Reacción a "Abdominal fat is a better predictor of cardiovascular risk than body mass index"

Does the press release accurately reflect the study?

“The key message is correct insofar as it refers to adding anthropometric waist measurements to improve the assessment of cardiovascular risk. At present, there is insufficient robust evidence in the literature to support replacing BMI with the waist-to-height ratio (WHtR), for example, in the assessment of cardiovascular risk.” Is the study of good quality? Are the conclusions supported by solid data?

“From my perspective, and delving into the pathophysiology of obesity, there is data supporting the conclusion that WC and WHR contain solid information to conclude that central adiposity alone causes the observed differences.” How does this study fit in with the existing evidence?

“Rather than studying mortality or a single specific event, the study examines nine cardiovascular and mortality outcomes in a population with a very large sample size. This supports the robustness of the results.” Are there any significant limitations to bear in mind?

“There are several limitations, some of which have been mentioned, whilst others have not been explored in great detail. For example:

• There is a lack of information on physical activity, diet and the genetics of obesity. Some types of obesity have a very significant genetic component.
• Waist circumference and WHR were measured only once, at a single point in time, and we do not know how they have changed over the course of the follow-up period or whether this may have influenced the results.
• The follow-up period was very long, and lifestyle habits spanning several generations were mixed together; cultural specificities and changes over time may have had an influence. For example, precisely for this reason, we do not place much faith in prediction models based on artificial intelligence, because from the outset the computer system assumes that patients’ living conditions remain the same throughout the virtual years analysed by the system. And in real life, that is not the case. Furthermore, we must not forget that BW and WHtR are indirect measures of central adiposity; they are not equivalent to directly quantifying visceral fat using imaging techniques.
• It is an observational study, with the inherent limitations of such designs: it is non-randomised and non-interventional.
• The WHtR is more sensitive than the WHR and the WC.”

What are the implications for the real world?

“This has a significant practical advantage: measuring waist circumference is inexpensive, and calculating the WHtR is just as quick as calculating BMI. Consequently, both the results and, increasingly, expert opinions support the routine incorporation of some measure of central adiposity into clinical assessment, particularly in cardiovascular prevention. The paper by the EASO supports this idea. That is also the final recommendation. We should not “replace BMI” for the time being, but rather “it is advisable to supplement BMI with a measure of central adiposity, particularly waist circumference”. There is still a lack of data to tell us whether reducing WHtR actually leads to improved health outcomes, for the simple reason that, in the management of obesity, everyone has traditionally focused on weight, and the incorporation of WHtR into this management is a relatively recent development. There has not been enough time. There is a study which supports the view that reducing WHtR by <0.53 improves cardiovascular risk parameters".