Intermuscular adipose tissue and thigh muscle area dynamics during an 18-month randomized weight loss trial

It remains unclear whether intermuscular adipose tissue (IMAT) has any metabolic influence or whether it is merely a marker of abnormalities, as well as what are the effects of specific lifestyle strategies for weight loss on the dynamics of both IMAT and thigh muscle area (TMA). We followed the trajectory of IMAT and TMA during 18-mo lifestyle intervention among 278 sedentary participants with abdominal obesity, using magnetic resonance imaging. We measured the resting metabolic rate (RMR) by an indirect calorimeter. Among 273 eligible participants (47.8 ± 9.3 yr of age), the mean IMAT was 9.6 ± 4.6 cm2. Baseline IMAT levels were directly correlated with waist circumference, abdominal subdepots, C-reactive protein, and leptin and inversely correlated with baseline TMA and creatinine ( P < 0.05 for all). After 18 mo (86.3% adherence), both IMAT (−1.6%) and TMA (−3.3%) significantly decreased ( P < 0.01 vs. baseline). The changes in both IMAT and TMA were similar across the lifestyle intervention groups and directly corresponded with moderate weight loss ( P < 0.001). IMAT change did not remain independently associated with decreased abdominal subdepots or improved cardiometabolic parameters after adjustments for age, sex, and 18-mo weight loss. In similar models, 18-mo TMA loss remained associated with decreased RMR, decreased activity, and with increased fasting glucose levels and IMAT ( P < 0.05 for all). Unlike other fat depots, IMAT may not represent a unique or specific adipose tissue, instead largely reflecting body weight change per se. Moderate weight loss induced a significant decrease in thigh muscle area, suggesting the importance of resistance training to accompany weight loss programs.

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Decreased TLR3 in Hyperplastic Adipose Tissue, Blood and Inflamed Adipocytes is Related to Metabolic Inflammation

Cellular Physiology and Biochemistry ◽

10.1159/000495487 ◽

2018 ◽

Vol 51 (3) ◽

pp. 1051-1068 ◽

Cited By ~ 7

Author(s):

Jèssica Latorre ◽

José M. Moreno-Navarrete ◽

Mónica Sabater ◽

Maria Buxo ◽

José I. Rodriguez-Hermosa ◽

...

Keyword(s):

Weight Loss ◽

Adipose Tissue ◽

Low Grade ◽

Metabolic Inflammation ◽

Fat Depots ◽

Acute Surgery ◽

Obese Subjects ◽

Anti Inflammatory ◽

The Impact

Background/Aims: Obesity is characterized by the immune activation that eventually dampens insulin sensitivity and changes metabolism. This study explores the impact of different inflammatory/ anti-inflammatory paradigms on the expression of toll-like receptors (TLR) found in adipocyte cultures, adipose tissue, and blood. Methods: We evaluated by real time PCR the impact of acute surgery stress in vivo (adipose tissue) and macrophages (MCM) in vitro (adipocytes). Weight loss was chosen as an anti-inflammatory model, so TLR were analyzed in fat samples collected before and after bariatric surgery-induced weight loss. Associations with inflammatory and metabolic parameters were analyzed in non-obese and obese subjects, in parallel with gene expression measures taken in blood and isolated adipocytes/ stromal-vascular cells (SVC). Treatments with an agonist of TLR3 were conducted in human adipocyte cultures under normal conditions and upon conditions that simulated the chronic low-grade inflammatory state of obesity. Results: Surgery stress raised TLR1 and TLR8 in subcutaneous (SAT), and TLR2 in SAT and visceral (VAT) adipose tissue, while decreasing VAT TLR3 and TLR4. MCM led to increased TLR2 and diminished TLR3, TLR4, and TLR5 expressions in human adipocytes. The anti-inflammatory impact of weight loss was concomitant with decreased TLR1, TLR3, and TLR8 in SAT. Cross-sectional associations confirmed increased V/ SAT TLR1 and TLR8, and decreased TLR3 in obese patients, as compared with non-obese subjects. As expected, TLR were predominant in SVC and adipocyte precursor cells, even though expression of all of them but TLR8 (very low levels) was also found in ex vivo isolated and in vitro differentiated adipocytes. Among SVC, CD14+ macrophages showed increased TLR1, TLR2, and TLR7, but decreased TLR3 mRNA. The opposite patterns shown for TLR2 and TLR3 in V/ SAT, SVC, and inflamed adipocytes were observed in blood as well, being TLR3 more likely linked to lymphocyte instead of neutrophil counts. On the other hand, decreased TLR3 in adipocytes challenged with MCM dampened lipogenesis and the inflammatory response to Poly(I:C). Conclusion: Functional variations in the expression of TLR found in blood and hypertrophied fat depots, namely decreased TLR3 in lymphocytes and inflamed adipocytes, are linked to metabolic inflammation.

