Regarding Cardiovascular Risk, Women are 10 years younger than Men!
This essay studies the interaction between various factors affecting the risk of atherosclerotic cardiovascular disease (ASCVD) events (stroke, heart attack, etc.) over the next 10 years.
After benchmarking several models that estimate such risk, I selected the Framingham one. You can read about the model benchmarking in the linked article below.
I selected the Framingham model for two reasons. The first one is that it is more sensitive to factors input (cholesterol, blood pressure, etc.). The second one is that the model has an Excel interface that allows the generation of many scenarios.
Factors affecting the 10-year ASCVD risk
I focused on age, gender, cholesterol (total), and blood pressure (systolic). And, I am particularly interested in their respective interaction.
The type of questions I am addressing are:
- How does high blood pressure combined with high cholesterol affect the 10-year ASCVD risk of a 60-year-old male?
- How much higher is that risk vs another 60-year-old male who has healthier (or lower) levels of blood pressure and cholesterol?
- How about comparing men vs women on ASCVD risk?
The range of inputs I used to test the impact of those four factors is shown in the table below.
I also included a default input for all scenarios for HDL cholesterol of 70 (a reasonable level), as this one input is necessary to run the Framingham model. I also assume that individuals do not smoke, do not have diabetes, and are not treated for hypertension (these are other inputs you need to run the Framingham model).
ASCVD risk for 50-year-olds
I use a color coding that denotes relatively lower risk (green), intermediary risk (yellow to orange), and higher risk (red). These categories have no clinical significance. However, they visually inform how the risk increases with scenarios associated with higher cholesterol and blood pressure levels.
From low to high blood pressure & cholesterol levels, the ASCVD 10-year risk increases from 4.8% to 12.1% for 50-year-old men and from 2.8% to 9.3% for 50-year-old women. As shown, the men move out of the low green zone faster than women.
Notice that the ASCVD risk is more sensitive to systolic blood pressure than to total cholesterol. The far left column that sensitizes only cholesterol assuming the same healthy blood pressure of 120 remains mainly in the green. Meanwhile, the scenarios assuming a healthy total cholesterol level of 180 but a rise in systolic blood pressure very quickly go into the yellow intermediary risk zone.
ASCVD risk for 60-year-old
As age increases from 50 to 60-year-old, all the scenarios are associated with higher risk levels. The colors shift quickly into yellow and orange and even onset of red.
From low to high blood pressure & cholesterol levels, the ASCVD 10-year risk increases from 8.2% to 20.1% for 60-year-old men and from 4.2% to 13.9% for 50-year-old women. As shown, the men's scenarios move deeper into orange and red zones.
ASCVD risk for 70-year-old
The impact of age is clearly visible. Now many men (or male) scenarios are in the red.
From low to high blood pressure & cholesterol levels, the ASCVD 10-year risk increases from 12.8% to 30.1% for 70-year-old men and from 6.0% to 19.3% for 70-year-old women. As shown, the men's scenarios move deeper into orange and red zones.
Regarding ASCVD risk, women are 10 years younger
After doing the above analysis, this was an accidental finding… that women are very much 10 years younger than men when it comes to ASCVD 10-year risk.
The table below shows the difference in the ASCVD 10-year risk between 60-year-old women vs. 50-year-old men. The scenarios highlighted in pink denote the ones where that difference is negative, meaning that 60-year-old women have a lower ASCVD risk than 50-year-old men.
We rerun these differences now between 70-year-old women and 60-year-old men. Now, every single scenario shows that 70-year-old women have a lower ASCVD risk than 60-year-old men!
The 10-year gap in the ASCVD Risk conundrum
This 10-year gap in ASCVD risk is surprising. That is given that cardiovascular diseases are a leading cause of mortality. And, that the gap in remaining life expectancy for individuals between 60 and 70 is less than 3 years as shown in the table below.
There are a few non-behavioral explanations regarding the difference in remaining life expectancy between genders.
- Men have a single X chromosome, which makes them more vulnerable to X-linked genetic disorders. Women, having two X chromosomes, can often compensate for defective genes on one chromosome with the other.
- Men have higher prevalence and death rates from chronic conditions such as heart disease, stroke, and diabetes. Women, while having higher rates of autoimmune diseases, generally have lower mortality rates from these conditions.
- The COVID-19 pandemic has disproportionately affected men, contributing to a significant drop in their life expectancy. Men are more likely to suffer severe outcomes from COVID-19 due to higher comorbidities and occupational exposures.
THE END
