scholarly journals What Are the Physical Characteristics Associated with a Normal Metabolic Profile Despite a High Level of Obesity in Postmenopausal Women?1

2001 ◽  
Vol 86 (3) ◽  
pp. 1020-1025 ◽  
Author(s):  
Martin Brochu ◽  
André Tchernof ◽  
Isabelle J. Dionne ◽  
Cynthia K. Sites ◽  
Georgia H. Eltabbakh ◽  
...  

Although obesity is often associated with insulin resistance and a cluster of metabolic disturbances, the existence of a subgroup of healthy but obese individuals has been postulated. It is unclear why some obese individuals fail to show traditional risk factors associated with the insulin resistance syndrome despite having a very high accumulation of body fat. To address this issue, we identified and studied a subgroup of metabolically normal but obese (MNO) postmenopausal women to gain insight into potential physiological factors that may protect them against the development of obesity-related comorbidities. We carefully examined the metabolic characteristics of 43 obese, sedentary postmenopausal women (mean ± sd, 58.0± 6.0 yr). Subjects were classified as MNO or as metabolically abnormal obese (MAO) based on an accepted cut-point for insulin sensitivity (measured by the hyperinsulinemic/euglycemic clamp technique). Thereafter, we determined 1) body composition (fat mass and lean body mass), 2) body fat distribution (abdominal visceral and sc adipose tissue areas, midthigh sc adipose tissue and muscle attenuation), 3) plasma lipid-lipoprotein levels, 4) plasma glucose and insulin concentrations, 5) resting blood pressure, 6) peak oxygen consumption, 7) physical activity energy expenditure, and 8) age-related onset of obesity with a questionnaire as potential modulators of differences in the risk profile. We identified 17 MNO subjects who displayed high insulin sensitivity (11.2 ± 2.6 mg/min·kg lean body mass) and 26 MAO subjects with lower insulin sensitivity (5.7 ± 1.1 mg/min·kg lean body mass). Despite comparable total body fatness between groups (45.2 ± 5.3% vs. 44.8 ± 6.6%; P = NS), MNO individuals had 49% less visceral adipose tissue than MAO subjects (141 ± 53 vs. 211 ± 85 cm2; P < 0.01). No difference was noted between groups for abdominal sc adipose tissue (453 ± 126 vs. 442 ± 144 cm2; P = NS), total fat mass (38.1 ± 10.6 vs. 40.0 ± 11.8 kg), muscle attenuation (42.2± 2.6 vs. 43.6 ± 4.8 Houndsfield units), and physical activity energy expenditure (1060 ± 323 vs. 1045 ± 331 Cal/day). MNO subjects had lower fasting plasma glucose and insulin concentrations and lower insulin levels during the oral glucose tolerance test (P values ranging between 0.01–0.001). No difference was observed between groups for 2-h glucose levels and glucose area during the oral glucose tolerance test. MNO subjects showed lower plasma triglycerides and higher high density lipoprotein cholesterol concentrations than MAO individuals (P < 0.01 in both cases). Results from the questionnaire indicated that 48% of the MNO women presented an early onset of obesity (<20 yr old) compared with 29% of the MAO subjects (P = 0.09). Stepwise regression analysis showed that visceral adipose tissue and the age-related onset of obesity explained 22% and 13%, respectively, of the variance observed in insulin sensitivity (total r2 = 0.35; P < 0.05 in both cases). Our results support the existence of a subgroup of obese but metabolically normal postmenopausal women who display high levels of insulin sensitivity despite having a high accumulation of body fat. This metabolically normal profile is associated with a lower accumulation of visceral adipose tissue and an earlier age-related onset of obesity.

Diabetes Care ◽  
1999 ◽  
Vol 22 (9) ◽  
pp. 1471-1478 ◽  
Author(s):  
A. Pascot ◽  
S. Lemieux ◽  
I. Lemieux ◽  
D. Prud'homme ◽  
A. Tremblay ◽  
...  

