Do current body mass index criteria for obesity surgery reflect cardiovascular risk?

Abstract 

Background

Obesity is an underlying cause of the development of cardiovascular disease (CVD). Obesity itself does not result in CVD, rather, it acts through intermediate-risk factors. Most, but not all, studies examining the obesity–CVD relationship have found them to be correlated. We hypothesized that the inconsistencies among the studies of the obesity–cardiovascular relationship were attributable to an irregular relationship between obesity and the presence of risk factors for CVD.

Methods

The Third National Health and Nutrition Examination Surgery database was queried regarding the presence of known cardiovascular risk factors as a function of obesity. These were further related to anthropomorphic measurements and analyzed by regression and contour mapping techniques.

Results

Of the conventional CVD risk factors, blood pressure, serum glucose, and waist circumference increased linearly with adiposity. The reverse was observed for high-density lipoprotein. Insulin, C-peptide, apolipoprotein B, non–high-density lipoprotein cholesterol, low-density lipoprotein, and serum triglycerides all peaked in the body mass index range of 30–40 kg/m² and then decreased with increasing degrees of obesity.

Conclusion

Cardiovascular risk factors are markedly increased for many individuals with a body mass index >30 kg/m². Massively obese individuals might have better CVD risk profiles than less obese individuals. The discrepancy is related, in part, to body conformation. The criteria for obesity surgery should be changed to lower BMIs than are currently used if patients have risk factors for CVD.

Keywords: Apolipoprotein B, Triglycerides, Cholesterol, Cardiovascular risk factors, Contour analysis, NHANES III