BMI Poor Measure of Body Fat in Heart Failure

Body mass index (BMI) is a widely used anthropmetric surrogate for body composition as it correlates well with body fat content across a wide range of body ages, shapes, and sizes.

However it does have its limitations in special populations (e.g. infants, competitive athletes, pregnancy, etc.). It may now be time to add patients with heart failure to this list.

In a study just published by Antigone Oreopoulos and colleagues from the University of Alberta, Edmonton, Canada, in Congestive Heart Failure, we examined the relationship between various anthropometric indices and body composition in men and women with heart failure.

Body composition was assessed by dual-energy x-ray absorptiometry in 140 patients with congestive heart failure and compared to BMI, waist circumference, waist-stature ratio, and waist index. Diagnostic accuracy of detecting obesity or high central fat was also examined.

While in men, all of the anthropometric indices except waist index were just as well (albeit moderately) correlated with lean body mass as with the actual percentage of body fat, in women, all 4 anthropometric measures were unable to significantly differentiate between body fat and lean body mass.

Thus, none of the anthropometric indices accurately reflected body composition in women with congestive heart failure and were also of limited use in men.

These finding may be due to the remarkable variability in lean body mass and fluid retention seen in these patients – both of which can strongly determine body weight irrespective of changes in body fat.

The implications for clinicians are to interpret anthropometric indices including BMI with caution in patients with heart failure – both with regard to predicting excess fat as well as in regard to any changes in body weight.

AMS
Edmonton, Alberta

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Oreopoulos A, Fonarow GC, Ezekowitz JA, McAlister FA, Sharma AM, Kalantar-Zadeh K, Norris CM, Johnson JA, & Padwal RS (2011). Do Anthropometric Indices Accurately Reflect Directly Measured Body Composition in Men and Women With Chronic Heart Failure? Congestive heart failure (Greenwich, Conn.), 17 (2), 90-92 PMID: 21449998