Adipose tissue in muscle: a novel depot similar in size to visceral adipose tissue.
BACKGROUND
The manner in which fat depot volumes and distributions, particularly the adipose tissue (AT) between the muscles, vary by race is unknown.


OBJECTIVE
The objective was to quantify a previously unstudied and novel intermuscular AT (IMAT) depot and subcutaneous AT, visceral AT (VAT), and total-body skeletal muscle mass in healthy sedentary African American (AA), Asian, and white adults by whole-body magnetic resonance imaging. IMAT is the AT between muscles and within the boundary of the muscle fascia.


METHODS
Analyses were conducted on 227 women [AA (n = 79): body mass index (BMI; in kg/m(2)), 29.0 +/- 5.5; age, 45.7 +/- 16.9 y; Asian (n = 38): BMI, 21.7 +/- 2.9; age, 47.2 +/- 19.9 y; whites (n = 110): BMI, 24.9 +/- 5.4; age, 43.7 +/- 16.2 y]) and 111 men [AA (n = 39): BMI, 25.6 +/- 3.2; age, 45.5 +/- 18.8 y; Asian (n = 13): BMI, 24.9 +/- 2.5; age, 45.6 +/- 25.0 y; white (n = 59): BMI, 25.8 +/- 3.8; age 44.5 +/- 16.3 y].


RESULTS
IMAT depots were not significantly different in size between race groups at low levels of adiposity; however, with increasing adiposity, AAs had a significantly greater increment in the proportion of total AT (TAT) than did the whites and Asians (58, 46, and 44 g IMAT/kg TAT, respectively; P = 0.001). VAT depots were not significantly different in size at low levels of adiposity but, with increasing adiposity, VAT accumulation was greater than IMAT accumulation in the Asians and whites; no significant differences were observed in AAs.


CONCLUSIONS
Race differences in AT distribution extend to IMAT, a depot that may influence race-ethnicity differences in dysglycemia.
Gallagher
Dympna
D
Department of Medicine, Obesity Research Center, St Luke's-Roosevelt Hospital, New York, NY, USA.
Kuznia
Patrick
P
Heshka
Stanley
S
Albu
Jeanine
J
Heymsfield
Steven B
SB
Goodpaster
Bret
B
Visser
Marjolein
M
Harris
Tamara B
TB
D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001213:Asian; D044383:Black People; D001823:Body Composition; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000378:metabolism; D014018:Tissue Distribution; D044465:White People; D001741:Black or African American