Researchers at the University of Minnesota and the VA Medical Center in Minneapolis showed in a cohort study (an observational study that includes an analysis of risk factors and follows a group of people who do not have the disease, and uses correlations to determine the absolute risk of subjects achieving a particular outcome) that the risk of sudden cardiac death increased along with waist-to-hip ratio (WHR).
Here are two graphics to illustrate how one measure WHR.
According to Dr. Selcuk Adabag, the lead researcher, the WHR, when it comes to the risk for sudden death, was the greatest determinant, ranking even higher than body mass index and waist circumference.
The general rule of thumb for WHR is lower numbers are better.
A WHR of 0.7 for women and 0.9 for men has been shown to correlate strongly with general health and fertility. Women within the 0.7 range have optimal levels of estrogen and are less susceptible to major diseases such as diabetes, cardiovascular disorders and ovarian cancers. Men with WHRs around 0.9, similarly, have been shown to be more healthy and fertile with less prostate and testicular cancer.
The study showed that for individuals in the top quintile of waist-to-hip ratio (0.97 and higher for women and 1.01 and higher for men), the risk of sudden cardiac death was a relative 40% greater compared with those in the lowest quintile (less than 0.82 for women and less than 0.92 for men).
The lead researcher speculates that the reason for this correlation may have to do with the inflammatory markers produced by abdominal fat. Those markers result in fibrosis in the heart muscle, which could ultimately lead to arrhythmias and sudden cardiac death. Abdominal fat is composed of the more harmful white fat cells.
So if you didn't have enough reasons, motivation, incentives until now to lose weight and get into shape, maybe avoiding sudden death may help?
Here's a WHR calculator so you can calculate your own WHR: