Abdominal Subcutaneous Adipose Tissue: A Protective Fat Depot?
- Stacy A. Porter, MA1,2,
- Joseph M. Massaro, PHD1,3,
- Udo Hoffmann, MD, MPH4,
- Ramachandran S. Vasan, MD1,5,
- Christopher J. O'Donnel, MD, MPH1,6 and
- Caroline S. Fox, MD, MPH1,7
- 1National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts;
- 2Harvard Medical School, Boston, Massachusetts;
- 3Department of Mathematics, Boston University and School of Public Health, Division of Biostatistics, Boston, Massachusetts;
- 4Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
- 5Department of Cardiology and Preventive Medicine, Boston University, Boston, Massachusetts;
- 6Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
- 7Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
- Corresponding author: Caroline S. Fox, foxca{at}nhlbi.nih.gov.
Abstract
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.
RESEARCH DESIGN AND 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/m2[women]; 28.1 to 35.7 kg/m2[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.
Footnotes
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- Received December 20, 2008.
- Accepted February 20, 2009.
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Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.
- © 2009 by the American Diabetes Association.
