Waist Size Beats BMI for Predicting Heart Disease Risk

For non-invasive heart disease risk prediction nothing beat ECG, period.

Somehow American Heart Association and its European counterpart are in denial, and still pushing dinasour screening mechanism with very low accuracy for heart disease risk prediction.

The standard risk model for CVD based on PREVENT (US) and SCORE-2 (Europe) like parameters are very poor as reported in the recently published paper on the their accuracy performance by the Swedish team [1]. As all CVD risk stratification with cardiologist review (expert-in-the-loop), the most important accuracy metric is sensivity/recall (avoiding false negative that will escape review) of PREVENT and SCORE-2, 26% and 48%, respectively.

The paper alternative proposal increased the sensitivity to 58% by performing clustering instead of conventional regression models as practiced in the PREVENT and SCORE-2.

These type of models including the latest proposal performed very poorly as indicated by their otherwise excellent and intuitive display of graphical abstract results [1].

[1] Risk stratification for cardiovascular disease: a comparative analysis of cluster analysis and traditional prediction models:

https://academic.oup.com/eurjpc/advance-article/doi/10.1093/...

I thought this was pretty well known already. Being “overfat” is the problem, not being overweight (though they’re often correlated). BMI is really easy to measure, and is mostly accurate, that’s why it’s so pervasive. However it remains a pretty rudimentary metric (and really should use the third power or your height instead of the second).

A nitpick about the title: Not strictly abdominal fat, but visceral abdominal fat, which surrounds the organs. Not all abdominal fat is visceral; in fact, in many people the majority is not.

The article mentions visceral early on, which is the subject.

So this study basically compares,

BMI

Waist circumference (WC)

Waist to hip ratio (WHR)

Subsequent risk of nine cardiovascular/mortality outcomes in >260,000 people followed for ~20 years

To make it even more useful they should have included DEXA scan bodyfat%.

Also, BMI becomes somewhat biased at height extremes because body mass doesn't scale exactly with height². Humans aren't geometrically scaled copies of one another and empirical scaling exponents are often somewhere between 2 and 3. Conventional BMI tends to read relatively high in very tall people and relatively low in very short people. But changing the exponent would only fix one relatively small limitation of BMI

For better height adjusted replacement for BMI itself, one option is Trefethen’s BMI

WHR and WC is positively correlated to bodyfat% but this may get distorted for strongmen or sumo wrestler who tend to have much higher than average lean mass, may also have higher WC and WHR but difference maybe waist to shoulder ratio, they tend to have much bigger and powerful shoulders.

what's interesting is, for sumo wrestlers specifically, WC still correlates strongly with BF% one study reported r ≈ 0.86

There is a category in fitness called "skinny fat" where you are at low bodyweight (so low BMI) but your fat mass is relatively higher when compared to lean mass, so higher bodyfat%

Many skinny fat people refuse to believe they carry higher bodyfat% because they think they've low bodyweight so they can't possibly carr […]

> Those with obesity and low WC [waist circumference] were not found to be associated with a significantly different risk of outcomes compared with those who had normal weight and low WC, except for all-cause mortality, for which risk was significantly lower.

If I'm reading that right, it sounds like obesity (and therefore BMI) is still a better predictor for all-cause mortality. Perhaps waist circumference is better at predicting cardiovascular risk but BMI is still useful.

This is new? I thought they have been saying this for years

You can control your CVD risk.

Cutting saturated fat to under 15g per day and increasing intake of viscose fibre (e.g. beans) will reduce your LDL particle count in a few weeks, which reduces your CVD hazard ratio. You can measure your LDL and look up the papers yourself. Statins will reduce it a lot too (potentially with side effects). Replace solid fats like butter with liquid fats like olive oil.

Literally any amount of regular exercise, including walking, will decrease CVD HR. The more the better (up until quite a large amount e.g. professional athlete). The more your heart is steadily pumping during exercise the better. Every bit helps reduce CVD risk. Movement is medicine.

For the love of God do not smoke. Literally one of the surest ways to die a horrible death. Stopping smoking reduces CVD risk by a large amount.

Do not give yourself diabetes by eating vast amounts of sugar. If you are doing this, stop. Not having diabetes decreases CVD risk.

Other factors you probably can't change so focus on these.

Doctors, if I got anything wrong please correct me.