and 66 females) aged 5.0 to 14.9. According to IOTF criteria, 46 were classified as normal weight, 28 overweight and 52 obese. Weight, height, waist (WC) and hip circumferences were measured. The body mass index (BMI) was calculated. Total body fat, trunkal and abdominal fat were also assessed by dual energy x-ray absorptiometry (DXA). Glucose, insulin, HDL-Cholesterol, triglycerides (TG), ferritine, homocystein and C-reactive protein (CRP) were measured. Obesity status was related with insulin concentrations, CRP, TG and HDL. Obese patients had higher abdominal fat and higher CRP values than overweight and normal subjects. All markers of central body adiposity were related with insulin and lipid metabolism; however, they were not related with homocystein or ferritin. A simple anthropometric measurement, like waist circumference, seems to be a good predictor of the majority of the obesity related metabolic risk variables.     

Omental 11beta-hydroxysteroid dehydrogenase 1 correlates with fat cell size independently of obesity

Objectives: In ideopathic obesity, there is evidence that enhanced cortisol regeneration within abdominal subcutaneous adipose tissue may contribute to adiposity and metabolic disease. Whether the cortisol regenerating enzyme, 11β‐hydroxysteroid dehydrogenase type 1 (11βHSD1), or glucocorticoid receptor (GRα) levels are altered in other adipose depots remains uncertain. Our objective was to determine the association between 11βHSD1 and GRα mRNA levels in four distinct adipose depots and measures of obesity and the metabolic syndrome. Research Methods and Procedures: Adipose tissue biopsies were collected from subcutaneous (abdominal, thigh, gluteal) and intra‐abdominal (omental) adipose depots from 21 women. 11βHSD1 and GRα mRNA levels were measured by real‐time polymerase chain reaction. Body composition, fat distribution, fat cell size, and blood lipid, glucose, and insulin levels were measured. Results: 11βHSD1 mRNA was highest in abdominal subcutaneous (p < 0.001) and omental (p < 0.001) depots and was positively correlated with BMI and visceral adiposity in all depots. Omental 11βHSD1 correlated with percent body fat (R = 0.462, p < 0.05), fat cell size (R = 0.72, p < 0.001), and plasma triglycerides (R = 0.46, p < 0.05). Conversely, GRα mRNA was highest in omental fat (p < 0.001). GRα mRNA was negatively correlated with BMI in the abdominal subcutaneous (R = ?0.589, p < 0.05) and omental depots (R = ?0.627, p < 0.05). Omental GRα mRNA was inversely associated with visceral adiposity (R = ?0.507, p < 0.05), fat cell size (R = ?0.52, p < 0.01), and triglycerides (R = ?0.50, p < 0.05). Discussion: Obesity was associated with elevated 11βHSD1 mRNA in all adipose compartments. GRα mRNA is reduced in the omental depot with obesity. The novel correlation of 11βHSD1 with omental fat cell size, independent of obesity, suggests that intracellular cortisol regeneration is a strong predictor of hypertrophy in the omentum.     

Fitness Alters the Associations of BMI and Waist Circumference with Total and Abdominal Fat

Objective: We tested the following hypotheses in black and white men and women: 1) for a given BMI or waist circumference (WC), individuals with moderate cardiorespiratory fitness (CRF) have lower amounts of total fat mass and abdominal subcutaneous and visceral fat compared with individuals with low CRF; and 2) exercise training is associated with significant reductions in total adiposity and abdominal fat independent of changes in BMI or WC. Research Methods and Procedures: The sample included 366 sedentary male (111 blacks and 255 whites) and 462 sedentary female (203 blacks and 259 whites) participants in the HERITAGE Family Study. The relationships between BMI and WC with total fat mass (determined by underwater weighing) and abdominal subcutaneous and visceral fat (determined by computed tomography) were compared in subjects with low (lower 50%) and moderate (upper 50%) CRF. The effects of a 20‐week aerobic exercise training program on changes in these adiposity variables were examined in 86% of the subjects. Results: Individuals with moderate CRF had lower levels of total fat mass and abdominal subcutaneous and visceral fat than individuals with low CRF for a given BMI or WC value. The 20‐week aerobic exercise program was associated with significant reductions in total adiposity and abdominal fat, even after controlling for reductions in BMI and WC. With few exceptions, these observations were true for both men and women and blacks and whites. Discussion: These findings suggest that a reduction in total adiposity and abdominal fat may be a means by which CRF attenuates the health risk attributable to obesity as determined by BMI and WC.     

Relationships between direct and indirect measures of central and total adiposity in children: What are we measuring?

Objective: The relationship between central and total fat measured by anthropometry, dual energy X‐ray absorptiometry, and magnetic resonance imaging (MRI) with each other and systolic blood pressure (SBP) was examined. Design and Methods: Participants of the Avon Longitudinal Study of Parents and Children were examined at ages 9, 11, 13, and 15 years (n = 3,796‐6,567). MRI was available on a subset of children at 11 (n = 156) and 13 (n = 95). Results: Body mass index (BMI) and waist circumference (WC) were highly correlated (r = 0.84‐0.91, across ages), and total body fat mass (TBFM) and trunk fat mass (TFM) were very strongly correlated (r ≥ 0.98). Among boys, BMI vs. WC explained a similar degree of variation in TBFM and TFM (41‐71% vs. 43‐76%, across age and overweight groups); in girls, BMI accounted for 62‐73% variance and WC 47‐69%. Adiposity measures were generally similarly correlated with SBP within age groups. Further, the relationship between intra‐abdominal adipose tissue (IAAT) volume and adiposity measures did not vary greatly at 11 (0.65‐0.67) and 13 (0.64‐0.67). Conclusions: BMI and WC contain a large amount of overlapping information as evidenced by their high correlation and similarly sized associations with fat mass, SBP, and IAAT. This suggests that WC may be an inadequate marker of central adiposity during childhood.     

The relationship of waist circumference and BMI to visceral, subcutaneous, and total body fat: sex and race differences

The purpose of this study was to examine sex and race differences in the relationship between anthropometric measurements and adiposity in white and African-American (AA) adults. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured with computed tomography (CT). Fat mass (FM) was measured with dual-energy-X-ray absorptiometry (DXA). Correlation coefficients were used to assess the relationship of waist circumference (WC) and BMI to VAT, SAT, and FM within sex-by-race groups. General linear models were used to compare relationships between WC or BMI, and adiposity across sex and race, within age groups (18-39 and 40-64 years). The sample included 1,667 adults (men: 489 white; 120 AA; women: 666 white, 392 AA). WC and BMI correlations were highest for FM and SAT compared to VAT. Women had higher FM levels than men regardless of WC, but the sex difference in FM was attenuated in younger AA adults with a high BMI. For a given level of WC or BMI, women had higher levels of SAT than men; however, significant interactions indicated that the relationship was not consistent across all levels of BMI and WC. Sex and race differences in VAT varied significantly with WC and BMI. In general, white adults had higher levels of VAT than AA adults at higher levels of BMI and WC. Sex differences, and in some instances race differences, in the relationships between anthropometry and fat-specific depots demonstrate that these characteristics need to be considered when predicting adiposity from WC or BMI.     

Relationship of Adipocyte Size with Adiposity and Metabolic Risk Factors in Asian Indians

Background

Enlargement of adipocyte is associated with their dysfunction and alterations in metabolic functions.

Objectives

We evaluated the association of adipocyte size of subcutaneous and omental adipose tissue with body composition and cardiovascular risk factors in Asian Indians.

Methodology

Eighty (40 males and 40 females) non-diabetic adult subjects undergoing elective abdominal surgery were included. Pre-surgery evaluation included anthropometric measurements, % body fat by bioimpedance, abdominal fat area at L_2–3 level (computed tomography) and biochemical investigations (fasting blood glucose and insulin, lipids and hsCRP). During surgery, about 5 grams each of omental and subcutaneous adipose tissue was obtained for adipocyte size determination.

Results

Females had higher BMI, % body fat, skinfold thickness, total and subcutaneous abdominal fat area as compared to males. Overweight was present in 42.5% and 67.5%, and abdominal obesity in 5% and 52.5% males and females, respectively. Subcutaneous adipocyte size was significantly higher than omental adipocyte size. Omental adipocyte size correlated more strongly than subcutaneous adipocyte size with measures of adiposity (BMI, waist circumference, %BF), total and subcutaneous abdominal fat area and biochemical measures (fasting glucose, total cholesterol, triglycerides and HOMA-IR), the correlations being stronger in females. The correlation of adipocyte size with metabolic parameters was attenuated after adjusting for measures of adiposity.

