Patients may benefit from lower recommended BMI targets

Issue: May 2011

American College of Cardiology 60th Annual Scientific Sessions

NEW ORLEANS — Recommended normal BMI parameters may be higher than necessary, as new data indicate that cardiovascular risk factors increase as BMI increases, beginning with a BMI of 20.

Glenn Lee, MBBS, and colleagues from the National University Health System and Khoo Puat Hospital in Singapore studied more than 3,000 adults who were referred for routine employment health screening for traditional CV risk factors. The mean age of the cohort was 38.9 years; mean BMI was 25.2; and 89.9% were men. The researchers excluded patients with diabetes and vascular disease.

According to the results, the overall prevalence of new diabetes cases was 2.4%. The majority of patients (84.5%) were classified as low risk, using the Framingham Risk Score.

The mean BMI of the cohort was 25.2. Analysis indicated a strong association between BMI and blood pressure, HDL and LDL levels; HDL and LDL levels were significantly worse with a BMI greater than 20. Systolic and diastolic BP rose significantly with a BMI greater than 22. The researchers noted a dose-response relationship for all risk factors, with the exception of LDL levels. Instead, these levels plateaued with a BMI greater than 26.

"Significant dose-response increases in traditional risk factors occurred at a BMI that is well within the normal range. Given the step-wise and additive nature of CV risk factors and the consistent correlation with a rising BMI of above 20, this calls into question what can be considered a truly normal BMI," Lee told Endocrine Today. "That's our major concern. Are we really being too lenient with these recommended guidelines for Caucasian populations (25) and Asian populations (23) or should we lower it?"

Lee also noted that several other studies support their findings, with one trial, which was published in Circulation in 2007 by Razak et al, suggesting that Asians may benefit from lowering the recommended BMI to 21. Another study conducted by Odegaard et al and published in PLoS One also suggested that the normal BMI for nonsmokers aged younger than 65 years should range from 18.5 to 21.4. Lee said this area requires further investigation.

"We would like to investigate and follow this cohort to see if this trend between CV risks and BMI persists as they age, and if these trends translate into increased cardiovascular event and mortality rates," Lee said. – by Melissa Foster

Disclosure: Dr. Lee reports no relevant financial disclosures.

For more information:

Lee G. Poster 1079-304. Presented at: ACC 60th Annual Scientific Sessions; April 2-5, 2011; New Orleans.

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