A February 6, 2016 Mayo Clinic Proceedings article concludes that having a normal body-mass index (BMI) and a high waist circumference (WC) or high waist/hip ratio (WHR), representing “normal-weight central obesity,” can increase risk of mortality in patients with coronary artery disease.

This study analyzed more than 7000 CAD patients from five cohort studies (US, France, Denmark, and Korea) showed that those with a normal BMI and high WHR or high WC had significantly higher mortality risk vs those with lower WHR or WC (both comparisons, P<0.001).

In the overall population, having a high WHR alone was associated with twice the mortality risk as a low WHR. High WHR was also associated with increased mortality in the women-only and men-only subgroups (all comparisons, P<0.001). However, having a high WC was significantly associated with a higher mortality risk only in the men (P=0.02).

This is consistent with other studies that show the same risk of central obesity and point to the significant problem that BMI is not the best screening tool for obesity.

According to an article published in the September 9 issue of the Journal of the American College of Cardiology, Abdominal fat may be more of a factor in hypertension than overall body fat.  This study looked as at  measures of BMI, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT)

Using multivariable risk regression models, the researchers calculated that BMI was significantly associated with the development of hypertension (P < .0001). Then, when they added in VAT and SAT as variables, they found that higher VAT remained as the only fat parameter independently associated with developing hypertension (relative risk [RR], 1.22; 95% confidence interval [CI], 1.07-1.39; P = .004). They observed no differences in the association among sex, age, or race variables.

The results suggested that abdominal/visceral adipose fat tissue is more important than than total adiposity, is more important in leading to the development of hypertension

Sources: Normal-Weight Central Obesity and Mortality Risk in Older Adults With Coronary Artery Disease – Mayo Clinic Proceedings

J Am Coll Cardiol. 2014;64:997-1004.