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Abstract P106: Stabilization Muscles Drive Associations Between Lipoproteins And Total Abdominal Muscle And Intermuscular Adipose Tissue In The Multi-ethnic Study Of Atherosclerosis

Circulation ◽

10.1161/circ.143.suppl_1.p106 ◽

2021 ◽

Vol 143 (Suppl_1) ◽

Author(s):

Megan M Marron ◽

Matthew Allison ◽

Britta A Larsen ◽

Joachim H Ix ◽

Alexis C Wood ◽

...

Keyword(s):

Adipose Tissue ◽

Abdominal Muscle ◽

Rectus Abdominis ◽

Lipid Lowering ◽

Resonance Spectroscopy ◽

Lipoprotein Subclass ◽

Muscle Area ◽

Ethnic Study ◽

Intermuscular Adipose Tissue ◽

Muscle Groups

Introduction: Quality and quantity of skeletal muscle decrease with age, largely due to adipose tissue infiltration, and are important determinants of metabolic health. To inform efforts to slow aging-related decline in muscle mass and prevent myosteatosis, a better understanding of the biological determinants of muscle atrophy and quality is needed. We used targeted lipidomics to identify, with a greater specificity, lipoproteins associated with muscle and intermuscular adipose tissue (IMAT) area (quantity) and density (quality) of the total abdominal, locomotion, and stabilization muscles in the Multi-Ethnic Study of Atherosclerosis. Hypothesis: Lower density lipoproteins will be positively associated with muscle and IMAT quantity, but negatively associated with quality. Methods: At visit one, 105 serum lipoproteins were measured by Bruker lipoprotein subclass analysis with 1 H-Nuclear Magnetic Resonance spectroscopy. Muscle and IMAT area (cm 2 ) and density (Hounsfield units) were estimated 2.6 years, on average, after visit 1 for the total abdominal, locomotion (psoas), and stabilization (paraspinal, oblique, and rectus abdominis) muscles from computed-tomography scans at the L4/L5 spinal junction. We identified lipoproteins associated with body composition using linear regression adjusting for age, gender, race, diet, physical activity, lipid-lowering medication, and multiple comparisons using a 1% false discovery rate. Results: Participants (N=947) were 44-84 years old (mean: 63), 51% men, 40% White, 16% Black, 16% Chinese American, and 27% Hispanic American. Among 105 lipoproteins, 24 were associated with total muscle area, whereas none were associated with muscle density. When examining specific muscle groups, 25 lipoproteins were associated with stabilization muscle area, driven by the oblique muscles. As for total IMAT area, there were 27 associations with lipoproteins. Specifically, 27 lipoproteins were associated with stabilization muscle IMAT area, driven by oblique and rectus abdominis muscles. Last, 39 lipoproteins were associated with total IMAT density, with 28 and 33 associated with locomotion and stabilization (driven by obliques) IMAT density, respectively. Higher VLDL: cholesterols, free cholesterols, phospholipids, and triglycerides and lower HDL: cholesterols and free cholesterols were associated with higher muscle area and IMAT area, but lower IMAT density (

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Weight loss and exercise differentially affect insulin sensitivity, body composition, cardiorespiratory fitness and muscle strength in older adults with obesity; a randomized controlled trial

The Journals of Gerontology Series A ◽

10.1093/gerona/glab240 ◽

2021 ◽

Author(s):

Andrea M Brennan ◽

Robert A Standley ◽

Steven J Anthony ◽

Kory E Grench ◽

Nicole L Helbling ◽

...

