Population Distribution for Heart Attacks


This population distribution curve for heart attacks has been known for decades, but is not well appreciated by the general population.

The slide above actually shows two curves. The blue curve represents the distribution of people with various cholesterol levels who in their lifetime never have heart attacks. You will note that this curve is zero only at a total cholesterol of 127. Also for an given level of cholesterol, 50% who have heart attacks have the same level of cholesterol as those who do not. Except for these facts, this curve for all practical purposes should be further ignored.

The second curve represents the distribution of cholesterol levels for those who in their lifetime do have heart attacks. You should note that this curve is slightly shifted to the right which is consistent with the fact that heart attacks are more frequent as cholesterol increases. What is important is that an individual can have a heart attack with a cholesterol as high as 350 all the way down to 150. 

An analysis shows that even if your total cholesterol is below 200, over one’s lifetime, 20% i.e. one in five still will suffer a heart attack and that represents 35% of all events. For each individual within that 20%, their heart attack rate is 100%.

Furthermore, this graph is deceptive in that it suggests that if your total cholesterol is 150, the heart attack rate appears to be zero. However, that is not true.  The rate is approximately 1%. However, 1% of over a million heart attacks per year is a greater than 10,000. Conclusion there are many heart attacks individuals whose total cholesterol is at or near 150. In fact there are an additional greater than 190,000 heart attacks per year in people with total cholesterols of 200 or less.

In order to approach zero one’s total cholesterol would have to be 127 or lower, i.e. the level of the people in the world who never suffer from this disease called atherosclerosis.


Relative, Absolute, Population Attributable Risk Fraction

Courtesy of William Castelli MD