scholarly journals The Metabolic Significance of Intermuscular Adipose Tissue: Is IMAT a Friend or a Foe to Metabolic Health?

2021 ◽  
Author(s):  
Lauren M. Sparks ◽  
Bret H. Goodpaster ◽  
Bryan C. Bergman
Keyword(s):  
Adipose Tissue ◽  
Race And Ethnicity ◽  
Activity Level ◽  
Tissue Quality ◽  
Intermuscular Adipose Tissue ◽  
Secreted Factors ◽  
Diet And Physical Activity ◽  
Adipose Tissue Depot

Adipose tissues are not homogeneous and show site-specific properties. An elusive and understudied adipose tissue depot – most likely due to its limited accessibility – is the intermuscular adipose depot (IMAT). Adipose tissue is a pliable organ with the ability to adapt to its physiological context, yet whether that adaptation is harmful or beneficial in the IMAT depot remains to be explored in humans. Potential reasons for IMAT accumulation in humans being deleterious or beneficial include: 1) sex and related circulating hormone levels, 2) race and ethnicity and 3) lifestyle factors (e.g. diet and physical activity level). IMAT quantity <i>per se</i> may not be the driving factor in the etiology of insulin resistance and type 2 diabetes but rather the quality of the IMAT itself is the true puppeteer. Adipose tissue quality likely influences its secreted factors which are also likely to influence metabolism of surrounding tissues. The advent of molecular assessments such as RNAseq, ATACseq and DNA methylation at the single cell and single nuclei levels, as well as the potential for ultrasound-guided biopsies specifically for IMAT, will permit more sophisticated investigations of human IMAT and dramatically advance our understanding of this enigmatic adipose tissue.

scholarly journals The Metabolic Significance of Intermuscular Adipose Tissue: Is IMAT a Friend or a Foe to Metabolic Health?

2021 ◽  
Author(s):  
Lauren M. Sparks ◽  
Bret H. Goodpaster ◽  
Bryan C. Bergman
Keyword(s):  
Adipose Tissue ◽  
Race And Ethnicity ◽  
Activity Level ◽  
Tissue Quality ◽  
Intermuscular Adipose Tissue ◽  
Secreted Factors ◽  
Diet And Physical Activity ◽  
Adipose Tissue Depot

Adipose tissues are not homogeneous and show site-specific properties. An elusive and understudied adipose tissue depot – most likely due to its limited accessibility – is the intermuscular adipose depot (IMAT). Adipose tissue is a pliable organ with the ability to adapt to its physiological context, yet whether that adaptation is harmful or beneficial in the IMAT depot remains to be explored in humans. Potential reasons for IMAT accumulation in humans being deleterious or beneficial include: 1) sex and related circulating hormone levels, 2) race and ethnicity and 3) lifestyle factors (e.g. diet and physical activity level). IMAT quantity <i>per se</i> may not be the driving factor in the etiology of insulin resistance and type 2 diabetes but rather the quality of the IMAT itself is the true puppeteer. Adipose tissue quality likely influences its secreted factors which are also likely to influence metabolism of surrounding tissues. The advent of molecular assessments such as RNAseq, ATACseq and DNA methylation at the single cell and single nuclei levels, as well as the potential for ultrasound-guided biopsies specifically for IMAT, will permit more sophisticated investigations of human IMAT and dramatically advance our understanding of this enigmatic adipose tissue.

scholarly journals On the role of macrophages in the control of adipocyte energy metabolism

2019 ◽  
Vol 8 (6) ◽  
pp. R105-R121 ◽  
Author(s):  
Michaela Keuper
Keyword(s):  
Adipose Tissue ◽  
Mitochondrial Function ◽  
Current Knowledge ◽  
Human Adipose Tissue ◽  
White Adipocytes ◽  
Secreted Factors ◽  
Adipose Tissue Macrophages

