Abdominal subcutaneous adipose tissue: a protective fat depot?
OBJECTIVE
Obesity is associated with increased metabolic and cardiovascular risk. The ectopic fat hypothesis suggests that subcutaneous fat may be protective, but this theory has yet to be fully explored.


METHODS
Participants from the Framingham Heart Study (n = 3,001, 48.5% women) were stratified by visceral adipose tissue (VAT) into sex-specific tertiles. Within these tertiles, age-adjusted abdominal subcutaneous adipose tissue (SAT) tertiles were examined in relation to cardiometabolic risk factors.


RESULTS
In the lowest VAT tertile, risk factor prevalence was low, although systolic blood pressure in women and rates of high triglycerides, impaired fasting glucose, hypertension, and the metabolic syndrome in men increased with increasing SAT tertile (all P < 0.04). In contrast, in the top VAT tertile, lower triglycerides were observed in men with increasing SAT (64.4% high triglycerides in SAT tertile 1 vs. 52.7% in SAT tertile 3, P = 0.03). Similar observations were made for women, although results were not statistically significant (50.6% high triglycerides in SAT tertile 1 vs. 41.0% in tertile 3, P = 0.10). Results in the highest VAT tertile were notable for a lack of increase in the prevalence of low HDL in men and women and in rates of impaired fasting glucose in men with increasing subcutaneous fat, despite sizable differences in BMI across SAT tertiles (27.1 to 36.3 kg/m(2)[women]; 28.1 to 35.7 kg/m(2)[men]).


CONCLUSIONS
Although adiposity increases the absolute risk of metabolic and cardiovascular disease, abdominal subcutaneous fat is not associated with a linear increase in the prevalence of all risk factors among the obese, most notably, high triglycerides.
Porter
Stacy A
SA
National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, USA.
Massaro
Joseph M
JM
Hoffmann
Udo
U
Vasan
Ramachandran S
RS
O'Donnel
Christopher J
CJ
Fox
Caroline S
CS
D050153:Abdominal Fat / Q000000981:diagnostic imaging / Q000254:growth & development / Q000502:physiology* / Q000503:physiopathology; D000328:Adult; D000375:Aging; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D015992:Body Mass Index; D049628:Body Size; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors; D012727:Sex Characteristics; D050151:Subcutaneous Fat / Q000000981:diagnostic imaging / Q000254:growth & development / Q000502:physiology* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D014280:Triglycerides