Keyword(s):

Older Adults ◽

Weight Loss ◽

Body Composition ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Lean Mass ◽

Disease Risk ◽

Controlled Trial ◽

Statistical Significance ◽

Intermuscular Adipose Tissue

Abstract Background Aging-related disease risk is exacerbated by obesity and physical inactivity. It is unclear how weight loss and increased activity improve risk in older adults. We aimed to determine the effects of diet-induced weight loss with and without exercise on insulin sensitivity, VO2peak, body composition, and physical function in older obese adults. Methods Physically inactive older (68.6 ± 4.5 years) obese (BMI 37.4 ± 4.9 kg/m 2) adults were randomized to: Health education control (HEC; n=25); Diet-induced weight loss (WL; n=31); or Weight loss and exercise (WLEX; n=28) for 6 months. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp, body composition by DXA and MRI, strength by isokinetic dynamometry, and VO2peak by graded exercise test. Results WLEX improved (p<0.05) peripheral insulin sensitivity (+75 ± 103%) vs. HEC (+12 ± 67%); WL (+36 ± 47%) vs. HEC did not reach statistical significance. WLEX increased VO2peak (+7 ± 12%) vs. WL (-2 ± 24%), and prevented reductions in strength and lean mass induced by WL (p<0.05). WLEX decreased abdominal adipose tissue (-16 ± 9%) vs. HEC (-3 ± 8%) and intermuscular adipose tissue (-15 ± 13 %) vs. both HEC (+9 ± 15%) and WL (+2 ± 11%) (p<0.01). Conclusions Exercise with weight loss improved insulin sensitivity and VO2peak, decreased ectopic fat, and preserved lean mass and strength. Weight loss alone decreased lean mass and strength. Older adults intending to lose weight should perform regular exercise to promote cardiometabolic and functional benefits, which may not occur with calorie restriction-induced weight loss alone.

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Roles of Gastrointestinal and Adipose Tissue Peptides in Childhood Obesity and Changes After Weight Loss Due to Lifestyle Intervention

Archives of Pediatrics and Adolescent Medicine ◽

10.1001/archpediatrics.2009.265 ◽

2010 ◽

Vol 164 (2) ◽

Cited By ~ 34

Author(s):

Christian L. Roth ◽

Thomas Reinehr

Keyword(s):

Weight Loss ◽

Adipose Tissue ◽

Childhood Obesity ◽

Lifestyle Intervention

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Preferential reductions in intermuscular and visceral adipose tissue with exercise-induced weight loss compared with calorie restriction

Journal of Applied Physiology ◽

10.1152/japplphysiol.00355.2011 ◽

2012 ◽

Vol 112 (1) ◽

pp. 79-85 ◽

Cited By ~ 35

Author(s):

Joan C. Murphy ◽

Jennifer L. McDaniel ◽

Katherine Mora ◽

Dennis T. Villareal ◽

Luigi Fontana ◽

...

Keyword(s):

Weight Loss ◽

Adipose Tissue ◽

Calorie Restriction ◽

Visceral Adipose Tissue ◽

Control Group ◽

Oral Glucose ◽

Sensitivity Index ◽

Fat Depots ◽

Exercise Induced ◽

Visceral Adipose

Intermuscular adipose tissue (IMAT) and visceral adipose tissue (VAT) are associated with insulin resistance. We sought to determine whether exercise-induced weight loss (EX) results in greater reductions in IMAT and VAT compared with similar weight loss induced by calorie restriction (CR) and whether these changes are associated with improvements in glucoregulation. Sedentary men and women (50–60 yr; body mass index of 23.5–29.9 kg/m2) were randomized to 1 yr of CR ( n = 17), EX ( n = 16), or a control group (CON; n = 6). Bilateral thigh IMAT and VAT volumes were quantified using multi-slice magnetic resonance imaging. Insulin sensitivity index (ISI) was determined from oral glucose tolerance test glucose and insulin levels. Weight loss was comparable ( P = 0.25) in the CR (−10.8 ± 1.4%) and EX groups (−8.3 ± 1.5%) and greater than in the control group (−2.0 ± 2.4%; P < 0.05). IMAT and VAT reductions were larger in the CR and EX groups than in the CON group ( P ≤ 0.05). After controlling for differences in total fat mass change between the CR and EX groups, IMAT and VAT reductions were nearly twofold greater ( P ≤ 0.05) in the EX group than in the CR group (IMAT: −45 ±5 vs. −25 ± 5 ml; VAT: −490 ± 64 vs. −267 ± 61 ml). In the EX group, the reductions in IMAT were correlated with increases in ISI ( r = −0.71; P = 0.003), whereas in the CR group, VAT reductions were correlated with increases in ISI ( r = −0.64; P = 0.006). In conclusion, calorie restriction and exercise-induced weight loss both decrease IMAT and VAT volumes. However, exercise appears to result in preferential reductions in these fat depots.