Conclusion

Omental adipocyte size, though smaller than the subcutaneous adipocyte size, was more closely related to measures of adiposity and metabolic parameters. However, the relationship was not independent of measures of adiposity.     

Rapid Postnatal Weight Gain and Visceral Adiposity in Adulthood: The Fels Longitudinal Study

Rapid infant weight gain is associated with increased abdominal adiposity, but there is no published report of the relationship of early infant growth to differences in specific adipose tissue depots in the abdomen, including visceral adipose tissue (VAT). In this study, we tested the associations of birth weight, infant weight gain, and other early life traits with VAT, abdominal subcutaneous adipose tissue (ASAT), and other body composition measures using magnetic resonance imaging (MRI) and dual‐energy X‐ray absorptiometry in middle adulthood (mean age = 46.5 years). The sample included 233 appropriate for gestational age singleton white children (114 males) enrolled in the Fels Longitudinal Study. Multivariate‐adjusted general linear models were used to test the association of infant weight gain (from 0 to 2 years), maternal BMI, gestational age, parity, maternal age, and other covariates with adulthood body composition. Compared to infants with slow weight gain, rapid weight gain was associated with elevated risk of obesity (adjusted odds ratio = 4.1, 95% confidence interval = 1.4, 11.1), higher total body fat (+7 kg, P = 0.0002), percent body fat (+5%, P = 0.0006), logVAT mass (+0.43 kg, P = 0.02), logASAT mass (+0.47 kg, P = 0.001), and percent abdominal fat (+5%, P = 0.03). There was no evidence that the increased abdominal adipose tissue was due to a preferential deposition of VAT. In conclusion, rapid infant weight gain is associated with increases in both VAT and ASAT, as well as total adiposity and the risk of obesity in middle adulthood.     

Distribution of subcutaneous fat predicts insulin action in obesity in sex-specific manner

The pattern of adipose tissue (AT) distribution is an important predictor of metabolic risk. The aim of this study was to analyze the association of peripheral (insulin-mediated glucose disposal--M) and hepatic (suppression of endogenous glucose production--EGP) insulin action with abdominal (subcutaneous abdominal AT-SAAT intraabdominal AT-IAAT) and thigh AT depots in obese individuals. Fifty-seven Pima Indians with normal glucose tolerance underwent magnetic resonance imaging (MRI) and euglycemic-hyperinsulinemic clamp. M was negatively related to intraperitoneal IAAT (P = 0.02) and deep SAAT (P = 0.03). Suppression of EGP was negatively related to total (P < 0.05) or deep SAAT (P < 0.05 and P = 0.01, respectively), and total or intraperitoneal IAAT (P = 0.009 and P = 0.002, respectively). A significant interaction with sex was found in the association between superficial SAAT and M, so that in women, but not men, M negatively correlated with superficial SAAT (P = 0.02). In stepwise regression analysis, both M (r2 = 0.09) and EGP suppression (r2 = 0.17) were associated only with intraperitoneal IAAT in the whole group. In the sex-specific analysis (because of the significant interaction), lower M was associated with higher deep SAAT (r2 = 0.15) in combination with lower superficial SAAT (r2 = 0.09) in men, and with higher superficial SAAT (r2 = 0.29) in combination with lower thigh subcutaneous AT (r2 = 0.16) in women. Although intraperitoneal IAAT and deep SAAT were major predictors of peripheral and hepatic insulin action in obese Pima Indians, the largest variance in M rate was explained in a sex-specific manner by relative size of subcutaneous AT depots.     

Differences in adiponectin protein expression: effect of fat depots and type 2 diabetic status.