The crosstalk between macrophages (MΦ) and adipocytes within white adipose tissue (WAT) influences obesity-associated insulin resistance and other associated metabolic disorders, such as atherosclerosis, hypertension and type 2 diabetes. MΦ infiltration is increased in WAT during obesity, which is linked to decreased mitochondrial content and activity. The mechanistic interplay between MΦ and mitochondrial function of adipocytes is under intense investigation, as MΦ and inflammatory pathways exhibit a pivotal role in the reprogramming of WAT metabolism in physiological responses during cold, fasting and exercise. Thus, the underlying immunometabolic pathways may offer therapeutic targets to correct obesity and metabolic disease. Here, I review the current knowledge on the quantity and the quality of human adipose tissue macrophages (ATMΦ) and their impact on the bioenergetics of human adipocytes. The effects of ATMΦ and their secreted factors on mitochondrial function of white adipocytes are discussed, including recent research on MΦ as part of an immune signaling cascade involved in the ‘browning’ of WAT, which is defined as the conversion from white, energy-storing adipocytes into brown, energy-dissipating adipocytes.

scholarly journals 4126 Intermuscular adipose tissue secretes pro-inflammatory, extracellular matrix, and lipid signals related to insulin resistance and type 2 diabetes

2020 ◽  
Vol 4 (s1) ◽  
pp. 9-9
Author(s):  
Darcy Kahn ◽  
Simona Zarini ◽  
Emily Macias ◽  
Amanda Garfield ◽  
Kathleen Harrison ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Adipose Tissue ◽  
Functional Role ◽  
Vastus Lateralis ◽  
Laparoscopic Bariatric Surgery ◽  
Intermuscular Adipose Tissue

OBJECTIVES/GOALS: Intermuscular adipose tissue (IMAT) has been associated with insulin resistance and type 2 diabetes, yet mechanistic studies addressing the functional role of IMAT are lacking. The aim of this work was to identify novel mechanisms by which IMAT may directly impact skeletal muscle metabolism. METHODS/STUDY POPULATION: We quantified the secretome of IMAT, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) to determine if there are differences between depots in the secretion of cytokines, eicosanoids, FFAs and proteins that influence metabolic function. SAT and VAT biopsies from patients undergoing laparoscopic bariatric surgery and IMAT extracted from vastus lateralis biopsies of individuals with Obesity were cultured for 48 hours in DMEM, and the conditioned media was analyzed using nanoflow HPLC-MS, multiplex ELISAs and LC/MS/MS for proteins, cytokines and eicosanoids/FFA, respectively. RESULTS/ANTICIPATED RESULTS: IMAT secretion of various extracellular matrix proteins (fibrinogen-β, collagenV1a3, fibronectin) was significantly different than VAT and SAT. Pro-inflammatory cytokine secretion of IFNg, TNFa, IL-8 and IL-13 from IMAT was higher than VAT and significantly higher than SAT (p < 0.05). IMAT secretes significantly more pro-inflammatory eicosanoids TXB2 and PGE2 than VAT (p = 0.02, 0.05) and SAT (p = 0.01, 0.04). IMAT and VAT have significantly greater basal lipolysis assessed by FFA release rates compared to SAT (p = 0.01, 0.04). DISCUSSION/SIGNIFICANCE OF IMPACT: These data begin to characterize the disparate secretory properties of SAT, VAT and IMAT and suggest a metabolically adverse secretome of IMAT, that due to its proximity to skeletal muscle may play an important functional role in the pathogenesis of insulin resistance and type 2 diabetes.

scholarly journals COVID-19 Lockdown and Changes of the Dietary Pattern and Physical Activity Habits in a Cohort of Patients with Type 2 Diabetes Mellitus

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2327 ◽  
Author(s):  
María Belén Ruiz-Roso ◽  
Carolina Knott-Torcal ◽  
Diana C. Matilla-Escalante ◽  
Alba Garcimartín ◽  
Miguel A. Sampedro-Nuñez ◽  
...  
Keyword(s):  
Physical Activity ◽  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Activity Level ◽  
Food Craving ◽  
Diet And Physical Activity ◽  
Snack Consumption ◽  
The Impact

