It is true that statins have been shown in randomized controlled trials to reduce the risk of a first cardiovascular event. The number of patients needed to treat to prevent one event is relatively high, as I have previously discussed, but it is true that there can be a role for statins in primary prevention.
The problem is that the real world doesn't function like a clinical trial. People who are on a statin know that they are taking a medication with the purpose of lowering their cholesterol. An important question that I've wondered is, how much does knowing that one is taking a statin affect behavior?
Anecdotally, I can tell you I've had conversations with patients in which they have rationalized less than ideal diet choices by stating that they are taking a cholesterol-lowering statin. Or more blatantly, the person who goes out for a decadent dinner and then doubles up on his statin dose.
There is a study that was published in JAMA Internal Medicine this week on that subject. This was a retrospective study looking at the caloric intake of statin users and statin non-users. The study found that statin users increased their caloric intake by 9.6% and fat intake by 14.4% over the course of the ten year period studied, while non-users had no significant change in caloric or fat intake over that time. Further, the statin users' body mass index (BMI) increased by 1.2 kg/m2 during that time, while the non-users BMI increased by only 0.4.
So, the increased calorie and fat intake and weight gain of a statin user may negate much of the beneficial effect of the statin medication.
What's a clinician to do? I think it's important that we make sure our patients realize that a statin medication is not a carte blanche to eat whatever and however much they want. But I think we also need to be judicious in choosing who we put on a statin as well, and make sure that their risk is appropriate to justify the statin prescription.