Intermuscular adipose tissue (IMAT): association with other adipose tissue compartments and insulin sensitivity.
OBJECTIVE
To quantify intermuscular adipose tissue (IMAT) of the lower leg as well as to investigate associations with other adipose tissue (AT) compartments. The relationship between IMAT and insulin sensitivity was also examined.


METHODS
Standardized quantification of IMAT was performed in a large cohort (N = 249) at increased risk for type 2 diabetes in the right calf by T1-weighted fast spin-echo imaging at 1.5T (Magnetom Sonata; Siemens Healthcare). Additionally, whole-body AT distribution was assessed. Insulin sensitivity was determined by glucose clamp.


RESULTS
Males showed significantly more IMAT than females (2.1 +/- 1.1 cm(2) vs. 1.5 +/- 0.9 cm(2); P < 0.001). IMAT correlated well with other AT depots, especially with visceral AT (VAT; r(females) = 0.52, P < 0.0001 vs. r(males) = 0.42, P < 0.0001). Moreover, IMAT showed a negative correlation with the glucose infusion rate (GIR; r(females) = -0.43, P = 0.0002 vs. r(males) = -0.40, P = 0.0007).


CONCLUSIONS
Quantification of IMAT is possible by standard MR techniques. AT distribution of the lower leg is comparable to the visceral compartment with males having higher IMAT/VAT but lower subcutaneous AT (SCAT). IMAT seems to be involved in the pathogenesis of insulin resistance, as shown by the significant negative correlation with GIR.
Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Tübingen, Germany.
Michael
M
Boettcher
Jürgen
J
Machann
Norbert
N
Stefan
Claus
C
Thamer
Hans-Ulrich
HU
Häring
Claus D
CD
Claussen
Andreas
A
Fritsche
Fritz
F
Schick
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000378:metabolism*; D000886:Anthropometry; D005080:Exercise Test; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007328:Insulin / Q000378:metabolism*; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology / Q000378:metabolism*; D007866:Leg; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism*; D012737:Sex Factors
D007328:Insulin