The COVID-19 lockdown clearly affected the lifestyle of the population and entailed changes in their daily habits, which involved potential health consequences, especially on patients with Type 2 Diabetes Mellitus (T2DM). We aimed to examine the impact of the lockdown caused by COVID-19 pandemic on both nutrition and exercise habits, as well as the psychological effects in patients with T2DM, compared to their usual diet and physical activity level previous to the complete home confinement. We also intended to analyse any potential variables that may have influenced these lifestyle modifications. A Food Frequency Questionnaire (FFQ), Physical Activity Questionnaire (IPAQ), Food Craving Questionnaire-State (FCQ-S) and Food Craving Questionnaire-Trait (FCQ-T) were used. Our results showed an increase in vegetable, sugary food and snack consumption. An association between levels of foods cravings and snack consumption was also found. Data also showed a high percentage of physical inactivity before the COVID-19 lockdown, which was exacerbated during the home confinement. These findings emphasise the great importance to do further research with larger study samples to analyse and explore dietary habits and to develop public health policies to promote a healthy lifestyle in terms of diet and physical activity in these patients, especially after this strict period of lockdown.

scholarly journals Endocrine and Metabolic Effects of Adipose Tissue in Children and Adolescents / Endokrina in Presnovna Funkcija Maščobnega Tkiva Pri Otrocih in Mladostnikih

2015 ◽  
Vol 54 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Primož Kotnik ◽  
Pamela Fischer Posovszky ◽  
Martin Wabitsch
Keyword(s):  
Adipose Tissue ◽  
Children And Adolescents ◽  
Metabolic Effects ◽  
Cancer Development ◽  
Biological Processes ◽  
The Metabolic Syndrome ◽  
Secreted Factors ◽  
Tissue Factors ◽  
Therapeutic Possibilities

Abstract Adipose tissue is implicated in many endocrine and metabolic processes. Leptin was among the first identified adipose-secreted factors, which act in an auto-, para- and endocrine manner. Since leptin, many other adipose tissue factors were determined, some primarily secreted from the adipocytes, some from other cells of the adipose tissue. So-called adipokines are not only involved in obesity and its complications, as are insulin resistance, type 2 diabetes and other components of the metabolic syndrome, but also in growth, reproduction, bone metabolism, immune response, cancer development and many other important biological processes. Research in the field of adipokines has revealed new insights into the physiological and pathophysiologal processes and opened new therapeutic possibilities. In the present article, a special emphasis is devoted to research in children and adolescents.

scholarly journals PHYSICAL ACTIVITY AS AN IMPORTANT FACTOR IN IMPROVING HEALTH IN THE ELDERLY WITH TYPE 2 DIABETES

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Ivana Crnković ◽  
Aleksandar Aleksandar Racz ◽  
Danica Železnik ◽  
Janko Babić
Keyword(s):  
Quality Of Life ◽  
Physical Activity ◽  
Type 2 Diabetes ◽  
Social Relations ◽  
The Elderly ◽  
Activity Level ◽  
Healthy Population ◽  
Quantitative Methodology

The goal of the study was to research the level of the quality of life as a whole and within certain domains, the level of physical activity, and to establish the correlation between physical activity and the quality of life in the elderly suffering from type 2 diabetes and the elderly not suffering from from type 2 diabetes in the Republic of Croatia. Quantitative methodology was used in the research. 120 examinees from 65 to 93 years of age participated in the rand were divided into two groups. The study used a sociodemographic  questionnaire for the examinees, WHOQOL-bref questionnaire for the evaluation of the quality of life and PASE questionnaire for the evaluation of the physical activity level in the elderly.In accordance with the set goals, this research established that the perceived quality of life in the elderly does not deviate from the values to be found in the healthy population. The greatest value within the total sample was taken by the domain of satisfaction with the environmental domain, while the satisfaction with the social relations had the lowest average value compared to the other domains. The range of index ITM results amounts to 18.90 to 46.77 with the mean value of 26.47. Persons with type 2 diabetes have a low level of estimated bodily activity and do not participate in any activities such as walking or moving lasting for longer periods of time or being of a higher intensity, which is due to the primary disease.

scholarly journals A Behavioral Lifestyle Intervention to Improve Frailty in Overweight or Obese Older Adults with Type 2 Diabetes: A Feasibility Study

2021 ◽  
pp. 1-9
Author(s):  
R. Jiwani ◽  
J. Wang ◽  
C. Li ◽  
B. Dennis ◽  
D. Patel ◽  
...  
Keyword(s):  
Physical Activity ◽  
Type 2 Diabetes ◽  
Older Adults ◽  
Lifestyle Intervention ◽  
Self Monitoring ◽  
Potential Efficacy ◽  
Session Attendance ◽  
Diet And Physical Activity