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Association of total adiposity and computed tomographic measures of regional adiposity with incident cancer risk: a prospective population-based study of older adults

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2013-0360 ◽

2014 ◽

Vol 39 (6) ◽

pp. 687-692 ◽

Cited By ~ 17

Author(s):

Rachel A. Murphy ◽

Taylor F. Bureyko ◽

Iva Miljkovic ◽

Jane A. Cauley ◽

Suzanne Satterfield ◽

...

Keyword(s):

Adipose Tissue ◽

Cancer Risk ◽

Fatty Infiltration ◽

Cox Proportional Hazards ◽

Thigh Muscle ◽

Intermuscular Adipose Tissue ◽

Incident Cancer ◽

Increased Risk ◽

Total Adipose Tissue ◽

Risk Of Cancer

Obesity is associated with increased risk of many types of cancer. Less is known regarding associations between adipose depots and cancer risk. We aimed to explore relationships between adipose depots, risk of cancer, and obesity-related cancer (per NCI definition) in participants initially aged 70–79 years without prevalent cancer (1179 men, 1340 women), and followed for incident cancer for 13 years. Measures included body mass index (BMI), total adipose tissue from dual-energy X-ray absorptiometry, and computed tomography measures of visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue, thigh intermuscular adipose tissue, and thigh muscle attenuation (Hounsfield unit, HU), where low HU indicates fatty infiltration. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards models adjusted for demographics, lifestyle variables, and medical conditions. During follow-up, 617 participants developed cancer of which 224 were obesity-related cancers. Total adipose tissue and VAT were positively associated with cancer risk among women (HR 1.14, 95% CI 1.01–1.30 per SD increase; HR 1.15, 95% CI 1.02–1.30 per SD increase). There were no associations with cancer risk among men. Total adipose tissue was positively associated with obesity-related cancer risk among women (HR 1.23, 95% CI 1.03–1.46 per SD increase). VAT was positively associated with obesity-related cancer risk among men (HR 1.30, 95% CI 1.06–1.60 per SD increase) and remained associated even with adjustment for BMI (HR 1.40, 95% CI 1.08–1.82 per SD increase). These findings provide insight into relationships between specific adipose depots and cancer risk and suggest differential relationships among men and women.

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Intermuscular Adipose Tissue: A Brief Review of Etiology, Association With Physical Function and Weight Loss in Older Adults

Annals of Geriatric Medicine and Research ◽

10.4235/agmr.19.0001 ◽

2019 ◽

Vol 23 (1) ◽

pp. 3-8 ◽

Cited By ~ 2

Author(s):

Debra Lynn Waters

Keyword(s):

Older Adults ◽

Weight Loss ◽

Adipose Tissue ◽

Physical Function ◽

Intermuscular Adipose Tissue

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Measuring leg muscle and fat mass in humans: comparison of CT and dual-energy X-ray absorptiometry

Journal of Applied Physiology ◽

10.1152/jappl.2000.88.2.452 ◽

2000 ◽

Vol 88 (2) ◽

pp. 452-456 ◽

Cited By ~ 114

Author(s):

James A. Levine ◽

Lana Abboud ◽

Mitchel Barry ◽

Judd E. Reed ◽

Patrick F. Sheedy ◽

...

Keyword(s):

Adipose Tissue ◽

Soft Tissue ◽

Fat Mass ◽

Multislice Ct ◽

Dual Energy ◽

Fat Free Mass ◽

Thigh Muscle ◽

Muscle Area ◽

X Ray ◽

Leg Muscle

Dual-energy X-ray absorptiometry (DEXA) is reported to be inferior to computed tomography (CT) to measure changes in appendicular soft tissue composition. We compared CT- and DEXA-measured thigh muscle and fat mass to evaluate the random and systematic discrepancies between these two methods. Thigh skeletal muscle area (single-slice CT) was suboptimally ( r 2= 0.74, P < 0.0001) related to DEXA-measured thigh fat-free mass (FFM). In contrast, thigh muscle and adipose tissue volumes (multislice CT) were highly related to DEXA-measured thigh FFM and fat (both r 2 = 0.96, P < 0.0001). DEXA-measured leg fat was significantly less than multislice-CT-measured leg adipose tissue volume, whereas multislice-CT-measured leg muscle mass was less ( P < 0.0001) than DEXA-measured leg FFM. The systematic discrepancies between the two approaches were consistent with the 10–15% nonfat components of adipose tissue. In conclusion, CT and DEXA measures of appendicular soft tissue are highly related. Systematic differences between DEXA and CT likely relate to the underlying principles of the techniques.

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