Adiponectin is an adipocyte-derived hormone associated with insulin sensitivity and atherosclerotic risk. As central rather than gluteofemoral fat is known to increase the risk of type 2 diabetes and cardiovascular disease, we investigated the mRNA and protein expression of adiponectin in human adipose tissue depots. RNA was extracted from 46 human adipose tissue samples from non-diabetic subjects aged 44.33 +/- 12.4 with a BMI of 28.3 +/- 6.0 (mean +/- SD). The samples were as follows: 21 abdominal subcutaneous, 13 omentum, 6 thigh; samples were also taken from diabetic subjects aged 66.6 +/- 7.5 with BMI 28.9 +/- 3.17; samples were: 6 abdominal subcutaneous; 3 thigh. Quantitative PCR and Western analysis was used to determine adiponectin content. Protein content studies determined that when compared with non-diabetic abdominal subcutaneous adipose tissue (Abd Sc AT) (values expressed as percentage relative to Abd Sc AT -100 %). Adiponectin protein content was significantly lower in non-diabetic omental AT (25 +/- 1.6 %; p < 0.0001, n = 6) and in Abd Sc AT from diabetic subjects (36 +/- 1.5 %; p < 0.0001, n = 4). In contrast, gluteal fat maintained high adiponectin protein content from non-diabetic patients compared with diabetic patients. An increase in BMI was associated with lower adiponectin protein content in obese ND Abd Sc AT (25 +/- 0.4 %; p < 0.0001). These findings were in agreement with the mRNA expression data. In summary, this study indicates that adiponectin protein content in non-diabetic subjects remains high in abdominal subcutaneous fat, including gluteal fat, explaining the high serum adiponectin levels in these subjects. Omental fat, however, expresses little adiponectin. Furthermore, abdominal and gluteal subcutaneous fat appears to express significantly less adiponectin once diabetic status is reached. In conclusion, the adipose tissue depot-specific expression of adiponectin may influence the pattern of serum adiponectin concentrations and subsequent disease risk.     

Genome-wide association for abdominal subcutaneous and visceral adipose reveals a novel locus for visceral fat in women

Body fat distribution, particularly centralized obesity, is associated with metabolic risk above and beyond total adiposity. We performed genome-wide association of abdominal adipose depots quantified using computed tomography (CT) to uncover novel loci for body fat distribution among participants of European ancestry. Subcutaneous and visceral fat were quantified in 5,560 women and 4,997 men from 4 population-based studies. Genome-wide genotyping was performed using standard arrays and imputed to ~2.5 million Hapmap SNPs. Each study performed a genome-wide association analysis of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), VAT adjusted for body mass index, and VAT/SAT ratio (a metric of the propensity to store fat viscerally as compared to subcutaneously) in the overall sample and in women and men separately. A weighted z-score meta-analysis was conducted. For the VAT/SAT ratio, our most significant p-value was rs11118316 at LYPLAL1 gene (p = 3.1 × 10E-09), previously identified in association with waist-hip ratio. For SAT, the most significant SNP was in the FTO gene (p = 5.9 × 10E-08). Given the known gender differences in body fat distribution, we performed sex-specific analyses. Our most significant finding was for VAT in women, rs1659258 near THNSL2 (p = 1.6 × 10-08), but not men (p = 0.75). Validation of this SNP in the GIANT consortium data demonstrated a similar sex-specific pattern, with observed significance in women (p = 0.006) but not men (p = 0.24) for BMI and waist circumference (p = 0.04 [women], p = 0.49 [men]). Finally, we interrogated our data for the 14 recently published loci for body fat distribution (measured by waist-hip ratio adjusted for BMI); associations were observed at 7 of these loci. In contrast, we observed associations at only 7/32 loci previously identified in association with BMI; the majority of overlap was observed with SAT. Genome-wide association for visceral and subcutaneous fat revealed a SNP for VAT in women. More refined phenotypes for body composition and fat distribution can detect new loci not previously uncovered in large-scale GWAS of anthropometric traits.     