Background: Older adults with Type 2 diabetes (T2D) are more likely to be frail, which increases the risk for disability and mortality. Objectives: To determine the feasibility of a behavioral lifestyle intervention, enhanced with mobile health technology for self-monitoring of diet and activity, to improve frailty in overweight/obese older adults (≥65 years) diagnosed with T2D. Design, Setting, and Participants: Single arm, 6-month study of a behavioral lifestyle intervention in 20 overweight/obese (BMI>25) older adults (≥ 65 years) with self-reported T2D diagnosis who owned a smartphone. A Fitbit tracker was provided to all participants for self-monitoring of diet and physical activity. Our primary outcome of feasibility was measured by session attendance, adherence to Fitbit usage to self-monitor diet and physical activity, and study retention. Secondary outcomes included the preliminary efficacy of the intervention on frailty, physical function, quality of life, and T2D-related outcomes. Results: Eighteen participants completed the study. The mean age was 71.5 (SD ± 5.3) years, 56% were female, and half were Hispanic. At baseline, 13 (72%) were pre-frail, 4 (22%) were frail, and 1 (6%) were non-frail. At follow-up, frailty scores improved significantly from 1.61 ± 1.15 to 0.94 ± 0.94 (p=0.01) and bodyweight improved from 205.66 ± 45.52 lbs. to 198.33 ± 43.6 lbs. (p=<0.001). Conclusion: This study provides evidence for the feasibility of a behavioral lifestyle intervention in overweight/obese older adults with T2D and preliminary results support its potential efficacy in improving frailty score.

scholarly journals Adipose tissue biomarkers and type 2 diabetes incidence in normoglycemic participants in the MESArthritis Ancillary Study: A cohort study

PLoS Medicine ◽  
2021 ◽  
Vol 18 (7) ◽  
pp. e1003700
Author(s):  
Farhad Pishgar ◽  
Mahsima Shabani ◽  
Thiago Quinaglia A. C. Silva ◽  
David A. Bluemke ◽  
Matthew Budoff ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Population Based ◽  
Diabetes Incidence ◽  
Intermuscular Adipose Tissue ◽  
Measurement Protocol ◽  
Tissue Biomarkers

Background Given the central role of skeletal muscles in glucose homeostasis, deposition of adipose depots beneath the fascia of muscles (versus subcutaneous adipose tissue [SAT]) may precede insulin resistance and type 2 diabetes (T2D) incidence. This study was aimed to investigate the associations between computed tomography (CT)–derived biomarkers for adipose tissue and T2D incidence in normoglycemic adults. Methods and findings This study was a population-based multiethnic retrospective cohort of 1,744 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) with normoglycemia (baseline fasting plasma glucose [FPG] less than 100 mg/dL) from 6 United States of America communities. Participants were followed from April 2010 and January 2012 to December 2017, for a median of 7 years. The intermuscular adipose tissue (IMAT) and SAT areas were measured in baseline chest CT exams and were corrected by height squared (SAT and IMAT indices) using a predefined measurement protocol. T2D incidence, as the main outcome, was based on follow-up FPG, review of hospital records, or self-reported physician diagnoses. Participants’ mean age was 69 ± 9 years at baseline, and 977 (56.0%) were women. Over a median of 7 years, 103 (5.9%) participants were diagnosed with T2D, and 147 (8.4%) participants died. The IMAT index (hazard ratio [HR]: 1.27 [95% confidence interval [CI]: 1.15–1.41] per 1-standard deviation [SD] increment) and the SAT index (HR: 1.43 [95% CI: 1.16–1.77] per 1-SD increment) at baseline were associated with T2D incidence over the follow-up. The associations of the IMAT and SAT indices with T2D incidence were attenuated after adjustment for body mass index (BMI) and waist circumference, with HRs of 1.23 (95% CI: 1.09–1.38) and 1.29 (95% CI: 0.96–1.74) per 1-SD increment, respectively. The limitations of this study include unmeasured residual confounders and one-time measurement of adipose tissue biomarkers. Conclusions In this study, we observed an association between IMAT at baseline and T2D incidence over the follow-up. This study suggests the potential role of intermuscular adipose depots in the pathophysiology of T2D. Trial registration ClinicalTrials.gov NCT00005487

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