Differential Relationship between Intermuscular Adipose Depots with Indices of Cardiometabolic Health

Abstract

Background Globally, accumulation of intermuscular adipose tissue (IMAT) is positively associated with insulin resistance. Whether this association is observed consistently in different skeletal muscles and encompasses other markers of cardiometabolic health is not well known. Objectives The purpose of this secondary analysis study was to investigate associations among thigh or calf IMAT stores and indices of cardiometabolic health in adults who are overweight and obese participating in dietary interventions. A subset of calf data was analyzed to assess relations between IMAT in the gastrocnemius (type II fiber predominance) and soleus (type I fiber predominance) with markers of cardiometabolic health. Materials and Methods Thigh and calf compositions were assessed via magnetic resonance imaging in 113 subjects (mean ± SD, age: 50 ± 16 y (range: 21–77 y), BMI: 31 ± 3 kg/m2), 103 of which completed dietary interventions with or without energy restriction-induced weight loss. A subset of data (n = 37) was analyzed for relations between muscle compartments (gastrocnemius and soleus) and cardiometabolic health. IMAT was regressed separately against fasting serum glucose concentrations, insulin, homeostatic model assessment-insulin resistance (HOMA-IR), and lipids and lipoproteins. Results In general, total thigh IMAT was predictive of markers of glucose control, while total calf IMAT was not. Specifically, baseline thigh IMAT was positively associated with fasting glucose, insulin, and HOMA-IR. IMAT content changes in any depot did not predict improvement in cardiometabolic health. Conclusions The strength of the relationship between IMAT and glucose control-related indices of cardiometabolic health is dependent on IMAT location. Specifically, greater IMAT in the thigh is a better predictor of cardiometabolic risk than greater IMAT in the calf in adults who are overweight and obese.

Neck circumference is associated with adipose tissue content in thigh skeletal muscle in overweight and obese premenopausal women

“…Each one-standard deviation increase in IMAT (~6.8% greater IMAT) is associated with a 40% greater mortality risk over a 10-year period 7 . IMAT volume is higher in individuals with obesity and type 2 diabetes 8,9 and is associated with high levels of inflammation, insulin resistance, obesity, sarcopenia, and lower physical performance in adults and the elderly population 10,11 . Recently, Bergia et al showed that greater IMAT in the thigh is a better predictor of cardiometabolic risk than greater IMAT in the calf in adults who are overweight and obese 11 .…”

“…IMAT volume is higher in individuals with obesity and type 2 diabetes 8,9 and is associated with high levels of inflammation, insulin resistance, obesity, sarcopenia, and lower physical performance in adults and the elderly population 10,11 . Recently, Bergia et al showed that greater IMAT in the thigh is a better predictor of cardiometabolic risk than greater IMAT in the calf in adults who are overweight and obese 11 . Interestingly, IMAT is a unique ectopic adipose depot involved in a range of adverse health outcomes similar to VAT 12 .…”

Associations of Thigh and Abdominal Adipose Tissue Radiodensity with Glucose and Insulin in Nondiabetic African‐Ancestry Men

“…In contrast, our study found no associations between lower thigh IMAT radiodensities and fasting glucose but did find significant associations with higher insulin and insulin resistance, even after adjustment for VAT radiodensities. It is important to note that regional IMAT accumulation may differentially impact the relationship between IMAT and metabolic health . Comparisons of regional distribution of IMAT are not well studied; however, results from Ruan et al suggest that the thigh may have a greater amount of IMAT compared with the waist.…”

“…Statistical significance was based on α = 0.05, and analyses were performed using SAS software version 9.4 (SAS Institute, Inc., Cary, North Carolina). A graphical three‐dimensional scatterplot was generated using the package “scatterplot3d” in R version 3.5.2 (R Foundation for Statistical Computing, Vienna, Austria).…”

Incorporating Milk Protein Isolate into an Energy-Restricted Western-Style Eating Pattern Augments Improvements in Blood Pressure and Triglycerides, but Not Body Composition Changes in Adults Classified as Overweight or Obese: A Randomized Controlled Trial

“…Whole body lean (non-bone soft tissue) and fat tissue masses were measured by dual-energy X-ray absorptiometry (DXA, GE Lunar Prodigy with version 11.1 enCORE iDXA software, Madison, WI) during baseline week 3 and intervention week 16. Right mid-thigh and mid-calf cross-sectional areas, muscle areas, subcutaneous fat areas, and intramuscular adipose tissue (IMAT) areas were measured using magnetic resonance imaging (MRI, 3T General Electric Signa HDx system), as described [23]. Abdominal MRIs at the L3-L4 vertebral disc were also taken due to high correlations with whole abdominal visceral adipose tissue (VAT) volume [24].…”