Impact of different ectopic fat depots on cardiovascular and metabolic diseases

A growing body of evidence is pointing out the pathophysiological role of fat accumulation in different organs. Ectopic fat depots within heart, liver, skeletal muscle, kidney, and pancreas as well as around blood vessels might be more associated to cardiometabolic risk than classical variables, such as body mass index. Among different mechanisms, lipid metabolism appears to be particularly influenced by ectopic fat depots. Indeed, intracellular accumulation of nonesterified fatty acids, and triglycerides promotes endoplasmic reticulum stress, mitochondrial uncoupling, oxidative stress, and altered membrane composition/function, finally promoting inflammatory response and cell death. The dysfunctional adipose tissue was shown to induce both local and systemic effects, with relevant clinical consequences. Epicardial fat and myocardial steatosis have been associated with the development of atrial fibrillation and ventricular dysfunction. Similarly perivascular adipose tissue appears to trigger atherosclerosis and hypertension. Nonalcoholic fatty liver disease has been recognized both as the hepatic manifestation of metabolic syndrome and as a cardiovascular (CV) risk factor. Importantly, the renal sinus fat emerged as a potential player in kidney dysfunction. Finally, both skeletal muscle and pancreatic fat depots have been indicated as potential endocrine modulators of insulin resistance. Considering the global rise in the prevalence of obesity, the understanding of mechanisms underlying ectopic fat accumulation represents an urgent need, with potential clinical implications for CV risk stratification. Here, we attempt to update the current knowledge of the different ectopic fat depots, focusing on underlying mechanisms and potential clinical implications.     

Co-methylated genes in different adipose depots of pig are associated with metabolic, inflammatory and immune processes

It is well established that the metabolic risk factors of obesity and its comorbidities are more attributed to adipose tissue distribution rather than total adipose mass. Since emerging evidence suggests that epigenetic regulation plays an important role in the aetiology of obesity, we conducted a genome-wide methylation analysis on eight different adipose depots of three pig breeds living within comparable environments but displaying distinct fat level using methylated DNA immunoprecipitation sequencing. We aimed to investigate the systematic association between anatomical location-specific DNA methylation status of different adipose depots and obesity-related phenotypes. We show here that compared to subcutaneous adipose tissues which primarily modulate metabolic indicators, visceral adipose tissues and intermuscular adipose tissue, which are the metabolic risk factors of obesity, are primarily associated with impaired inflammatory and immune responses. This study presents epigenetic evidence for functionally relevant methylation differences between different adipose depots.     

Intra-abdominal adipose tissue is independently associated with sex-hormone binding globulin in premenopausal women

Lower serum concentrations of sex-hormone binding globulin (SHBG) are associated with increased risk for several obesity-related diseases in women including hormone-sensitive cancers, type 2 diabetes, metabolic syndrome, and cardiovascular disease. Previous investigations have reported that body composition, specifically central obesity, and/or higher insulin concentrations are key factors associated with lower SHBG in overweight and obese women; however, these studies were limited by their cross-sectional design. We hypothesized that intra-abdominal adipose tissue (IAAT), a fat depot linked with an abnormal metabolic profile, is inversely and independently associated with SHBG. Therefore, we determined the longitudinal associations among SHBG, insulin, and IAAT in 107 premenopausal women enrolled in a weight loss study. Overweight (BMI 27-30 kg/m(2)) women were weight reduced until BMI of ≤ 24 was achieved. Body composition and IAAT were measured at baseline and after weight loss with dual-energy X-ray absorptiometry and computed tomography, respectively. Serum concentrations of insulin and SHBG were determined. Paired t-test showed that insulin and IAAT decreased significantly and SHBG increased significantly following weight loss (P < 0.0001 for all). Simple correlations from baseline showed no association with insulin and SHBG (r = -0.142, P = 0.143) and a significant inverse association between IAAT and SHBG (r = -0.43, P < 0.0001). Repeated measures mixed-model showed that after adjusting for age and time (weight loss), IAAT was significantly inversely associated with SHBG (P = 0.0002) and there was no association with insulin and SHBG (P = 0.180). We conclude that SHBG concentrations are influenced by IAAT and not insulin in premenopausal women.     

