Cholesterol-lowering statin drugs fight inflammation and lower the risk of heart disease, but sometimes they also seem to cause diabetes. Is the risk of diabetes worth the benefit of the statin?
All over the world, doctors prescribe cholesterol-lowering statin drugs to lower the risk of heart attack. Atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor, also found in variable amounts in red yeast rice), pitavastatin (Livalo), pravastatin (Pravacol), rosuvastatin (Crestor), and simvastatin (Zocor) are prescribed tens of millions of times per year to patients who have any indicator of elevated risk of heart disease. Some doctors are so enthusiastic about statins they have even suggested that they should be added to the municipal water supply in the US and UK, like fluoride.
The widespread enthusiasm for statin drugs is dampened when serious students of the issue notice that:
- Diabetes is just as serious a risk factor for heart disease as high cholesterol, especially when you have been diabetic for 10 years or more, and
- Taking statin drugs increases the risk of diabetes.
To be fair, it is not true that every last research study conducted anywhere in the world finds that taking statin drugs increases the risk of diabetes.
Exactly one study found that taking statin drugs lowers the risk of diabetes. Every other study, however, finds that people who are given these ubiquitous medications for cholesterol and inflammation are at greater risk for developing problems with insulin resistance and blood sugar regulation.
Consider, for example, this evidence from the United States, where doctors are particularly enthusiastic about cholesterol-lowering medications. The highly respected Nurses Health Initiative Study found that women who started taking statins were twice as likely to develop diabetes. The researchers noted that:
"Statin use at baseline was associated with an increased risk of DM (hazard ratio [HR], 1.71; 95% CI, 1.61-1.83). This association remained after adjusting for other potential confounders (multivariate-adjusted HR, 1.48; 95% CI, 1.38-1.59) and was observed for all types of statin medications."
In plain language, nurses were 61 to 83 percent more likely to become diabetic if they took statin drugs, no matter which statin drug they took.
Doctors tended to interpret these results something like this: "Sure, diabetes is bad, but the main reason we are worried about diabetes (overlooking kidney disease, blindness, neuropathy, and amputations after infections) is that it increases the risk of heart diseasse. We're raising the risk of heart disease but we're lowering it at the same time, so let's give our patients more statins."
Here's the problem with this approach.
LDL cholesterol lodges in the linings of arteries. If you have less LDL cholesterol, then you should have fewer hardened, cholesterol-laden atherosclerotic plaques to clog your arteries.
However, LDL cholesterol does not actually lodge in the linings of arteries unless it becomes sticky. What makes LDL cholesterol sticky is glucose, blood sugar. Glucose levels go up, and LDL cholesterol becomes stickier and more atherogenic, in diabetes. Diabetes turns harmless LDL cholesterol into potentially deadly cholesterol. The drugs that doctors prescribe for high cholesterol make the remaining cholesterol more dangerous. This does not seem to be a very sensible approach to managing heart disease.
To be fair, the risk of heart disease in diabetes does not go up sharply until someone has been diabetic for at least eight to ten years. This detrimental effect may not be immediate, and there are even some diabetics who benefit from statin drugs.