Evaluating CMR

Measuring Intra-abdominal Fat Using MRI and CT

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There is a growing literature on the importance of intra-abdominal fat as a strong predictor of dyslipidemia (18-24), glucose tolerance (25, 26), insulin resistance (26), and incidence of hypertension (20-22, 27), cardiovascular disease (28), and type 2 diabetes (29). Even within a given BMI category, men and women with greater amounts of intra-abdominal fat are more likely to be at increased risk of developing the metabolic syndrome (30), disturbances in glucose tolerance (31, 32), and insulin resistance (31, 33). Further, prospective studies have indicated that intra-abdominal fat predicts future hypertension independent of age, BMI, weekly energy expenditure, systolic blood pressure, and glucose tolerance (27). Similarly, intra-abdominal fat is a significant predictor of future type 2 diabetes independent of age, BMI, glucose intolerance, and family history (29).  It is not surprising, then, that intra-abdominal fat has also recently been linked to increased risk for all-cause mortality (34).

Although excess intra-abdominal fat is increasingly recognized as a health hazard, there is little consensus as to optimal cut-offs for identifying individuals with excess intra-abdominal fat and therefore at increased health risk. Suggested cut-offs range from 100 to 130 cm². Regardless of optimal cut-off values, an increase in intra-abdominal fat clearly worsens the metabolic profile, even among normal weight individuals (35). Consequently, individuals should try to minimize intra-abdominal adiposity and avoid increases in intra-abdominal fat regardless of cut-off values. Moreover, because it is not possible to routinely measure intra-abdominal fat using MRI and CT, individuals should focus on routinely measuring waist circumference, which is the best surrogate measure currently available.

Reference

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