2008 ◽  
Vol 93 (5) ◽  
pp. 1931-1938 ◽  
Author(s):  
Amélie Cartier ◽  
Isabelle Lemieux ◽  
Natalie Alméras ◽  
Angelo Tremblay ◽  
Jean Bergeron ◽  
...  

Abstract Objective: This study examined the relationships of two inflammatory cytokines, IL-6 and TNF-α, to visceral adiposity and indices of plasma glucose-insulin homeostasis. Research Design and Methods: Plasma levels of IL-6 and TNF-α were measured in 189 untreated asymptomatic men (aged 43.7 ± 7.8 yr; body mass index 29.0 ± 4.3 kg/m2; waist girth 98.6 ± 10.3 cm). Results: Significant and positive associations were found between both cytokines with adiposity and adipose tissue distribution indices (0.15 ≤ r < 0.32; P < 0.05) as well as plasma glucose-insulin homeostasis variables (0.22 ≤ r < 0.28; P <0.05). Comparison of two subgroups, each composed of 32 overweight men (≥25 kg/m2) with similar body mass index values (28.7 kg/m2 in both groups) but with markedly different levels of visceral adipose tissue (< vs. ≥ 130 cm2), revealed significant differences only for IL-6 levels (1.42 ± 1.15 vs. 0.86 ± 0.52 pg/ml; P < 0.02 for men with high vs. low visceral adipose tissue, respectively). Finally, when subjects were stratified on the basis of their respective concentrations of IL-6 and TNF-α (using the 50th percentile of their overall distribution), an ANOVA revealed an independent contribution of IL-6 to the variation of fasting insulin (P < 0.01) and each of these two cytokines to the variation of insulin levels measured after a 75-g oral glucose challenge (P <0.01 for IL-6 and P < 0.05 for TNF-α). Conclusions: Because IL-6 appeared to be clearly associated with visceral adiposity, TNF-α rather showed associations with indices of total body fatness. Thus, TNF-α may contribute to the insulin resistance of overall obesity, whereas IL-6 may be one of the mediators of the hyperinsulinemic state specifically related to excess visceral adiposity.


Author(s):  
Julie A. Côté ◽  
Julie Lessard ◽  
Jacques Mailloux ◽  
Philippe Laberge ◽  
Caroline Rhéaume ◽  
...  

AbstractThe association between circulating androgen levels and fat distribution in women has been widely inconsistent among existing studies.We sought to investigate the relation between plasma adrenal and gonadal androgen levels and body fat distribution, as well as abdominal adipocyte characteristics.Paired omental and subcutaneous adipose tissue samples were surgically obtained from 60 women (age, 47±5 years; body mass index, 26±5 kg/mSignificant negative associations were found between plasma dihydrotestosterone (DHT) levels and total adiposity (body mass index, r=–0.35, p<0.05; fat mass, r=–0.31, p<0.05) as well as computed tomography assessments of abdominal adiposity (r=–0.30, p<0.05 and r=–0.44, p<0.005 for subcutaneous and visceral adipose tissue area, respectively). The association between DHT levels and visceral adipose tissue area was independent of total body fat mass. A significant negative association was also observed between plasma DHT and omental adipocyte diameter (r=–0.27, p<0.05). When expressed as the omental/subcutaneous ratio, heparin-releasable lipoprotein lipase activity was negatively and significantly related to plasma DHT, androstenedione, and dehydroepiandrosterone (DHEA) levels.Abdominally obese women with large, metabolically active omental adipocytes appear to be characterized by reduced endogenous levels of DHT. The assumption that high androgen levels are associated with an android body fat distribution pattern in women should be critically re-examined.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Daniela Usuga ◽  
David W McMillan ◽  
Kevin A Jacobs ◽  
Mark S Nash ◽  
Rodrigo J Valderrabano