Breast Volume is an Independent Predictor of Visceral and Ectopic Fat in Premenopausal Women

It is suggested that a large breast size among women may predict type 2 diabetes risk independent of BMI and waist circumference (WC). The purpose of this study was to determine the independent associations of breast volume with cardiometabolic risk factors and regional fat distribution. A total of 92 overweight or obese premenopausal women (age = 39.9 ± 6.8 years) underwent full‐body magnetic resonance imaging (MRI) for the assessment of breast volume, visceral adipose tissue (VAT), abdominal and lower‐body subcutaneous AT (SAT), and intermuscular AT (IMAT), a 2‐h oral glucose tolerance test (OGTT), and fasting phlebotomy for assessment of triglyceride, total, high‐density lipoprotein–, and low‐density lipoprotein–cholesterol levels. Breast volume was not associated with any of the cardiometabolic risk factors assessed (P > 0.05). However, VAT was consistently associated with a number of cardiometabolic risk factors (OGTT glucose, OGTT insulin, and triglyceride levels) after controlling for age, BMI, WC, breast volume, and the other AT depots. In univariate models, breast volume was positively associated with VAT, IMAT, and abdominal and lower‐body SAT (P < 0.05). After controlling for age, BMI, and WC level, breast volume remained positively associated with VAT and IMAT (P < 0.05), such that women with the highest breast volume had ～1.1 and 1.3 kg more VAT and IMAT, respectively, but no more abdominal or lower‐body SAT, by comparison to women with the smallest breast volume. Thus, the previously documented association between breast size and type 2 diabetes risk may be in part explained by excess VAT and/or IMAT deposition.     

Childbearing may increase visceral adipose tissue independent of overall increase in body fat

Objective: To examine whether childbearing is associated with increased visceral adiposity and whether the increase is proportionally larger than other depots. Methods and Procedures: This prospective study examined changes in adiposity assessed via computed tomography (CT) and dual‐energy X‐ray absorptiometry among 122 premenopausal women (50 black, 72 white) examined in 1995–1996 and again in 2000–2001. During the 5‐year interval, 14 women had one interim birth and 108 had no interim births. Multiple linear regression models estimated mean (95% confidence interval (CI)) 5‐year changes in anthropometric and adiposity measures by interim births adjusted for age, race, and changes in total and subcutaneous adiposity. Results: We found no significant differences between one interim birth and no interim births for 5‐year changes in weight, BMI, total body fat, subcutaneous adipose tissue, or total abdominal adipose tissue. Visceral adipose tissue increased by 40 and 14% above initial levels for 1 birth and 0 birth groups, respectively. Having 1 birth vs. 0 births was associated with a greater increase in visceral adipose tissue of 18.0 cm² (4.8, 31.2), P < 0.01; gain of 27.1 cm² (14.5, 39.7) vs. 9.2 cm² (4.8, 13.6), and a borderline greater increase in waist girth of 2.3 cm (0, 4.5), P = 0.05; gain of 6.3 cm (4.1, 8.5) vs. 4.0 cm (3.2, 4.8), controlling for gain in total body fat and covariates. Discussion: Pregnancy may be associated with preferential accumulation of adipose tissue in the visceral compartment for similar gains in total body fat. Further investigation is needed to confirm these findings and determine whether excess visceral fat deposition with pregnancy adversely affects metabolic risk profiles among women.     

Tissue leptin and plasma insulin are associated with lipoprotein lipase activity in severely obese patients

The development of metabolic complications of obesity has been associated with the existence of depot-specific differences in the biochemical properties of adipocytes. The aim of this study was to investigate, in severely obese men and women, both gender- and depot-related differences in lipoprotein lipase (LPL) expression and activity, as well as the involvement of endocrine and biometric factors and their dependence on gender and/or fat depot. Morbidly obese, nondiabetic, subjects (9 men and 22 women) aged 41.1+/-1.9 years, with a body mass index (BMI) of 54.7+/-1.7 kg/m(2) who had undergone abdominal surgery were studied. Both expression and activity of LPL and leptin expression were determined in adipose samples from subcutaneous and visceral fat depots. In both men and women, visceral fat showed higher LPL mRNA levels as well as lower ob mRNA levels and tissue leptin content than the subcutaneous one. In both subcutaneous and visceral adipose depots, women exhibited higher protein content, decreased fat cell size and lower LPL activity than men. The gender-related differences found in abdominal fat LPL activity could contribute to the increased risk for developing obesity-associated diseases shown by men, even in morbid obesity, in which the massive fat accumulation could mask these differences. Furthermore, the leptin content of fat depots as well as plasma insulin concentrations appear in our population as the main determinants of adipose tissue LPL activity, adjusted by gender, depot and BMI.