Do Statins Improve HDL?

Statins, also known as HMG-CoA reductase inhibitors, are a class of drugs that lower cholesterol levels. Statins have been shown to be effective in reducing levels of LDL (low-density lipoprotein, also known as "bad cholesterol") from the bloodstream, and are prescribed in cases where risk of cardiovascular or artery disease is perceived to be threatening. However, there is no evidence that statin usage changes HDL levels significantly, although other methods to increase HDL cholesterol levels have been shown to be successful.

Statins and LDL

• Statins were first developed after initial research efforts by Akira Endo and Masao Kuroda of Japan in 1971. They quickly become known as effective in reducing general cholesterol levels in patients through a number of metabolic pathways.

  First, drugs of the statin class inhibit the synthesis of cholesterol in the liver, which lowers blood cholesterol levels (more cholesterol comes from production in the liver than from dietary causes). Second, statins increase the LDL uptake of the liver, as the liver seeks to compensate for reduced internal levels of liver cholesterol, further lowering blood cholesterol levels. In addition, doctors recognize that statins not only lower LDL content in the bloodstream, but also may help prevent atherosclerosis in other ways, such as by modulating inflammation response, maintaining plaque stability, and preventing blood clots (see References 1).

Statin Use and Cardiovascular Risk

• Although statin therapy has led to reduced risk of cardiovascular disease, the high-percentage reduction in cardiovascular risk hoped for with statin therapy did not appear in clinical trials. Instead, clinical trials demonstrated only a 45 percent to 50 percent reduction in rates of cardiovascular disease through statin therapy and reduction of LDL cholesterol, even when LDL target values were reached.

  Dr. H. Bryan Brewer, Jr., director of lipoprotein and atherosclerosis research at the Cardiovascular Research Institute in Washington, D.C., suggests that to decrease risk of cardiovascular disease in patients even further, doctors must move toward not only lowering LDL levels, but raising HDL levels, as low HDL cholesterol levels represent "a significant independent risk factor at high and even at low levels of LDL" (see Reference 2).

Ways to Increase HDL

• While the statin drug class has not been shown to increase HDL cholesterol levels despite lowering overall cholesterol and LDL "bad" cholesterol, other methods can be used to increase HDL levels. Diet and lifestyle changes, while relatively simple, can have a positive impact on HDL levels. This includes increasing aerobic exercise, weight loss, quitting smoking, eating less trans fats, and eating less meat. Also, adding Omega-3 fish oil, flax oil, or soluble fiber as a supplement to a daily diet can also increase HDL levels.

  A few drugs have been shown to be effective at raising HDL levels, unlike the statin class. Of these, niacin (vitamin B3) has been most effective (when compared to other HDL-increasing drugs like fibrates), and in a randomized clinical trial niacin was shown to significantly reduce the progression of atherosclerosis and the likelihood of cardiovascular events (see Reference 3). However, this effect was diminished using other forms of niacin, such as "no-flush" or "sustained-release" -- therefore, the cheapest, immediate-release preparation is recommended.