Abstract Introduction: Following spinal cord injury (SCI) lower extremity bone mineral density (BMD) losses are as high as 40% due to mechanical unloading and autonomic dysfunction. While lumbar spine (LS) BMD appears to be relatively spared, evidence suggests BMD by dual-energy radiographic absorptiometry (DXA) may overlook bone pathology in this region. Trabecular Bone Score (TBS), representative of bone microarchitecture, may be a more informative measurement of LS pathology in SCI. Our objective was to determine differences in BMD and TBS within the LS in humans with and without SCI. Correlation of fitness and body composition measures with TBS and BMD were also explored to determine their role in bone health after SCI. Methods: Seven male participants with paraplegia (level T3 – T7) were recruited through The Miami Project to Cure Paralysis, and 6 males without SCI were recruited from local advertisement. DXA scans of the lumbar spine and whole body were performed using Hologic Discovery A densitometer. TBS score (unitless) was derived from L1-L4 scans using TBS iNsight software v3.0.2. A graded arm exercise test directly measured cardiorespiratory fitness (VO2peak) for all subjects. An independent samples t-test determined between-group differences in LS BMD and TBS. Pearson correlation analysis investigated within-group relations among LS BMD, TBS and VO2peak (ml/kg/min), weight (kg), total body fat (%), and visceral adipose tissue (estimated VAT mass(g)). Results: In SCI, the mean duration of injury was 8.6 years. Mean LS BMD was not different (p=.47) between non-injured (1.10 ±0.11 g/cm2) and SCI (1.10 ±0.13 g/cm2) groups. However, mean TBS score was different (p=.053) between non-injured (1.55±0.09) and SCI (1.47±0.07) groups. In non-injured, VO2peak was correlated with LS BMD (r=.356) and TBS (r=.244). In SCI, VO2peak was correlated with LS BMD (r=.111) and TBS (r=.822). In non-injured, TBS was correlated with body mass (r=.244), total body fat (%) (r=.382), and visceral adipose tissue (r=.361). In SCI, negative correlations were observed; TBS was correlated with body mass (r= -.255), total body fat (%) (r= -.474), and visceral adipose tissue (r= -.513). LS BMD was positively correlated with body mass, total body fat (%) and visceral adipose tissue in both non-injured and SCI groups. Conclusion: Men with and without SCI displayed similar BMD but differed in TBS at the LS. Correlations with measures of fitness and body composition were similar for LS BMD but discordant for TBS between non-injured and SCI groups. The data suggest changes in the relationships between cardiorespiratory fitness, metabolism and bone quality in SCI. TBS may capture alterations in bone microarchitecture at the spine after SCI that are undetected by conventional DXA.


Author(s):  
Gabriel Wagner ◽  
Anna Fenzl ◽  
Josefine Lindroos-Christensen ◽  
Elisa Einwallner ◽  
Julia Husa ◽  
...  

