Wednesday, August 15, 2012

Keep that heart ticking

kw: heart disease, medicine, risk analysis

My doctor always has something to exhort me about: losing weight, reducing blood pressure, getting more exercise. Of course, he is right. Being an analytical sort, though, I decided to dig into his main worry, which is heart disease. I think it is mainly reflex on his part, because I have no risk factors. So I looked up the risk calculators for coronary heart/vascular disease (you can search for "(CHD OR CVD) AND risk"). The one I settled on is this one at Medical College of Wisconsin. I entered my information, and learned I have a 10% risk of developing cardiovascular disease in the coming ten years.

I dug a little further. The calculation is not a continuous formula in several variables, as I had thought. It is based on a block model. This table is the relevant set of blocks for my age (65), no smoking or diabetes, and systolic blood pressure of 140:
I also included an ancillary table for the block I am in (Total Cholesterol below 159 and HDL 35-44), for blood pressure. You can see that blood pressure is a significant factor, and that 10 points in systolic BP is about equivalent to 10 points in HDL, but negatively correlated. My doctor thinks I ought to take a medication to try to reduce my BP into the 120 range. It looks like he has a point; that would cut my risk in half. Were I a smoking diabetic, the risk would be doubled, to 20%.

I would like to see these calculators include a few more factors, assuming the relevant risk functions are known. Factors such as BMI (I am at 29, not so good) and HeartCam score (mine is zero, the same as a very healthy 30-year-old), for example.

Based on my family history, and my own history (!), what we really need is a cancer risk calculator. Hmmm (running a search…). Siteman Cancer Center has one. Pick one of 12 kinds of cancer, and have at it. I'll have to look into it.

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