On low cholesterol, statins and heart-disease risk
Dear Dr. Roach: You have written many times about elevated cholesterol, but I have never seen anything about low cholesterol. I am an 86-year-old man with Type 2 diabetes that has been treated with moderate success using oral medication. I am 5 feet, 10 inches tall and weigh 160 pounds. I exercise regularly. My total cholesterol has always been low (under 125). Recently it was 103 — with HDL 41 (it also has always been low), LDL 38, triglycerides 112 and total/HDL ratio of 2.4. I have high blood pressure under control on lisinopril and HCTZ. My physician has suggested using a statin to raise the HDL.
S.J.Z. Statin drugs reduce the risk of having a first heart attack in people at moderate to high risk for heart disease. I think of statins not just as drugs that lower cholesterol or raise HDL (although they do), but also as drugs that reduce heart risk when used appropriately. This includes not only people with very high total or LDL cholesterol levels, but also those with low HDL cholesterol levels. It also includes people who, because of other reasons, have a high risk for developing heart disease within the next 10 years. The exact number varies, but most experts recommend statin drugs to those with 10-year risk that’s over 10 per cent (some have a lower threshold of 7.5 per cent).
One major risk for developing heart disease is age. Despite your low cholesterol and blood pressure, which I assume is under control, your age alone puts you at high risk for heart disease. The diabetes, even if well-controlled, adds additional risk. None of the calculators available can calculate your risk, because your total cholesterol is so low, and because they aren’t valid for people over 80, but when I put in age 80 and the lowest LDL the calculator accepts, the calculator estimates your risk of developing heart disease in the next 10 years at about 50 per cent. That could be reduced with treatment, and my best estimate is that your risk on medication might be about 40 per cent.
On the one hand, a statin is likely to decrease your risk of a heart attack. On the other hand, you have gone 86 years without developing heart disease. Further, serious side effects, although still not common, are more common in older people. There is no answer that all experts would agree on, and it is left to the judgment of you and your doctor.
Since it seems you are generally doing well and keeping active, I would be more inclined to support a decision to try the medication — and if you did so, being careful to look for side effects and being ready to stop the medication if necessary.