Abstract Obesity and body fat distribution are important risk factors for the development of type 2 diabetes and metabolic syndrome. Evidence has accumulated that this risk is related to intrinsic differences in behavior of adipocytes in different fat depots. We recently identified LIM domain only 3 (LMO3) in human mature visceral adipocytes; however, its function in these cells is currently unknown. The aim of this study was to determine the potential involvement of LMO3-dependent pathways in the modulation of key functions of mature adipocytes during obesity. Based on a recently engineered hybrid rAAV serotype Rec2 shown to efficiently transduce both brown adipose tissue (BAT) and white adipose tissue (WAT), we delivered YFP or Lmo3 to epididymal WAT (eWAT) of C57Bl6/J mice on a high-fat diet (HFD). The effects of eWAT transduction on metabolic parameters were evaluated 10 weeks later. To further define the role of LMO3 in insulin-stimulated glucose uptake, insulin signaling, adipocyte bioenergetics, as well as endocrine function, experiments were conducted in 3T3-L1 adipocytes and newly differentiated human primary mature adipocytes, engineered for transient gain or loss of LMO3 expression, respectively. AAV transduction of eWAT results in strong and stable Lmo3 expression specifically in the adipocyte fraction over a course of 10 weeks with HFD feeding. LMO3 expression in eWAT significantly improved insulin sensitivity and healthy visceral adipose tissue expansion in diet-induced obesity, paralleled by increased serum adiponectin. In vitro, LMO3 expression in 3T3-L1 adipocytes increased PPARγ transcriptional activity, insulin-stimulated GLUT4 translocation and glucose uptake, as well as mitochondrial oxidative capacity in addition to fatty acid oxidation. Mechanistically, LMO3 induced the PPARγ coregulator Ncoa1, which was required for LMO3 to enhance glucose uptake and mitochondrial oxidative gene expression. In human mature adipocytes, LMO3 overexpression promoted, while silencing of LMO3 suppressed mitochondrial oxidative capacity. LMO3 expression in visceral adipose tissue regulates multiple genes that preserve adipose tissue functionality during obesity, such as glucose metabolism, insulin sensitivity, mitochondrial function, and adiponectin secretion. Together with increased PPARγ activity and Ncoa1 expression, these gene expression changes promote insulin-induced GLUT4 translocation, glucose uptake in addition to increased mitochondrial oxidative capacity, limiting HFD-induced adipose dysfunction. These data add LMO3 as a novel regulator improving visceral adipose tissue function during obesity. Key messages LMO3 increases beneficial visceral adipose tissue expansion and insulin sensitivity in vivo. LMO3 increases glucose uptake and oxidative mitochondrial activity in adipocytes. LMO3 increases nuclear coactivator 1 (Ncoa1). LMO3-enhanced glucose uptake and mitochondrial gene expression requires Ncoa1.


Obesity ◽  
2013 ◽  
Vol 21 (11) ◽  
pp. 2264-2271 ◽  
Author(s):  
Diana M. Thomas ◽  
Carl Bredlau ◽  
Anja Bosy-Westphal ◽  
Manfred Mueller ◽  
Wei Shen ◽  
...  

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
N A Mohamed ◽  
A A Seif ◽  
M S Abdelhamid ◽  
R S A Eissa

Abstract Background Obesity is a worldwide problem and is a major risk factor for chronic diseases. The relation between obesity and vitamin D is not completely understood. Obesity is associated with vitamin D insufficiency. Some studies claim that vitamin D may reduce lipogenesis and others claim that vitamin D can promote adipogenesis. Aim of the study This study was planned to evaluate the effect of alteration in vitamin D level on body weight and adipose tissue metabolism in an obese rat model. Methods 32 Female Albino-rats were randomly allocated into: control group (C, n = 8), fed on control diet containing 1000 IU vitamin D/kg diet, and a high caloric diet group (HCD, n = 32). The HCD group was further subdivided into 3 groups according to the vitamin D dose into: standard vitamin D dose group (HCD+SVD) containing 1000 IU vitamin D/kg diet, low vitamin D dose group (HCD+LVD) containing 25 IU vitamin D/kg diet and high vitamin D dose group (HCD+HVD) containing 5169 IU vitamin D/kg diet. Body mass index, serum vitamin D, glucose, lipid profile, TNF-α and adipose tissue UCP-1 were measured. Different fat depots were weighed and histopathologically assessed. Results HCD+HVD group showed a significant increase in the final body mass index and in the different fat depot weights compared to all groups. Compared to the HCD+SVD group, the HCD+HVD group showed significantly lower serum total cholesterol and LDL-c levels, while it showed a non-significant change in serum glucose, TNF-α and visceral adipose tissue UCP-1. A significant negative correlation was found between serum 25(OH)D and visceral adipose tissue UCP-1. HCD+LVD showed the highest visceral adipose tissue UCP-1 compared to all groups. Conclusion Vitamin D promoted adiposity and decreased visceral adipose tissue UCP-1 but improved the associated derangements in lipid profile.


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