scholarly journals Circulating steroid levels as correlates of adipose tissue phenotype in premenopausal women

Author(s):  
Geneviève B. Marchand ◽  
Anne-Marie Carreau ◽  
Sofia Laforest ◽  
Julie-Anne Côté ◽  
Marleen Daris ◽  
...  

AbstractBackgroundObesity-related alterations in the circulating steroid hormone profile remain equivocal in women. Our objective was to identify circulating steroid levels that relate to increased adiposity and altered adipose phenotype in premenopausal women.Materials and methodsIn a sample of 42 premenopausal women [age 46 ± 3 years; body mass index (BMI) 27.1 ± 4.2 kg/m2], 19 plasma steroids were quantified by electrospray ionization-liquid chromatography-tandem mass spectroscopy (ESI-LC-MS/MS). Body composition and fat distribution were assessed by dual-energy X-ray absorptiometry (DXA) and computed tomography (CT), respectively. Markers of adipose tissue function including adipocyte size distributions, radiological attenuation and macrophage infiltration were also analyzed in surgically obtained visceral and subcutaneous fat samples.ResultsMany negative correlations were observed between adiposity measurements such as BMI, body fat percentage or total abdominal adipose tissue area and plasma levels of androstenedione (Δ4) (r = −0.33 to −0.39, p ≤ 0.04), androsterone (ADT) (r = −0.30 to −0.38, p ≤ 0.05) and steroid precursor pregnenolone (PREG) (r = −0.36 to −0.46, p ≤ 0.02). Visceral adipocyte hypertrophy was observed in patients with low PREG concentrations (p < 0.05). Visceral adipose tissue radiologic attenuation, a potential marker of adipocyte size, was also positively correlated with PREG levels (r = 0.33, p < 0.05). Low levels of PREG were related to increased number of macrophages infiltrating visceral and subcutaneous adipose tissue (p < 0.05).ConclusionPlasma levels of androgens and their precursors are lower in women with increased adiposity and visceral adipocyte hypertrophy. Low circulating PREG concentration may represent a marker of adipose tissue dysfunction.

2020 ◽  
Vol 21 (21) ◽  
pp. 8289
Author(s):  
Mari T. Kaartinen ◽  
Mansi Arora ◽  
Sini Heinonen ◽  
Aila Rissanen ◽  
Jaakko Kaprio ◽  
...  

Transglutaminases TG2 and FXIII-A have recently been linked to adipose tissue biology and obesity, however, human studies for TG family members in adipocytes have not been conducted. In this study, we investigated the association of TGM family members to acquired weight gain in a rare set of monozygotic (MZ) twins discordant for body weight, i.e., heavy–lean twin pairs. We report that F13A1 is the only TGM family member showing significantly altered, higher expression in adipose tissue of the heavier twin. Our previous work linked adipocyte F13A1 to increased weight, body fat mass, adipocyte size, and pro-inflammatory pathways. Here, we explored further the link of F13A1 to adipocyte size in the MZ twins via a previously conducted TWA study that was further mined for genes that specifically associate to hypertrophic adipocytes. We report that differential expression of F13A1 (ΔHeavy–Lean) associated with 47 genes which were linked via gene enrichment analysis to immune response, leucocyte and neutrophil activation, as well as cytokine response and signaling. Our work brings further support to the role of F13A1 in the human adipose tissue pathology, suggesting a role in the cascade that links hypertrophic adipocytes with inflammation.


2012 ◽  
Vol 166 (3) ◽  
pp. 469-476 ◽  
Author(s):  
L Frederiksen ◽  
K Højlund ◽  
D M Hougaard ◽  
T H Mosbech ◽  
R Larsen ◽  
...  

