MedicalResearch.com Interview with:
Venkatesh L. Murthy, MD, PhD
Department of Medicine (Cardiovascular Medicine Division) and Department of Radiology (Nuclear Medicine and Cardiothoracic Imaging Divisions),
University of Michigan, Ann Arbor, Michigan and
Dr. Ravi Shah MD
Cardiology Division, Department of Medicine
Massachusetts General Hospital, Boston, Massachusetts
Medical Research: What is the background for this study? What are the main findings?
Response: Prior studies in Framingham, MESA and other cohorts have demonstrated that obesity is an important risk factor for the metabolic syndrome. However, the observations that many non-obese individuals develop metabolic syndrome and diabetes and, conversely, that not all obese individuals develop these complications has motivated the search for better markers of risk than
BMI. More recently, it has been shown that the location of adipose tissue is an important factor. The amount of visceral fat, which is thought to be more harmful from a metabolic perspective, can be accurately quantified with CT imaging. In many prior studies, waist circumference has been used as an approximate measure of visceral adiposity.
For this study, we analyzed data from the Multi-Ethnic Study of Atherosclerosis (MESA). We found that the amount of visceral fat (as quantified by CT) was an important predictor of metabolic syndrome, even after adjusting for weight, waist circumference, gender, race, smoking, exercise, serum lipids and glucose. Each additional 100 cm2/m of height of visceral fat was associated with a 29% increase in the risk of developing metabolic syndrome. In contrast, subcutaneous fat burden (also quantified by CT) was a much weaker predictor.
One of the very novel findings of our study arises from an analysis of subjects who had multiple CTs longitudinally in MESA. Using these data, we found that change in visceral fat burden was associated with a corresponding 5% increase in the risk of metabolic syndrome. In part, this is because very small changes in weight could result in very large changes in visceral fat.
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