Friday, April 15, 2011

Cardiovascular Disease Burden Around the World

Some more graphs and maps from the World Health Organization. Up above is a large map showing the total burden of heart disease around the world (you should really click to get the large version in a new window).  The unit here is DALY's lost = Disability Adjusted Life Years lost.  So the idea is, given a thousand population how many of them will either be prematurely dead, or effectively disabled, by heart disease.

The surprising thing about this is that the burden of heart disease, measured this way, is generally higher in developing countries, despite their lower fat diets, less obesity, etc.  I'm assuming the explanation for this is that the actual incidence of heart disease is higher in developed countries, but that care is also much better.  If a fifty year old man in a France or the US keels over, he will be rushed to a hospital and given high tech care.  A fifty year old Zambian in a village is perhaps less likely to get a heart attack, but if he does, he's a lot less likely to get to the hospital in time, and when he does, they aren't going to perform triple bypass surgery on him.  However, I haven't yet found international incidence data to confirm this - when I do, I'll post about it.

Of course, it's also noteworthy that most developing countries have experienced large changes of diet in recent decades.  They eat a lot more food, and more of it from animal products.  This is perhaps being increasingly reflected in some of the standard risk factors for cardiovascular disease (heart disease and strokes).  For example, here are WHO estimates for average total cholesterol levels of men, age 15+:

Look at China!  Amongst the highest cholesterol levels in the world.  Note that here the scale is in mMol/L, versus the mg/dL common in the US.  In the US, the official medical advice is that cholesterol levels should be below 200mg/dL to be "normal", which corresponds to about 5.2 mMol/L.  However, the Campbell/Ornish/Esselstyn faction of nutrition scientists argue you should really be below 150mg/dL to pretty much eliminate the risk of cardiovascular disease.  That corresponds to 3.9 mMol/L - levels that are now only common in Africa.

These are very complex statistics to interpret.  In addition to the dietary/exercise input factors, we also have issues like genetic variation: much of the Chinese population has been living largely on rice and vegetables for thousands of years, versus people of European descent who's ancestors have been eating a lot of wheat bread and some dairy and meat for millenia.  This must have led to genetic differences (lactose tolerance for certain, and likely others), that may contribute to different tolerances for modern industrial diets.

Furthermore, we also have large scale interventions in some places.  For example, a sizeable fraction of the US population is on statin drugs that lower cholesterol level, and this is less true in China (though there would appear to be a very large market opportunity there now).  How much of the variation is explained by these different factors, versus others, I do not know.

Moving on to being overweight, here American dominance is unquestioned (except for some very small Polynesian islands).  This map shows the fraction of men 15+ who have a body mass index over 25:

80.5% of American men are overweight (and this is even when you go all the way down to age 15).  And if we look at the fraction of men who are formally obese (BMI > 30), that is even more concentrated:

The data for women are roughly similar, with some interesting wrinkles:

Note that in Latin America and parts of North Africa and the Middle East, women are more apt to be obese than men.

It seems increasingly clear to me that health variables are essentially conjugate to global energy/food issues.  The places where everyone is overweight are for the most part, also the places where per capita oil and food consumption are very high and people drive everywhere.  We in the developed world, and particularly in the US, are living wrong in important ways.  Not only is it destabilizing the biosphere and the climate, but a lot of us carry around the ever increasing evidence in distended folds draped about our midriffs.


p01 said...

Cholesterol and Heart Disease.
Follow the money ;)
Eat like your grandparents did :)


Stuart Staniford said...


That presentation is a poster-child for how not to do statistical inference in a complex multivariate problem. You've got masses of variables (like amount of medical care, genetics, etc, etc) that he's not controlling for in making his argument.

p01 said...

The argument is that cholesterol alone is not linked to heart disease.
Do you dispute this? The data is freely available.

Trying to input more variables to make it seem like it does, is what epidemiologists turned statisticians have done and created this massive health destruction.
Behold the original data. I would keep cholesterol out of this mess.

Eric Thurston said...

I would also check out Taubes on the subject of the 'Changing American Diet.' Seems less there than meets the eye.

Mister Roboto said...

1) What Paul said.

2) Another way to interpret this is that stress is a major contributor to heart disease. Neither Russia nor India are among the most pleasant places to live in the world today!

David said...

Poor Bear the Burden of Rising Heart Disease in Nepal

Southeast Asians suffer heart attacks six years earlier than the rest of the global population. Here, where most can’t afford proper nutrition and health care, new initiatives aim to increase access to cardiac care options. Still, experts say programs can’t keep up with rising rates of heart disease, the region’s leading killer.

Read more:

bordoe said...

Recall reading an article reviewing this book:

The Impact of Inequality: How to Make Sick Societies Healthier;jsessionid=7F66D22F527F6E6EB6064DDE7D7107A0.jvm4

Not sure what to think as health stats are way outside my area of understanding and I've found often have highly confusing and confounding results.

But it seems from a quick glance at this big, highly aggregate chart, that incomes just high enough for a 'bad' diet along with massively unequal social treatment (stress?) may lead to cardiovascular disease.

Wont be a shock if it was true; but I wont try to prove it :-)

jemand said...

I also wonder to what extent gender inequalities in a society lead to these outcomes, particularly inequalities as they were 30 to 40 years ago. When women are considered less valuable and get fewer resources, they carry pregnancies while suffering through lower quality nutrition, which leaves a permanent marker on the fetus's future metabolism to be tuned for starvation conditions in life.

If these children get any kind of marginal financial success (or are male and thus valued above their mothers in society), they can be in conditions not similar to the near-starvation level their mothers experienced during pregnancy, and be additionally sensitive to metabolic syndrome, diabetes, and heart disease.

Even today, many Indian women are underweight, up to 45% in some areas:

(remember, the healthiest category tends to be at the medium to high end of what's classified as "normal" or the very low end of what's classified as "overweight")

and for evidence this can affect children's metabolism:

I would not be surprised if areas in which mothers may be considered of less value than sons would end up with a metabolism for these boys completely unsuited to the conditions they will experience.

Anonymous said...

Regardless of how these stats are interpreted, there is plenty of evidence showing that a diet full of animal-based products, processed foods and high fat foods contributes to heart disease and and variety of other chronic illnesses. There are doctors, including Dr. Caldwell Esselstyn and Dr. Baxter Montgomery, who consistently help patients reverse heart disease, type 2 diabetes and other conditions just by changing to a low fat, plant-based diet. This is just one example.