ObjectiveTestosterone therapy increases lean body mass and decreases total fat mass in aging men with low normal testosterone levels. The major challenge is, however, to determine whether the metabolic consequences of testosterone therapy are overall positive. We have previously reported that 6-month testosterone therapy did not improve insulin sensitivity. We investigated the effect of testosterone therapy on regional body fat distribution and on the levels of the insulin-sensitizing adipokine, adiponectin, in aging men with low normal bioavailable testosterone levels.DesignA randomized, double-blinded, placebo-controlled study on 6-month testosterone treatment (gel) in 38 men, aged 60–78 years, with bioavailable testosterone <7.3 nmol/l, and a waist circumference >94 cm.MethodsCentral fat mass (CFM) and lower extremity fat mass (LEFM) were measured by dual X-ray absorptiometry. Subcutaneous abdominal adipose tissue (SAT), visceral adipose tissue (VAT), and thigh subcutaneous fat area (TFA) were measured by magnetic resonance imaging. Adiponectin levels were measured using an in-house immunofluorometric assay. Coefficients (b) represent the placebo-controlled mean effect of intervention.ResultsLEFM was decreased (b=−0.47 kg, P=0.07) while CFM did not change significantly (b=−0.66 kg, P=0.10) during testosterone therapy. SAT (b=−3.0%, P=0.018) and TFA (b=−3.0%, P<0.001) decreased, while VAT (b=1.0%, P=0.54) remained unchanged. Adiponectin levels decreased during testosterone therapy (b=−1.3 mg/l, P=0.001).ConclusionTestosterone therapy decreased subcutaneous fat on the abdomen and lower extremities, but visceral fat was unchanged. Moreover, adiponectin levels were significantly decreased during testosterone therapy.


Author(s):  
Qingyi Jia ◽  
B Gisella Carranza Leon ◽  
Michael D Jensen

Abstract Context The factors that determine the recycling of free fatty acids (FFA) back into different adipose tissue depots via the direct storage pathway are not completely understood. Objective To assess the interactions between adipocyte factors and plasma FFA concentrations that determine regional FFA storage rates. Design We measured direct adipose tissue FFA storage rates before and after weight loss under high FFA (intravenous somatostatin and epinephrine) and low (intravenous insulin and glucose) FFA concentrations. Setting Mayo Clinic Clinical Research Unit. Patients Sixteen premenopausal women, BMI 30 - 37 kg/m 2. Intervention Comprehensive lifestyle weight loss program. Main Outcome Measure Direct FFA storage rates in upper and lower body subcutaneous fat. Results Over the entire range of FFA and under isolated conditions of elevated FFA concentrations the storage rates of FFA into upper and lower body subcutaneous fat per unit lipid were associated with concentrations, not adipocyte fatty acid storage factors. Under low FFA conditions, direct FFA storage rates were related to adipocyte CD36 content, not tissue level content of fatty acid storage factors. Weight loss did not change these relationships. Conclusions The regulation of direct FFA storage under low FFA concentration conditions appears to be at the level of the cell/adipocyte content of CD36, whereas under high FFA concentration conditions direct FFA storage at the tissue level is predicted by plasma FFA concentrations, independent of adipocyte size or fatty acid storage factors. These observations offer novel insights into how adipose tissue regulates direct FFA storage in humans.


Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5973-5974
Author(s):  
Julia Kovsan ◽  
Matthias Blüher ◽  
Tanya Tarnovscki ◽  
Nora Klöting ◽  
Boris Kirshtein ◽  
...  

Context: Autophagy is a housekeeping mechanism, involved in metabolic regulation and stress response, shown recently to regulate lipid droplets biogenesis/breakdown and adipose tissue phenotype. Objective: We hypothesized that in human obesity autophagy may be altered in adipose tissue in a fat depot and distribution-dependent manner. Setting and Patients: Paired omental (Om) and sc adipose tissue samples were used from obese and nonobese (n = 65, cohort 1); lean, sc-obese and intraabdominally obese (n = 196, cohort 2); severely obese persons without diabetes or obesity-associated morbidity, matched for being insulin sensitive or resistant (n = 60, cohort 3). Results: Protein and mRNA levels of the autophagy genes Atg5, LC3A, and LC3B were increased in Om compared with sc, more pronounced among obese persons, particularly if with intraabdominal fat accumulation. Both adipocytes and stromal-vascular cells contribute to the expression of autophagy genes. The increased number of autophagosomes and elevated autophagic flux assessed in fat explants incubated with lysosomal inhibitors were observed in obesity, particularly in Om. The degree of visceral adiposity and adipocyte hypertrophy accounted for approximately 50% of the variance in Atg5 mRNA levels by multivariate regression analysis, whereas age, sex, measures of insulin sensitivity, inflammation, and adipose tissue stress were excluded from the model. Moreover, in cohort 3, the autophagy marker genes were increased in those who were insulin resistant compared with insulin sensitive, particularly in Om. Conclusions: Autophagy is up-regulated in adipose tissue of obese persons, especially in Om, correlating with the degree of obesity, visceral fat distribution, and adipocyte hypertrophy. This may precede the occurrence of obesity-associated morbidity.


2010 ◽  
Vol 31 (6) ◽  
pp. 947-947
Author(s):  
Julia Kovsan ◽  
Matthias Blüher ◽  
Tanya Tarnovscki ◽  
Nora Klöting ◽  
Boris Kirshtein ◽  
...  

Context Autophagy is a housekeeping mechanism, involved in metabolic regulation and stress response, shown recently to regulate lipid droplets biogenesis/breakdown and adipose tissue phenotype. Objective We hypothesized that in human obesity autophagy may be altered in adipose tissue in a fat depot and distribution-dependent manner. Setting and Patients Paired omental (Om) and sc adipose tissue samples were used from obese and nonobese (n = 65, cohort 1); lean, sc-obese and intraabdominally obese (n = 196, cohort 2); severely obese persons without diabetes or obesity-associated morbidity, matched for being insulin sensitive or resistant (n = 60, cohort 3). Results Protein and mRNA levels of the autophagy genes Atg5, LC3A, and LC3B were increased in Om compared with sc, more pronounced among obese persons, particularly if with intraabdominal fat accumulation. Both adipocytes and stromal-vascular cells contribute to the expression of autophagy genes. The increased number of autophagosomes and elevated autophagic flux assessed in fat explants incubated with lysosomal inhibitors were observed in obesity, particularly in Om. The degree of visceral adiposity and adipocyte hypertrophy accounted for approximately 50% of the variance in Atg5 mRNA levels by multivariate regression analysis, whereas age, sex, measures of insulin sensitivity, inflammation, and adipose tissue stress were excluded from the model. Moreover, in cohort 3, the autophagy marker genes were increased in those who were insulin resistant compared with insulin sensitive, particularly in Om. Conclusions Autophagy is up-regulated in adipose tissue of obese persons, especially in Om, correlating with the degree of obesity, visceral fat distribution, and adipocyte hypertrophy. This may precede the occurrence of obesity-associated morbidity.


1977 ◽  
Vol 25 (2) ◽  
pp. 165-179 ◽  
Author(s):  
A. J. Kempster ◽  
A. Cuthbertson

SUMMARYCommercial lamb carcasses were surveyed in 1971/72 as part of the development programme for a national classification scheme for Great Britain. Carcasses of 421 castrated male lambs were evaluated and their left sides dissected. The sample comprised seven groups representing the main breed types in the national population. Within these groups, lambs were selected from three regions on each of three occasions corresponding with the beginning, middle and end of the normal slaughtering season for each group.The overall means (±SD) for side weight and percentage subcutaneous fat in the side were 8·3 ± 1·8 kg and 12·6 ± 3·2 respectively. When adjusted to the overall mean subcutaneous fat percentage (constant % SF), the breed-type side weight means ranged from 6·4 kg (Welsh Mountain) to 10·8 kg (British Longwool). At constant% SF, lambs slaughtered earlier in the season were lighter than those of the same breed type slaughtered later.Significant differences (P<0·05) were recorded between breed-type groups in fat distribution and lean/bone ratio. These were reflected as important differences in percentage lean at constant % SF, group means ranging from 54·5 (lambs by Suffolk rams out of Scottish Halfbred ewes) to 56·7 (lambs by British Longwool rams out of hill ewes).When lambs of the same breed type from different regions were compared at constant % SF and constant side weight, there were few important differences in carcass characteristics.The results are discussed in relation to the classification scheme which has since been introduced by the Meat and Livestock Commission.


2009 ◽  
Vol 297 (2) ◽  
pp. E495-E504 ◽  
Author(s):  
Katja S. C. Gollisch ◽  
Josef Brandauer ◽  
Niels Jessen ◽  
Taro Toyoda ◽  
Ali Nayer ◽  
...  

Regular physical activity improves glucose tolerance and decreases adiposity. Our aim was to investigate the effects of exercise training on subcutaneous (inguinal) and visceral (parametrial) adipose tissue in rats that were fed a chow diet (13% fat) or made insulin resistant by a high-fat diet (60% fat). Sprague-Dawley rats performed 4 wk of voluntary wheel running or were kept as sedentary controls. The training groups fed chow and the high-fat diet achieved similar running distances (8.8 ± 1.8 and 9.3 ± 1.9 km/day, respectively). Training improved oral glucose tolerance in chow-fed rats and prevented the glucose intolerance that occurred in sedentary rats fed the high-fat diet. In both subcutaneous and visceral adipose tissue, the high-fat diet-induced increases in fat pad weight (67% and 133%, respectively), adipocyte size (20% and 43%), and cell number (36% and 65%) were completely prevented by exercise training. Cytokine mRNA expression in visceral fat did not change with exercise training. However, in subcutaneous fat, training actually increased mRNA expression of several cytokines [IL-6: 80% ( P < 0.05); TNF-α: 100% ( P < 0.05); IL-1 receptor antagonist (IL-1Ra): 57% ( P = 0.08)] with no detectable increases in serum cytokine concentrations. In summary, exercise training can overcome high-fat diet-induced impairments in glucose tolerance and increases in adipocyte size, cell number, and fat pad mass. Improved glucose tolerance was accompanied by an increase in cytokine gene expression in subcutaneous fat. This finding raises the possibility of a specific role of subcutaneous adipose tissue in adaptive responses to exercise training.


2017 ◽  
Vol 126 (05) ◽  
pp. 316-320 ◽  
Author(s):  
Okan Dikker ◽  
Seldag Bekpinar ◽  
Gul Ozdemirler ◽  
Mujdat Uysal ◽  
Muberra Vardar ◽  
...  

Abstract Introduction Crosstalk between bone and adipose tissues is implicated in several pathologic conditions related to bone metabolism. Omentin-1, a 34-kD protein, is released from omental adipose tissue. A few studies indicated the effect of omentin-1 on bone health and bone mineral density (BMD) and the interaction of omentin-1 with vitamin D. Therefore, this study aimed to investigate the relationship between omentin-1, vitamin D, and BMD in postmenopausal women with osteoporosis compared with non-osteoporotic counterparts. Materials and methods Forty postmenopausal women with osteoporosis (OP), 40 counterparts without OP, and 30 premenopausal women were enrolled. Dual-energy X-ray Absorptiometry results, body mass index, and some demographic and biochemical data were recorded. Vitamin D (25-hydroxyvitamin D3) levels were measured using liquid chromatography-tandem mass spectrometry. Serum omentin-1 was determined using an enzyme-linked immunosorbent assay. Results Omentin-1 levels tended to increase in both postmenopausal women groups compared with the control group, but this increase was significant only in women with osteoporosis. Vitamin D levels were not different between the groups. When women were categorized according to vitamin D levels, women with normal vitamin D levels had significantly higher omentin-1 levels. A positive correlation was found between omentin-1 and vitamin D levels in all groups (r=0.197, p=0.041, n=110). Conclusion The tendency to an increase in omentin-1 levels in postmenopausal women with osteoporosis may be due to a physiologic compensation against bone loss after menopause. The linear relationship between omentin-1 and vitamin D suggests that adipose tissue is one of the target tissues for the vitamin D effect.


2001 ◽  
Vol 85 (06) ◽  
pp. 1111-1116 ◽  
Author(s):  
E. Maquoi ◽  
P. Holvoet ◽  
A. Mertens ◽  
F. Lupu ◽  
P. Morange ◽  
...  

SummaryFollowing the observation by Brown et al. (Am J Physiol 1997; 272: C937-49) that primary rat adipocytes in culture secrete gelatinase A (MMP-2), we have evaluated gelatinase expression in adipose tissue with the use of mouse models of obesity. Wild-type mice were kept on a standard fat diet (SFD) or on a high fat diet (42% fat, HFD) and genetically obese db/db mice were kept on SFD; gonadal and subcutaneous fat pads were removed and analysed ex vivo. These studies revealed that: 1) the HFD induced adipocyte hypertrophy; 2) after 32 weeks, significantly higher levels of 70 kDa (p <0.05) and 65 kDa proMMP-2 (p < 0.01) were observed in extracts of gonadal fat pads of mice on HFD; 3) the contribution of active MMP-2 to the total level was comparable in SFD and HFD groups (20 to 30%); and 4) gelatinase B (MMP-9) was not consistently detected. These findings were confirmed by gelatin zymography and by mRNA determination using competitive RT-PCR. The presence of MMP-2 in the adipose tissue was confirmed immunologically and its localization in adipocytes revealed by immunogold electron microscopy. The potential functional role of MMP-2 in adipose tissue remains to be determined.


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